FXUS63 KDMX 072038 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 338 PM CDT SUN APR 7 2013 .SHORT TERM /TONIGHT/... TEMPERAMENTAL FOG AND STRATUS DECK THIS MORNING ALONG WITH A WARM FRONT LIFTING NORTH INTO SOUTHERN IOWA MADE FOR A TRICKY TEMP FORECAST FOR THIS AFTERNOON...AND SUBSEQUENTLY TONIGHT. ENDED UP ADJUSTING HIGH DOWN ACROSS THE NORTHERN TWO THIRDS OF THE CWA THIS AFTERNOON AND ALSO DROPPED LOWS A FEW DEGREES BELOW GUIDANCE BASED ON THIS TREND. HOWEVER...INCREASING CLOUDS AND CONTINUED GOOD SURFACE TO 850 MB THETA-E ADVECTION OVERNIGHT WILL NOT ALLOW FOR MUCH RADIATIONAL COOLING. WEAK RADAR ECHOES ACROSS THE WESTERN CWA HERALD THE APPROACH OF OUR NEXT SYSTEM...A LOW AMPLITUDE PROGRESSIVE UPPER LEVEL WAVE CURRENTLY TRACKING OUT OF THE HIGH PLAINS. ACTIVITY WILL BECOME MORE WIDESPREAD AFTER SUNSET AS UPPER LEVEL FORCING BECOMES MORE ESTABLISHED. THE HEAVIEST RAINFALL LOOKS TO FALL BETWEEN 06 AND 12Z OVER SOUTHERN IOWA WHERE DYNAMICS ARE STRONGEST WITH A CLOSED OFF LOW AT 850 MB. .LONG TERM /MONDAY THROUGH SUNDAY/... PLENTY OF CONCERNS THROUGH MIDWEEK WITH CONVECTIVE TRENDS AND PRECIP TYPE ALL ON THE TABLE. PERIOD BEGINS WITH WARM ADVECTION PRECIP EXITING NERN FORECAST AREA. CANNOT FIND MUCH IN THE WAY OF KINEMATIC OR THERMODYNAMIC FORCING MON WITH ATTENTION TURNING TOWARD WARM FRONT SETTING UP INTO HEART OF IA BY LATE AFTERNOON. NAM SEEMS OVERZEALOUS WITH LOW LEVEL MOISTURE RETURN WHICH IS MORE AGGRESSIVE WITH NRN EXTENT OF 60F PLUS DEWPOINTS. EVEN THE MODEL CONSENSUS WHICH DEPICTS 60F INTO SRN IA LATE MAY BE TOO AGGRESSIVE CONSIDERING VEGETATION IS DORMANT AND 19Z SURFACE ANALYSIS UPSTREAM INTO KS/MO/OK/NRN AK DOES NOT SHOW A 60F DEWPOINT YET. THE MORE CONSERVATIVE APPROACH...CLOSE TO THE GFS...DOES INDICATE UNCAPPED 1500 J/KG MLCAPES OVER SRN IA BUT THIS WOULD BE WITHOUT LARGER SCALE FORCING AND REMOVED FROM LOW LEVEL CONVERGENCE SO DO NOT EXPECT MUCH. THIS WOULD ALSO APPEAR TO BE OUR ONLY WINDOW FOR SURFACE BASED CONVECTION AS MLCAPES/CINS ARE MUCH LOWER/HIGHER RESPECTIVELY INTO THE WEEK. HOWEVER CONVECTION IS EXPECTED INTO MONDAY NIGHT AS ELEVATED CAPES APPROACHING 1000 J/KG SHOULD MOVE INTO IA COINCIDENT WITH SURGE OF THETA-E ADVECTION. PWS WILL INCREASE TO 1-1.25 INCHES...K INDICES RISE INTO THE 30S ALONG WITH 1-6KM SHEAR TO 40-50KTS. LIMITED INSTABILITY WILL LIKELY KEEP SEVERE WEATHER POTENTIAL DOWN...BUT WOULD NOT BE SURPRISED TO SEE SOME ELEVATED HAIL STORMS. THIS ANOMALOUSLY HIGH PW ENVIRONMENT /PUSHING 99TH PERCENTILE/ WITH WARM CLOUD DEPTHS TO 10KFT WILL REMAIN IN PLACE INTO TUE AS WELL BEFORE EXITING SE TUE NIGHT. ANY CONVECTION WILL LIKELY BE VERY EFFICIENT RAINFALL PRODUCERS. EVENT TOTAL QPF VARIES FROM ONE TO THREE INCHES WITH HIGHEST AMOUNTS SOUTH AND SEE NO REASON TO DOUBT THIS CONSIDERING THE ENVIRONMENT. HIGH POPS LOOK TO STAY IN PLACE RIGHT INTO WED AS SYSTEM FINALLY MOVES AWAY WITH BEST QPF AMOUNTS POSSIBLY FOCUSED ON INVERTED TROUGH PASSAGE TUE EVENING WITH MO TRIPLE POINT. TEMPS NORTH WILL SEE LITTLE REBOUND OR CHANGES TUE INTO WED SOCKED INTO SOLID 1.5KM MOISTURE AND BRISK NELY WINDS. MAY EVEN SEE PERIODS OF SNOW DURING FAVORED NIGHTTIME COOLING...AND AREA WIDE WED NIGHT INTO THU AS FORCING FINALLY EXITS. WOULD NOT BE SURPRISED TO SEE SOME MINOR ACCUMS NORTH...MAINLY ON GRASSY AREAS. FAIR WEATHER AND SEASONAL TEMPERATURES CAN BE EXPECTED TO END THE WORK WEEK WITH WEAK SHORT WAVE RIDGING AND A PERIOD OF MS VALLEY SURFACE HIGH PRESSURE. POPS WILL RETURN BY THE WEEKEND HOWEVER AS ANOTHER WRN CONUS THROUGH DEEPENS SOMEWHAT LEADING TO LEE SIDE CYCLOGENESIS AND SURFACE REFLECTION REACHING IA BY LATE SUN. && .HYDROLOGY... AFOREMENTIONED MODERATE TO HEAVY RAINS AND QPF WOULD MOST LIKELY PRODUCE HIGH END WITHIN BANK RISES AT ALL FORECAST SITES BASED ON ENSEMBLE QPF RIVER FORECASTS...ALTHOUGH THE HIGH END SCENARIO COULD PRODUCE MINOR FLOODING AT A FEW SITES SOUTHEAST. THIS IS LIKELY DUE TO GROUND FINALLY THAWING AND SOME DRYING AFTER DECENT MARCH PRECIP/SNOWMELT EVENT. && .AVIATION...07/18Z IFR TO LOW MVFR STRATUS DECK OVER NORTHERN IOWA WILL CONTINUE TO ERODE THIS AFTERNOON...WITH VRF CONDITIONS EXPECTED ELSEWHERE ACROSS THE STATE THROUGH THE AFTERNOON. WINDS WILL VEER TO THE SOUTH AS THE NEXT SYSTEM APPROACHES FROM THE WEST. THE BEST CHANCE FOR MODERATE RAINFALL TONIGHT FOR THE AFOREMENTIONED SYSTEM WILL BE OVER SOUTHERN IOWA. HAVE BROUGHT IN MVFR CONDITIONS FOR MOST TAF SITES AT SOME POINT OVERNIGHT...WITH LOWER MVFR CONDITIONS FOR THE SOUTHERN SITES. DEPENDING ON HOW MUCH RAIN THE AREA RECEIVES...LOW CLOUDS MAY LINGER INTO THE MORNING HOURS TOMORROW. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM/AVIATION...SKOW LONG TERM/HYDROLOGY...SMALL  FXUS63 KDMX 082053 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 353 PM CDT MON APR 8 2013 .SHORT TERM /TONIGHT/... CLOUDS WILL BE ON THE INCREASE THIS AFTERNOON AND EVENING AS THE FIRST IN A SERIES OF IMPULSES EJECTS FROM A POTENT LONGWAVE TROUGH DIGGING ACROSS SOUTHERN NEVADA. SIGNIFICANT LOW LEVEL MOISTURE POOLING HAS BEEN TAKING PLACE THIS AFTERNOON ACROSS SOUTHERN IOWA SOUTH OF A SYNOPTIC WARM FRONT LOCATED OVER NORTHERN IOWA. SURFACE DEW POINTS SOUTH OF THE BOUNDARY HAVE RISEN ABOUT TEN DEGREES SINCE SUNRISE AND ARE CURRENTLY RUNNING IN THE MID TO UPPER 50S. DEEPER GULF MOISTURE WORKS INTO THE REGION LATER THIS AFTERNOON WITH PWATS REACHING 1 TO 1.5 INCHES BY 06Z...ESPECIALLY ACROSS THE SOUTH. SUBSTANTIAL 305 TO 310K ISENTROPIC UPGLIDE INTO THIS MOISTURE RICH COLUMN WILL LEAD TO WIDESPREAD SHOWERS AND THUNDERSTORMS DEVELOPING AFTER 00Z AND SPREADING FROM SOUTH TO NORTH WITH THE ISENTROPIC FORCING. MLCAPE VALUES OF 600-1000 J/KG THIS EVENING ALONG WITH 0-6 KM SHEAR VALUES OF 40-50 KTS WOULD SUPPORT THE DEVELOPMENT OF STRONG TO MARGINALLY SEVERE ELEVATED STORMS WITH LARGE HAIL THE BIGGEST THREAT. HOWEVER...WITH A VERY MOIST COLUMN AND LOW NORMALIZED CAPE VALUES...HEAVY RAIN LOOKS TO BE THE BIGGEST THREAT WITH THESE STORMS. .LONG TERM /TUESDAY THROUGH MONDAY/... VERY COMPLICATED FORECAST AHEAD WITH CONVECTIVE AND WINTER ISSUES FOR THE NEXT SEVERAL DAYS. EXPECT WARM ADVECTION DRIVEN SHOWERS AND THUNDERSTORMS TO BE ONGOING AT THE BEGINNING OF THE PERIOD WITH TYPICAL DIURNAL DOWNWARD TREND INTO THE AFTERNOON. HOWEVER H85/H7 WARM/THETA-E ADVECTION REMAINS STRONG INTO THE AFTERNOON EVEN AS MID LEVEL FORCING BEGINS TO WANE. WITH SOLID 1-2KM MOISTURE REMAINING STILL EXPECT MEASURABLE LIGHT RAIN OR DRIZZLE TO CONTINUE WITH HIGH POPS DAY LONG. DO NOT EXPECT TOO MUCH IN THE WAY OF STRONG TO SEVERE STORMS. ALTHOUGH MUCAPES WILL BE INTO THE HUNDREDS...EFFECTIVE SHEAR ESTIMATED BY 1-6KM LAYER DECREASES INTO THE DAY AS H85 FLOW VEERS. MLCAPE/CIN PROJECTIONS INDICATE MINIMAL SURFACE POTENTIAL DUE TO INHIBITION BEING TOO HIGH. EXPECT ANOTHER ROUND OF CONVECTION INTO TUE NIGHT WITH PERSISTENT THETA-E ADVECTION AND PASSAGE OF INVERTED TROUGH...WHICH SHOULD BE INTO SOUTHERN IA IN SOME FORM BY 06Z. ENVIRONMENT EARLY TUE AND AGAIN TUE NIGHT LOOKS FAVORABLE FOR MODERATE TO LOCALLY HEAVY RAINS WITH VERY ANOMALOUS PWS AND DEEP WARM CLOUD DEPTHS LEADING TO EFFICIENT RAINFALL. ALTHOUGH ELEVATED INSTABILITY WILL CHANGE LITTLE TUE NIGHT...PROJECTED EFFECTIVE SHEAR INCREASES ONCE AGAIN SO MARGINAL LARGE HAIL MAY DEVELOP ALONG AND JUST TO THE NORTH AND WEST OF THE INVERTED TROUGH. EVENT TOTAL PRECIP AMOUNTS STILL LOOK LIKE A WIDESPREAD ONE TO TWO INCHES WITH LOCALLY HIGHER AMOUNTS POSSIBLE. ENSEMBLE RIVER FORECAST RUNS STILL SUGGEST MAINLY WITHIN BANK RISES OUTSIDE OF POTENTIAL SOME MINOR FLOODING SOUTH AND EAST IF THE HIGH END MATERIALIZES. THIS IS ABOUT THE SAME TYPE PRECIP TYPE STARTS TO BECOME AN ISSUE FAR NW AS COLD AIR GRADUALLY FILTERS SOUTH AND EAST BEHIND DEPARTING SURFACE FEATURES. ALTHOUGH ICE IS INTRODUCED INTO THE COLUMN WED...SURFACE TEMPS LOOK TO STAY TOO WARM FOR ANYTHING OTHER THAN A COLD RAIN. BY WEDNESDAY NIGHT...SOUNDINGS AND PLAN VIEW RH FIELDS STRUGGLE TO FIND MUCH RH COLDER THAN -10C LEADING TO FREEZING RAIN BEING MORE OF A COOL SEASON CONCERN THAN SNOW. BY THU THE POTENTIAL OF ICE ALOFT AND FAVORABLE SURFACE TEMPS MAY COME TOGETHER FOR SOME ACCUMULATIONS NORTH. NO WATCH YET WITH NO GREAT CONFIDENCE IN HOW FORCING AND TEMPS AT THE SURFACE AND ALOFT WILL FAVORABLE PHASE...BUT WILL SURELY ADD MENTION OF SNOW AND FREEZING RAIN ACCUMS TO HAZARDOUS WEATHER OUTLOOK. SYSTEM SHOULD FINALLY EXIT BY THE END OF THE WORK WEEK WITH LINGERING LOW LEVEL CYCLONIC FLOW KEEPING TEMPERATURES COOL AND BELOW NORMAL. POPS WILL RETURN FOR THE WEEKEND HOWEVER AS A LONG WAVE TROUGH RE-DEVELOPS OVER THE ROCKIES LEADING TO LOW PRESSURE MOVING FROM THE PLAINS INTO THE MISSOURI VALLEY. TIMING STILL UP IN THE AIR WITH 12Z GFS FASTER THAN THE 12Z ECMWF SO THE WEEKEND SEEMS MOST FAVORABLE AT THIS POINT. HAVE CARRIED LOW POPS MON BUT PEAK AT 12Z ECMWF IS NOW DRY SO THESE MAY END UP BEING OVERZEALOUS IF THAT TREND CONTINUES. ALTHOUGH IT IS CERTAINLY POSSIBLE...HAVE NOT INCLUDED THUNDER MENTION AS OF YET UNTIL CONFIDENCE INCREASES IN PREFERRED PERIOD INCREASES. && .AVIATION...08/18Z MVFR STRATUS OVER SOUTHERN AND FAR NORTHERN IOWA WILL CONTINUE TO DISSIPATE WITH DAYTIME HEATING THIS AFTERNOON WITH A SCT TO OCCASIONAL BKN CU FIELD AOA 2500 FT DEVELOPING LATER THIS AFTERNOON. CONDITIONS DETERIORATE TONIGHT AS A STRONG SYSTEM BEGINS TO AFFECT THE CENTRAL PLAINS. WINDS WILL BACK TO THE EAST AND CEILINGS WILL QUICKLY LOWER WITH THE ONSET OF RAIN TONIGHT. DROPPED CONDITIONS TO LOW MVFR AT ALL TAF SITES AFTER 06Z BUT WOULD NOT BE SURPRISED TO SEE IFR OR LOWER CONDITIONS BY TOMORROW MORNING. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM/AVIATION...SKOW LONG TERM...SMALL  FXUS63 KDMX 131743 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1243 PM CDT SAT APR 13 2013 .SHORT TERM.../TODAY/... ISSUED AT 330 AM CDT SAT APR 13 2013 MAIN CONCERNS TODAY WILL BE CLOUD COVER AND TEMPERATURES. CLOUDS BEGINNING TO PULL OUT NORTHEAST OF AREA BY AFTERNOON WITH CLOSED UPPER LOW NOW OVER THE UPPER PENINSULA OF MICHIGAN. HOWEVER... UPSTREAM WARM AIR ADVECTION ALREADY BEGINNING TO FILL IN ANOTHER AREA OF CLOUD COVER OVER THE DAKOTAS. THE OVERALL THEME FOR TODAY WILL BE FOR THE LESSENING OF CLOUDS IN THE MORNING AND THEN SOME CLOUDS CREEPING BACK INTO THE REGION DURING THE AFTERNOON. BY 00Z OVERCAST SKIES LIKELY ONCE AGAIN OVER THE AREA. TEMPS SHOULD RESPOND TO SUNSHINE...EVEN IF NOT FULLY REALIZED FOR ALL LOCATIONS. THE SOUTH LOOKS MORE LIKELY TO REACH HIGHS IN THE MID 50S BY AFTERNOON WHILE THE NORTH WILL BE HELD BACK SOMEWHAT AND SHOULD REACH THE LOWER 40S BY AFTERNOON. WINDS WILL BE FAIRLY LIGHT TODAY AS THE OLD SYSTEM PULLS OUT AND A RIDGE OF HIGH PRESSURE PASSES QUIETLY EAST THROUGH THE DAYTIME HOURS. DESPITE THE WARM UP TODAY...WE WILL STILL BE ABOUT 5 TO 10 DEGREES COLDER THAN NORMAL WITH THE COLDER DEPARTURES ALONG AND NORTH OF HIGHWAY 20. THE CLOUDS APPROACHING BY LATE DAY WILL SIGNAL A SHIFT TO WARMER CONDITIONS ON SUNDAY AS A STRONGER WAVE APPROACHES IOWA ON SUNDAY. .LONG TERM.../TONIGHT THROUGH FRIDAY/... ISSUED AT 330 AM CDT SAT APR 13 2013 THE WEATHER WILL BE ON A ROLLER COASTER FOR THE COMING WEEK. MODELS ARE AMAZINGLY IN AGREEMENT TONIGHT WITH A WEAK UPPER LEVEL RIDGING PUSHING EAST BY SUNDAY MORNING. SURFACE FEATURES ARE NOT IN AS GOOD AGREEMENT WITH THE LOW ANYWHERE FROM NW KANSAS TO SW SOUTH DAKOTA. THE EURO IS THE OUTLIER AT THIS POINT BUT ALL MODELS DRAPE A WARM FRONT FROM THE LOW INTO SW IA. THE WARM FRONT WILL LIFT ACROSS SOUTHERN AND CENTRAL IOWA OVERNIGHT. IN ADDITION...STRONG THETA-E ADVECTION WILL PUSH INTO SW IA. PRECIPITATION WILL MOVE INTO CENTRAL IOWA LATE TOMORROW EVENING. INSTABILITY INCREASES AS WELL AS SHEAR FOR SOME ISOLATED THUNDERSTORMS MOST LIKELY NEAR THE FRONTAL BOUNDARY BETWEEN 09Z AND 12Z. FOR SUNDAY AN UPPER LEVEL LOW PUSHES ACROSS THE NORTHERN PLAINS SWINGING A SHORT WAVE ACROSS IOWA WHILE AT THE SURFACE THE LOW PUSHES INTO SE MN DRAWING A COLD FRONT ACROSS CENTRAL IOWA. INSTABILITY AND SHEAR INCREASE AHEAD OF THE FRONT AS DEEPER MOISTURE MOVES IN. SURFACE DEWPOINTS WILL INCREASE TO THE LOWER 50S ACROSS MUCH OF IOWA. WITH THE BOUNDARY COMING THROUGH CENTRAL IOWA IN THE AFTERNOON...EASTERN/SOUTHEAST IOWA WILL LIKELY SEE SOME THUNDERSTORMS. THERE IS SOME POTENTIAL FOR STRONG STORMS FAR SOUTHEAST BUT THE MODELS ARE NOW KEEPING THE STRONGER INSTABILITY OVER MISSOURI. ITS TOO EARLY TO TELL IF ANY STORMS WILL BECOME SEVERE OVER THE SOUTHEAST BUT THIS AREA WILL BEAR WATCHING. COLDER AIR WILL PUSH INTO THE STATE SUNDAY NIGHT AND MONDAY AS THE SYSTEM LIFTS INTO THE GREAT LAKES REGION. FOR THE REMAINDER OF THE FORECAST PERIOD THE ATTENTION SHIFTS TO A DEEP TROUGH OVER THE SW U.S. THIS TROUGH WILL EJECT SHORTWAVE ACROSS THE REGION BRINGING ADDITIONAL PRECIP CHANCES PERIODICALLY THROUGH THE WORK WEEK FOLLOWED BY COOLER AIR. THE CLOUD COVER WILL DO NOTHING TO HELP THE SITUATION EITHER. EXPECT HIGHS THROUGH WEDNESDAY TO BE IN THE 40S WITH LOWS IN THE 30S. WEDNESDAY NIGHT THROUGH FRIDAY THIS LARGE TROUGH WILL SLOWLY SHIFT TO THE EAST KEEPING PRECIP CHANCES ACROSS CENTRAL IOWA. THE TROUGH AXIS WILL PASS TO THE EAST THURSDAY BRINGING MUCH COLDER AIR TO THE AREA THURSDAY THROUGH FRIDAY. PRECIP TYPE WILL LIKELY BE A MIX THESE TWO DAYS WITH PRECIP CHANGING TO SNOW THURSDAY NIGHT ACROSS THE CWA AS LOWS DROP WELL INTO THE MID 20S WEST AND NORTH AND AROUND 30 ELSEWHERE. && .AVIATION...13/18Z ISSUED AT 1239 PM CDT SAT APR 13 2013 HIGH PRESSURE RIDGE ERN DKTS THROUGH IA WILL MOVE TO THE EAST OF THE TAF SITES BY THIS EVENING. SCT-BKN LAYER OF STRATOCU HAS BEEN HARD TO SHAKE...BUT ONLY MVFR PROBLEMS WILL BE IN THE NRN SITES. WEATHER SYSTEM MOVING IN TONIGHT WITH INCREASING CLOUDS ALONG WITH BKN AREA OF SHOWERS AND ISOLATED TSRA DEVELOPING. LLWS IS LIKELY IN THE 09-15Z TIMEFRAME WITH SLY WINDS OF 45-55 KTS WITHIN 2 THOUSAND FEET OF THE SURFACE. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...REV LONG TERM...FAB AVIATION...MS APR 13  FXUS63 KDMX 160918 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 418 AM CDT TUE APR 16 2013 .SHORT TERM.../TODAY/ ISSUED AT 417 AM CDT TUE APR 16 2013 INTERESTING DAY TODAY...HIGH PRESSURE SHIFTS INTO THE AREA SUPPRESSING A BOUNDARY TO THE SOUTHEAST. LOW AND MID LEVEL CLOUD COVER ASSOCIATED WITH THIS AS WELL SO SUNSHINE WILL BE FILTERED AT BEST TODAY BUT THIS SHOULD BE ENOUGH TO EEK OUT A FEW MORE DEGREES IN TEMPERATURE FROM YESTERDAY. GENERALLY WARMED HIGHS TODAY 3 TO 5 DEGREES FROM YESTERDAY. THE MORNING SHOULD BE DRY BUT WILL START OUT VERY COOL. LATER THIS AFTERNOON THE BOUNDARY TO THE SOUTHEAST SHIFTS NORTHWARD AS THE HIGH MOVES EAST AND THE LARGE UPPER TROUGH IN THE WEST DEEPENS BUILDING A RIDGE ACROSS THE SOUTHEAST U.S. THERE IS A HINT OF A WEAK SHORT WAVE EJECTING FROM THE WESTERN TROUGH RIDING ACROSS CENTRAL/NORTHEAST MO. THIS SHOULD ENHANCE PRECIP CHANCES ACROSS THE FAR SOUTH AND EAST AFTER 18Z. THERE SHOULD BE ENOUGH INSTABILITY FOR AT LEAST SOME ISOLATED THUNDERSTORMS. AS THE WEAK WAVE PASSES EAST BY LATE AFTERNOON THERE MAY STILL BE SOME LINGERING CHANCES FOR SHOWERS ACROSS THE FAR SOUTH BUT NOT MUCH PAST THE SOUTHERN MOST COUPLE OF TIERS OF COUNTIES. THE BETTER SET UP FOR THUNDERSTORMS COMES TONIGHT AND WILL BE DISCUSSED LATER. THE GFS MOVES SOME THETA-E ADVECTION INTO THE FAR SOUTH BY 00Z BUT THE NAM IS WEAKER WITH THIS FEATURE AND HOLDS THIS BACK UNTIL AFTER 00Z. LOOKING AT SOUNDINGS AND IT IS PRETTY EVIDENT THAT THERE IS SOME POCKETS OF LOW AND MID LEVEL MOISTURE BUT THE BETTER DEEPER MOISTURE DOES NOT MOVE IN UNTIL 00Z OR AFTER. AS A RESULT...ANY RAINFALL TODAY SHOULD BE LIGHT. .LONG TERM.../TONIGHT THROUGH MONDAY/ ISSUED AT 417 AM CDT TUE APR 16 2013 DIFFICULT TO PIN DOWN PRIMARY FORECAST CONCERNS WITH SEVERE WEATHER...HEAVY RAIN AND FLOODING AND WIND BLOWN SNOW ALL NEEDING CONSIDERATION. PERIOD WILL BEGIN TONIGHT WITH THETA-E ADVECTION AND ELEVATED INSTABILITY SPREADING NORTHWARD. WARM ADVECTION WILL INITIALLY JUST DEVELOP SHOWERS SOUTH WITH INCREASING LIFT AND MOISTURE IN 1-2KM LAYER...HOWEVER SOUNDINGS MODIFY AFTER 06Z AS MOISTURE DEEPENS AND EVENTUALLY ALLOWS PARCELS TO SUFFICIENTLY REDUCE THEIR CINH TO REALIZE AVAILABLE ELEVATED CAPES. 00Z ECMWF AND GFS BOTH SHOW WIDESPREAD STRONG THETA-E ADVECTION BY 12Z WED SO EXPECT SUNRISE MCS AND CONVECTION FOR MOST FOLKS. THIS THERMODYNAMIC FORCING CHANGES LITTLE INTO THE DAY WED SO WHILE THERE WILL LIKELY BE SOME TYPICAL DIURNAL REDUCTION...STILL FEEL IT WOULD BE SUFFICIENT FOR CATEGORICAL POPS. EFFECTIVE SHEAR...ESTIMATED BY 1-6KM LAYER...SEEMS TO PEAK EARLY WED MORNING SO THIS MAY ALSO BE THE MORE LIKELY PERIOD FOR POTENTIAL ELEVATED HAIL STORMS. ATTENTION TURNS TO HEAVY RAIN POTENTIAL BY LATER IN THE DAY WED. STRONG 300K MOISTURE TRANSPORT AT ELEVATED CONVECTION BASE REGION WILL LIKELY REDEVELOP CONVECTION BY EARLY EVENING AND GREATLY INCREASE PW VALUES...WHICH NAM/GFS BOTH SUGGEST COULD REACH OR EXCEED 1.5 INCHES. THIS WOULD BE HIGHLY ANOMALOUS...ECLIPSE THE 99TH PERCENTILE EVEN TOWARD RECORD HIGHS BASED ON DVN CLIMO. WARM CLOUD DEPTHS REACH 10KFT SO EVERYTHING APPEARS TO BE IN PLACE FOR A HEAVY RAIN EVENT ALONG AND AHEAD OF THE INVERTED TROUGH AND THAT WORDING HAS BEEN INSERTED INTO THE SE. WARM SECTOR APPEARS TO BARELY CLIP THE FAR SE FORECAST AREA...ALTHOUGH DO NOT EXPECT MUCH IN THE WAY OF SURFACE BASED CONVECTION WITH CLOUDS AND PRECIP KEEPING THAT BETTER POTENTIAL SOUTH ALONG THE COLD FRONT. WOULD STILL EXPECT ELEVATED HAIL STORMS TO BE OUR MORE LIKELY SEVERE THREAT AGAIN BY LATE WED. MAY SEE A BRIEF LULL IN PRECIP LATE WED NIGHT AS THERMODYNAMIC FORCING EXITS TO THE EAST ALONG WITH SURFACE SYSTEM SO HAVE LOWERED POPS SOMEWHAT...MAINLY NW. PARENT SYSTEM THEN MOVES INTO MO RIVER VALLEY COINCIDENT WITH FALLING TEMPERATURES AND INCREASING WINDS. MODELS HAVE YET TO REACH A CONSENSUS WITH WESTWARD EXTENT OF DENDRITIC GROWTH ZONE AND BETTER MID LEVEL FORCING WEST OF DRY SLOT BUT IT APPEARS THAT AT LEAST THE NW THIRD OF IA WILL LIKELY SEE A WIND BLOWN SNOW EVENT AND AT LEAST SOME ACCUMULATIONS THU NIGHT INTO FRI MORNING. FORECAST SOUNDINGS ARE NOT TOTALLY MIXED AND DRY ADIABATIC BY 12Z FRI...BUT RAW WIND SPEEDS JUST OFF THE SURFACE WOULD STILL SUGGEST GUSTS MAY REACH 30KTS DURING THE TIME OF THE SNOW DRAMATICALLY REDUCING VISIBILITIES. ECMWF WOULD HAVE TO BE THE MORE FAVORED MODEL AT THIS POINT BASED ON PAST PERFORMANCE AND WOULD SUGGEST THAT WHILE OUR NW AREAS WOULD SEE SOME ACCUMULATIONS...BETTER POTENTIAL WOULD BE TO OUR NORTH AND WEST RATHER THAN THE MORE BULLISH SLOWER AND FARTHER EAST GFS. THE EXTENDED SHOWS LITTLE OVERALL CHANGE IN THE PATTERN...CONTINUED DAMP AND COOL. THERE MAY BE A BRIEF BREAK LATER FRI INTO EARLY SAT...BUT WELL ESTABLISHED LONG WAVE TROUGH WILL CONTINUE TO KEEP PRECIP CHANCES IN THE FORECAST WITH ANOTHER MINOR SURGE OF WARM ADVECTION EARLY SUN...AND THE PASSAGE OF ANOTHER SURFACE SYSTEM LATE SUN OR EARLY MON DEPENDING ON TIMING. && .AVIATION...16/06Z ISSUED AT 1117 PM CDT MON APR 15 2013 VFR CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD. THERE ARE STILL SOME MVFR CIGS ACROSS NORTHERN IOWA THAT MAY AFFECT MCW AND EVEN FOD OVER THE NEXT FEW HOURS...BUT NOTHING LONG LASTING AND MAY BE SLIGHTLY ABOVE 3000 FEET. OTHERWISE...HIGH CLOUD DECK REMAINS ACROSS THE STATE THROUGH TOMORROW BEFORE SOME MID-LEVEL THETA-E ADVECTION TUESDAY NIGHT AND BRING A CLOUD DECK FROM 3500-5000 FEET PAST 00Z WEDNESDAY. WINDS SHIFT MORE EAST AS WELL BY THEN. && .HYDROLOGY... ISSUED AT 417 AM CDT TUE APR 16 2013 THE PRESENTLY FORECAST RAINFALL AMOUNTS FROM THE MID-WEEK EVENT...WIDESPREAD 1 TO 3 INCH AMOUNTS...WILL LEAD TO SIGNIFICANT RISES ON AREA RIVERS...WITH THE POSSIBILITY OF AT LEAST MINOR FLOODING AT SEVERAL LOCATIONS. THE LATEST FORECAST HYDROGRAPH ENSEMBLES ARE FROM MON AS THEY ARE ONLY RUN ONCE PER DAY. HOWEVER PREVIOUS QPF IS SIMILAR TO LATEST EXPECTATIONS AND WOULD SUGGEST THAT THE BEST CHANCES OF FLOODING WOULD BE ACROSS THE SOUTHEAST HALF OF THE CWA. LARGER STREAMS OF MOST CONCERN INCLUDE THE CEDAR RIVER...BEAVER CREEK /TRIBUTARY TO THE CEDAR RIVER/...SOUTH SKUNK RIVER /ESPECIALLY DOWNSTREAM OF AMES/...DES MOINES RIVER /ESPECIALLY DOWNSTREAM OF DES MOINES/...AND SOUTH RIVER. IF RAINFALL IS GREATER THAN EXPECTED THEN A COUPLE LOCATIONS MAY SEE MODERATE FLOODING...WITH THE BEST CHANCES IN THE SOUTHEAST PORTIONS OF THE CWA. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...BOKSA LONG TERM...SMALL AVIATION...PODRAZIK HYDROLOGY...ZOGG/SMALL  FXUS63 KDMX 170937 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 437 AM CDT WED APR 17 2013 .SHORT TERM.../TODAY/ ISSUED AT 436 AM CDT WED APR 17 2013 THE COMBINATION OF A LOW LEVEL JET INCREASING ACROSS SOUTHERN IOWA AND STRONG THETA-E ADVECTION PUSHING ACROSS THE STATE HAS CAUSED SHOWERS AND THUNDERSTORMS TO BLOSSOM OVERNIGHT AND QUICKLY SPREAD INTO SOUTHERN IOWA. THESE STORMS WILL PUSH NORTHEAST ACROSS MUCH OF THE AREA THROUGH THE MORNING. THE BEST INSTABILITY REMAINS SOUTH OF IOWA...ACROSS KANSAS AND CENTRAL MO. THIS WILL WORK ITS WAY INTO IOWA AS WELL BUT PROBABLY NOT UNTIL LATER MORNING AND AFTERNOON. UNTIL THEN STORMS SHOULD BEHAVE THEMSELVES...PRODUCING LIGHT TO MODERATE RAINFALL AND PERHAPS SOME SMALL HAIL. DURING THE AFTERNOON INTO THE EVENING A BUILDING UPPER RIDGE TO OUR EAST AND THE WELL ADVERTISED DEEPENING TROUGH OVER THE SOUTHWEST WILL BRING A DEEP SOUTH TO SOUTHWEST FLOW ACROSS THE STATE AS WELL AS DEEPER MOISTURE. AT THE SURFACE AN INVERTED TROUGH WILL SET UP FROM ROUGHLY LAMONI THROUGH CHARLES CITY. THERE WILL BE DECENT SHEAR ALONG THAT SURFACE BOUNDARY THAT WILL SET UP IN THIS AREA SO I AM EXPECTING STORMS TO SORT OF FOCUS ON THAT BOUNDARY AND WHILE THE STRONGER STORMS WILL REMAIN SOUTH OF THE STATE...WE CANNOT RULE OUT SOME STORMS CAPABLE OF LARGE HAIL OR STRONG TO DAMAGING WIND. NOT EXPECTING A BIG SEVERE WEATHER DAY HERE AS STORMS WILL REMAIN ELEVATED BASED ON SOUNDINGS. HEAVY RAIN IS ALSO A CONCERN. WE HAVE BEEN GETTING DECENT RAINFALL OF LATE AND WITH QPF VALUES OF A HALF TO 6 TENTHS OF AN INCH THIS MORNING AND AT LEAST THAT THIS AFTERNOON WITH MORE HEAVY RAIN EXPECTED TONIGHT SOME POTENTIAL FOR FLOODING EXISTS. WE WILL BE ISSUING A FLASH FLOOD WATCH ACROSS MUCH OF THE SOUTHEAST BEGINNING AT NOON. MODERATE TO HEAVY RAIN SHOULD NOT BEGIN BEFORE MID TO LATE AFTERNOON BUT THIS MORNINGS RAIN WILL SATURATE SOILS AND PRIME THINGS FOR LATER. .LONG TERM.../TONIGHT THROUGH TUESDAY/ ISSUED AT 436 AM CDT WED APR 17 2013 VERY COMPLEX FORECAST EARLY IN THIS PERIOD WITH WINTER...HEAVY RAIN AND SEVERE WEATHER ELEMENTS ALL IN PLAY. HEAVY RAIN AND SEVERE WEATHER WILL INITIALLY BE THE CONCERN AS CONVECTION CONTINUES TO DEVELOP ALONG AND AHEAD OF MATURING INVERTED TROUGH WHICH IS EXPECTED TO REACH SRN IA BY LATE AFTERNOON. INSTABILITY WILL NOT BE EXTREME WITH MUCAPES TYPICALLY AT OR BELOW 1000 J/KG...LIKELY ELEVATED. ALTHOUGH FAR SE SECTION MAY BRIEFLY GET INTO THE WARM SECTOR...EXPECT MLCIN TO STAYING TOO HIGH TO GET ANYTHING SURFACE BASED DUE TO PERSISTENT CLOUDS AND PRECIP. SEVERE WEATHER POTENTIAL MAY WANE SOMEWHAT DURING THE EVENING AS EFFECTIVE /1-6KM/ SHEAR DIMINISHES. HOWEVER HEAVY RAIN THREAT...WHICH WOULD ALREADY BE IN PLACE...MAY INCREASE AS CONVECTION TRAINS ALONG TROUGH INTO SOUTHEAST IOWA SO FLASH FLOOD WATCH HAS BEEN ISSUED FOR THESE LOCATIONS. SEE HYDRO SECTION FOR MORE INFORMATION. PRECIPITATION MAY BRIEFLY DIMINISH SOMEWHAT INTO THURSDAY AS SURFACE FEATURES EXIT AND LARGE SCALE FORCING TAKES A TEMPORARY BREAK. HAVE LEANED TOWARD THE RECENT NAM AND ECMWF SOLUTIONS WHICH SEEM FAIRLY SIMILAR WHILE THE GFS APPEARS TO BE SOMEWHAT OF A SLOWER OUTLIER. WITH ALL THE CONVECTION AND LATENT HEAT RELEASE CANNOT ARGUE WITH LOWER SURFACE PRESSURES BEING FARTHER NE BY THU MORNING. MOST OF THE FORCING AND MOISTURE EARLY THU APPEARS TO BE BELOW 3KM SUGGESTING LIGHT PRECIP AMOUNTS BUT WITH NO ICE INTRODUCTION. THUS FREEZING RAIN MAY COME INTO PLAY NW WHERE TEMPS WILL HOVER AROUND THE FREEZING MARK AS COLDER AIR CONTINUES TO FILTER INTO THE STATE. IF SURFACE TEMPS DROP SUFFICIENTLY...AND THATS A CONDITIONAL IF...WE MAY SEE SOME ADVISORY LEVEL ICING. STUDIES HAVE SHOWN THAT SMALLER DROPS...WHICH WOULD BE THE CASE IN THIS LIGHTER PRECIP/RELATIVELY SHALLOWER MOISTURE...AND BRISK WINDS ENHANCE ICING. CONFIDENCE IN THERMAL PROFILE BEING FAVORABLE IS NOT GREAT HOWEVER SO WILL MENTION IN HWO BUT NOT INCLUDE IN ADVISORY AS OF YET. BY LATER IN THE DAY THE LARGE SCALE FORCING SHOULD INCREASE HAD OF THE PARENT SYSTEM..ESPECIALLY BY THE EVENING. WITH TEMPERATURES JUST ABOVE FREEZING BY LATE AFTERNOON AND SUFFICIENT MOISTURE DEPTH FOR ICE INTRODUCTION...PRECIP TYPE SHOULD FLIP TO EITHER RAIN OR SNOW. BEST DENDRITIC FORCING LOOKS TO BE NORTH OF FORECAST AREA BY THE TIME WE SWITCH TO SNOW NW SO COULD SEE AN INCH OR TWO FAR NW BUT NOTHING TO JUSTIFY A HEADLINE AT THE MOMENT. CONDITIONS MAY BRIEFLY DETERIORATE WITH LOW VISIBILITIES DURING THE SNOW AND BRISK NW WINDS HOWEVER. PATTERN REMAINS SIMILAR RIGHT INTO EARLY NEXT WEEK WITH DAMP AND GENERALLY COOL CONDITIONS. PRECIP RETURNS TO THE FORECAST BY LATE SATURDAY NIGHT AS WARM ADVECTION RETURNS. THIS WILL BE FOLLOWED BY DEEPER FORCING WITH PASSAGE OF SURFACE SYSTEM LATE SUNDAY. LONG WAVE TROUGH CONTINUES TO DEEPEN INTO EARLY NEXT WEEK WITH ANOTHER SYSTEM MATURING THROUGH MID MS VALLEY...IN SOME WAYS SIMILAR TO CURRENT SYSTEM. THIS WILL LIKELY BRING MORE WIDESPREAD TO SE IA AND WITH MORE COOL TEMPERATURES. && .AVIATION...17/06Z ISSUED AT 1148 PM CDT TUE APR 16 2013 VFR CIGS AT ALL TAF SITES FOR NOW...WITH CIGS STILL EXPECTED TO LOWER TO MVFR AND THEN IFR AS MOISTURE INCREASES AND PRECIPITATION OVERSPREADS THE AREA LATE TONIGHT INTO WEDNESDAY. VSBYS STILL EXPECTED TO DIP TO MVFR AND POSSIBLE IFR CONDITIONS IN HEAVIER SHOWERS AND THUNDERSTORMS AND DUE TO SOME FOG WITH THE ABUNDANT LOW LEVEL MOISTURE. INSTABILITY EXPECTED TO BE GREATEST AROUND THE SOUTHERN/EASTERN TAF SITES SO HAVE ONLY INCLUDED VCTS AT KALO...KDSM...AND KOTM...HOWEVER CANNOT RULE OUT AN ISOLATED THUNDERSTORM AT ANY TAF SITE. && .HYDROLOGY... ISSUED AT 436 AM CDT WED APR 17 2013 STORM MOTION BY LATE EVENING APPEARS TO BE PARALLEL TO THE FRONT AT 40-50KTS SUGGESTING SERN IA MAY BE ON THE NRN FRINGE OF WHAT RESEMBLES A MADDOX SYNOPTIC FLOODING EVENT. WITH PWS TO 1.5 INCHES...EXTREMELY ABOVE NORMAL...AND WARM CLOUD DEPTHS PUSHING 10KFT HAVE ISSUED A FLASH FLOOD WATCH FOR THESE LOCATIONS FROM THIS AFTERNOON INTO TONIGHT. RAINFALL AMOUNTS BY DAYBREAK THU MAY REACH 2-3 INCHES WITH LOCALLY HIGHER AMOUNTS POSSIBLE. WITH GROUNDS STILL RELATIVELY MOIST THERE AND MAINLY DORMANT VEGETATION RUNOFF WILL BE FAIRLY HIGH. RIVER FORECAST CENTER CONTINGENCY FORECASTS FROM TUE SUGGEST SEVERAL RIVERS MAY REACH FLOOD STAGE OVER THE EASTERN FORECAST AREA. CANDIDATES TO BE WATCHED WOULD BE THE CEDAR RIVER AND THERE TRIBUTARIES AND THE DES MOINES RIVER BELOW RED ROCK. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH THURSDAY MORNING FOR APPANOOSE-CLARKE-DAVIS-DECATUR-JASPER-LUCAS-MADISON-MAHASKA- MARION-MONROE-POWESHIEK-RINGGOLD-TAMA-TAYLOR-UNION-WAPELLO- WARREN-WAYNE. && $$ SHORT TERM...BOKSA LONG TERM/HYDROLOGY...SMALL AVIATION...BEERENDS  FXUS63 KDMX 190900 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 400 AM CDT FRI APR 19 2013 .SHORT TERM.../TODAY/ ISSUED AT 356 AM CDT FRI APR 19 2013 MAIN FORECAST CONCERN TODAY IS WITH STRONG NORTHWEST WINDS AND POTENTIAL FOR SCATTERED FLURRIES/SPRINKLES ACROSS THE CENTRAL TO NORTHEAST PORTION OF THE FORECAST AREA. LEANED TOWARD BLEND OF SREF/NAM/GFS TODAY AS MODELS ARE GENERALLY IN GOOD AGREEMENT. POTENT CAA WILL CONTINUE THROUGHOUT THE DAY TODAY ON THE BACKSIDE OF A STRONG LOW PRESSURE SYSTEM TRACKING ACROSS THE GREAT LAKES. SOME MID-LEVEL MOISTURE AND ENOUGH LIFT WITHIN THE SNOW GROWTH ZONE WILL CONTINUE TO PROVIDE SCATTERED FLURRIES OR SNOW SHOWERS THROUGH THE MORNING HOURS. SURFACE TEMPS WILL WARM ENOUGH TO MENTION SHOWERS/SPRINKLES PAST 15Z TODAY AND INTO THE AFTERNOON. KEPT MENTION OF LIGHT SNOW SHOWERS/FLURRIES ACROSS THE FAR NORTHEAST THIS AFTERNOON AS BOUNDARY LAYER VERY SHALLOW AND MAY NOT BE DEEP ENOUGH TO MELT FLAKES BEFORE REACHING THE SURFACE. SO CANNOT RULE OUT SOME LIGHT SNOW SHOWERS/FLURRIES NEAR THE MCW TO ALO AREA THROUGH 20Z. WENT AT OR SLIGHTLY ABOVE THE WARMEST GUIDANCE FOR MAX TEMPS...WHICH WAS GENERALLY THE MAV MOS. TIGHT PRESSURE GRADIENT BEGINS TO RELAX PAST 21Z TODAY...BUT WITH WINDS ATOP THE MIXED LAYER RANGE AROUND 35 KNOTS UNTIL THEN AND WILL CONTINUE TO SEE STOUT GUSTS DURING MUCH OF THE DAY EVEN WITHOUT MUCH CLEARING ANTICIPATED. .LONG TERM.../TONIGHT THROUGH THURSDAY/ ISSUED AT 356 AM CDT FRI APR 19 2013 ALTHOUGH NOTHING LIKE EXPERIENCED THE PAST SEVERAL DAYS...THE PATTERN WILL REMAIN ACTIVE THROUGH THE PERIOD WITH RELATIVELY HIGH AMPLITUDE AND PERSISTENT CENTRAL CONUS LONG WAVE TROUGH. WITH A FEW EXCEPTIONS...THIS WILL KEEP PRECIP IN THE FORECAST FOR SEVERAL DAYS WITH NORMAL TO BELOW NORMAL TEMPERATURES. THE MOST SUBSTANTIAL BREAK IN THE PRECIP INTO NEXT WEEK MAY BE TONIGHT AND SATURDAY. EFFECTS OF CURRENT SYSTEM WILL BE WELL TO THE EAST BY TONIGHT WITH COLD HIGH PRESSURE SETTLING INTO THE MO VALLEY. 00Z HIRES WRF RUNS...ESPECIALLY NMM CORE...DEPICT A NARROW BAND OF NW-SE ORIENTED SNOW SHOWERS THROUGH MASON CITY THIS EVENING. WHILE STEEP LAPSE RATES DO REMAIN IN PLACE...CANNOT FIND MUCH TO SUPPORT PRECIP IN OPERATIONAL MODELS OR ENSEMBLES SO NO MENTION RIGHT SNOW BUT SOMETHING TO WATCH. COULD BE SOME PATCHY FOG AS WELL OVERNIGHT WITH WET SOILS AND WINDS BECOMING LIGHT. NEXT WINDOW FOR PRECIP LOOKS TO BE BEGIN SAT NIGHT WITH INCREASING WARM ADVECTION FOLLOWED BY WEAK KINEMATIC FORCING WITH A MINOR SHORT WAVE PASSAGE INTO SUNDAY. SUNDAY WILL BE ONE OF THE WARMER DAYS AS WE MIX...BUT THAT MAY ALSO LEAD TO BRISK SOUTH WINDS GUSTING TO 30KTS OR HIGHER BY AFTERNOON. SOUNDINGS SHOW A SOMEWHAT HIGHER POTENTIAL AS WELL...BUT CLOUDS AND PRECIP MAY KEEP THAT FROM BEING REALIZED. ANOTHER STRONGER SHORT WAVE WILL FOLLOW INTO MONDAY AND APPEARS TO BE OUR MOST SUBSTANTIAL PRECIP EVENT OF THE PERIOD. THIS STRONGER SYSTEM WILL DEVELOP ITS SURFACE REFLECTION ALONG A TRACK SIMILAR TO WHAT RECENTLY OCCURRED. PWS AND WARM CLOUD DEPTHS ARE LESS FAVORABLE FOR EFFICIENT HEAVY RAINS...BUT PHASED THERMODYNAMIC AND KINEMATIC FORCING ALONG WITH SUFFICIENT INSTABILITY MAY LEAD TO MODERATE RAINFALL IN SIMILAR LOCATIONS THAT SAW HEAVY RAIN OVER THE PAST FEW DAYS. ALTHOUGH 00Z ECMWF IS LESS AGGRESSIVE...GFS AND GEM SOLUTIONS DEPICT AN INCH OR MORE OF PRECIP. THIS WOULD LIKELY NOT REINTRODUCE MUCH IN THE WAY OF ADDITIONAL FLOODING...BUT WOULD CERTAINLY NOT HELP DRY THINGS OUT. LOW POPS LINGER INTO TUE AND TUE NIGHT LENDING SOME CREDENCE TO THE SLOWER 00Z ECMWF SOLUTION. THERE LOOKS TO BE SOMEWHAT OF BREAK AROUND WED AND THU HOWEVER WITH RELATIVELY DRY NW FLOW STILL IN PLACE AND LITTLE CHANGE IN CENTRAL CONUS MEAN TROUGH. TONIGHT WILL LIKELY BE THE COLDEST NIGHT OF THE PERIOD BUT NO FROST OR FREEZE HEADLINES AS OF YET. VEGETATION IS BEHIND SCHEDULE AND THE AVERAGE LAST 32F OCCURRENCE VARIES FROM ABOUT NOW FAR SOUTH TO EARLY MAY NORTH. && .AVIATION...19/06Z ISSUED AT 1146 PM CDT THU APR 18 2013 CIGS REMAIN IN THE MVFR RANGE ACROSS THE CWA WITH MAINLY VFR VSBYS WITH LIGHT FLURRIES IMPACTING KMCW...KFOD...AND KDSM. KMCW WILL SEE SOME DIPS INTO MVFR VSBYS WITH THE LIGHT SNOW. FLURRIES TO TAPER OFF FRIDAY MORNING...WITH CHANCE FOR SOME LIGHT SPRINKLES/SHOWERS POSSIBLE TOWARD LATE FRIDAY MORNING INTO THE AFTERNOON HOURS. CONFIDENCE NOT AS HIGH...SO STUCK WITH VCSH. NORTHWEST WINDS TO REMAIN VERY GUSTY AND INCREASE THROUGHOUT THE DAY AS STRONGER WINDS ALOFT MIX TO THE SURFACE FRIDAY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...SMALL AVIATION...BEERENDS  FXUS63 KDMX 090851 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 351 AM CDT THU MAY 9 2013 .SHORT TERM.../TODAY /... ISSUED AT 348 AM CDT THU MAY 9 2013 MAIN CONCERN THIS MORNING WILL BE CONVECTIVE TRENDS...ESPECIALLY HEAVY RAIN POTENTIAL. COMPACT SHORT WAVE/PV ANOMALY CONTINUES TO SLOWLY CROSS THE NE/IA BORDER. FORCING AHEAD OF FEATURE IS NOT EXTREME...BUT COUPLED WEAK/MODERATE THERMODYNAMIC AND KINEMATIC FORCING HAS SUSTAINED AND EVEN RECENTLY ENHANCED CONVECTION FROM SW INTO CENTRAL IA. THIS IN SOME WAYS RESEMBLES A LOW END SHARS EVENT BUT WITH LESS FAVORABLE ENVIRONMENT. SEVERE POTENTIAL HAS DIMINISHED WITH NIL EFFECTIVE SHEAR AND MUCAPES ONLY SEVERAL HUNDRED J/KG. HEAVY RAIN CONDITIONS ARE NOT GREAT EITHER WITH PWS JUST OVER AN INCH AND WARM CLOUD DEPTHS UNDER 1K FT. HOWEVER MEAN CELL MOTION IS CURRENTLY 230 AT ONLY 16KTS SO SUM ALL FACTORS TOGETHER WITH SLOW MOVEMENT COULD STILL LEAD TO HEAVY RAINS WHICH UNFORTUNATELY MAY IMPACT THE MORNING COMMUTE. ADAIR AND PERRY HAVE ALREADY RECEIVED 1.7 INCHES SINCE MIDNIGHT. CONDITIONS CHANGE LITTLE THROUGH THE MORNING WITH CATEGORICAL POPS...BUT OVERALL FORCING DIMINISHES INTO THE AFTERNOON WITH LESS COVERAGE ANTICIPATED. CANNOT ARGUE WITH 05Z HRRR DEPICTION TOO MUCH. .LONG TERM.../TONIGHT THROUGH WEDNESDAY/... ISSUED AT 348 AM CDT THU MAY 9 2013 WE WILL BE CONTINUING TO DEAL WITH THE REMNANTS OF THE SOUTH DAKOTA LOW AND THE SOUTHERN STREAM SHORT WAVE PUSHING ACROSS THE FORECAST AREA TONIGHT. THE SLOW MOVEMENT OF THE STORMS IN THE WEAK FLOW OVER IOWA HAS PROVEN TO MAKE EFFICIENT RAIN PRODUCING STORMS BUT WE LOSE WHATEVER WEAK FORCING WE HAD IN PLACE FROM TODAY SO I DON'T SEE AS MUCH RAINFALL TONIGHT. SOME LINGERING PRECIP EXPECTED ACROSS THE SOUTHEAST INTO FRIDAY MORNING THEN A BREAK AS WEAK HIGH PRESSURE BUILDS IN AT THE SURFACE WHILE ALOFT WE ARE IN BETWEEN SYSTEMS. FRIDAY NIGHT INTO SATURDAY A LARGE LOW PRESSURE SYSTEM OVER CANADA CARVES A TROUGH INTO THE UPPER MIDWEST. AT THE SURFACE A STRONG COLD FRONT WILL WORK ACROSS THE AREA BRINGING A SHOT FOR MORE RAIN AND MUCH COLDER TEMPERATURES ALONG WITH BREEZY CONDITIONS FOR THE WEEKEND. TEMPERATURES WILL BE DROPPING INTO THE LOW TO MID 30S SATURDAY NIGHT SO FROST HAS TO ENTER THE THOUGHT PROCESS HERE BUT WINDS AT LEAST THROUGH THE EVENING...AND PROBABLY ALL NIGHT ACROSS THE EAST...WILL STAY UP ENOUGH TO MINIMIZE THE FROST THREAT. HOWEVER AT THIS POINT I THINK IT IS ENOUGH OF A THREAT TO PUT IT IN THE FORECAST GRIDS ACROSS NORTH FOR A FEW HOURS BEFORE DAYBREAK. THIS WILL NEED TO BE MONITORED FOR THE POTENTIAL FOR MORE THAN JUST A MENTION. THE COLD WILL BE SHORT LIVED AS A LARGE UPPER LEVEL RIDGE BUILDS ACROSS THE ROCKIES THEN SHIFTS EAST EARLY NEXT WEEK. TUESDAY STILL LOOKS VERY WARM AND WHILE I WAS NOT BOLD ENOUGH TO MENTION A 90 DEGREE READING I DID BUMP TEMPS UP INTO THE MID TO UPPER 80S. THE UPPER RIDGE FLATTENS INTO MIDWEEK KNOCKING TEMPS BACK SEVERAL DEGREES. A FRONTAL BOUNDARY WILL SAG INTO THE REGION PRODUCING A CHANCE FOR THUNDERSTORMS TUESDAY NIGHT. TEMPERATURES THROUGH MIDWEEK WHILE COOLER...WILL STILL BE SEASONAL INTO THURSDAY WITH HIGHS IN THE 70S. && .AVIATION...09/06Z ISSUED AT 1159 PM CDT WED MAY 8 2013 AN AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE NORTH THROUGH 09Z THEN EXPECT A BAND OF FOG AND STRATUS TO DEVELOP WITH IFR OR LOWER CONDITIONS POSSIBLE THROUGH MID MORNING. ANOTHER AREA OF THUNDERSTORMS WILL LIFT INTO SOUTHERN IOWA OVERNIGHT AND PRIMARILY IMPACT KOTM AND KDSM. AREAS OF PRECIPITATION WILL CONTINUE ON THURSDAY BEFORE GRADUALLY DIMINISHING LATER IN THE AFTERNOON AND EVENING. POTENTIAL FOR LOW STRATUS MOVING INTO THE AREA BEHIND A FRONTAL BOUNDARY IS INCREASING BY THE EVENING AS WELL. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMALL LONG TERM...FAB AVIATION...DONAVON  FXUS63 KDMX 091743 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1243 PM CDT THU MAY 9 2013 .SHORT TERM.../TODAY/ ISSUED AT 348 AM CDT THU MAY 9 2013 MAIN CONCERN THIS MORNING WILL BE CONVECTIVE TRENDS...ESPECIALLY HEAVY RAIN POTENTIAL. COMPACT SHORT WAVE/PV ANOMALY CONTINUES TO SLOWLY CROSS THE NE/IA BORDER. FORCING AHEAD OF FEATURE IS NOT EXTREME...BUT COUPLED WEAK/MODERATE THERMODYNAMIC AND KINEMATIC FORCING HAS SUSTAINED AND EVEN RECENTLY ENHANCED CONVECTION FROM SW INTO CENTRAL IA. THIS IN SOME WAYS RESEMBLES A LOW END SHRS EVENT BUT WITH LESS FAVORABLE ENVIRONMENT. SEVERE POTENTIAL HAS DIMINISHED WITH NIL EFFECTIVE SHEAR AND MUCAPES ONLY SEVERAL HUNDRED J/KG. HEAVY RAIN CONDITIONS ARE NOT GREAT EITHER WITH PWS JUST OVER AN INCH AND WARM CLOUD DEPTHS UNDER 1K FT. HOWEVER MEAN CELL MOTION IS CURRENTLY 230 AT ONLY 16KTS SO SUM ALL FACTORS TOGETHER WITH SLOW MOVEMENT COULD STILL LEAD TO HEAVY RAINS WHICH UNFORTUNATELY MAY IMPACT THE MORNING COMMUTE. ADAIR AND PERRY HAVE ALREADY RECEIVED 1.7 INCHES SINCE MIDNIGHT. CONDITIONS CHANGE LITTLE THROUGH THE MORNING WITH CATEGORICAL POPS...BUT OVERALL FORCING DIMINISHES INTO THE AFTERNOON WITH LESS COVERAGE ANTICIPATED. CANNOT ARGUE WITH 05Z HRRR DEPICTION TOO MUCH. .LONG TERM.../TONIGHT THROUGH WEDNESDAY/ ISSUED AT 348 AM CDT THU MAY 9 2013 WE WILL BE CONTINUING TO DEAL WITH THE REMNANTS OF THE SOUTH DAKOTA LOW AND THE SOUTHERN STREAM SHORT WAVE PUSHING ACROSS THE FORECAST AREA TONIGHT. THE SLOW MOVEMENT OF THE STORMS IN THE WEAK FLOW OVER IOWA HAS PROVEN TO MAKE EFFICIENT RAIN PRODUCING STORMS BUT WE LOSE WHATEVER WEAK FORCING WE HAD IN PLACE FROM TODAY SO I DON'T SEE AS MUCH RAINFALL TONIGHT. SOME LINGERING PRECIP EXPECTED ACROSS THE SOUTHEAST INTO FRIDAY MORNING THEN A BREAK AS WEAK HIGH PRESSURE BUILDS IN AT THE SURFACE WHILE ALOFT WE ARE IN BETWEEN SYSTEMS. FRIDAY NIGHT INTO SATURDAY A LARGE LOW PRESSURE SYSTEM OVER CANADA CARVES A TROUGH INTO THE UPPER MIDWEST. AT THE SURFACE A STRONG COLD FRONT WILL WORK ACROSS THE AREA BRINGING A SHOT FOR MORE RAIN AND MUCH COLDER TEMPERATURES ALONG WITH BREEZY CONDITIONS FOR THE WEEKEND. TEMPERATURES WILL BE DROPPING INTO THE LOW TO MID 30S SATURDAY NIGHT SO FROST HAS TO ENTER THE THOUGHT PROCESS HERE BUT WINDS AT LEAST THROUGH THE EVENING...AND PROBABLY ALL NIGHT ACROSS THE EAST...WILL STAY UP ENOUGH TO MINIMIZE THE FROST THREAT. HOWEVER AT THIS POINT I THINK IT IS ENOUGH OF A THREAT TO PUT IT IN THE FORECAST GRIDS ACROSS NORTH FOR A FEW HOURS BEFORE DAYBREAK. THIS WILL NEED TO BE MONITORED FOR THE POTENTIAL FOR MORE THAN JUST A MENTION. THE COLD WILL BE SHORT LIVED AS A LARGE UPPER LEVEL RIDGE BUILDS ACROSS THE ROCKIES THEN SHIFTS EAST EARLY NEXT WEEK. TUESDAY STILL LOOKS VERY WARM AND WHILE I WAS NOT BOLD ENOUGH TO MENTION A 90 DEGREE READING I DID BUMP TEMPS UP INTO THE MID TO UPPER 80S. THE UPPER RIDGE FLATTENS INTO MIDWEEK KNOCKING TEMPS BACK SEVERAL DEGREES. A FRONTAL BOUNDARY WILL SAG INTO THE REGION PRODUCING A CHANCE FOR THUNDERSTORMS TUESDAY NIGHT. TEMPERATURES THROUGH MIDWEEK WHILE COOLER...WILL STILL BE SEASONAL INTO THURSDAY WITH HIGHS IN THE 70S. && .AVIATION...09/18Z ISSUED AT 1240 PM CDT THU MAY 9 2013 UPPER LOW OVER IOWA WILL MOVE SLOWLY ESEWD WITH NUMEROUS SHOWERS AND ISOLATED TSRA EXPECTED THIS AFTERNOON. AREAS OF IFR CIGS WILL EXPAND SOUTH AND EAST AS TROF SHIFTS SOUTHEAST. EXPECT IFR CIGS ACROSS THE TAF SITES TONIGHT WITH MVFR VSBYS. CONDITIONS WILL IMPROVE ACROSS THE NRN TAFS EARLY FRIDAY MORNING WITH SKIES CLEARING...AND IMPROVE TO MVFR CIGS ACROSS THE SRN SITES BY MID MORNING. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ LONG TERM...FAB AVIATION...MS  FXUS63 KDMX 182043 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 343 PM CDT SAT MAY 18 2013 .SHORT TERM.../TONIGHT /... ISSUED AT 330 PM CDT SAT MAY 18 2013 MAIN CONCERNS TONIGHT WILL BE EXTENT OF CONVECTION ACROSS THE FORECAST AREA LATE NIGHT AND INTO EARLY MORNING. MODELS SIMILAR IN TIMING BUT VERY LITTLE AGREEMENT IN AREAL COVERAGE/PLACEMENT OF RAINFALL OVERNIGHT SO CONFIDENCE LOW AT THIS TIME. SYNOPTIC SETUP SHOWS APPROACHING H700 SHORTWAVE OVER PANHANDLE AREA OF TEXAS/OK NOW AND SIMPLE TIME OF ARRIVAL TOOL SHOWS AT CURRENT SPEED WILL ARRIVE INTO SW COUNTIES AFT 07Z AND INTO CENTRAL IOWA BY ABOUT 10Z...FAVORED TIME FOR NOCTURNAL CONVECTION. THIS CORRELATES PRETTY WELL WITH INCREASING WIND FIELDS FROM THE GFS OVERNIGHT WITH H850 40KT JET ENTERING AREA AND SUFFICIENT SPEED SHEAR FROM H700/H500 OF 40-60KTS RESPECTIVELY FROM 08-12Z. SFC BOUNDARY LOOKS TO MAKE IT AS FAR NORTH AS IA/MO BORDER BY 12Z AS WELL. MOISTURE IS QUITE HIGH FOR THIS EVENT WITH PWATS BY 12Z APPROACHING +90-95% LEVEL OF CLIMATOLOGICAL MAX AND NEAR 2 STANDARD DEVIATIONS FROM NORMAL. WARM CLOUD DEPTHS LOOK FAIRLY IMPRESSIVE WITH 10-11KFT EXPECTED LATE TONIGHT AND A GOOD SHARE OF SUNDAY AS WELL. WITH EXPECTED SHORT WAVE AND FORECAST CONDITIONS...HAVE SOME CONCERNS ABOUT LOCALLY HEAVY RAINFALL AND POTENTIAL FOR ISOLATED FLASH FLOODING OVER THE WEST/SOUTHWEST AREAS SHOULD MCS HOLD TOGETHER AS IT TRACKS NORTHEAST. CURRENT 3 HR GRIDDED FLASH FLOOD GUIDANCE OF +2-3 INCHES REMAINS PRETTY HIGH OVER MUCH OF SOUTHERN 2 TIER COUNTIES...BUT WEST OF I35 AND AREAS NORTH OF THERE HAVE LOWER VALUES OF 1.75 TO 2 INCHES IN GENERAL. WITH HIGH PWATS AND SIGNIFICANT WARM CLOUD DEPTHS COMBINED WITH SHORT WAVE WE CLOUD SEE ISOLATED RAINFALL AMOUNTS OF 1 TO 2+ INCHES OVER THE SOUTHWEST TO CENTRAL COUNTIES BY 12Z...WITHIN TRACK OF MCS. THE CHALLENGE REMAINS HOWEVER...IN THAT THE 4 KM WRF AND HRRR WILL NEED TO WATCH THIS THROUGH EVENING TO SEE HOW SITUATION EVOLVES. LOWS OVERNIGHT WILL BE QUITE MILD AGAIN WITH INCREASING MOISTURE PUTTING A CAP ON MINS IN THE LOWER TO MID 60S. SOME CONCERN REMAINS ABOUT POTENTIAL FOR SEVERE OVERNIGHT...BUT IF ANY OCCURS WILL BE MAINLY FOR LARGE HAIL OVER THE WEST. .LONG TERM.../SUNDAY THROUGH SATURDAY/... ISSUED AT 330 PM CDT SAT MAY 18 2013 MAIN FORECAST CONCERN REMAINS FOCUSED ON ACTIVE WEATHER PATTERN DEVELOPING OVER THE NEXT SEVERAL DAYS. MODELS IN GOOD AGREEMENT THROUGH EARLY IN THE WEEK WITH CUTOFF LOW LINGERING THROUGH THURSDAY. LEANED A BLEND OF THE NAM12 AND ARW-WRF FOR TIMING AND TRENDS TOMORROW INTO TOMORROW NIGHT...THEN A GFS/ECMWF THROUGH MIDWEEK. .SUNDAY INTO MONDAY...STRONG 500MB TROUGH DIGS INTO THE CENTRAL PLAINS TONIGHT AND SLOWLY MAKE ITS WAS INTO THE MIDWEST BY TOMORROW. FIRST SHORTWAVE THAT MAY SPAWN THUNDERSTORMS OVERNIGHT TONIGHT LINGERS INTO NORTHERN IOWA THROUGH SUNDAY MORNING AND DIMINISH AS THE LLJ DECREASES. DECREASED POPS ACROSS THE SOUTH CONSIDERABLY UNTIL THE LATE AFTERNOON BEFORE REDEVELOPMENT BY THE AFTERNOON BEFORE NEXT SHORTWAVE EJECTS ACROSS THE CENTRAL PLAINS AND INTO MO/IA BY 00Z MONDAY. DESTABILIZATION OCCURS LATE SUNDAY MORNING AND INTO THE AFTERNOON AS THE 0-3KM ML CAPE INCREASES TO 800 TO NEAR 2000 J/KG OVER CENTRAL AND SOUTHERN IOWA BY 00Z MONDAY WITH BREAK BETWEEN SHORTWAVES. SURFACE BASED CAPE INCREASES TO OVER 2500 J/KG BY THE SAME TIME AND LOCATION. LOW LEVEL SHEAR MORE FAVORABLE FOR TORNADIC DEVELOPMENT ACROSS FAR SOUTHWEST IOWA WHERE 0-1KM SHEAR INCREASE TO 20-25 KNOTS...MORE IN THE 10 TO 15 KNOTS RANGE FURTHER NORTH. DEEP LAYER SHEAR FAVORABLE FOR LONG LIVED STORMS LATE TOMORROW AFTERNOON INTO THE EVENING HOURS. KEPT MENTION OF SEVERE WX FOR SOUTHERN PORTIONS OF THE FORECAST AREA SUNDAY LATE AFTERNOON AND INTO THE EVENING. IN ADDITION TO SEVERE POTENTIAL...HEAVY RAIN LOOKS IMMINENT AS WELL WITH WARM LAYER CLOUD DEPTHS RANGING AROUND 11000 FEET AND PRECIPITABLE WATER VALUES IN THE 1.5 TO 1.75 INCH RANGE. CORFIDI VECTORS INDICATING TRAINING STORMS TOMORROW NIGHT LEADING TO FLASH FLOODING POTENTIAL. STORMS LOOK TO PUSH INTO NORTHERN IOWA EARLY MONDAY MORNING AND LOWERED POPS IN CENTRAL AND SOUTHERN IOWA. .TUESDAY THROUGH SATURDAY...UPPER LOW BECOMES CUTOFF AND LINGERS OVER THE REGION BEFORE FINALLY MOVES EAST BY THURSDAY MORNING. SEVERE WEATHER CHANCES LOOK MINIMAL...BUT ADDITIONAL PERIODS OF RAIN ARE LIKELY INTO THURSDAY. TEMPERATURES LOOK TO BE NEAR OR SLIGHTLY BELOW NORMAL BY WEDNESDAY AND THROUGH LATE IN THE WEEK. && .AVIATION...18/18Z ISSUED AT 1246 PM CDT SAT MAY 18 2013 OVERNIGHT CONCERNS REGARDING CONVECTION AND OVERALL COVERAGE. MODELS SUGGESTING MCS DEVELOPMENT NEAR/IN AREA BY 10-15Z SUNDAY BUT PLACEMENT SOMEWHAT CHALLENGING FOR NOW. HAVE CONSIDERED WARM AIR ADVECTION AND NOSE OF INCREASING SOUTHERLY JET WITH WARM FRONTAL PLACEMENT...ALL POINTING TO DEVELOPMENT AFFECTING EITHER KDSM OR KFOD GREATER THAN AREAS EAST/NORTH. THUS...FOR NOW HAVE INCREASED LIKELIHOOD OF TSRA AT THOSE TWO SITES FOR EARLY MORNING HOURS. WINDS WILL LIKELY REMAIN JUST UNDER 12KT OVERNIGHT WITH INCREASING SOUTHERLY FLOW AFT 04Z. WITH OVERNIGHT CONVECTION... BEGIN TO EXPECT THE MCS TO DIMINISH TOWARD THE END OF PERIOD AS JET WEAKENS AFTER 12Z. NEXT ROUND OF CONVECTION MORE LIKELY LATE AFTERNOON OR AFT 20/00Z AS SHORTWAVE APPROACHES FROM WEST. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...PODRAZIK AVIATION...REV  FXUS63 KDMX 222053 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 353 PM CDT WED MAY 22 2013 .SHORT TERM.../TONIGHT/ ISSUED AT 353 PM CDT WED MAY 22 2013 UPPER LOW IS MOVING VERY SLOWLY TO THE EAST TONIGHT AND AS A RESULT WILL LIKELY SEE LIGHT SHOWERS ACROSS THE NORTH THIS EVENING AND FAR EAST MUCH OF THE NIGHT. STILL EXPECTING SOME LIGHT SHOWERS OR SPRINKLES ELSEWHERE AS WELL BUT THESE WILL BE MUCH LIGHTER AND MUCH MORE HIT AND MISS THAN NORTH AND EAST. THE NAM12 SHOWS ANOTHER WAVE OF THETA-E ADVECTION PUSHING SOUTH ACROSS THE CWA THIS EVENING BUT FORCING IS WEAK IF THERE AT ALL. THIS SHOULD PROVIDE FOR A BRIEF PERIOD OF BETTER SHOWER ACTIVITY ACROSS THE NORTH THROUGH MID EVENING BEFORE EVERYTHING FINALLY PUSHES EAST OVERNIGHT. WITH EXPANSIVE CLOUD SHIELD IN PLACE AND LOW CEILINGS IN PLACE...I WOULD EXPECT THE LOWER CLOUDS TO LINGER FOR A FAIR PART OF THE NIGHT WITH CLEARING EXPECTED ACROSS THE NORTH LATE. TEMPS WILL NEED TO BE MONITORED IF WE CLEAR OUT A LITTLE QUICKER AS THE AIRMASS IN PLACE IS PRETTY COOL FOR LATE MAY. TEMPS COULD FALL QUICKER AND FARTHER WITH A FASTER CLEARING SKY. .LONG TERM.../THURSDAY THROUGH WEDNESDAY/ ISSUED AT 353 PM CDT WED MAY 22 2013 PRIMARY CONCERN WILL BE CONVECTIVE TRENDS AND PRECIP FROM THE WEEKEND RIGHT ON THROUGH THE MIDDLE OF NEXT WEEK. PERIOD WILL BEGIN WITH A FEW DAYS OF FAIR WEATHER HOWEVER AS CURRENT SYSTEM EXITS AND IA REMAINS UNDER THE INFLUENCE OF UPPER LEVEL RIDGE. PROGRESSION OF RIDGE AND INTRODUCTION OF PROLONGED INTERMITTENT WARM/THETA-E ADVECTION WILL BEGIN FRI NIGHT HOWEVER AND LAST FROM THE MEMORIAL DAY WEEKEND RIGHT INTO THE MIDDLE OF NEXT WEEK. WITH HEIGHTS GRADUALLY LOWERING IN PERSISTENT WSW FLOW BETWEEN SLOW MOVING WRN TROUGH AND DEPARTING MS/OH VALLEY RIDGE...THIS WILL PLACE IA INTO WHAT LOOKS TO BE A NOCTURNAL MAX PATTERN WITH SOUNDINGS SHOWING ONLY MINIMAL POTENTIAL FOR SURFACE BASED CONVECTION. DIFFICULT TO PROVIDE TOO MANY DETAILS YET...BUT SAT NIGHT INTO SUN MORNING IS ONE PERIOD OF CONCERN WITH REGARD TO SEVERE WEATHER AND HEAVY RAINS WITH LOW LEVEL JET AND 300K INFLOW RIGHT INTO WRN IA. GFS ELEVATED CAPES APPROACHING 1500 J/KG WITH SEASONALLY HIGH PWS AND WARM CLOUD DEPTHS UP TO 12KFT WILL PROVIDE FAVORABLE ENVIRONMENT FOR EFFICIENT RAINFALL. STORM MOVEMENT WILL NOT BE MUCH EITHER WITH MEAN WIND 20KTS OR LESS. DO NOT EXPECT MCSS EVERY NIGHT BUT PATTERN REALLY CHANGES LITTLE INTO THE MIDDLE OF NEXT WEEK WITH H85 FLOW REMAINING FOCUSED FROM SRN PLAINS INTO IA. THUS HAVE KEPT PROLONGED PERIOD WITH CHANCE WORDING AND...UNFORTUNATELY...LITTLE CONFIDENCE IN WHEN TO HIGHLIGHT PARTICULAR PERIODS WITH HIGHER OR LOWER POPS AT THIS POINT. ELEVATED CAPES ARE NOT AS IMPRESSIVE AS SAT NIGHT FOR FOLLOWING NIGHTS...BUT STAGNANT PATTERN WILL KEEP POTENTIAL FOR AT LEAST WEAK MCS ACTIVITY IN THE FORECAST. CUMULATIVE RAINFALL WILL KEEP THINGS WET WITH LITTLE HYDROLOGIC RECOVERY AND AT LEAST SOME POTENTIAL FOR ADDITIONAL FLOODING. && .AVIATION...22/18Z ISSUED AT 1239 PM CDT WED MAY 22 2013 AN UPPER LEVEL LOW WILL CONTINUE TO MOVE EAST TODAY WITH BANDS OF IFR CONDITIONS AND LIGHT SHOWERS PASSING ACROSS THE TAF LOCATIONS. AFTER 23/15Z THE LOW WILL SHIFT FAR ENOUGH EAST THAT CONDITIONS WILL BECOME VFR FROM W TO E. SFC WIND WILL BE WEST TO NW AT 15G25KTS DIMINISHING AFTER 02Z TO 10-15KTS AND BECOMING NORTH THEN INCREASING AGAIN AFTER 23/12Z. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...FAB LONG TERM...SMALL AVIATION...FAB  FXUS63 KDMX 242100 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 400 PM CDT FRI MAY 24 2013 .SHORT TERM.../TONIGHT/ ISSUED AT 400 PM CDT FRI MAY 24 2013 SURFACE HIGH PRESSURE WILL REMAIN IN PLACE OVER THE GREAT LAKES AS A SOUTH-SOUTHWEST FLOW ALOFT SETS UP A FEW THOUSAND FEET ALOFT AND AIMS INTO IOWA. THIS WILL RESULT IN THE THERMAL GRADIENT AND ZONE OF FRONTOGENESIS SETTING UP FROM NW TO SE ACROSS IOWA. LEADING EDGE OF WARM ADVECTION IS PRODUCING ISOLATED TO SCATTERED THUNDER FROM THE MISSOURI RIVER NORTH INTO THE DAKOTA/MINNESOTA BORDER REGION. THIS WILL CONTINUE TO DRIBBLE EAST AND EVENTUALLY TURN SOUTHEAST ACROSS NORTH AND NORTHEAST IOWA. AROUND MIDNIGHT THE SOUTHWESTERLY LOW-LEVEL JET WILL INCREASE AND MORE WIDESPREAD THUNDERSTORMS ARE EXPECTED TO DEVELOP ON THE BACK SIDE OF THIS REGION...MOST LIKELY OVER NORTH CENTRAL IOWA AND THEN EXPANDING EAST AND SOUTH DURING THE OVERNIGHT HOURS. SHEAR AND INSTABILITY ARE NOT FAVORABLE FOR SEVERE WEATHER...BUT CONDITIONS ARE SOMEWHAT FAVORABLE FOR HEAVY RAINFALL DUE TO FAIRLY SLOW STORM MOTION TO THE EAST AND POSSIBLE TRAINING OF STORMS. PINPOINTING THE LOCATION OF HEAVIER RAIN IS DIFFICULT DUE TO ELEVATED NATURE OF STORMS...BUT AGAIN NORTH CENTRAL INTO EAST CENTRAL IOWA WOULD BE MOST LIKELY TO SEE OVER 1 INCH OF RAIN OVERNIGHT. SHORT TERM RUNOFF PROBLEMS IN AREAS OF HIGH RAIN RATES WOULD BE THE MOST LIKELY FLOOD THREAT TONIGHT SINCE WE HAVE NOT SEEN RAINFALL IN SEVERAL DAYS. .LONG TERM.../SATURDAY THROUGH FRIDAY/ ISSUED AT 400 PM CDT FRI MAY 24 2013 THE PRIMARY CONCERN THROUGH THIS PERIOD WILL REMAIN CONVECTIVE TRENDS AND HEAVY RAINS...AND EVENTUALLY BETTER SEVERE POTENTIAL INTO NEXT WEEK. EVALUATION WILL CHANGE LITTLE FROM AS OUTLIER IN ABOVE SHORT TERM DISCUSSION WITH DETAILS HARD TO COME BY. MAIN THEME WILL BE NOCTURNAL/WARM ADVECTION MAX WITH BETTER CHANCES DURING THE NIGHTTIME AND EARLY MORNING HOURS. EXPECT MCS TO BE ONGOING AT BEGINNING OF THE PERIOD WITH THETA-E ADVECTION STILL FOCUSED RIGHT INTO CENTRAL IA. TYPICAL DIURNAL DECREASE IN POPS IS ANTICIPATED LATER IN THE DAY UNTIL THE NEXT ROUND OF OVERNIGHT CONVECTION CYCLES UP. THETA-E ADVECTION SAT NIGHT DOES NOT APPEAR TO BE AS STRONG AS WHAT MAY OCCUR TONIGHT...BUT WHAT OCCURS MAY BE MORE CONDUCTIVE FOR HEAVY RAINS. PRECIPITATION POTENTIAL PLACEMENT...WARM CLOUD DEPTHS AND PRECIPITABLE WATER WILL ALL EITHER APPRECIABLY INCREASE OR BE MORE ENTRENCHED INTO IA WITH MEAN WIND EVEN A TAD WEAKER. THIS COULD CERTAINLY RESULT IN LOCALLY HEAVY RAINS AND EFFICIENT RAINFALL PRODUCERS. DO NOT EXPECT WIDESPREAD RAINFALL WITH ANY PARTICULAR MCS...BUT CUMULATIVE EFFECTS FROM NIGHT AFTER NIGHT WILL LIKELY PRODUCE WIDESPREAD ONE TO TWO INCH AMOUNTS BY MONDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE. TEMPERATURE FORECASTS WILL BE PROBLEMATIC THIS WEEKEND TOO DUE TO UNCERTAINTY WITH REGARD TO MIXING...CLIMATOLOGY VS MODELS SELY FLOW/STRATUS SIGNAL. GENERALLY PLAYED A MIDDLE OF THE ROAD APPROACHING BUT LESS CONVECTION COULD CERTAINLY END UP WITH HIGHER TEMPS. AIRMASS WILL DEFINITELY BECOME MORE SUMMER-LIKE INTO NEXT WEEK WITH PERSISTENT 1KM SOUTHERLY FETCH BOOSTING DEWPOINTS INTO THE 60S. THIS MAY ALSO INCREASE OUR SEVERE AND SURFACE BASED POTENTIAL SETTING UP SOMEWHERE IN THE VICINITY OF IA...WHOSE LATITUDINAL EXTENT WILL BE DIFFICULT TO PINPOINT DUE TO REPETITIVE CONVECTIVE OUTFLOW. THERE MAY BE SOMEWHAT OF A LULL AROUND WED AS WARM SECTOR BECOMES BETTER ENTRENCHED INTO IA AND WARM ADVECTION ZONE LIFTS NORTHWARD. HOWEVER SHORTLY AFTER THIS TIME LONG WAVE TROUGH WILL FINALLY ADVANCE INTO THE PLAINS INCREASING KINEMATIC FORCING. THIS MAY INCREASE SEVERE THREAT ALTHOUGH SURFACE FEATURES AND ASSOCIATED CONVERGENCE ZONES STILL LOOK TO BE OFF TO OUR NORTH AND WEST...ESPECIALLY IF THE ECMWF VERIFIES. && .AVIATION...24/18Z ISSUED AT 1142 AM CDT FRI MAY 24 2013 INCREASING MOISTURE OVERNIGHT ALONG WITH INCREASING CHANCES OF THUNDERSTORMS TOWARD MIDNIGHT. UNTIL THEN GENERALLY VFR CONDITIONS WITH MID CLOUD DEVELOPMENT AND ISOLATED SHRA/-TSRA OVER THE NW HALF OF IOWA. MUCH MORE WIDESPREAD CONVECTION TO DEVELOP ESPECIALLY NORTH CENTRAL AND LATER NE AND EAST CENTRAL IOWA. THIS WILL BE ONLY MVFR IN HEAVIER RAIN BUT AFTER A TIME...CEILINGS ARE EXPECTED TO LOWER IN PERSISTENT SELY FLOW. AFTER 12-15Z SATURDAY THUNDERSTORMS SHOULD MOVE EAST LEAVING MVFR CEILINGS AND POSSIBLY SOME AREAS OF SHOWERS. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...JUNGBLUTH LONG TERM...SMALL AVIATION...JUNGBLUTH  FXUS63 KDMX 250835 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 335 AM CDT SAT MAY 25 2013 .SHORT TERM.../TODAY/... ISSUED AT 332 AM CDT SAT MAY 25 2013 STRONG MOISTURE TRANSPORT FEEDING THE COMPLEX IN NEBRASKA THIS MORNING WILL TRANSLATE EAST AS WINDS VEER SOMEWHAT TOWARD SUNRISE. IT APPEARS THE STRONGEST ACTIVITY IS PUNCHING SOUTH WITH THE CORFIDI VECTORS...BUT PLENTY OF RECENT DEVELOPMENT INTO WEST CENTRAL IA. HEAVIEST RAIN SHOULD BE OVER THE SOUTH TWO THIRDS OF THE CWA...WITH MUCH OF IT FALLIN IN THE MORNING. SHOULD SEE THE PRECIP BECOME MORE SCATTERD FOR THE AFTERNOON. RAIN MAKES FOR A TRICKY FORECAST FOR A COUPLE REASONS. ONE BEING THE PERSISTENT RAIN WILL KEEP TEMPS DOWN. THE OTHER IS THE DRY AIR AT LOW LEVELS FEEDING INTO EASTERN IA. DEW POINTS IN THE MID 30S COMBINED WITH THE TSRA GOING OVER THE TOP TO TRY TO SATURATE THE LOW LEVELS SUGGESTS THERE MAY BE VERY LITTLE RISE FROM THE CURRENT READINGS. NON-DIURNAL TRACE OVER THE CWA WITH MAX TEMPS REACHED LATE IN THE PERIOD. .LONG TERM.../TONIGHT THROUGH FRIDAY/... ISSUED AT 332 AM CDT SAT MAY 25 2013 NEARLY CONTINUOUS POPS THROUGH FORECAST AS SOUTH/SOUTHWESTERLY FLOW PERSISTS ACROSS AREA WITH MULTIPLE SYSTEMS PASSING ACROSS REGION. FOR BEGINNING OF PERIOD DO NOT HAVE HIGH CONFIDENCE IN LOCATION OF POPS...AS ONGOING MCS ACROSS NEBRASKA WILL INFLUENCE LOCATION OF OVERNIGHT DEVELOPMENT. MCS CURRENTLY LOOKS TO TRACK A BIT FURTHER SOUTH THAN ORIGINALLY ANTICIPATED...AND OUTFLOW BOUNDARY MAY LINGER INTO KANSAS/MISSOURI WITH THAT BECOMING FOCUS FOR OVERNIGHT DEVELOPMENT TONIGHT. HOWEVER...MODELS CONTINUE TO DEVELOP PRECIP NEAR A BOUNDARY WITH GOOD THETA-E ADVECTION NEAR THE MISSOURI RIVER VALLEY...LIFTING SLIGHTLY TO THE NORTHEAST OVERNIGHT. HAVE TRENDED TOWARDS THIS SOLUTION...WITH AT LEAST SCATTERED PRECIPITATION LIKELY ALONG THIS REGION. HOWEVER...HIGHEST PRECIPITATION MAY AGAIN BE SOUTH OF THE AREA. SYSTEM WILL CONTINUE TO PULL EASTWARD THROUGHOUT THE DAY SUNDAY...WITH ADDITIONAL DEVELOPMENT AGAIN POSSIBLE MONDAY NIGHT BEHIND BOUNDARY AS A SHORT WAVE PUSHES EAST. AGAIN...PREVIOUS NIGHTS CONVECTION WILL INFLUENCE LOCATION OF SUNDAY NIGHT PRECIPITATION. SYSTEM WILL CONTINUE TO LIFT ACROSS NORTHERN IOWA THROUGH THE DAY MONDAY. WILL LIKELY SEE BREAKS IN PRECIPITATION FOR THE AFTERNOON SUNDAY AND AGAIN MONDAY...ESPECIALLY ACROSS THE WEST. HOWEVER...AN AREA OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY WILL CONTINUE TO INFLUENCE WEATHER ACROSS IOWA WITH ANOTHER BOUNDARY LIFTING NORTH THROUGH THE AREA FOR MONDAY NIGHT INTO TUESDAY...WITH AGAIN...GOOD CHANCE FOR PRECIPITATION ALONG BOUNDARY. AS SYSTEM CONTINUES TO LIFT NORTH...WILL SEE LINGERING PRECIPITATION ALONG THE BOUNDARY THROUGH MUCH OF THE REMAINDER OF THE PERIOD...BEFORE YET ANOTHER LOW PUSHES THROUGH FOR THE END OF THE WEEK BRINGING CONTINUED PRECIPITATION CHANCES. WHILE POPS ARE IN NEARLY EVERY PERIOD...WITH SEE BREAKS IN PRECIPITATION...ESPECIALLY DURING THE LATE MORNING AND EARLY AFTERNOON HOURS...AND BEST CHANCES FOR DRY WEATHER ACROSS THE SOUTH MID WEEK WITH SYSTEM TO THE NORTH. PWAT VALUES REMAIN VERY HIGH FOR LATE MAY...REACHING 1.5 IN OR GREATER...AND GOOD CLOUD DEPTHS WOULD ALLOW FOR VERY EFFICIENT RAINFALL RATES. IF STORMS TRAIN OVER AN AREA MAY SEE FLASH FLOODING...HOWEVER...ANTICIAPTE FAIRLY PROGRESSIVE NATURE TO SYSTEMS AND HAVE NOT ISSUED FLASH FLOOD WATCH...THOUGH ONE MAY BE NEEDED IN AREAS WHERE HEAVY RAINFALL OCCURS OVERNIGHT. MODELS CONTINUE TO KEEP TEMPERATURES COOLER WITH ONGOING PRECIPITATION...AND HAVE LOWERED TEMPERATURES A BIT FOR THE NEAR TERM. HOWEVER...ANTICIPATE TEMPERATES TO WARM THROUGH THE PERIOD WITH WAA AND SOUTHWESTERLY FLOW RETURNING MID WEEK. && .AVIATION...25/06Z ISSUED AT 1146 PM CDT FRI MAY 24 2013 THE FORECAST PERIOD WILL BE DOMINATED BY PRECIPITATION CHANCES AND LOWERING CEILINGS. EXPECT SHOWERS AND THUNDERSTORMS TO EXPAND ACROSS THE AREA OVERNIGHT AND INTO SATURDAY MORNING. CIGS WILL LOWER TO MVFR WITH PRECIPITATION AND POSSIBLE LOWER SATURDAY AFTERNOON OVER THE NORTH. THE PRECIPITATION WILL BECOME LESS INTENSE BY SATURDAY AFTERNOON INTO THE EVENING WITH THE PRIMARY ISSUE BEING CIGS BY THAT TIME. WINDS WILL BE OUT OF THE SOUTHEAST THROUGH MUCH OF THE PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...MS LONG TERM...AWB AVIATION...DONAVON  FXUS63 KDMX 260855 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 355 AM CDT SUN MAY 26 2013 .SHORT TERM.../TODAY /... ISSUED AT 322 AM CDT SUN MAY 26 2013 S/WV LIFTING ACROSS IOWA THIS MORNING HAS SET OFF A DECENT LINE OF TSRA ON THE H8 FRONT. LACK OF NEWD PROGRESS OF THE FRONT AND CONTINUED FEED OF MOISTURE HAS LEAD TO SOME BIG PRECIP AMOUNTS IN THE AREA EAST KDSM. NEXT AREA DROPPING SOUTHEAST OUT OF NWRN IA MAY ENHANCE DEVELOPMENT FOR A FEW HOURS BEFORE THE LLJ WEAKENS. ALSO SCATTERED CONVECTION OVER NORTH CENTRAL MO WILL LIKELY LIFT/SPREAD INTO SRN IA THIS MORNING. WILL LIMIT POPS BY LATER THIS MORNING AND AFTERNOON OVER THE SOUTH BUT KEEP THE CLOUDS IN. RAIN CHANCES CONTINUE THROUGH THE DAY OVER THE NORTHEAST. WENT BELOW MOS AND CLOSER TO THE ECMWF FOR TEMPS TODAY WITH A VERY SLOW RISE EXPECTED. A DECENT RAIN RANGE IN TEMPS FOR LATE MAY HOWEVER. .LONG TERM.../TONIGHT THROUGH SATURDAY/... ISSUED AT 322 AM CDT SUN MAY 26 2013 PERSISTENT POPS FOR THE EXTENDED WILL LEAD TO MANY ISSUES/CONCERNS WITH EXTENDED. INCREASED CONFIDENCE IN PROLONGED PRECIPITATION...WITH HIGH PRECIP RATES POSSIBLE AT TIMES ACROSS THE CWA. PWAT VALUES REMAIN HIGH THROUGH THE PERIOD...NEAR 1.5 OR HIGHER AT TIMES...WHICH IS WELL ABOVE CLIMATOLOGY FOR LATE MAY/EARLY JUNE. TONIGHT WILL SEE ANOTHER SHORTWAVE LIFTING NORTHEAST ALONG THE MO VALLEY...WITH THETA-E ADVECTION AHEAD OF SHORTWAVE...SPREADING INTO CENTRAL IOWA ALONG WITH GOOD MOISTURE TRANSPORT ON NOSE OF LLJ. SOUNDINGS ALSO INDICATE DEEP WARM CLOUD DEPTH LAYER...ESPECIALLY ACROSS THE NORTH OVERNIGHT AND ANTICIPATE HEAVY RAINFALL RATES. MAY NEED A FLASH FLOOD WATCH AGAIN FOR THE OVERNIGHT PERIOD...HOWEVER HAVE HELD OFF FOR NOW WITH CURRENT HEADLINES...AND NORTHERN PORTIONS OF CWA HAVE NOT RECEIVED AS MUCH RAINFALL AS CENTRAL. EXPECT PRECIPITATION TO CONTINUE INTO THE DAY MONDAY AS THETA-E ADVECTION AND MOISTURE TRANSPORT INCREASE AHEAD OF AN APPROACHING FRONTAL BOUNDARY. NEAR FRONTAL BOUNDARY IN THE FAR WEST...SB CAPE VALUES SUPPORT CHANCES FOR SEVERE WEATHER...WITH SHEAR INCREASING 18-00Z ALONG BOUNDARY. SYSTEM LIFTS AGAIN NE ACROSS THE STATE...WITH HIGHEST PRECIPITATION CHANCES/QPF AGAIN ACROSS THE NORTH...THOUGH DEEP LAYER SATURATION WAINS TOWARDS 12Z TUESDAY. HOWEVER...AREAS OF HEAVY RAIN AGAIN LOOK POSSIBLE AS SOUTHERLY FLOW PERSISTS...WITH ADDITIONAL FLOOD/FLASH FLOOD HEADLINES POTENTIALLY NEEDED. FRONTAL BOUNDARY LINGERS INTO TUESDAY...WITH ADDITIONAL CHANCES FOR PRECIPITATION. AGAIN...NEAR FRONTAL BOUNDARY COULD SEE STRONG/SEVERE STORMS...BUT SHEAR IS A BIT WEAKER. CURRENTLY...BEST CHANCES FOR PRECIPITATION ACROSS THE NORTH...THOUGH STILL MODEL DISAGREEMENT ON LOCATION OF THE FRONT...AND MAY BE FURTHER SOUTH. LARGE AREA OF LOW PRESSURE IS SET TO IMPACT THE REGION FOR THE MIDDLE/END OF THE WEEK. MAY SEE A BREAK BETWEEN SYSTEMS AHEAD OF SECONDARY LOW FOR WEDNESDAY AND EARLY THURSDAY...THOUGH HAVE KEPT LINGERING POPS WITH MODEL UNCERTAINTIES. LOW EXPECTED TO DIG INTO SOUTHERN DAKOTAS FOR THURSDAY...WITH FRONTAL BOUNDARY SPREAD ACROSS IOWA...SLOWLY LIFTING NORTHEASTWARD THROUGH FRIDAY AS NEGATIVELY TILTED TROUGH. HOWEVER...THERE ARE STILL SIGNIFICANT MODEL DISCREPANCIES IN TIMING/LOCATION OF LOW AND FRONTAL BOUNDARY FOR THURSDAY/FRIDAY...BUT PERIOD HAS POTENTIAL TO BE ACTIVE WITH SEVERE STORMS POSSIBLE. THIS WILL NEED TO BE CLOSELY MONITORED BY FUTURE SHIFTS. && .AVIATION...26/06Z ISSUED AT 1159 PM CDT SAT MAY 25 2013 AN AREA OF THUNDERSTORMS ACROSS CENTRAL IOWA WILL CONTINUE TO BECOME MORE FOCUSED FARTHER NORTH OVERNIGHT AND GENERALLY IMPACT THE NORTHERN SITES. DRIER AIR ADVECTING IN FROM GREAT LAKES HIGH PRESSURE HAS HELPED CIGS INCREASE TO VFR OVER EASTERN IOWA AND INTO THE EASTERN SITES. WHILE SOME IFR CONDITIONS ARE POSSIBLE YET THROUGH THE PERIOD...THE DRIER AIR SHOULD TREND CIGS TO MVFR AND VFR. PRECIPITATION WILL MAINLY BE FOCUSED THROUGH MID SUNDAY MORNING THEN AGAIN SUNDAY EVENING. && .HYDROLOGY... ISSUED AT 322 AM CDT SUN MAY 26 2013 STRONG MOISTURE FLUX INTO THE STATE CONTINUES TO FOCUS ON THE H8 WARM FRONT AND SHOULD CONTINUE TO PRESENT PROBLEMS FOR THE NEXT FEW HOURS. DOPPLER ESTIMATES SUGGEST RAINFALL OF 3 TO 5 INCHES MAY HAVE OCCURRED IN PARTS OF JASPER COUNTY. THE CURRENT FLASH FLOOD WATCH WILL CONTINUE THROUGH 14Z. FEEL FLOODING THREAT WILL DIMINISH ONCE THE LLJ WEAKENS. FOR THAT REASON WOULD WANT TO HOLD OFF UNTIL AT LEAST MID DAY BEFORE ISSUING ADDITIONAL HEADLINES. OVERNIGHT TONIGHT LLJ AGAIN KICKS UP NOSING INTO IOWA WITH THETA-E ADVECTION AND CONTINUED STRONG MOISTURE TRANSPORT AHEAD OF A SHORTWAVE. POTENTIAL AGAIN EXISTS OVERNIGHT FOR AREAS OF HEAVY RAIN WITH EFFICIENT RAIN PRODUCING STORMS AS PWATS REMAIN HIGH. CHANCES FOR FLASH FLOOD AGAIN EXIST OVERNIGHT ESPECIALLY IN AREAS WHICH HAVE ALREADY RECEIVED SUBSTANTIAL RAINFALL. IN ADDITION...PATTERN LOOKS TO PERSIST INTO MONDAY NIGHT...THOUGH FURTHER NORTH. MAY SEE RIVERS BEGIN TO REACT TO HEAVY RAINFALL...ESPECIALLY IN THE NORTHEAST WHERE RIVERS ARE RUNNING HIGH...WITH RIVER FLOODING POSSIBLE. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 9 AM CDT THIS MORNING FOR AUDUBON-BLACK HAWK-BOONE-CALHOUN-CARROLL-CRAWFORD-DALLAS-GREENE-GRUNDY-GUTHRIE- HAMILTON-HARDIN-JASPER-MAHASKA-MARION-MARSHALL-POLK-POWESHIEK- SAC-STORY-TAMA-WAPELLO-WEBSTER. && $$ SHORT TERM...MS LONG TERM...AWB AVIATION...DONAVON HYDROLOGY...MS/AWB  FXUS63 KDMX 282058 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 358 PM CDT TUE MAY 28 2013 .SHORT TERM.../TONIGHT /... ISSUED AT 358 PM CDT TUE MAY 28 2013 FORECAST FOR TONIGHT IS LARGELY PREDICATED ON CONVECTIVE EVOLUTION...WHICH IS UNFORTUNATELY AMBIGUOUS AND OF SOMEWHAT LOW CONFIDENCE. CURRENTLY STORMS ARE DEVELOPING RAPIDLY ALONG A BOUNDARY SOUTH OF INTERSTATE 80 WHERE SEVERE WEATHER AND LOCALLY HEAVY RAIN ARE LIKELY. FURTHER NORTH INSTABILITY HAS BEEN INCREASING THIS AFTERNOON...DESPITE BEING HAMPERED BY PERSISTENT CLOUDS...BUT THE FLOW IS MORE NEBULOUS WITH A LACK OF FORCING MECHANISM. EXPECT THAT STORMS WILL BE LARGELY CONFINED TO OUR SOUTH THROUGH THIS EVENING...BUT AFTERWARD AS SEVERAL SUBTLE MID-LEVEL FEATURES UPSTREAM OVER THE HIGH PLAINS APPROACH...SHORT RANGE MODELS SHOW A TREMENDOUS AMOUNT OF DISAGREEMENT AS TO WHETHER ADDITIONAL STORMS WILL DEVELOP OR NOT. IT DOES APPEAR PROBABLE THAT LARGE SCALE FORCING ASSOCIATED WITH ONE OR MORE OF THESE FEATURES COULD AFFECT THE REMAINDER OF OUR CWA...AND WITH STEERING FLOW TURNING TO MORE SOUTHWESTERLY EXPECT THAT ACTIVITY ACROSS SOUTHERN IOWA/NORTHERN MISSOURI COULD ADVECT NORTHWARD AS WELL. ON THE OTHER HAND...IF THE STORMS IN THE SOUTH THIS EVENING PROPAGATE OR SEND AN OUTFLOW BOUNDARY SOUTHWARD THEN IT COULD CHOKE THINGS OFF IN THAT DIRECTION AND STABILIZE THE REGION...MITIGATING ADDITIONAL DEVELOPMENT OVERNIGHT. GIVEN THE INHERENT UNCERTAINTY IN SUCH A SCENARIO HAVE OPTED FOR BROAD SLIGHT CHANCE TO CHANCE POPS OVERNIGHT...SLOWLY SPREADING NORTHWARD...BUT ANTICIPATE THAT THESE WILL NEED TO BE UPDATED BASED ON SHORT TERM OBSERVATIONAL TRENDS AS THE EVENING PROGRESSES. OUTSIDE OF THE CONVECTIVE POTENTIAL...WHICH WILL ALSO EFFECT CLOUD COVER AND OTHER FORECAST PARAMETERS...THERE IS SOME POTENTIAL FOR ADDITIONAL FOG DEVELOPMENT OVERNIGHT. HOWEVER...HAVE NOT INCLUDED IT IN THE FORECAST AT THIS TIME AS CONFIDENCE IN DENSE FOG IS LOW. IF STORMS REMAIN CONFINED TO THE SOUTH THIS EVENING AND SKIES MANAGE TO LARGELY CLEAR OVERNIGHT THEN IT COULD BECOME MORE OF A CONCERN. .LONG TERM.../WEDNESDAY THROUGH TUESDAY/... ISSUED AT 358 PM CDT TUE MAY 28 2013 ACTIVE WEATHER PATTERN TO CONTINUE THROUGH THE END OF THE WEEK...WITH A POTENTIAL BREAK IN THE PRECIPITATION CHANCES TOWARD THE WEEKEND INTO EARLY NEXT WEEK. CONCERNS CONTINUE TO CENTER AROUND THUNDERSTORM CHANCES...HEAVY RAINFALL...AND POTENTIAL FOR SEVERE WEATHER WEDNESDAY INTO THURSDAY. SHORTWAVE TROUGH LIFTING NORTHWARD THROUGH THE STATE WEDNESDAY MORNING...WITH CONTINUED MOISTURE STREAMING NORTHWARD INTO THE STATE. STORM MOTIONS BECOME SIMILAR ARE SLOWER WITH MUCH OF THE STATE IN THE WARM SECTOR FOR WEDNESDAY INTO THURSDAY AS THE WARM FRONT STRETCHED ACROSS THE STATE TODAY LIFTS NORTHWARD. ACTIVITY POSSIBLE THROUGHOUT THE DAY WEDNESDAY...WITH HEAVY RAIN STILL A THREAT DUE TO SLOW STORM MOTIONS...POSSIBILITY OF TRAINING STORMS AND DEEP WARM CLOUD DEPTHS. GREATEST THREAT FOR ADDITIONAL FLASH FLOODING AND HEAVY RAINFALL COMES WEDNESDAY NIGHT INTO THURSDAY...AS THE MAIN UPPER LOW BEGINS TO LIFT OUT OF THE ROCKIES AND INTO THE NORTH CENTRAL PLAINS. STORM MOTION BECOMES MORE PARALLEL TO THE FRONT INCREASING THE THREAT FOR TRAINING STORMS...WITH CONTINUED SLOW STORM MOTIONS. OVERALL PRECIPITATION AMOUNTS FORECAST FOR TONIGHT THROUGH FRIDAY SUGGESTS WIDESPREAD 1 TO 3 INCHES OF PRECIPITATION ACROSS THE CWA...WITH HIGHER AMOUNTS POSSIBLE BENEATH THE STRONGER THUNDERSTORMS. WEDNESDAY INTO THURSDAY ALSO LOOK LIKE INCREASING CHANCES FOR SEVERE WEATHER EACH DAY...WITH STRONGER ENERGY LIFTING NORTHWARD THROUGH THE CWA ASSOCIATED WITH THE UPPER LOW OFF TO THE WEST/NORTHWEST. DECENT SHEAR WITH INSTABILITY ANTICIPATED. STORM SYSTEM FINALLY BEGINS TO PROGRESS THROUGH THE REGION FRIDAY INTO SATURDAY...WITH SOME LINGERING CHANCES FOR PRECIPITATION. HOWEVER OVERALL THREAT OF FLASH FLOODING AND SEVERE WEATHER BEGINS TO DECREASE WITH MAINLY LIGHT RAIN CHANCES POSSIBLE. DRY CONDITIONS ARE THEN EXPECTED INTO SUNDAY AND MONDAY. MODELS THEN DIVERGE ON SOLUTIONS TOWARD THE MIDDLE OF NEXT WEEK...WITH THE EC BRINGING ANOTHER UPPER LOW ACROSS THE NORTHERN PLAINS. THIS COULD BRING SOME CHANCES FOR PRECIPITATION TO THE REGION. HOWEVER THE GFS IS WEAKER WITH THE SYSTEM MOVING THROUGH THE NORTHERN PLAINS...THUS KEEPING ANY PRECIP CHANCES FURTHER NORTH OF THE CWA. OVERALL TEMPERATURES LOOKING WARMER THROUGH THE NEXT FEW DAYS...AND THEN COOLER AGAIN TOWARD THE WEEKEND INTO EARLY NEXT WEEK. && .AVIATION...28/18Z ISSUED AT 1228 PM CDT TUE MAY 28 2013 GENERALLY CONVECTIVE ENVIRONMENT THAT HAS PREVAILED OVER THE LAST SEVERAL DAYS WILL PERSIST THROUGH THE COMING TAF PERIOD AND BEYOND. THIS MEANS MULTIPLE OPPORTUNITIES FOR THUNDERSTORMS...LOW CIGS/VSBYS...FOG DEVELOPMENT...ETC. FOR NOW IT APPEARS THAT THE BEST TS CHANCES WILL BE IN THE SOUTH THIS EVE AND TONIGHT...SPREADING INTO THE NORTH TOWARD WED MORNING...BUT THERE IS A CONSIDERABLE DEGREE OF UNCERTAINTY SO HAVE JUST GONE WITH VCTS FOR NOW. FOG REDEVELOPMENT WILL ALSO RELY HEAVILY ON THE THUNDERSTORMS AND ASSOCIATED CONVECTIVE DEBRIS CLOUDS...OR LACK THEREOF...SO WHILE DENSE FOG IS POSSIBLE HAVE ONLY GONE WITH MVFR VSBYS FOR NOW. EXPECT DETAILS TO BE BETTER REFINED FOR THE 00Z ISSUANCE AND SUBSEQUENT AMENDMENTS. && .HYDROLOGY... ISSUED AT 358 PM CDT TUE MAY 28 2013 THUNDERSTORMS WILL IMPACT PARTS OF OUR SOUTHERN AND SOUTHEASTERN COUNTIES THROUGH THIS EVENING AND INTO TONIGHT. GIVEN THAT THE ENVIRONMENT CONTINUES TO BE FAVORABLE FOR LOCALLY HEAVY RAINFALL FROM THESE STORMS...AND THAT SOILS ARE ALREADY SATURATED WITH RIVER AND AREAL FLOODING ONGOING...IT WILL NOT TAKE MUCH FOR ADDITIONAL FLASH FLOODING ACROSS MOST OF THIS AREA. THEREFORE HAVE ISSUED A FLASH FLOOD WATCH RUNNING THROUGH TONIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR ADAMS-APPANOOSE- CLARKE-DAVIS-DECATUR-JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE- POWESHIEK-RINGGOLD-TAYLOR-UNION-WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...LEE LONG TERM...BEERENDS AVIATION...LEE HYDROLOGY...LEE/ZOGG  FXUS63 KDMX 292030 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 330 PM CDT WED MAY 29 2013 .DISCUSSION... ISSUED AT 329 PM CDT WED MAY 29 2013 FOCUS REMAINS ON HEAVY RAIN AND SEVERE WEATHER POTENTIAL THROUGH FRIDAY. TREMENDOUS MOISTURE ADVECTION WILL PERSIST WELL INTO THURSDAY THEN LIFT BACK INTO THE SOUTHEAST ON FRIDAY. THE PRIMARY UPPER LOW IS LOCATED TO THE NORTHWEST OVER MONTANA AND WYOMING WITH SEVERAL STRONG WAVES YET TO ROTATE AROUND THE BASE. INITIAL WAVE GOING THROUGH THE STATE CURRENTLY WITH AREAS OF SEVERE WEATHER AND HEAVY RAINFALL. THERE SHOULD BE A BREAK FOR A PERIOD THIS EVENING BEFORE THE LOW LEVEL JET STRENGTHENS AGAIN LATE THIS EVENING AND FORCING ANOTHER SURGE OF STRONG MOISTURE ADVECTION INTO THE STATE. THIS FOCUS WILL GRADUALLY SHIFT EAST THROUGH THE DAY THURSDAY. THE PRIMARY ISSUE WILL BE THE SOUTH TO NORTH MOTION OF THE STORMS THROUGH THE PERIOD RESULTING IN TRAINING ACROSS SIMILAR AREAS. PWATS INCREASING TO 1.5 TO 1.75 INCHES DURING THIS PERIOD AND WARM CLOUD DEPTHS NEARING 12 KFT WILL RESULT IN EFFICIENT RAIN PRODUCING STORMS. STILL EXPECT A WIDESPREAD ONE TO THREE INCH RAINFALL WITH LOCAL AMOUNTS EXCEEDING 5 INCHES. SEVERE WEATHER WITH LARGE HAIL WITH THE STRONGER UPDRAFTS NEAR BETTER MID LEVEL LAPSE RATES...DAMAGING WINDS AND ISOLATED TORNADOES WILL BE POSSIBLE THROUGH THURSDAY. A FLASH FLOOD WATCH HAS BEEN ISSUED THROUGH THE DAY THURSDAY FOR THE HEAVY RAIN THREAT. GIVEN THE CURRENT CONDITIONS AND RECENT HEAVY RAINS...LIFE THREATENING FLASH FLOODING AND SIGNIFICANT RIVER FLOODING MAY OCCUR WITH THIS EVENT. A BAND OF DRIER AIR MOVES IN LATE THURSDAY INTO THURSDAY EVENING WHICH WILL BRING A BREAK FROM WEST TO EAST OVERNIGHT. ONE FINAL SHORT WAVE LIFTS UP LATE THURSDAY NIGHT INTO FRIDAY MORNING. THE LOW LEVEL JET AND MOISTURE ADVECTION WILL BECOME REESTABLISHED WITH ANOTHER ROUND OF THUNDERSTORMS FOCUSED OVER SOUTHERN IOWA. THIS COULD BRING ONE MORE HEAVY RAIN THREAT. DUE TO THE EXPECTED BREAK BEFORE THIS ARRIVES AND A REFOCUS OF THE AREA. ADDITIONAL PRECIPITATION WITH WRAP AROUND UPPER LOW ACTIVITY WILL BE POSSIBLE ENTERING THE FAR NORTHWEST AND IMPACT MAINLY NORTHERN IOWA ON SATURDAY. THE THREAT FOR HEAVY RAIN WILL END BUT STEEPENING LAPSE RATES COULD POSE A HAIL THREAT. THE REMAINDER OF THE FORECAST WILL FEATURE AN UPPER LOW MOVING ACROSS THE NORTHERN PLAINS AND BRING BACK WEST TO SOUTHWEST FLOW TO THE STATE AND THE RETURN OF THUNDERSTORM CHANCES. TEMPERATURES WILL BE GENERALLY BELOW NORMAL. && .AVIATION...29/18Z ISSUED AT 1252 PM CDT WED MAY 29 2013 SCATTERED THUNDERSTORMS ACROSS NORTHWESTERN HALF OF IOWA CURRENTLY ONGOING...WITH THUNDERSTORMS TO BECOME MORE WIDESPREAD BY LATE AFTERNOON INTO THE EVENING AND OVERNIGHT HOURS. CIGS ARE EXPECTED TO DROP INTO THE MVFR TO POSSIBLY IFR RANGE WITH THE THUNDERSTORMS. VERY HEAVY RAINFALL IS EXPECTED WITH THE THUNDERSTORMS...THEREFORE A REDUCTION IN VSBYS TO LIFR/IFR IS EXPECTED IF THE HEAVIEST PORTION OF A THUNDERSTORM TRAVELS OVER ONE OF THE TERMINAL SITES. TIMING OF SPECIFIC THUNDERSTORMS AT THE TERMINAL SITES IS UNCERTAIN SO JUST WENT WITH THE VCTS FOR THE PERIOD BEYOND THE CRITICAL TAF PERIOD. ALSO SOUTHERLY WINDS EXPECTED TO BE GUSTY THROUGHOUT THE PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR ADAIR-ADAMS- AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CASS- CERRO GORDO-CLARKE-CRAWFORD-DALLAS-DECATUR-EMMET-FRANKLIN-GREENE- GRUNDY-GUTHRIE-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH- MADISON-MARSHALL-PALO ALTO-POCAHONTAS-POLK-RINGGOLD-SAC-STORY- TAYLOR-UNION-WARREN-WEBSTER-WINNEBAGO-WORTH-WRIGHT. FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH THURSDAY EVENING FOR APPANOOSE-DAVIS-LUCAS-MAHASKA-MARION-MONROE- POWESHIEK-TAMA-WAPELLO-WAYNE. && $$ DISCUSSION...DONAVON AVIATION...BEERENDS  FXUS63 KDMX 010851 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 351 AM CDT SAT JUN 1 2013 .SHORT TERM.../TODAY/ ISSUED AT 349 AM CDT SAT JUN 1 2013 THE UPPER LEVEL LOW NOW OVER WEST CENTRAL MN WILL FINALLY SHIFT EAST TODAY AS IT OPENS INTO A TROUGH THIS AFTERNOON. LIGHT WRAP AROUND PRECIP WILL MOVE IN FROM THE WEST DURING THE MORNING THEN SHIFT EAST ACROSS THE FORECAST AREA THIS AFTERNOON. THERE IS SOME INSTABILITY STILL OVER CENTRAL IOWA SO AS THE TROUGH CROSSES THE FORECAST AREA SOME ISOLATED THUNDERSTORMS WILL ALSO BE POSSIBLE. NOT LOOKING FOR ANY SEVERE STORMS OR HEAVY RAINFALL OUT OF THE PRECIP TODAY SO THERE SHOULD BE MINIMAL IMPACT TO AREAS IN FLOOD. COOLER AIR WILL DEFINITELY BE SPREADING INTO IOWA TODAY AND HIGHS WILL REFLECT THIS WITH READINGS IN THE 60S TO LOWER 70S IN THE SOUTHEAST PORTION OF THE FORECAST AREA. CONSIDERED THE POTENTIAL FOR COLD AIR FUNNELS TODAY BUT NON SUPERCELL TOR PARAMETERS ARE NOT CONCLUSIVE AT THIS POINT BUT WILL BE WORTH WATCHING FOR THIS AFTERNOON. TEMPS ARE STILL GOING TO BE TRICKY AS SOME STRATUS WILL WORK ITS WAY INTO THE FORECAST AREA. WE SHOULD GO OVERCAST FROM NORTHWEST TO SOUTHEAST THROUGH THE MORNING THEN CEILINGS WILL LOWER THIS AFTERNOON IN COLD ADVECTION. FORECAST SOUNDINGS REALLY MOISTEN UP BETWEEN 18Z AND 00Z. KEPT WARMEST TEMPS ACROSS THE EAST AS THEY WILL BE THE LAST TO CLOUD UP BUT THE WEST...AND ESPECIALLY NORTHWEST WILL BE QUITE COOL TODAY. .LONG TERM.../TONIGHT THROUGH FRIDAY/ ISSUED AT 349 AM CDT SAT JUN 1 2013 GENERAL THEME THROUGH THE PERIOD WILL BE A MORE TRANQUIL PATTERN...ALTHOUGH PRECIP MAY LINGER INTO THIS EVENING AND THEN CHANCES RETURN AGAIN EARLY NEXT WEEK. FORCING WITH CURRENT SYSTEM WILL HAVE JUST EXITED THE AREA BY 00Z ALTHOUGH 1-3KM MOISTURE AND REMNANTS OF PEAK HEATING CONVECTION MAY STILL PRODUCE SCATTERED SHOWERS AND A FEW RUMBLES OF THUNDER INTO THE EVENING. INSTABILITY AND DEEP SHEAR WILL BE MUCH LESS THAN RECENT DAYS SO DO NOT EXPECT ANYTHING SIGNIFICANT. FAIR AND COOL WEATHER THEN SETTLES IN FOR THE REMAINDER OF THE WEEKEND AND INTO THE START OF THE NEXT WORK WEEK. AIRMASS WILL COOL AND ESPECIALLY DRY OUT WITH LITTLE FORCING. FORECAST SOUNDINGS...EVEN THOSE WITH MOST AGGRESSIVE MIXING...STRUGGLE TO REACH MOS GUIDANCE WHICH MAY BE TOO WARM AND BIASED BY CLIMO. ANOTHER UPPER LEVEL TROUGH WILL DRIFT FROM THE PACIFIC NW INTO THE NRN PLAINS BY TUE. THE NEXT PRECIP CHANCES APPEAR TO BARELY ARRIVE LATE MON NW WITH THE START OF WARM ADVECTION ALTHOUGH THE AIRMASS WILL BE FAIRLY STABLE. CHANCES INCREASE INTO MON NIGHT AND TUE WITH MORE SIGNIFICANT THERMODYNAMIC AND KINEMATIC FORCING. SOME LOCALLY HEAVY RAIN POTENTIAL TUE NIGHT WITH STRONGER LOW LEVEL MOISTURE TRANSPORT...BUT NEITHER PWS OR WARM CLOUD DEPTHS WILL BE EXTREME. THIS SHOULD LIMIT THE SIGNIFICANT AND POTENTIAL TO EXASPERATE CURRENT SITUATION. PASSAGE OF BOUNDARY LATE WEDNESDAY MAY ALSO PRODUCE SOME SURFACE BASED CONVECTION. WEAK/MODERATE INSTABILITY AND ADEQUATE DEEP SHEAR MAY ALSO BE SUFFICIENT FOR ORGANIZED CONVECTION AND POTENTIALLY SEVERE WEATHER BUT THAT WINDOW DOES NOT APPEAR EXTREME OR LONG LIVED. CONFIDENCE IN TIMING NOT GREAT ENOUGH TO HIGHLIGHT AT THIS TIME. && .AVIATION...01/06Z ISSUED AT 1137 PM CDT FRI MAY 31 2013 WINDS WILL SHIFT TO SOUTHWEST THEN WEST OVERNIGHT BUT REMAIN LIGHT. ON SATURDAY A TROUGH WILL MOVE ACROSS THE AREA...WITH WINDS SHIFTING TO NORTHWEST AND INCREASING TO AROUND 15 KT AND GUSTY BY THE AFTERNOON. THE TROUGH WILL BE ACCOMPANIED BY WDLY SCT SHRA/TSRA AND PREVAILING LOW CIGS. FORECAST SOUNDINGS INDICATE CIG HEIGHTS ANYWHERE FROM FL025-035...BUT STILL BELIEVE PREVAILING CIGS WILL BE MVFR FOR MOST OF THE DAY AND HAVE MAINTAINED THAT IN THE 06Z TAFS. BY SATURDAY EVENING THE PRECIP WILL CLEAR OUT...WITH THE CIGS BREAKING UP TOWARD THE END OF THE TAF PERIOD OR SHORTLY THEREAFTER. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...FAB LONG TERM...SMALL AVIATION...LEE  FXUS63 KDMX 020901 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 401 AM CDT SUN JUN 2 2013 .SHORT TERM.../TODAY/ ISSUED AT 400 AM CDT SUN JUN 2 2013 HIGH PRESSURE BOTH AT THE SURFACE AND ALOFT WILL BE SHIFTING INTO IOWA TODAY. THE MAIN FORECAST PROBLEM TODAY WILL BE WITH HIGHS. BROAD AREA OF STRATUS WILL SLOWLY SHIFT EAST THROUGH THE MORNING SO THIS WILL HOLD TEMPS BACK THROUGH THE MORNING. WE WILL CONTINUE TO HAVE COLD ADVECTION THROUGH THE MORNING WHICH WILL PERSIST INTO THE AFTERNOON HOURS. TEMPS NOT EXPECTED TO DO MUCH TODAY AS A RESULT. WE SHOULD BE WARMER TODAY THAN YESTERDAY BUT STILL WELL BELOW NORMAL WITH HIGHS ONLY IN THE MID TO UPPER 60S. WE SHOULD ALSO CONTINUE TO HAVE BRISK WIND THROUGH THE MORNING THEN DIMINISHING IN THE AFTERNOON. LONG TERM.../TONIGHT THROUGH SATURDAY/ ISSUED AT 400 AM CDT SUN JUN 2 2013 MAIN CONCERN THIS PERIOD WILL BE PRECIP TRENDS AS PATTERN BECOMES ACTIVE ONCE AGAIN...BUT LIKELY NOT TO THE EXTENT WE SAW LAST WEEK. EXPECT FAIR AND COOL WEATHER TONIGHT AS HIGH PRESSURE CROSSES THE STATE. HOWEVER BY MONDAY AS THE CURRENT BC UPPER LOW SETTLES INTO MT WARM ADVECTION WILL RETURN TO IA POSSIBLY BRINGING SOME WEAK CONVECTION TO NWRN SECTIONS BY LATE AFTERNOON. WARM/THETA-E ADVECTION WILL FURTHER STRENGTHEN INTO MON NIGHT WHICH IS NICELY NOTED BY LIFT ZONE ACROSS 305K ISENT SURFACE. ELEVATED INSTABILITY APPEARS MINIMAL...HOWEVER JET SEGMENT UNDER UPPER LOW THROUGH THE NRN PLAINS COULD ENHANCE THE EFFECTIVE SHEAR SUFFICIENTLY TO ORGANIZE ANY STRONGER CELLS AND POTENTIALLY LEAD TO LOW END SEVERE WEATHER...LIKELY HAIL. SIMILAR SITUATION EXISTS INTO TUE ALTHOUGH WITH SLIGHTLY HIGHER INSTABILITY...A WEAK MLCAPE SIGNAL...AND SOMEWHAT BETTER POTENTIAL FOR STRONGER STORMS. HIGHS TUE WILL BE SOMEWHAT IN QUESTION DEPENDING ON THE DEGREE OF LOW CLOUDS...PRECIP AND SUBSEQUENT MIXING. SOUNDINGS SUGGEST COOLER THAN MOS...BUT WITH JUN SUNSHINE EVEN A BRIEF PERIOD OF SUN WOULD TRIGGER ADEQUATE MIXING SO HAVE NOT GONE TOO COOL AS OF YET. HEAVY RAIN PARAMETERS INCREASE LATE ON TUE WITH PWS...K INDICES AND WARM CLOUD DEPTHS ALL BEGINNING TO ELEVATE SOMEWHAT IN ZONE OF H85 MOISTURE TRANSPORT...WHICH MOVES NW-SE OVERNIGHT. DO NOT EXPECT WIDESPREAD HEAVY RAINS...BUT LOCAL AREAS MAY AGAIN SEE RAINFALLS IN EXCESS OF AN INCH. BOTH THE SEVERE AND HEAVY RAIN WINDOWS APPEAR TO BE TRANSIENT WITH THIS SYSTEM HOWEVER...ENDING BY EARLY WED. DO NOT EXPECT SUFFICIENT RAINFALL AMOUNTS TO PRODUCE MUCH NEW FLOODING OR EXACERBATE CURRENT FLOODING. POPS SHOULD WANE WED NIGHT INTO THU AS SYSTEM SLOWLY MOVES AWAY LEADING TO A BRIEF BREAK LATER INTO THU. HOWEVER THERMODYNAMIC AND KINEMATIC FORCING WILL BOTH INCREASE AGAIN BY NEXT WEEKEND. WEAK MEAN TROUGH WILL REMAIN IN PLACE THROUGH THE CENTRAL CONUS WITH NEXT SHORT WAVE ITERATION REACHING THE MO VALLEY. POTENTIAL FOR STRONGER STORMS AND HEAVY RAIN INCREASES YET AGAIN...BUT THIS WOULD LIKELY BE JUST BEYOND THE CURRENT VALID FORECAST PERIOD /SAT NIGHT OR SUN/. TEMPS LOOK TO BE BELOW SEASONAL NORMALS NEXT WEEK DUE TO LOWER HEIGHTS WITH AFOREMENTIONED TROUGH. HAVE NOT COOLED THINGS TOO MUCH FROM PREVIOUS FORECAST BUT EVEN GOING LOWER READINGS MAY BE A TAD TOO HIGH. && .AVIATION...02/06Z ISSUED AT 1142 PM CDT SAT JUN 1 2013 MVFR STRATUS CONTINUES TO PLAGUE THE AREA WITH CIGS GENERALLY BETWEEN FL016 AND FL025...BUT UPSTREAM OBS INDICATE THAT THE CIGS IN CENTRAL MN HAVE RISEN TO VFR BETWEEN FL030 AND FL040 AND SATELLITE IMAGERY SHOWS THE WESTERN EDGE OF THE CLOUDS APPROACHING THE WESTERN BORDER OF IOWA. BELIEVE THE CIGS WILL GO TO VFR TOWARD SUNRISE AND CLEAR OUT SOON THEREAFTER...WITH VFR CONDITIONS AND SLOWLY DECREASING WINDS DURING THE DAY ON SUNDAY. NO PRECIPITATION OR OBSCURATIONS ARE FORECAST THROUGH THE TAF PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...FAB LONG TERM...SMALL AVIATION...LEE  FXUS63 KDMX 030910 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 410 AM CDT MON JUN 3 2013 .SHORT TERM.../TODAY/ ISSUED AT 409 AM CDT MON JUN 3 2013 FOR THE MOST PART TODAY WILL BE A PRETTY NICE DAY FOR CENTRAL IOWA. HIGH PRESSURE AT THE SURFACE WILL BE DEPARTING TO THE EAST. THE FLOW AROUND THE HIGH WILL BECOME SOUTH TO SOUTHEAST AND OVERSPREAD THE FORECAST AREA THROUGH THE AFTERNOON HOURS. ALOFT A RIDGE OF HIGH PRESSURE WILL BE IN PLACE OVER THE STATE. FORECAST SOUNDINGS ACROSS THE FORECAST AREA SHOW A VERY DRY AIRMASS IN PLACE BUT THERE ARE POCKETS OF LOWER LEVEL MOISTURE AROUND SO WE COULD SEE SCATTERED CLOUDS...ESPECIALLY LATE MORNING AND AFTERNOON. BY MID AFTERNOON A WEAK SHORT WAVE IS EXPECTED TO TOP THE UPPER LEVEL RIDGE AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE ROCKIES AND HEADING INTO THE NORTHERN PLAINS. THIS WILL BECOME A PLAYER IN OUR WEATHER IN LATER PERIODS BUT FOR LATER TODAY THE WEAK SHORTWAVE THAT EJECTS OUT OF THE HIGH PLAINS ACROSS THE RIDGE AXIS WILL BRING SOME MID LEVEL MOISTURE WITH IT. THERE IS ALSO SOME WEAKER FORCING ASSOCIATED WITH THE WEAK SHORTWAVE SO THERE IS AT LEAST SOME POSSIBILITY OF LIGHT SHOWERS ACROSS THE FAR NORTHWEST AND WEST LATE IN THE PERIOD. THE BETTER INSTABILITY DOES NOT ARRIVE UNTIL TONIGHT BUT WITH WARM ADVECTION IN PLACE AND SOME WEAK FORCING I KEPT THE MENTION OF ISOLATED THUNDER IN THE FAR NORTHWEST LATE IN THE DAY DESPITE THE LOW CONFIDENCE. TEMPS WILL BE ABOUT LIKE THEY WERE YESTERDAY EXPECT FOR WARMER IN THE SOUTHWEST WHERE THE BETTER WARM ADVECTION WILL BE TAKING PLACE. STILL VERY COOL FOR EARLY JUNE WITH HIGHS ONLY IN THE MID 60S TO LOWER 70S. .LONG TERM.../TONIGHT THROUGH SUNDAY/ ISSUED AT 409 AM CDT MON JUN 3 2013 PATTERN DOES NOT CHANGE TOO MUCH THROUGH THE PERIOD WITH TWO SYSTEMS OF CONCERN PASSING THROUGH BROAD CENTRAL CONUS TROUGH. CURRENT ID/MT SYSTEM WILL BE THE INITIAL CONCERN AND ASSOCIATED WEAK WARM ADVECTION HAS ALREADY DEVELOPED INTO THE MO VALLEY. THIS WARM/THETA-E ADVECTION WILL GRADUALLY STRENGTHEN AS IT MOVES INTO IA TONIGHT...AND ALSO BE SOMEWHAT AIDED BY KINEMATIC FORCING ALTHOUGH MUCH OF THAT WILL REMAIN TO OUR NORTH CLOSER TO THE UPPER LOW. PRECIP WILL BE ELEVATED AND TAKE AWHILE TO MATURE WITH A NOSE OF DRY AIR AROUND 1KM. COLUMN WILL EVENTUALLY SATURATE INTO TUE WITH PERSISTENT 1-3KM FORCING...MAINLY THERMODYNAMIC...DRIVING PRECIP. THIS PROGRESSION IS SHOWN QUITE WELL IN 300K ISENT SURFACES. GEFS/SREF PRECIP PROBS ARE FAIRLY HIGH SUGGESTING CATEGORICAL POPS ARE WARRANTED. ALTHOUGH INSTABILITY WILL BE FAIRLY WEAK INITIALLY...MUCAPES AND ESTIMATED EFFECTIVE SHEAR WILL GRADUALLY INCREASE LATER INTO THE DAY AND THE EVENING. THIS WOULD BE OUR WINDOW FOR ANY THREAT OF STRONG TO SEVERE STORMS...WITH LARGE HAIL OUR ONLY CONCERN. SEEMS TO BE TOO MUCH SUB 3KM MOISTURE FOR WIND AND NIL MLCAPES FOR TORNADOES. THIS MAY ALSO BE A TIME FOR SOME LOCALLY HEAVY RAINS WITH PWS...WARM CLOUD DEPTHS AND MOISTURE TRANSPORT ALL INCREASING...HOWEVER SYSTEM SHOULD BE TRANSIENT ENOUGH TO AVOID MUCH IN THE WAY OF ADDITIONAL FLOODING PROBLEMS. THIS WINDOW WOULD BE 12 HOURS OR LESS AND NOT REPETITIVE. ENSEMBLE RIVER FORECASTS FROM SUN SUGGEST EITHER SLOWING OR STEADYING CURRENT FALLS WHERE FLOODING IS IN PROGRESS OR PRODUCING ADDITIONAL WITHIN BANK RISES. CEDAR BASIN IS THE MOST SENSITIVE HOWEVER AND WOULD BE THE MAIN CONCERN FOR ADDITIONAL FLOODING IF LOCAL AMOUNTS GREATER THAN EXPECTED RAINS OCCUR...WHICH ARE GENERALLY UNDER AN INCH AT THE MOMENT. EFFECTS OF THIS SYSTEM SHOULD SLOWLY WANE AS AIRMASS DRIES AND FORCING DEPARTS WED INTO THU. NEXT SYSTEM WILL DROP INTO THE BASE OF THE BROAD WEAK LONG WAVE TROUGH SAT. FORCING DEEPENS AND STRENGTHENS INTO NEXT WEEKEND...MAINLY AROUND SAT NIGHT AND SUN. SEVERE POTENTIAL WITH THIS SYSTEM IS SIMILAR TO NEAR TERM ONE...NOT THAT IMPRESSIVE BASED ON LOW MUCAPES...HOWEVER HEAVY RAIN CONCERNS DO ELEVATE ONCE AGAIN. THIS SYSTEM WILL LINGER LONGER WITH WEAK MEAN WINDS. HEAVY RAIN PARAMETERS ARE NOT TOO EXTREME...HOWEVER SLOWER MOVEMENT AND BETTER BAROCLINIC ZONE/WARM FRONTAL FOCUS COULD ENHANCE RAINFALL RATES WHICH ARE NOTED IN THE HIGHER QPFS. SRN IA JUST NORTH OF THE MO WARM FRONT APPEARS TO BE THE AREA OF CONCERN WITH THIS EVENT AT THE MOMENT. && .AVIATION...03/06Z ISSUED AT 1144 PM CDT SUN JUN 2 2013 CLEAR SKIES AND LIGHT AND VARIABLE WINDS WILL PREVAIL OVERNIGHT...WITH SE FLOW AROUND 10 KT BECOMING ESTABLISHED ON MONDAY AND HIGH CLOUDS SLOWLY INCREASING FROM THE WEST. AFTER DARK MONDAY EVENING LOWER CLOUDS LAYERED BETWEEN ABOUT FL030 AND FL090 WILL FILL IN AND SHRA/TSRA WILL BECOME POSSIBLE...BUT CONFIDENCE IS TOO LOW AT THIS RANGE OF THE 06Z TAFS TO INCLUDE PRECIP/TS AT THIS TIME. EXPECT INTRODUCTION IN FOLLOWING TAF ISSUANCES AS POPS WILL INCREASE FURTHER TOWARD TUESDAY MORNING. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...FAB LONG TERM...SMALL AVIATION...LEE  FXUS63 KDMX 032028 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 328 PM CDT MON JUN 3 2013 .SHORT TERM.../TONIGHT/... ISSUED AT 319 PM CDT MON JUN 3 2013 INITIALLY...RATHER QUIET THROUGH MIDNIGHT WITH DRY LOW LEVELS AS RIDGE AXIS PUSHES TO THE EAST. WILL SEE PLEASANT CONDITIONS WITH SOME DECOUPLING OF THE STRONGER WINDS IN THE WEST. LOW LEVEL JET WILL BE FOCUSED TO THE WEST IN NEBRASKA DURING THE EVENING WHERE CONVECTION IS INITIALLY EXPECTED TO DEVELOP. THE JET WILL VEER TO THE EAST OVERNIGHT WITH CONVECTION EXPECTED TO MOVE TOWARD THE MISSOURI RIVER VALLEY DURING THE EARLY MORNING HOURS. AT THIS POINT...THE BEST THREAT OF CONVECTION IN CENTRAL IOWA WILL REMAIN IN THE FAR WEST OVERNIGHT WHERE THETA-E ADVECTION IS EXPECTED TO INCREASE AFTER MIDNIGHT. FARTHER EAST...PRECIPITATION WILL BE HARDER TO COME BY WITH MANY AREAS STAYING DRY THROUGH THE NIGHT. INSTABILITY REMAINS QUITE LOW THROUGH DAYBREAK WITH SEVERE CONVECTION NOT ANTICIPATED AT THIS TIME. .LONG TERM.../TUESDAY THROUGH MONDAY/... ISSUED AT 319 PM CDT MON JUN 3 2013 FORECAST CONCERNS FOR EXTENDED ONCE AGAIN REVOLVE AROUND PRECIPITATION CHANCES...IN THE BEGINNING AND END OF EXTENDED. UPPER LEVEL LOW CURRENTLY LOCATED IN CENTRAL MONTANA WILL PUSH EASTWARD ACROSS NORTH DAKOTA THROUGH THE OVERNIGHT...WITH THETA-E ADVECTION INCREASING AHEAD OF FRONTAL BOUNDARY NEAR THE MISSOURI RIVER VALLEY. ANTICIPATE ONGOING PRECIPITATION ACROSS THE WEST AT BEGINNING OF PERIOD. THIS WILL PUSH EASTWARD THROUGHOUT THE DAY...WITH BEST CHANCES ACROSS THE SOUTH EARLY...AND THE NORTH IN THE AFTERNOON ASSOCIATED WITH SHORT WAVES. CHANCES REMAIN FOR HEAVY RAINFALL AT TIMES...ESPECIALLY ACROSS THE SOUTH WITH BEST MOISTURE TRANSPORT. PWAT VALUES INCREASE...AND WILL BE NEAR 1.5 BY THE LATE MORNING AND EARLY AFTERNOON...AS WELL AS DEEP WARM CLOUD DEPTHS ATTM AS WELL. CHANCES WILL PERSIST THROUGH THE OVERNIGHT...WITH ADDITIONAL SHORTWAVE PUSHING IN BEHIND FRONT. HOWEVER...BOUNDARY WILL PUSH THROUGH QUICKLY AND MAY SEE BREAKS IN PRECIPITATION BY THE AFTERNOON HOURS. IN ADDITION...WIDESPREAD HEAVY RAINFALL IS NOT ANTICIPATED...THOUGH LOCALLY HEAVY RAINS ARE POSSIBLE. SYSTEM WILL SLOW ACROSS THE EAST AS LOW BEGINS TO LIFT NORTHEAST. HOWEVER...WESTWARD EXTENT OF POPS IS UNCERTAIN...AND HAVE CUT BACK SIGNIFICANTLY IN THE WEST FOR WEDNESDAY. MUCH STRONGER SHORTWAVE WILL PUSH EAST ACROSS KANSAS AND MISSOURI FOR TUESDAY NIGHT AND WEDNESDAY AND MAY FURTHER LIMIT PRECIPITATION CHANCES WITH PRECIP CONFINED TO KS/MO. HOWEVER...IF WAVE TRACKS NORTH...MAY SEE PRECIPITATION IN SOUTHERN IOWA. SECONDARY FRONT EXPECTED TO DROP INTO NORTHERN IOWA BEHIND RETREATING LOW FOR THURSDAY WITH PRECIP POSSIBLE...ESPECIALLY IN THE NORTH. HOWEVER...AGAIN HAVE CONCERNS WITH AMOUNT OF AVAILABLE MOISTURE...AND HAVE KEPT ONLY SLIGHT CHANCES FOR PRECIPITATION GOING. BEST DYNAMICS FOR THUNDERSTORMS REMAIN WELL SOUTH OF IOWA INTO MISSOURI AND KANSAS FOR THE MAJORITY OF THE EXTENDED. HOWEVER...AXIS OF CAPE WILL STRETCH INTO SOUTHERN/WESTERN IOWA FOR TUESDAY NEAR FRONTAL BOUNDARY. SHEAR IS RELATIVELY WEAK WITH BOUNDARY...BUT SUFFICIENT TO WHERE A FEW STORMS MAY BECOME SEVERE...WITH HAIL THE MAIN THREAT. HIGH PRESSURE WILL PUSH IN BEHIND SYSTEM WITH NORTHWESTERLY FLOW OVER STATE. THIS WILL HELP TO KEEP TEMPERATURES BELOW NORMAL. LINGERING POPS ARE POSSIBLE ACROSS THE EAST THURSDAY AND FRIDAY AS ENERGY ROTATES AROUND LOW. NEXT BEST CHANCE FOR PRECIPITATION WILL COME FOR THE WEEKEND WHEN ANOTHER ROUND OF HEAVY RAIN APPEARS POSSIBLE. MODELS CONTINUE TO PUSH ANOTHER UPPER LEVEL LOW ACROSS THE NORTHERN PLAINS. HOWEVER...THERE STILL REMAINS SIGNIFICANT DISAGREEMENT IN PLACEMENT AND STRENGTH OF LOW. THOUGH GIVEN CURRENT TRACK SET UP LOOKS VERY SIMILAR TO BEGINNING OF PERIOD SYSTEM WITH SHORTWAVE TRACKING ACROSS NE/IA WITH FRONTAL SYSTEM. SYSTEM WILL NEED TO BE MONITORED AS IT APPROACHING FOR HEAVY RAIN AND SEVERE POTENTIALS. && .AVIATION...03/18Z ISSUED AT 1255 PM CDT MON JUN 3 2013 WIDESPREAD VFR CONDITIONS ARE EXPECTED THIS AFTERNOON INTO THE EVENING WITH UNRESTRICTED VSBYS. SOME HIGH CIRRUS WILL PASS ACROSS FAR NORTHERN IOWA...OTHERWISE CEILINGS WILL REMAIN UNRESTRICTED AS WELL. BY TONIGHT...CLOUDS WILL INCREASE AS LOW LEVEL JET AND INCREASING MOISTURE ADVECTION PRODUCES CONVECTION ACROSS NEBRASKA THAT WILL EVENTUALLY ADVECT INTO IOWA TOWARD DAYBREAK. ANY CEILINGS OVERNIGHT WILL BE VFR AS WELL ALTHOUGH THEY WILL LOWER AS PRECIPITATION ADVANCES INTO THE STATE. SHOWERS AND SOME THUNDERSTORMS WILL PASS INTO WESTERN IOWA ON TUESDAY MORNING SOUTHEAST WINDS ACRS THE AREA. SOME MVFR CEILINGS WILL OCCUR IN ANY AROUND THE PRECIPITATION...OTHERWISE VFR CONDITIONS WILL CONTINUE. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...COGIL LONG TERM...AWB AVIATION...COGIL  FXUS63 KDMX 070809 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 309 AM CDT FRI JUN 7 2013 .SHORT TERM.../TODAY /... ISSUED AT 308 AM CDT FRI JUN 7 2013 PERSISTENT UPPER LEVEL ENERGY OVER THE WESTERN GREAT LAKES WILL BECOME MORE PROGRESSIVE SHIFTING EAST TODAY. ANOTHER PV ANOMALY IS DROPPING SOUTHEAST FROM MANITOBA THIS MORNING AND INTO THE NORTHERN PLAINS. THE ENERGY FOCUS WITH THIS SYSTEM WILL BE THROUGH NORTHERN MINNESOTA AND INTO WISCONSIN HOWEVER IT WILL KEEP THE STATE IN COOL NORTHWEST FLOW TODAY WITH THE THERMAL TROUGH OVERHEAD. PRIMARY FORECAST CHALLENGE TODAY WILL BE CLOUDS AND TEMPERATURES. A VAST STRATUS FIELD IS CURRENTLY IN PLACE OVER NORTHEAST IOWA AND ADJACENT AREAS TO THE NORTH AND EAST. CURRENT STEERING FLOW IS FROM THE EAST/NORTHEAST THOUGH IT WILL TRANSITION TO MORE NORTHERLY THROUGH THE NEXT SEVERAL HOURS. SFC HIGH PRESSURE WILL SLOWLY MOVE EAST AND BE CENTERED OVER IOWA BY THIS AFTERNOON. THE STRATUS DECK SHOULD ERODE FROM THE WEST THROUGH THE DAY THOUGH SOME CUMULUS DEVELOPMENT IMMEDIATELY BEHIND THE EROSION MAY OCCUR. MOST LOCATIONS SHOULD HAVE SOME SUN DURING THE AFTERNOON TO SALVAGE TEMPERATURES A BIT THOUGH HIGHS WILL STILL BE 5 TO 12 DEGREES BELOW SEASONAL AVERAGES. A VERY LIGHT SHOWER OR TWO MAY DEVELOP THIS MORNING BUT GENERALLY DRY TODAY. .LONG TERM.../TONIGHT THROUGH WEDNESDAY/... ISSUED AT 308 AM CDT FRI JUN 7 2013 EXTENDED FORECAST REMAINS FOCUSED ON SYSTEM MOVING ACROSS THE STATE ON SATURDAY INTO SUNDAY. THE SREF/GFS/NAM ARE IN VERY GOOD AGREEMENT THROUGH SUNDAY WITH THE ECMWF BEING THE OUTLIER BY SUNDAY. LEANED TOWARD THE BLEND OF THE THREE. TONIGHT THROUGH SUNDAY...MODELS CONTINUE TO SHOW STRONG THETA-E ADVECTION BEGINNING ACROSS WESTERN IOWA BY 12Z SATURDAY AND SPREADING EAST THROUGHOUT THE DAY AHEAD OF A DEEPENING LOW PRESSURE SYSTEM MOVING OUT OF THE DAKOTAS. BEST FORCING MOVES ACROSS THE FORECAST AREA PAST 21Z SATURDAY AND NEARLY CLEARS THE EASTERN SECTIONS OF THE FORECAST AREA BY 12Z SUNDAY AS THE TROUGH MOVES INTO THE WESTERN GREAT LAKES. PRECIPITABLE WATER VALUES RANGE IN THE 1.5 TO 1.75 INCH RANGE AND WARM LAYER CLOUD DEPTHS RANGE AROUND 11000 FEET BY SATURDAY NIGHT. SURFACE DEW POINTS RISE INTO THE UPPER 50S/LOWER 60S BY SATURDAY AFTERNOON AS GOOD MOISTURE TRANSPORT PERSIST AHEAD OF THE TROUGH. SO LIKELY TO SEE SOME LOCALIZED HEAVY RAIN AS THE TROUGH MOVES THROUGH SATURDAY EVENING. BEST ELEVATED INSTABILITY AND SHEAR PARAMETERS ARE CONFINED TO THE SOUTHWEST SATURDAY AFTERNOON AND EVENING. HOWEVER...LIMITED SURFACE INSTABILITY PRESENT AS MUCH OF THE STATE WILL BE CLOUDED OVER ON SATURDAY. THE DEEP LAYER SHEAR VALUES RANGE FROM 30 TO 40 KNOTS AND 0-1KM SHEAR RANGES FROM 15 TO 25 KNOTS BY 00Z SUNDAY. SO CANNOT RULE OUT THE POTENTIAL FOR THE ELEVATED HAIL AND DAMAGING WIND THREAT. SUNDAY THE ECMWF KEEPS THE UPPER LOW STALLED ACROSS IOWA THROUGH MUCH OF THE DAY...WHILE THE SREF/NAM/GFS ARE MUCH QUICKER IN PULLING IT EASTWARD INTO WISCONSIN. WRAP-AROUND MOISTURE MOVES INTO NORTHERN IOWA BY SUNDAY AFTERNOON AND HAVE HIGHEST POPS GOING PAST 18Z SUNDAY. MAYBE TOO LOW ON POPS SUNDAY MORNING IF ECMWF SOLUTION HOLDS TRUE...BUT LEANED TOWARD THE MORE PROGRESSIVE NAM/SREF/GFS. MONDAY THROUGH THURSDAY...UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE BUILD INTO REGION ON MONDAY THEN THE SURFACE HIGH QUICKLY DEPARTS TUESDAY. WEAK THETA-E ADVECTION BETWEEN 850-700MB MOVES INTO WESTERN IOWA MONDAY NIGHT INTO TUESDAY AND HAVE SMALL POPS GOING DURING THIS TIME FRAME. STILL SOME UNCERTAINTY WRT TO NEXT SHORTWAVE MOVING ACROSS THE REGION ON TUESDAY INTO WEDNESDAY...WITH THE GFS FURTHER SOUTH THAN THE ECMWF. BEST FORCING LOOKS TO BE TUESDAY NIGHT INTO WEDNESDAY...AND HAVE HIGHEST POPS MENTIONED THROUGH 12Z WEDNESDAY. WARMER TEMPS LOOK POSSIBLE LATE NEXT WEEK AS 850MB TEMPS WARM INTO THE 20-25C RANGE BY FRIDAY. && .AVIATION...07/06Z ISSUED AT 1102 PM CDT THU JUN 6 2013 CLOUDS REMAIN ACROSS THE NORTH WITH POCKETS OF MVFR AND VFR AT THIS TIME. LOWER CLOUDS REMAIN JUST TO THE EAST WITH TROUGH EXTENDING BACK INTO EASTERN IOWA THIS EVENING. SOUTHERN EDGE OF CLOUDS HAS ERODED WITH DIURNAL HEATING OVER. NORTHEASTERN DECK MAY STILL ROTATE SOUTHWEST A BIT AND HAVE KEPT LOWERING CLOUD DECK FOR KALO AND KMCW. ELSEWHERE THERE MAY BE A BRIEF PERIOD OF MVFR CIGS BETWEEN 10-14Z AS LOW LEVEL STRATUS REDEVELOPS. OTHERWISE EXPECTING SOME BR FOG OVER MOST OF THE AREA BY 10-13Z WITH THE POTENTIAL FOR 1-2SM NEARER KFOD WHICH MAY COOL FASTER THAN REST OF AREA. WINDS TO REMAIN LIGHT THROUGH PERIOD...NW GRADUALLY BECOMING ESE BY 00Z TO 06Z TIMEFRAME. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...DONAVON LONG TERM...PODRAZIK AVIATION...REV  FXUS63 KDMX 080828 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 328 AM CDT SAT JUN 8 2013 .SHORT TERM.../TODAY /... ISSUED AT 328 AM CDT SAT JUN 8 2013 A POTENT UPPER LEVEL ANOMALY HAS BEEN RACING SOUTHEAST ACROSS MONTANA AND WYOMING THIS MORNING WITH THE AID OF A 130 KT UPPER LEVEL JET. THIS FEATURE WILL BE ARRIVING OVER WESTERN IOWA BY LATE THIS AFTERNOON INTO THE EVENING. CONVECTION IS ALREADY ONGOING ACROSS SOUTH DAKOTA AND NEBRASKA UNDER THE REGION OF GOOD UPPER DIFFLUENCE AND ALONG THE NOSE OF A 40 KT LOW LEVEL JET(LLJ). THE LLJ IS PROVIDING EXCELLENT MOISTURE ADVECTION INTO THE REGION. THIS ENTIRE REGION WILL GRADUALLY SHIFT EAST INTO IOWA AS THE UPPER ANOMALY APPROACHES. ATYPICAL OF MANY DIURNAL SITUATIONS...THE LLJ WILL MAINTAIN STRENGTH THROUGH THE DAY AND WILL STREAM MOISTURE INTO CENTRAL AND WESTERN IOWA THROUGH THE DAY. THE ELEVATED CONVECTION TO THE WEST LIKELY WILL MAKE INTO THE NORTHWEST FORECAST AREA THIS MORNING WITH CHANCES INCREASE OVER THE WESTERN TWO THIRDS BY 00Z. PWAT VALUES WILL NEARLY DOUBLE FROM 12Z TO 00Z OVER THE WEST OF INTERSTATE 35 TODAY AS PROFILES MOISTEN AND SATURATE. THESE PROFILES COMBINED WITH WARM CLOUD DEPTHS OF 11-12 KFT WILL LEAD TO EFFICIENT RAIN PRODUCING STORMS WHILE LITERALLY DAMPENING THE SEVERE WEATHER THREAT FOR MUCH OF THE AREA. ONE INCH OR MORE OF PRECIPITATION IS POSSIBLE OVER THE FAR WEST BY 00Z. THE BEST POTENTIAL FOR ANY SEVERE WEATHER WILL BE OVER THE SOUTHWEST WHERE BETTER INSTABILITY ARRIVES FROM THE SOUTHWEST LATE THIS AFTERNOON. TEMPERATURES TODAY WILL FOLLOW NON DIURNAL TRENDS WITH TEMPERATURES FALLING ONCE THE THICKER CLOUD COVER AND PRECIPITATION ARRIVE. .LONG TERM.../TONIGHT THROUGH FRIDAY/... ISSUED AT 328 AM CDT SAT JUN 8 2013 MAIN FOCUS THROUGHOUT THE EXTENDED WILL BE ON SYSTEM MOVING THROUGH TONIGHT INTO SUNDAY/SUNDAY NIGHT. UPPER WAVE DROPPING SOUTHEASTWARD THROUGH THE NORTHERN ROCKIES/MONTANA TO CONTINUE TO DIG AS IT PUSHES SOUTHEASTWARD AND MOVES THROUGH IOWA TONIGHT INTO SUNDAY...BEFORE PUSHING INTO THE OHIO VALLEY BY MONDAY. AN ASSOCIATED AREA OF SFC LOW PRESSURE WILL BECOME CENTERED OVER THE NORTHWESTERN PORTION OF THE STATE BY 06Z TONIGHT...WITH THE ATTENDANT WARM FRONT LIFTING NORTH THROUGH THE STATE THIS EVENING BECOMING STRETCHED ACROSS THE IA/MN BORDER BY 06Z TONIGHT. THIS WILL ALLOW SOUTHERLY FLOW...WAA AND INCREASING MOISTURE ADVECTION ACROSS THE CWA THIS EVENING INTO TONIGHT. EXPECT WIDESPREAD ACTIVITY ACROSS THE CWA THIS EVENING TRANSLATING EASTWARD INTO THE EARLY MORNING HOURS...WITH DRY PUNCH PUSHING INTO THE CWA LATE TONIGHT. AS SYSTEM BECOMES NEARLY STACKED ACROSS THE NORTHERN CWA AND UPPER LOW CLOSING OFF...MOISTURE WRAPPING AROUND ALOFT WITH ANOTHER AREA OF PRECIPITATION EXPECTED TO MOVE THROUGH THE CWA SUNDAY. SOME WEAK INSTABILITY ALOFT...SO COULD STILL SEE SOME THUNDER SUNDAY...BUT MAJORITY OF ANY HEAVIER PRECIPITATION EXPECTED WITH THE ACTIVITY TONIGHT. AS UPPER LOW PROGRESSES THROUGH THE CWA SUNDAY INTO SUNDAY NIGHT...SHOULD SEE PRECIPITATION CHANCES TAPER OFF FROM WEST TO EAST LATE SUNDAY/SUNDAY NIGHT. SOME CONCERNS AROUND AMOUNT OF PRECIP/CHANCES FOR FLASH FLOODING ACROSS THE CWA. WARM CLOUD DEPTH EXPECTED TO BE QUITE HIGH WITH PWAT VALUES INCREASING TO AROUND 1.5 TO 1.7 INCHES SUGGESTING THAT EFFICIENT PRECIP PRODUCTION. THEREFORE HEAVY RAINFALL COULD POSE A FLASH FLOOD THREAT...HOWEVER STORM MOTIONS EXPECTED TO BE QUITE FAST LIMITING THE HEAVY RAIN THREAT SOMEWHAT. FLASH FLOOD GUIDANCE IN THE 1.7 TO 2.3 RANGE IN 3 HRS ACROSS MUCH OF THE CWA WHERE HEAVY RAIN IS POSSIBLE. THESE AMOUNTS ARE POSSIBLE...BUT UNCERTAINTY IS STILL HIGH SO FOR NOW WILL HIGHLIGHT IN THE HWO AND WILL CONTINUE TO MONITOR THE HEAVY RAIN POTENTIAL. BROAD FLATTER UPPER LEVEL RIDGING TO BUILD INTO THE CENTRAL US FOR EARLY NEXT WEEK...WITH SFC HIGH PRESSURE BRIEFLY IN PLACE ACROSS THE STATE MONDAY. RIDGE FLATTENS EVEN FURTHER INTO TUESDAY...WITH AN AREA OF SFC LOW PRESSURE DEVELOPING ACROSS THE WESTERN HIGH PLAINS. A WEAK SHORTWAVE MOVES THROUGH TOPPING THE BROAD FLAT RIDGE...WITH THE SFC LOW TO SLIDE ACROSS IOWA WEDNESDAY. SOUTHERLY FLOW AHEAD OF THIS SYSTEM...ALLOWS FOR WAA/MOISTURE ADVECTION. 700MB TEMPS CLIMB INTO THE MID TEENS CELSIUS ACROSS MUCH OF THE CENTRAL US SUGGESTING DECENT CAP ACROSS THE AREA. HOWEVER WITH THE WEAK WAVE MOVING THROUGH...CHANCE FOR ACTIVITY TO DEVELOP ON NORTHERN EDGE OF THE CAP LATE TUESDAY INTO TUESDAY NIGHT...WITH POSSIBLE MCS TO MOVE THROUGH THE NORTHERN CWA. CAP WEAKENS INTO WEDNESDAY WITH ADDITIONAL ACTIVITY POSSIBLE ACROSS THE STATE WITH ANOTHER SHORTWAVE MOVING THROUGH THE UPPER RIDGE. RIDGE THEN BUILDS BACK IN FOR THE LATTER HALF OF THE WEEK...WITH RIDGE BEGINNING TO BREAK DOWN TOWARD NEXT WEEKEND WITH ADDITIONAL PRECIPITATION CHANCES EXPECTED TOWARD FRIDAY INTO NEXT WEEKEND. WITH THE UPPER RIDGE AND WARMER AIRMASS IN PLACE...SHOULD SEE TEMPS CLIMBING MORE TOWARD THE SEASONAL AVERAGES NEXT WEEK WITH HIGHS IN THE UPPER 70S TO AROUND 80 ACROSS THE CWA. && .AVIATION...08/06Z ISSUED AT 1126 PM CDT FRI JUN 7 2013 MAIN CHALLENGES REMAIN FOR TOMORROW. MODELS GENERALLY ON TRACK WITH TIMING...THOUGH HAVE SLOWED DOWN ARRIVAL BY 1-2 HOURS FOR MOST SITES. BEST INSTABILITY WILL BE EARLY EVENING BUT WITH SUFFICIENT H850 JET MOST OF EVENING AND STRONG WARM AIR ADVECTION... AM EXPECTING A 3 TO 5 HOUR PERIOD OF THUNDER ACROSS MOST SITES BEGINNING 22-23Z WEST AND ENDING 04-06Z WEST. EAST SOUTHEAST WINDS WILL BE INCREASING DURING THE LATE AFTERNOON AND EVENING AS WARM FRONT APPROACHES AND CONTINUE INTO THE EVENING. VSBY AND CIGS WILL LOWER TO MVFR AND POSSIBLY LOWER TO IFR NORTH SITES AFT 03Z. ONCE SYSTEM BEGINS TO OCCLUDE...EXPECT CIGS TO REMAIN LOWER THROUGH 12Z AS STORMS LIFT NORTHEAST AND SHOWERS REMAIN. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...DONAVON LONG TERM...BEERENDS AVIATION...REV  FXUS63 KDMX 082039 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 339 PM CDT SAT JUN 8 2013 .SHORT TERM.../TONIGHT/... ISSUED AT 337 PM CDT SAT JUN 8 2013 FAIRLY HIGH CONFIDENCE IN PRECIP TRENDS TONIGHT WITH MOST OPERATIONAL AND HI RES CONVECTION ALLOWING MODELS ALL ON THE SAME PAGE. CURRENT GENERALLY BROAD WEAK CONVECTION THROUGH THE MO VALLEY AHEAD OF NRN PLAINS TROUGH SHOULD EXPAND SOUTHWARD THIS EVENING INTO STRENGTHENING 0-1KM MOISTURE CONVERGENCE ZONE ASSOCIATED WITH KS/NE SURFACE PRESSURE TROUGH. CONVERGENCE WILL EVENTUALLY SWING INTO IA TONIGHT AIDED BY SHARPLY INCREASING THERMODYNAMIC FORCING. THIS MAY BECOME SURFACE BASED TO OUR SOUTH INITIALLY WITH LITTLE CINH CURRENTLY NOTED ALONG KS/NE BORDER...HOWEVER REDDING FORECAST SOUNDINGS ESSENTIALLY BECOME MOIST ADIABATIC BY 03Z WITH MINIMAL ESTIMATED EFFECTIVE SHEAR /1-6KM/ SO DO NOT FEEL THERE IS TOO MUCH SEVERE POTENTIAL INTO IA WITH HEAVY RAIN A GREATER THREAT. FORCING LATER THIS EVENING IS NOTED NICELY BY MOST MODELS WITH 30-50KT FLOW AND DECENT LIFT ACROSS 300K ISENT SURFACE. THIS WILL LIKELY PRODUCE CONCENTRATED BUT FORTUNATELY TRANSIENT AXIS OF HEAVY RAIN AS MEAN WIND BECOMES SLY AT 30-40 KTS BY MIDNIGHT AND 0-1KM MOISTURE CONVERGENCE MOVES FROM WRN IA THIS EVENING INTO AND OUT OF NERN SECTIONS 09-12Z. EFFICIENT RAIN ENVIRONMENT WILL BECOME MORE FAVORABLE OVERNIGHT WITH WARM CLOUD DEPTHS AT OR ABOVE 11KFT AND PWATS OVER 1.5 INCHES SO WOULD NOT BE SURPRISED TO SEE LOCALLY HEAVY RAINS AND POTENTIALLY ISOLATED FLASH FLOODING. RIVER FORECASTS WITH RAINFALL ENDING AT 12Z SUN MAINLY DEPICT SIGNIFICANT WITHIN BANK RISES...ALTHOUGH A FEW SPOTS MAY EVENTUALLY JUST REACH FLOOD STAGE DEPENDING ON WHERE THE HEAVY RAINS FALL WITH THE RACCOON AND CEDAR BASINS MOST SUSCEPTIBLE. .LONG TERM.../SUNDAY THROUGH SATURDAY/... ISSUED AT 337 PM CDT SAT JUN 8 2013 UPPER LEVEL LOW WILL PUSH ACROSS CENTRAL IOWA THROUGHOUT THE DAY SUNDAY...WHICH WILL KEEP PRECIPITATION CHANCES THROUGHOUT THE DAY AS SHORTWAVE WRAPS AROUND THE LOW. MODELS INDICATE A SIGNIFICANTLY SLOWER SOLUTION AS LOW PUSHES EAST...AND HAVE KEPT WITH SLOW PROGRESSION...WITH PRECIPITATION CHANCES LINGERING INTO SUNDAY NIGHT BEHIND LOW. CHANCES FOR HEAVY RAIN WILL AGAIN ACCOMPANY THIS WAVE...WITH PWAT VALUES AROUND 1.3 INCHES...THOUGH MOISTURE TRANSPORT IS WEAKER...ALONG WITH THETA-E ADVECTION...AND THEREFORE DO NOT ANTICIPATE WIDESPREAD HEAVY RAINFALL. WITH UPPER LEVEL LOW OVER IOWA...CLOUDS WILL LINGER AND TEMPERATURES WILL BE MUCH COOLER THAN NORMAL...ESPECIALLY ACROSS THE NORTH. BEHIND RETREATING LOW WEAK RIDGE BUILDS IN FOR MONDAY AND TUESDAY WITH TEMPERATURES WARMING UNDER RIDE AS WAA INCREASES. HAVE KEPT TEMPS NEAR GOING FOR TUESDAY...BUT MAY SEE SIGNIFICANT WARMING IN THE WEST WITH MIXING. TEMPS MAY BE A BIT WARMER ON WEDNESDAY AS WELL...BUT CLOUD COVER WILL LIMIT MIXING SOMEWHAT. NEXT CHANCE FOR PRECIPITATION COMES WEDNESDAY AS LOW PRESSURE SYSTEM PUSHES ACROSS KANSAS/MISSOURI. THIS MAY BRING ANOTHER CHANCE FOR RAINFALL TO THE STATE...BEGINNING LATE TUESDAY...WITH PWAT VALUES NEAR 2 INCHES. HOWEVER...SOUNDINGS INDICATE MORE CONVECTIVE PRECIPITATION THAN WIDESPREAD HEAVY RAIN. MODELS ARE NOT IN GOOD AGREEMENT WITH TIMING AND PLACEMENT OF LOW ATTM...WITH ECMWF TAKING LOW FURTHER NORTH...WITH GFS AND GEM TRENDING FURTHER SOUTH. ONLY HAVE CHANCE MENTION FOR NOW WITH UNCERTAINTIES. SYSTEM WILL PUSH EASTWARD QUICKLY...WITH ANOTHER RIDGE BUILDING INTO SATE FOR THE END OF THE WEEK. HOWEVER...THIS WILL AGAIN BE SHORT LIVED AS A ANOTHER LOW PRESSURE SYSTEM TRACKS ACROSS CANADA...BRINGING ADDITIONAL CHANCES FOR PRECIPITATION FOR THE WEEKEND. TEMPERATURES WILL REMAIN GENERALLY NEAR NORMAL WITH HIGHS IN THE UPPER 70S/LOW 80S AND LOWS IN THE 60S AND 70S. && .AVIATION...08/18Z ISSUED AT 1249 PM CDT SAT JUN 8 2013 MVFR CONDITIONS ASSOCIATED WITH WRN IA SHOWERS WILL CONTINUE SLOWLY ADVANCING EWD WITH THE PRECIP THROUGH THE AFTERNOON. MODELS DO SUGGEST THIS MOVEMENT WILL CEASE SOMEWHAT HOWEVER SO HAVE NOT EXTRAPOLATED MVFR ALL THE WAY TO KALO/KOTM AREAS BUT DELAYED UNTIL UPPER LEVEL SYSTEM ADVANCES FARTHER INTO THE MO VALLEY PRODUCING ADDITIONAL PRECIP AND LOWERING CIGS. EXPECT AT LEAST MVFR INTO SUN MORNING...POSSIBLY DOWN TO IFR AT TIMES. STRATUS AND SCT SHOWERS SHOULD LINGER THROUGH THE VALID PERIOD. THERE IS SOME POTENTIAL FOR THUNDER WITH ANY OF THE PRECIP...ALTHOUGH CHANCES ARE SOMEWHAT LOW AND CONFIDENCE IN TIMING OR LOCATION NOT THERE TO INJECT AT THIS TIME. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SMALL LONG TERM...AWB AVIATION...SMALL  FXUS63 KDMX 102054 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 354 PM CDT MON JUN 10 2013 .SHORT TERM.../TONIGHT/ ISSUED AT 354 PM CDT MON JUN 10 2013 UPPER LEVEL RIDGE OF HIGH PRESSURE WILL REMAIN IN PLACE OVERNIGHT WHILE AT THE SURFACE...A LOW OVER THE PLAINS WITH AN ASSOCIATED FRONTAL BOUNDARY WILL LIFT INTO NORTHERN MO AND MAKING SOME ADVANCEMENT INTO SOUTHWEST IOWA BY 12Z. I REALLY DO NOT SEE MUCH IN THE WAY OF FORCING...FRONTOGENETICAL OR OTHERWISE...SO I DON'T EXPECT TO SEE ANY PRECIP BUT SOUNDINGS AND TIME HEIGHT PROFILES LOOK INTERESTING. THERE IS VERY SHALLOW ABUNDANT LOW LEVEL MOISTURE THAT REMAINS IN PLACE WITH SOME VERY DRY AIR ABOVE THAT...FROM ABOUT 600 TO 700 MB. WINDS BECOME SOUTHERLY BUT ARE GOING TO BE LIGHT AT THE SURFACE. GIVEN THE INVERSION THE SOUNDINGS ARE SHOWING I AM NOT EXPECTING ANY MIXING. SO MY FORECAST WILL LEAN HEAVY ONCE AGAIN TO LOW CLOUDS AND FOG DEVELOPING OVER THE FORECAST AREA BETWEEN 08Z THROUGH THE REMAINDER OF THE FORECAST PERIOD. GIVEN THE SHALLOW DEPTH OF THE MOISTURE AND THE DRY AIR OFF THE SURFACE...I DID NOT FORECAST DENSE FOG THOUGH LOCALIZED DENSE FOG IS CERTAINLY POSSIBLE. THE STRATUS SHOULD ALSO NOT LINGER AS LONG ON TUESDAY BUT THE FACT THAT WE WILL HAVE STRATUS IN THE MORNING WILL ADD SOME CHALLENGE TO THE TUESDAY FORECAST WHICH WILL BE DISCUSSED LATER. TEMPS WILL BE AT LEAST A CATEGORY ABOVE LAST NIGHT WITH WARMER READING ACROSS THE SOUTHWEST. THESE WILL FEEL COOL COMPARED TO THE REST OF THE WEEK. .LONG TERM.../TUESDAY THROUGH MONDAY/ ISSUED AT 354 PM CDT MON JUN 10 2013 TYPICAL MID JUNE PATTERN WILL BE IN PLACE THROUGH THE PERIOD WITH SRN CONUS RIDGING AND IA ON THE EDGE OF THE WESTERLIES. CURRENT KS WARM FRONT WILL CONTINUE LIFTING NWD OVERNIGHT REACHING AT LEAST IA/MO BORDER BY AFTERNOON. THIS WILL BRING A NOTED AIRMASS CHANGE...ESPECIALLY TO CENTRAL AND SRN SECTIONS WHERE DEWPOINTS AROUND 70 WILL BE COMMON BY AFTERNOON. MUCAPES WILL SURGE TO SEVERAL THOUSAND J/KG BUT LIKELY BE UNREALIZED DUE TO CAPPING CONSTRAINTS AND 1-2KM WARM LAYER. SOME MODELS ARE GENERATING QPF THROUGH THE DAY BUT THIS WOULD BE VERY ELEVATED AND HIGH BASED...AT OR ABOVE 12KFT...WITH MUCH LESS INSTABILITY. ALTHOUGH IT WOULD BE DIFFICULT FOR MUCH TO REACH THE SURFACE DUE TO CONSIDERABLE DRY AIR UNDERNEATH...GFS/NAM 315/320K ISENT SURFACES SHOW NOTABLE BAROCLINIC ZONE AND WARM ADVECTION THROUGH THE DAY SO HAVE ADDED SLIGHT CHANCES NORTHEAST INTO THE AFTERNOON. SIMILAR PATTERN EXISTS INTO THE NIGHT TUESDAY. ALTHOUGH H85/H7 THETA-E ADVECTION IS NOT AS STRONG AS PREVIOUS DAYS RUNS...VERY ELEVATED WARM ADVECTION STILL EXISTS AND COULD POTENTIALLY PRODUCE AN MCS. HI RES MODELS SUGGEST THIS SCENARIO AND/OR HIGH PLAINS SURFACE BASED CONVECTION FROM EARLIER IN THE DAY REACHING IA OVERNIGHT IN THE FORM OF A MORE POTENT MCS. TOUGH TO INJECT DETAILS AT THIS POINT...BUT HAVE MAINTAINED LIKELY POPS FOR EITHER INSTANCE. WED MORNING COULD SEE LINGERING MCS BUT ATTENTION TURNING TO MORE SURFACE BASED DEVELOPMENT ALONG AND AHEAD OF THE TRIPLE POINT. POTENT SHORT WAVE/PV ANOMALY NOW INTO CA SHOULD TOP THE RIDGE BY WED AND LIKELY BRING SUFFICIENT FORCING AND LIFT TO COOL MID LEVELS AND MODIFY SOUNDINGS ENOUGH TO REDUCE CINH. OTTUMWA SOUNDINGS SHOW THIS TREND WELL. ONE PROBLEM WILL BE HOW FAR EAST THE LOW AND TRIPLE POINT GET BY PEAK HEATING. ALTHOUGH IT IS A SLOWER OUTLIER...THE 12Z ECMWF IS MORE CONDUCIVE FOR SIGNIFICANT CONVECTION OVER DMX AREA RATHER THAN OTHER MODELS WHICH BRUSH ERN SECTIONS AND QUICKLY PUSH OFF TO THE EAST. THIS SOLUTION WOULD LIKELY RESULT IN DAY 3 SLIGHT RISK BEING PULLED FARTHER WEST WITH ALL MODES OF SEVERE WEATHER POSSIBLE AND CERTAINLY NEEDS TO BE WATCHED. SUBSIDENCE SHOULD SETTLE IN LATER WED NIGHT INTO THU WITH ATTENTION TURNING TOWARD ANOTHER SYSTEM OVER THE WEEKEND. TIMING WILL BE SOMEWHAT OF AN ISSUE WITH FASTER 12Z ECMWF SHOWING WARM ADVECTION FRI INTO FRI NIGHT AND LOWER ROOTED POTENTIAL WITH WEAK SURFACE FEATURES SAT. GFS IS SOMEWHAT SLOWER WITH A FEW ROUNDS OF WARM ADVECTION BEFORE SURFACE PASSES AROUND SUNDAY. DETAILS ARE NOT CLEAR...BUT EITHER SCENARIO SUGGESTS LIKELY POPS ARE NEEDED FRI NIGHT WITH CHANCES ON EITHER SIDE. PWATS AND WARM CLOUD DEPTHS WILL INCREASE SHARPLY WITH THIS AIRMASS CHANGE AND COULD RESULT IN A FEW INSTANCES OF HEAVY RAIN AND POTENTIALLY ISOLATED FLASH FLOODING. HOWEVER OVERALL PATTERN SEEMS PROGRESSIVE ENOUGH TO AVOID REPETITIVE EVENTS AND RETURN TO WIDESPREAD FLOODING. && .AVIATION...10/18Z ISSUED AT 1145 AM CDT MON JUN 10 2013 LOW LEVEL MOISTURE IS SLOW TO LIFT OVER THE TAF LOCATIONS BUT WILL EVENTUALLY DO SO AS DAYTIME HEATING CONTINUES AND HOLES IN THE STRATUS ALLOW WARMING OF THE LOWER LEVELS. IN GENERAL TAF LOCATIONS WILL BE UNDER THE INFLUENCE OF AN UPPER RIDGE OF HIGH PRESSURE AND A SURFACE LOW OVER THE PLAINS WITH AN ATTENDANT WARM FRONT THAT WILL LIFT INTO IA DURING THE MORNING. WARMER AIR ALONG WITH MORE MOISTURE WILL WORK ITS WAY INTO IOWA AND THIS COMBINED WITH A LIGHT SOUTH FLOW RAISES CONCERNS FOR ANOTHER NIGHT WHERE STRATUS AND FOG MOVE INTO TAF LOCATIONS AFT 06Z THROUGH ABOUT 14Z. I HAVE LEANED TAFS THIS WAY. HOWEVER...IT SHOULD BE NOTED THAT JUST OFF THE SURFACE THE AIRMASS IS FAIRLY DRY. THAT STRATUS SHOULD NOT BE VERY DEEP AND FOG NOT LIKELY AS DENSE AS IT WAS LAST NIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BOKSA LONG TERM...SMALL AVIATION...FAB  FXUS63 KDMX 140828 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 328 AM CDT FRI JUN 14 2013 .SHORT TERM.../TODAY /... ISSUED AT 330 AM CDT FRI JUN 14 2013 FORECAST FOR TODAY CENTERS AROUND CONVECTIVE EVOLUTION ASSOCIATED WITH A COUPLE OF SHORTWAVES OVERTOPPING THE DEEP LAYER RIDGE OVERHEAD WITHIN A BROAD WARM ADVECTION REGIME. CURRENTLY RADAR IMAGERY SHOWS SHOWERS AND THUNDERSTORMS DEVELOPING RAPIDLY ACROSS WESTERN IOWA IN CONJUNCTION WITH THE NOCTURNAL MAX TIME AND LLJ...BUT AS THIS ACTIVITY MOVES EASTWARD IT WILL ENCOUNTER A SOMEWHAT MORE STABLE AIRMASS AND SHOULD SLOWLY WEAKEN. LATER TODAY DIURNAL HEATING SHOULD SUPPORT ANOTHER ROUND OR TWO OF TSTORM DEVELOPMENT...HOWEVER THE TIMING AND LOCATION OF THIS PRECIP WILL BE DEPENDENT ON THE DEGREE OF DESTABILIZATION AND LOCATION OF OUTFLOWS AND OTHER REMNANT BOUNDARIES FROM MORNING CONVECTION. IN OTHER WORDS...STORMS WILL BE AROUND AT INTERVALS ALL DAY BUT POPS WILL NECESSARILY BE BROAD BRUSHED AND MAINLY IN THE CHANCE/SCATTERED CATEGORY. ASIDE FROM THE RAINFALL ASPECT THE DAY WILL BE CHARACTERIZED BY SEASONAL MILD TEMPERATURES AND FAIRLY HUMID CONDITIONS WITH LIGHT TO MODERATE SOUTHEAST BREEZES. .LONG TERM.../TONIGHT THROUGH WEDNESDAY/... ISSUED AT 330 AM CDT FRI JUN 14 2013 CONVECTION IS EXPECTED TO BE ONGOING AT THE BEGINNING OF THE PERIOD ACRS MUCH OF CENTRAL IOWA WITH FOCUS ACROSS THE NORTHERN HALF OF THE STATE WHERE MOISTURE TRANSPORT IS MAXIMIZED. THERE MAY BE SOME SEVERE CONVECTION...HOWEVER MAIN THREAT WILL BE FROM HEAVY RAINFALL FROM TRAINING AND HAVE DISCUSSED THESE ISSUES IN THE HYDROLOGY SECTION BELOW. OTHERWISE...THREAT OF CONVECTION WILL PERSIST INTO SATURDAY AHEAD OF A SURFACE WAVE WHICH WILL PASS THROUGH THE STATE DURING THE DAY. MAIN CONCERN FOR SEVERE WEATHER WOULD BE IN THE SOUTHEAST FORECAST AREA AHEAD OF THE SURFACE WAVE WHERE SOME HAIL AND DAMAGING WINDS WILL BE POSSIBLE. THERE DOES APPEAR TO BE SOMEWHAT OF A BREAK ON SATURDAY NIGHT AS WEAK SURFACE RIDGING CROSSES THE STATE. HAVE DECREASED POPS SOME DURING THIS TIME...ESPECIALLY LATE AS SUBSIDENCE CROSSES THE STATE. AN UPPER LOW DROPPING SOUTHEAST ACROSS THE REGION ON SUNDAY INTO MONDAY WILL PROVIDE ANOTHER THREAT FOR RAINFALL LATER SUNDAY INTO EARLY MONDAY...HOWEVER THE BULK OF CONVECTION AND RAINFALL WILL BE FARTHER SOUTH DURING THIS TIME WITH AMOUNTS EXPECTED TO BE MUCH LIGHTER THAN TONIGHT AND SATURDAYS RAINFALL. AFTER THIS TIME...DRIER AND COOLER AIR WILL MOVE INTO THE STATE WITH THE THREAT OF PRECIPITATION SUBSIDING BY LATER MONDAY. QUIET WEATHER IS THEN EXPECTED ON TUESDAY AND WEDNESDAY WITH SEASONABLE TEMPERATURES. RETURN FLOW AND INCREASING THETA-E ADVECTION RETURN BY THURSDAY WITH AN INCREASING THREAT OF THUNDERSTORMS. && .AVIATION...14/06Z ISSUED AT 1137 PM CDT THU JUN 13 2013 VFR CEILINGS AND LIGHT WINDS THROUGH THE OVERNIGHT. ANTICIPATE SHRA/TSRA DEVELOPMENT IN NEBRASKA OVERNIGHT...PUSHING EASTWARD INTO SITES AFTER 12Z. MAY SEE MVFR CEILINGS AT TIME WITH SHRA/TSRA BUT HAVE NOT INCLUDED MENTION ATTM WITH LOW CONFIDENCE. IN ADDITION...MAY SEE TSRA ACROSS WESTERN SITES...KFOD/KDSM LATE IN THE AFTERNOON..BUT AGAIN HAVE NOT INCLUDED MENTION WITH UNCERTAINTY. WINDS WILL SHIFT TO THE SOUTH AND WILL BE GUSTY THROUGH THE AFTERNOON...BUT GUSTS WILL DECREASE AFTER 00Z. && .HYDROLOGY... ISSUED AT 330 AM CDT FRI JUN 14 2013 THERE WILL BE STRONG MOISTURE TRANSPORT INTO THE STATE TODAY WITH PWAT VALUES INCREASING TO 1.5-2.0 INCHES OVER MUCH OF CENTRAL IOWA. WARM CLOUD DEPTH IS GENERALLY FROM 11-14KFT FROM LATE THIS AFTERNOON INTO SATURDAY MORNING WITH SOME SLIGHT DECREASE ON SATURDAY. WARM CLOUD PROCESSES ARE ANTICIPATED DURING THIS TIME WITH SOME TRAINING LIKELY UNTIL SURFACE WAVE PASSES BY SATURDAY AFTERNOON. MODELS HAVE GENERALLY BEEN INDICATING ONE TO TWO INCHES OF RAINFALL ACROSS THE NORTHERN HALF OF THE STATE AN WITH THE CONVECTION...ISOLATED HIGHER AMOUNTS ARE ANTICIPATED. GIVEN THE RECENT HEAVY RAINFALL AND RELATIVELY LOW FFG VALUES ACROSS THE NORTH...HAVE GONE WITH A FLASH FLOOD WATCH IN NORTHERN IOWA FROM LATE THIS AFTERNOON THROUGH SATURDAY AFTERNOON WHEN THE RAIN SHOULD TAPER OFF AS A SURFACE WAVE PASSES. MAY SEE SOME RENEWAL OF RIVER FLOODING AS WELL AS THE RUNOFF ENTERS THE STREAMS AND RIVERS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM THIS AFTERNOON THROUGH SATURDAY EVENING FOR BLACK HAWK-BREMER-BUTLER-CALHOUN-CERRO GORDO-EMMET-FRANKLIN- GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-PALO ALTO- POCAHONTAS-SAC-WEBSTER-WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...LEE LONG TERM...COGIL AVIATION...AWB HYDROLOGY...COGIL  FXUS63 KDMX 142052 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 352 PM CDT FRI JUN 14 2013 .SHORT TERM.../TONIGHT /... ISSUED AT 346 PM CDT FRI JUN 14 2013 PRIMARY CONCERNS WILL OF COURSE BE CONVECTIVE TRENDS OVERNIGHT. CURRENT SCENARIO HAS TYPICAL MID JUNE RING OF FIRE IN PLACE OVER SRN CONUS RIDGE WITH RING DELINEATED FAIRLY NICELY BY NARROW RIBBON OF HIGH K INDICES FROM NE ACROSS NE INTO IA. MCV FROM OVERNIGHT CONVECTION IS CURRENTLY MOVING INTO SERN IA WITH DEPARTING MCS...WHILE ANOTHER CLUSTER HAS DEVELOPED ON TRAILING SPIRAL WITHIN WEAK BROAD QG FORCING. PRIMARY ATTENTION WILL BE UPSTREAM HOWEVER LOOKING AT GENESIS REGION OVER NE. K INDEX RIBBON IS CURRENT COINCIDENT WITH SURFACE BOUNDARY JUST WEST OF O NEILL AND BROKEN BOW...WHICH IS ALSO AN AREA OF DEEPER MOISTURE CONVERGENCE. NOSE OF 3000 PLUS MLCAPES REACHES INTO THIS AREA WITH MLCINH CONTINUING TO ERODE. THIS COULD CERTAINLY BE AN AREA WHERE SURFACE BASED CONVECTION DEVELOPS AND EVENTUALLY REACHES IA LATER THIS EVENING. IF STORMS FROM THIS AREA DO NOT MAKE IT INTO IA...ADDITIONAL ELEVATED DEVELOPMENT MAY OCCUR WITH STRONG ISENT LIFT NOTED ALONG 310K ISENT SURFACE AT BASE OF STEEPER LAPSE RATES AND SHOULD TRIGGER MCS ANYWAY. ELEVATED CINH APPEARS DECENT BUT LIKELY NOT GREAT ENOUGH TO OVERCOME ISENT LIFT. SOUNDINGS ARE SOMEWHAT DRY 1-3KM SO WITH ELEVATED CAPES OVER 2000 J/KG AT TIMES LARGE HAIL AND DAMAGING WINDS WOULD BOTH BE A THREAT. .LONG TERM.../SATURDAY THROUGH FRIDAY/... ISSUED AT 346 PM CDT FRI JUN 14 2013 MAIN FORECAST CONCERN IS WITH TIMING OF CONVECTION AND HEAVY RAIN/SEVERE POTENTIAL ASSOCIATED WITH THE CONVECTION SATURDAY AND SATURDAY NIGHT. MODELS IN GOOD OVERALL SYNOPTIC AGREEMENT THROUGH SUNDAY...BUT HAVE DIFFERENCES WRT TO PRECIP TOTALS...LOCATION AND TIMING. LEANED TOWARD A BLEND THROUGH SUNDAY...THEN THE ECMWF MONDAY THROUGH THURSDAY. SATURDAY AND SUNDAY...SURFACE BOUNDARY LAYS UP ACROSS NORTHERN IOWA SATURDAY MORNING AND SHOULD ALLOW FOR OVERNIGHT CONVECTION TO BE CONFINED TO NORTHERN PORTIONS OF THE FORECAST AREA BETWEEN 12 AND 18Z SATURDAY. ONCE THE NEXT 500MB VORT MAX AND SHORTWAVE MOVE ACROSS THE STATE BY THE AFTERNOON SATURDAY...CONVECTION LOOKS TO REDEVELOP OVER CENTRAL AND SOUTHEAST PORTIONS OF THE FORECAST AREA PAST 20Z SATURDAY AND PERSIST INTO THE EVENING HOURS. WARM LAYER CLOUD DEPTH RANGES FROM 12000 TO 13000 FEET WITH PRECIPITABLE WATER VALUES NEARING 2 INCHES BY SATURDAY AFTERNOON...SO EFFICIENT RAIN PRODUCERS ARE LIKELY. AS FAR AS THE SEVERE POTENTIAL...BEST INSTABILITY WILL BE CONFINED GENERALLY ALONG AND EAST OF INTERSTATE 35 SATURDAY AFTERNOON WITH MLCAPE RANGING FROM 2000 J/KG TO NEAR 4000 J/KG. NOT ANTICIPATING MUCH CLEARING ACROSS THE FORECAST AREA SATURDAY TO ALLOW FOR SURFACE BASED INSTABILITY TO INCREASE. DEEP LAYER SHEAR IN THE 25 TO 40 KNOT RANGE AND SO NOT THE BEST ENVIRONMENT OF ORGANIZED LONG UPDRAFTS...BUT LOW LEVEL SHEAR SOME WHAT FAVORABLE FOR TORNADIC POTENTIAL. HAVE BEST POPS ACROSS CENTRAL TO SOUTHEAST PORTIONS OF THE FORECAST AREA SATURDAY AFTERNOON AND EVENING. FRONT LOOKS TO SAG FAR ENOUGH SOUTH TO CONFINE POPS ACROSS SOUTHERN IOWA BY SUNDAY MORNING. WENT A LITTLE ABOVE GUIDANCE FOR MAX TEMPS ON SUNDAY WITH DRY WEATHER ANTICIPATED MUCH OF THE DAY. SUNDAY NIGHT THROUGH THURSDAY...COLD FRONT MOVES THROUGH DURING THE DAY MONDAY WITH CONVECTION POTENTIAL LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING. GFS HAS MUCH MORE PRECIP THAN THE ECMWF AND LEANED TOWARD THE ECMWF AS SOUNDINGS NOT REALLY SUPPORTIVE OF THE AMOUNT PRECIP GFS HAS GOING ON MONDAY. REGARDLESS...KEPT POPS ACROSS THE EAST MONDAY MORNING AND INCREASED POPS OVER THE SOUTH LATE SUNDAY NIGHT. HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN THROUGH MUCH OF THE WEEK AND ALLOW FOR SOME MUCH NEEDED DRY WEATHER. NEXT POTENTIAL FOR RAIN LOOKS TO BE BY THURSDAY WITH A WEAK SHORTWAVE CUTTING ACROSS THE REGION. && .AVIATION...14/18Z ISSUED AT 1243 PM CDT FRI JUN 14 2013 CONFIDENCE IS QUITE LOW THROUGH THE PERIOD DUE TO VARIATIONS IN CONVECTIVE TRENDS...WHICH HI RES MODELS DO NOT APPEAR TO BE CAPTURING WELL. ALTHOUGH HAVE NOTHING MORE THAN VCSH WORDING AT THIS POINT WITH QUESTIONS IN LOCATION AND TIMING...HAVE GENERALLY FOCUSED ON TWO PERIODS. FIRST WOULD BE NEAR TERM WITH EXITING SE CONVECTION AND ARRIVAL OF NARROW LINE JUST CROSSING MO RIVER NEAR KSUX WHICH SHOULD CONTINUE TO BRING SCATTERED CONVECTION THROUGH THE AFTERNOON. VISIBLE SATELLITE IMAGERY SHOWS ADDITIONAL VERTICAL DEVELOPMENT OVER WRN IA AS WELL...SO MAY SEE FURTHER EXPANSION AFFECTING KDSM/KOTM. SECOND MENTION WILL BE PROLONGED VCSH WORDING TONIGHT IN RESPONSE TO SECOND SURGE OF WARM ADVECTION. ANY OF THESE INSTANCES COULD PRODUCE MVFR OR LESS CONDITIONS WITH THUNDER...BUT DO NOT WANT TO MENTION EXTENDED PERIODS OF EITHER UNTIL TRENDS BECOME MORE CLEAR...FOCUSING ON CRITICAL TAF PERIOD. && .HYDROLOGY... ISSUED AT 346 PM CDT FRI JUN 14 2013 ALTHOUGH THE ENVIRONMENT IS NOT IDEAL WITH SOUNDINGS STILL SHOWING SOME 1-3KM DRY AIR...SOUNDINGS DO SHOW SOMEWHAT MORE FAVORABLE CONDITIONS AND DEEPER MOISTURE ACROSS NERN SECTIONS OVERNIGHT. CURRENT 1.7 INCH PLUS PWATS REMAIN IN PLACE AND EVEN PUSH 2 INCHES AT TIMES WITH WARM CLOUD DEPTHS INCREASING. MEAN WINDS ARE A LITTLE STRONG...UP TO 35 KTS AT TIMES...HOWEVER STRONG MOISTURE TRANSPORT WILL HELP FEED MCS AND ALSO CAUSE CORFIDI VECTORS TO REGENERATE SRN PORTIONS OF COMPLEX. THUS SEE NO REASON TO ALTER GOING FLASH FLOOD WATCH AT THIS POINT. FURTHER EXPANSION MAY BE NEEDED SOUTHWARD AS WELL DEPENDING ON HOW CONVECTIVE TRENDS PLAY OUT. WILL CONTINUE HEAVY RAIN WORDING IN FORECAST AS WELL. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR BLACK HAWK-BREMER- BUTLER-CALHOUN-CERRO GORDO-EMMET-FRANKLIN-GRUNDY-HAMILTON- HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-PALO ALTO-POCAHONTAS-SAC-WEBSTER- WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...SMALL LONG TERM...PODRAZIK AVIATION...SMALL HYDROLOGY...SMALL  FXUS63 KDMX 152045 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 345 PM CDT SAT JUN 15 2013 .SHORT TERM.../TONIGHT /... ISSUED AT 345 PM CDT SAT JUN 15 2013 WATER VAPOR IMAGERY SHOWS WELL DEFINED AXIS OF WEAK SHORT WAVES FROM KS INTO MN WITH NOTED SUBSIDENCE AND FORCING ON EITHER SIDE. ONE OF IMMEDIATE CONCERN IS NEAR THE NE/IA/KS/MO BORDER AND IS CURRENTLY PRODUCING WEAK ELEVATED CONVECTION. RECENT RADAR LOOP SUGGESTS THIS CLUSTER IS STEADY STATE...HOWEVER IT IS MOVING INTO A SOMEWHAT MORE FAVORABLE ENVIRONMENT. RAP2 MLCAPE ANALYSIS SHOWS UNCAPPED 2-3K J/KG DOWNSTREAM WITH 30-40 KTS OF EFFECTIVE SHEAR...MORE THAN ENOUGH FOR SUPERCELLS IF CONVECTION HAPPENS TO STRENGTHEN AND BECOME ROOTED LOWER. MAIN THREATS WOULD BE LARGE HAIL AND DAMAGING WIND...IF IT HAPPENS TO ORGANIZE. MEAN WIND...SUPERCELL STORM MOTION AND FORWARD PROPAGATING CORFIDI VECTORS SUGGEST OK/KS/MO CONVECTION WILL TAKE A RIGHT TURN AND NOT AFFECT FORECAST AREA. WILL CANCEL NRN PORTION OF FLASH FLOOD WATCH NEAR AND BEHIND SYNOPTIC SUBSIDENCE AND WEAK BOUNDARY NOTED WHERE RAP2 MLCINH IS QUITE STRONG. CENTRAL AND SRN SECTIONS WILL BE LEFT INTACT. IF COMPLEX HAPPENS TO INTENSIFY...PWATS WILL STILL BE 1.5 TO JUST UNDER 2 INCHES WITH INCREASING WARM CLOUD DEPTHS. MOISTURE TRANSPORT WILL BE VEERING HOWEVER SO THREAT SHOULD NOT LAST TOO LONG BEYOND 00Z...IF AT ALL. SKIES SHOULD GRADUALLY CLEAR OVERNIGHT AND WITH DIMINISHING WINDS AND WET SOILS FOG WILL BE SOMEWHAT OF A CONCERN. HAVE NOT INTRODUCED INTO THE PUBLIC FORECAST AS OF YET WITH NW WINDS APPEARING JUST STRONG ENOUGH FOR SIGNIFICANT REDUCTIONS...HOWEVER THESE TRENDS WILL HAVE TO BE MONITORED. .LONG TERM.../SUNDAY THROUGH SATURDAY/... ISSUED AT 345 PM CDT SAT JUN 15 2013 FAST NEAR ZONAL/NORTHWEST FLOW PATTERN ALOFT...WITH SHORTWAVE EMBEDDED IN THE FLOW TO MOVE THROUGH NE/IA/MO TOWARD LATE SUNDAY AFTERNOON INTO SUNDAY EVENING. MOISTURE ADVECTION TO NOSE INTO THE FAR WEST CENTRAL/SOUTHWESTERN CWA SUNDAY AFTERNOON INTO THE OVERNIGHT HOURS SUNDAY NIGHT. NAM SOUNDINGS INDICATE SOUTHWESTERN/WEST CENTRAL CWA BECOMING UNCAPPED BY 21Z INTO EARLY EVENING. THEREFORE HAVE INCREASING CHANCES OF THUNDER ACROSS THE WEST/SOUTHWEST STARTING AROUND 21Z WITH CHANCES FOR THUNDER POSSIBLE ACROSS ENTIRE CWA BY LATE IN THE EVENING/OVERNIGHT HOURS. MAY HAVE SOME LINGERING ACTIVITY INITIALLY BY EARLY MONDAY...OTHERWISE WEAK FRONTAL BOUNDARY EXPECTED TO BE IN PLACE ACROSS THE SOUTHERN CWA. COULD SEE SOME REDEVELOPMENT MONDAY AFTERNOON ACROSS THE SOUTH. HOWEVER BETTER CHANCES WILL BE IN MISSOURI CLOSER TO THE UPPER LEVEL SHORTWAVE. HAVE KEPT TUESDAY DRY FOR NOW...BUT WILL HAVE TO MONITOR AS THE EC STARTING TO ADVERTISE A WEAK SHORTWAVE DROPPING THROUGH EASTERN IOWA. IF WOULD HAVE SOME PRECIP WITH THIS WAVE...CHANCES WOULD BE ACROSS THE FAR EASTERN CWA...WITH BETTER CHANCES TO THE NORTH/EAST OF THE CWA. OTHERWISE UPPER RIDGING TO SHIFT EAST SLIGHTLY WITH HIGH PRESSURE DOMINATING THE REGION...SUGGESTING DRY CONDITIONS FOR THE MIDWEEK TIME PERIOD. THE UPPER RIDGING BEGINS TO FLATTEN TOWARD THE LATTER HALF OF THE WEEK INTO THE WEEKEND...WITH AN UPPER LOW DIGGING ONSHORE OVER THE NORTHERN ROCKIES TOWARD THURSDAY NIGHT INTO FRIDAY. ENERGY EJECTING OUT OF THE WEST COAST TROUGH AND TRAVELING THROUGH THE UPPER RIDGE ACROSS THE CENTRAL US WILL BRING A RETURN OF PRECIPITATION CHANCES FOR THE LATTER HALF OF THE WEEK INTO THE WEEKEND. BEST CHANCES APPEAR TO BE FRIDAY NIGHT THROUGH SATURDAY NIGHT...AS SFC LOW AND ASSOCIATED INVERTED TROUGH AXIS STRETCHED ACROSS THE CWA. LOOKS LIKE A NEAR REPLICA OF THE PAST 24 HOURS...WITH ACTIVITY EXPECTED TO DEVELOP FRIDAY AFTERNOON DEVELOPING INTO AN MCS FRIDAY NIGHT...AND REDEVELOPMENT/ONGOING ACTIVITY FOR SATURDAY. REGARDING TEMPERATURES...WITH MID TEENS CELSIUS ALOFT THROUGHOUT THE PERIOD SHOULD CONTINUE TO SEE HIGHS IN THE UPPER 70S TO LOWER 80S THROUGHOUT THE NEXT WEEK. && .AVIATION...15/18Z ISSUED AT 1253 PM CDT SAT JUN 15 2013 SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO AFFECT SITES INTO AT LEAST THE EARLY EVENING. CONDITIONS WILL MAINLY BE VFR OUTSIDE OF HEAVIER STORMS...WHICH APPEAR TO BE ISOLATED AT THE MOMENT. GENERAL TREND IS FOR CONVECTION TO GRADUALLY PUSH OFF TO THE SOUTH AND EAST THROUGH THE AFTERNOON AND EVENING...ENDING AT KFOD BY 23Z AND KOTM BY 05Z. OUTSIDE OF PRECIP IMMEDIATELY AFFECTING SITES...HAVE GENERIC VCSH WORDING UNTIL TRENDS AND TIMING BECOME MORE CLEAR. SOME CONCERN THAT FOG MAY ALSO DEVELOP OVERNIGHT AS WELL. MOS GUIDANCE IS NOT TOO BULLISH BUT WITH RECENT RAINS...CLEARING SKIES AND WINDS BECOMING LIGHT HAVE ADDED MVFR MENTION IN SOME LOCATIONS FOR A START. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 7 PMCDT THIS EVENING FOR ADAIR-ADAMS- APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN-CARROLL- CASS-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-FRANKLIN-GREENE-GRUNDY- GUTHRIE-HAMILTON-HARDIN-HUMBOLDT-JASPER-LUCAS-MADISON-MAHASKA- MARION-MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD-SAC-STORY-TAMA- TAYLOR-UNION-WAPELLO-WARREN-WAYNE-WEBSTER-WRIGHT. && $$ SHORT TERM...SMALL LONG TERM...BEERENDS AVIATION...SMALL  FXUS63 KDMX 212109 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 409 PM CDT FRI JUN 21 2013 .SHORT TERM.../TONIGHT /... ISSUED AT 407 PM CDT FRI JUN 21 2013 FORECAST FOR TONIGHT IS DOMINATED BY POTENTIAL FOR THUNDERSTORMS AND ASSOCIATED EFFECTS. CURRENTLY A COMPLEX OF THUNDERSTORMS IS DEVELOPING ACROSS EASTERN SOUTH DAKOTA AND MOVING STEADILY EASTWARD. MOST SHORT TERM MODELS HAVE HANDLED CONVECTION POORLY TODAY AND ARE DIFFICULT TO TRUST FOR TONIGHT. HOWEVER...CONCEPTUAL MODELS WOULD DICTATE THAT WITH A FLATTENING MID LEVEL RIDGE OVERHEAD AND A CORRIDOR OF INSTABILITY LEADING EAST SOUTHEAST FROM THE STORM COMPLEX...IT SHOULD CONTINUE TO MOVE EASTWARD ACROSS SOUTHERN MINNESOTA EARLY TONIGHT AND ALSO BEGIN TO SAG SOUTHWARD WITH TIME. IT SHOULD ALSO LEAVE BEHIND A ROUGHLY EAST WEST OUTFLOW BOUNDARY SOMEWHERE NEAR THE IA/MN BORDER...WHICH WILL LIKELY CONTINUE TO CREEP SOUTHWARD AND PROVIDE A FOCUS MECHANISM FOR CONTINUING THUNDERSTORM DEVELOPMENT ACROSS NORTHERN IOWA LATER TONIGHT AS THE NOCTURNAL LLJ KICKS IN. GIVEN AMPLE INSTABILITY AND MOISTURE...SEVERE WEATHER AND HEAVY RAIN WILL CERTAINLY BE POSSIBLE IN THIS AREA. HAVE ORIENTED AND TRENDED POPS ACCORDINGLY AND WILL ALSO ISSUE A FLASH FLOOD WATCH NORTH OF HIGHWAY 20 WHERE HEAVY RAIN IS MOST LIKELY. AT THIS TIME IT DOES NOT APPEAR THAT THUNDERSTORMS WILL BE ABLE TO GET MUCH FURTHER SOUTH THAN THAT...AND THEY MAY NOT EVEN BE ABLE TO GET INTO IOWA MUCH AT ALL...BUT THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE SOUTHWARD EXTENT AND THIS WILL NEED TO BE CLOSELY MONITORED TONIGHT. .LONG TERM.../SATURDAY THROUGH FRIDAY/... ISSUED AT 407 PM CDT FRI JUN 21 2013 GENERAL LOGISTICS OF THE FORECAST REMAIN UNCHANGED OVER THE PAST FEW DAYS. PRIMARY QUESTION FOR CONVECTION ON SATURDAY IS POTENTIAL FOR OUTFLOW TO DROP SOUTH INTO IOWA AGAIN OVERNIGHT INTO SATURDAY MORNING AND KEEP THE POTENTIAL FOR CONVECTION AS FAR SOUTH AS CENTRAL IOWA. MID LEVEL TEMPERATURES ARE A BIT COOLER ESPECIALLY EARLY SATURDAY WHICH WOULD LEAVE LESS INHIBITION ACROSS THE CENTRAL AND NORTH. PRIMARY FOCUS SHOULD BE OVER THE NORTH EARLY AND AGAIN LATE IN THE DAY AND OVERNIGHT WITH THE SHORT WAVE TRAINING CONTINUING TO PASS THROUGH NORTHWEST IOWA. THE INSTABILITY AXIS SHIFTS FURTHER SOUTHEAST INTO CENTRAL IOWA LATE SUNDAY INTO SUNDAY NIGHT AS A LARGE CHUNK THE PACIFIC NORTHWEST UPPER LOW ROTATES NORTHEAST INTO SOUTHERN CANADA. IN ADDITION TO A SEVERE WEATHER THREAT...THE POTENTIAL FOR HEAVY RAIN INCREASES ESPECIALLY SUNDAY NIGHT AS MOISTURE TRANSPORT INCREASES ALONG WITH DEEP WARM CLOUD DEPTHS WITH PWAT VALUES NEARING 1.75 INCHES. 850-300 MB FLOW WOULD SUGGEST THE POTENTIAL FOR TRAINING STORMS ACROSS THE REGION. THE SEVERE WEATHER THREAT WOULD BE MAINLY HAIL AND DAMAGING WINDS. WARM AND HUMID SATURDAY WITH A FEW LOCATIONS HAVING HEAT INDEX VALUES APPROACHING 100 ASSUMING CONVECTIVE DEBRIS DOES NOT PERSIST. GOOD OVERALL CONFIDENCE GOING INTO NEXT WEEK WITH 500 MB HEIGHTS INCREASING EARLY IN THE PERIOD BEFORE STRONG RIDGING DEVELOPS OVER THE INTER MOUNTAIN WEST MID TO LATE NEXT WEEK. THIS WILL ALLOW AN UPPER LOW TO DROP INTO THE WESTERN GREAT LAKES AND SLIGHT COOLER AND LESS HUMID AIR TO DROP INTO IOWA WITH NORTHWEST FLOW. THUNDERSTORM POTENTIAL WOULD BE WITH SHORT WAVE TIMING EARLY THEN THE BOUNDARY LATER IN THE PERIOD. AS MENTIONED PREVIOUSLY THOUGH...THE PRIMARY FOCUS WITH THE FORECAST IS THROUGH THE WEEKEND. && .AVIATION...21/18Z ISSUED AT 1232 PM CDT FRI JUN 21 2013 PROBLEMATIC CONVECTIVE FORECAST COMPLICATES THE TAFS THROUGH TONIGHT. CURRENTLY WDLY SCT SHRA/TSRA ARE AFFECTING OR APPROACHING KFOD/KDSM/KOTM...BUT THEY ARE SMALL AND OF MINIMAL/BRIEF IMPACT SO HAVE ADVERTISED ONLY WITH VCTS THIS AFTN AT THOSE TERMINALS. MEANWHILE A LARGE CLUSTER OF TSRA ACROSS CTL SDAK IS APPROACHING AND MAY IMPACT THE NORTHERN TERMINALS OVERNIGHT. THESE STORMS COULD HAVE A MORE SUBSTANTIAL IMPACT...HOWEVER UNCERTAINTY IN CONVECTIVE EVOLUTION IS HIGH AND THEY MAY NOT REACH THE AREA AT ALL. THUS HAVE ALSO GONE WITH VCTS FOR THAT SCENARIO. BR IS ALSO EXPECTED LATE TONIGHT...ESPECIALLY ACROSS THE NORTH...BUT DUE TO UNPREDICTABILITY OF OTHER VARIABLES HAVE ONLY INCLUDED 6SM AT THIS TIME. EXPECT FREQUENT TAF UPDATES LATER TODAY AND TONIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH SATURDAY MORNING FOR BREMER-BUTLER-CERRO GORDO-EMMET-FRANKLIN-HANCOCK- HUMBOLDT-KOSSUTH-PALO ALTO-WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...LEE LONG TERM...DONAVON AVIATION...LEE  FXUS63 KDMX 222048 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 348 PM CDT SAT JUN 22 2013 .SHORT TERM.../TONIGHT /... ISSUED AT 348 PM CDT SAT JUN 22 2013 COMPLICATED WX SITUATION WITH ALL THE BOUNDARIES AROUND. OUTFLOW BOUNDARY THAT DROPPED SOUTH ACROSS THE STATE THIS MORNING HAS ERODED AWAY FOR THE MOST PART. A DEFINITE TROUGH REMAINS ACROSS THE CWA FROM NEAR OMAHA TO JUST SOUTH OF MASON CITY. RESIDUAL CONVECTION REMAINS OVER NORTHWEST IA RIDING UP THE WEST SIDE OF THE UPPER LEVEL CAP. AS FOR WHAT WILL UNFOLD TONIGHT THINKING IS THE NMM EAST HIRES HAS A PRETTY DECENT HANDLE ON THINGS. IT IS AT LEAST ONE SCENARIO THAT COULD UNFOLD THAT SEEMS THE MOST REASONABLE GIVEN THE SPEED MAX RIDING UP THE EAST SIDE OF THE WESTERN TROUGH. CONVECTION IS LIKELY TO BREAK OUT OVER PARTS OF NEBRASKA AN SD. IT SHOULD INITIALLY LIFT NEWD WITH THE FLOW AND THEN TURN EAST TO EVENTUALLY SOUTHEAST AS IT COMES UNDER THE INFLUENCE OF THE CORFIDI VECTORS AND BECOMES MORE COOL POOL DOMINATED AS OCCURRED THIS MORNING WENT WITH THE HEAVIEST RAINFALL OVER THE NORTH AND NERN ZONES. CONCERN FOR FLASH FLOODING GIVEN THE LOW FFG VALUES BUT WILL HOLD OFF DUE TO UNCERTAINTY FOR NOW. .LONG TERM.../SUNDAY THROUGH SATURDAY/... ISSUED AT 348 PM CDT SAT JUN 22 2013 EXTENDED PERIOD FAIRLY ACTIVE IN THE FIRST FEW DAYS...WITH QUIETER WEATHER EXPECTED TOWARD THE END OF THE PERIOD. BIGGEST FOCUS WILL BE ON SUNDAY...WITH GREATEST POTENTIAL FOR WIDESPREAD SEVERE WEATHER/POSSIBLY HEAVY RAINFALL. SITUATION STILL SOMEWHAT MURKY DEPENDING ON WHERE ACTIVITY SETS UP TONIGHT...BUT INITIAL THOUGHTS WOULD LEAN TOWARD AN ONGOING MCS NEAR CENTRAL/EASTERN IOWA SUNDAY MORNING. THIS WOULD QUICKLY SLIDE EAST...WITH POSSIBLE LINGERING CLOUD COVER. SFC TROUGH AXIS TO BE SITUATED ACROSS THE NORTHWESTERN PORTION OF THE STATE BY MID SUNDAY AFTERNOON. MODEL EXPECT STORMS TO FIRE NEAR THIS BOUNDARY SUNDAY AFTERNOON AND SPREAD ACROSS THE CWA THROUGHOUT THE EVENING HOURS. STORM MOTIONS WILL BE PARALLEL TO THE BOUNDARY SUGGESTING TRAINING OF STORMS ACROSS THE AREA DESPITE THE FASTER STORM MOVEMENTS. ALSO MODELS INDICATING ABUNDANT AVAILABLE MOISTURE WITH PWATS IN THE 1.9 INCH RANGE...WITH VERY DEEP WARM CLOUD DEPTHS WITH THE FREEZING LEVEL AROUND 14-15KFT SUNDAY AFTERNOON. THIS WILL SET UP THE POSSIBILITY OF HEAVY RAINFALL WITH EFFICIENT RAINFALL PRODUCTION/TRAINING OF STORMS. ISSUES IS TRYING TO NAIL DOWN PLACEMENT AT THIS TIME...WITH SCENARIOS UP IN THE AIR GIVEN WHERE POTENTIAL MCS TRACKS LATE TONIGHT/SUNDAY MORNING. WILL HAVE TO MONITOR...FOR POSSIBLE ISSUANCE OF FLASH FLOOD WATCH DURING SUBSEQUENT SHIFTS. OTHERWISE WAA CONTINUES ACROSS THE CWA MONDAY...WITH THETA-E ADVECTION ALOFT. COULD AGAIN SEE POTENTIAL FOR THUNDERSTORMS ESPECIALLY ACROSS THE NORTHERN TWO-THIRDS OF THE CWA. CHANCES FOR STORMS THEN BECOME BETTER ORIENTED ACROSS THE NORTHERN CWA FOR TUESDAY INTO TUESDAY NIGHT AS THE JET STREAM LIFTS FURTHER NORTH AND NEAR ZONAL FLOW SETS UP ALOFT. THIS SHOULD KEEP THE CWA RELATIVELY DRY FOR WEDNESDAY INTO THURSDAY. NORTHWEST FLOW PATTERN SETS UP TOWARD THURSDAY INTO FRIDAY...WITH CHANCES FOR THUNDERSTORMS RETURNING TO THE FORECAST AND TEMPERATURES BEHIND A COLD FRONTAL PASSAGE FOR FRIDAY INTO SATURDAY. WARM AND HUMID CONDITIONS LOOK TO CONTINUE FOR SUNDAY INTO MID WEEK...AS H85 TEMPS CONTINUE TO WARM ALOFT AND DEWPOINTS REMAIN HIGHER. && .AVIATION...22/18Z ISSUED AT 1242 PM CDT SAT JUN 22 2013 COMPLEX WX SITUATION WITH DECAYING CONVECTION THIS AFTERNOON AND RESIDUAL OUTFLOW BOUNDARIES ACROSS THE STATE. GUSTY SLY WINDS ARE EXPECTED TO BECOME ESTABLISHED AT ALL TAF SITES THIS AFTERNOON. TSRA DEVELOPMENT IS LIKELY LATE THIS AFTERNOON OR EVENING WITH THE FAVORED AREA ACROSS THE NRN TAF SITES. CONFIDENCE AND TIMING ARE NOT HIGH AND WENT WITH A PERIOD OF VCTS IN THE TAFS FROM THIS EVE NORTH...AFT MIDNIGHT IN THE KDSM AREA. ENDED THE CHANCE SUN MRNG THINKING CONVECTION WILL SHIFT TO THE EAST. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...MS JUN13 LONG TERM...BEERENDS AVIATION...MS JUN 13  FXUS63 KDMX 230832 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 332 AM CDT SUN JUN 23 2013 .SHORT TERM.../TODAY /... ISSUED AT 259 AM CDT SUN JUN 23 2013 .SHORT TERM /TODAY/... CONCERNS FOR STRONG TO SEVERE THUNDERSTORMS AND HEAVY RAIN ARE THE FOCUS FOR THIS FORECAST PERIOD. THE MODELS CONTINUE TO ADVERTISE SOME OF THE WESTERN CONVECTION TO REACH THE AREA THIS MORNING AND THEN DIMINISH AS IT TRACKS TO THE EAST THROUGH MID MORNING. A WAVE ALONG THE BOUNDARY OVER NORTHWEST IOWA WILL TRACK EAST THIS MORNING WITH THE SOUTHERN WAVE BEGINS TO PUSH NORTHEAST THIS AFTERNOON AND TONIGHT. THIS WILL ENHANCE MOISTURE TRANSPORT NORTHEAST THROUGH THE AFTERNOON AND EVENING. TEMPERATURES THIS MORNING ARE ABOUT 5 TO 7 DEGREES WARMER THAN EXPECTED...SO HAVE RAISED THE HIGHS OVER THE SOUTH TO NEAR TO ABOVE 90 AGAIN TODAY. WITH SUFFICIENT INSTABILITY STORMS WILL BEGIN TO REFIRE NORTH NEAR THE NOON HOUR OR EARLY AFTERNOON AND BEGIN TO BUILD SOUTH. THE MODELS SUGGEST WE WILL SEE SOME BACK BUILDING ALONG THE BOUNDARY TODAY AND THIS EVENING WHICH WILL INCREASE THE POTENTIAL FOR HEAVY RAINFALL. THERE IS SOME UNCERTAINTY AS TO WHERE THE GREATEST POTENTIAL FOR FLASH FLOODING IS ...BUT THE NORTH TWO THIRDS LOOK TO BE THE MOST AT RISK FOR NOW...THE SOUTHERN AREAS MAY NEED TO BE ADDED YET TODAY...BUT THEY CAN TAKE A BIT MORE WATER THAN THE REST OF THE AREA. RAINFALL TOTALS OF 2 TO 4 INCHES OR MORE MAY BE POSSIBLE GIVEN POTENTIAL FOR BACK BUILDING ALONG THE FRONT...WARM CLOUD DEPTHS ABOVE 10KFT...AND PWATS OF 1.5 TO 2 INCHES OVER THE AREA. THE LATEST EURO MODEL SUGGESTS THAT THE BULK OF THE ACTIVITY WILL TAKE PLACE DURING THE EVENING AND OVERNIGHT HOURS WHILE THE MESO MODELS ARE HINTING AT AN EARLIER START THIS AFTERNOON. WILL LEAN TOWARD EARLIER START FOR NOW...GIVEN THE INSTABILITY EXPECTED BY THIS AFTERNOON. WINDS WILL BE GUSTY TODAY PRIOR TO THE ONSET OF STORMS. STORMS COULD BRING HIGH WIND AND SOME HAIL...ALONG WITH RAINFALL THREAT TODAY AND THIS EVENING. .LONG TERM.../TONIGHT THROUGH FRIDAY/... ISSUED AT 259 AM CDT SUN JUN 23 2013 FORECAST CONCERNS REVOLVE AROUND THUNDERSTORMS THROUGH TUESDAY. UPPER LEVEL LOW ACROSS SOUTHERN CANADA WILL BE RESPONSIBLE FOR SENDING NUMEROUS SHORTWAVES ACROSS THE UPPER RIDGE WHICH WILL FLATTEN IT. THUNDERSTORMS ARE EXPECTED TO BE ONGOING FROM THIS AFTERNOON ACROSS THE FORECAST AREA THEN BECOME RENEWED AS A LOW LEVEL JET DEVELOPS WITH STRONG MOISTURE TRANSPORT INTO AN AREA OF WARM ADVECTION NEAR A SLOW MOVING SURFACE BOUNDARY. SOME STRONG STORMS ARE POSSIBLE THIS EVENING THEN TRANSITION INTO A HEAVY RAIN THREAT. THE FRONTAL BOUNDARY FINALLY PUSHES EAST THROUGH MOST OF THE FORECAST AREA BY MONDAY EVENING BUT YET ANOTHER SHORTWAVE MOVES ACROSS THE NORTHWEST LIKELY TO DEVELOP ADDITIONAL THUNDERSTORMS. THE SEVERE THREAT FOR MONDAY NIGHT IS A LITTLE LESS CLEAR BUT SOME HEAVY RAINFALL IS POSSIBLE. ANOTHER SHORTWAVE MOVES ACROSS THE NORTHERN PLAINS AND DIVES SOUTHEAST ACROSS NORTHEAST IOWA. ANOTHER FRONTAL BOUNDARY WILL ESTABLISH ITSELF ACROSS THE AREA TUESDAY FOR A CHANCE OF STORMS ONCE AGAIN. FOR NOW I AM CARRYING CHANCE POPS ACROSS THE NORTH MONDAY NIGHT AND NORTHEAST TUESDAY BUT THE FRONTAL BOUNDARY WILL BE KEY TO THE AREAL EXTENT OF THE STORMS. THE LOCATION OF WHICH WILL HOPEFULLY BECOME MORE CLEAR WITH TIME. FOR THE REMAINDER OF THE EXTENDED A STRONG UPPER LEVEL RIDGE BUILDS ACROSS THE ROCKIES PUTTING IOWA IN NORTHWEST FLOW ALOFT. THIS WILL BRING SOME RELIEF FROM THE HEAT AND HUMIDITY HOWEVER...TIMING OF ANY SHORTWAVES DROPPING DOWN ACROSS IOWA IN THE NORTHWEST FLOW IS NEAR IMPOSSIBLE. FOR THIS REASON I DO NOT HAVE POPS IN THE EXTENDED BUT THIS IS DUE TO A LACK OF CONFIDENCE IN TIMING AND LOCATION AND NOT THINKING THAT SHORTWAVE WONT HAPPEN ACROSS THE AREA DURING THIS TIME. && .AVIATION...23/06Z ISSUED AT 1219 AM CDT SUN JUN 23 2013 MAIN CONCERNS FOR THE PERIOD WILL BE CONVECTION. SEVERAL ROUNDS ARE EXPECTED WITH ONE YET PRIOR TO 12Z ACROSS THE WEST AND POSSIBLY THE NORTH TAF SITES FOR KFOD AND KMCW AND TO A LESSER EXTENT KALO. BY 16-17Z THE REMNANTS OF THE OLD OUTFLOWS...AN APPROACHING TROUGH WITH BETTER SFC CONVERGENCE AND SIGNIFICANT AFTERNOON INSTABILITY SHOULD RESULT IN WIDESPREAD CONVECTION DURING THE AFTERNOON HOURS FROM 18Z NORTH TO ABOUT 02 TO 03Z IN THE SOUTH ON THE 24TH. THIS MAY IMPACT OPERATIONS...TIMING SEEMS TO FAVOR THE AFTERNOON AND EVENING HOURS AT KALO...KDSM...AND KOTM. WITH MORE SIGNIFICANT CAPE AVAILABLE...SOME CONCERNS OF HIGH WIND EVENT AND HEAVY RAINFALL COMBINED. WILL MONITOR THROUGH 12Z AND SUNDAY AS WELL. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 1 PM CDT THIS AFTERNOON THROUGH MONDAY MORNING FOR AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN- CARROLL-CERRO GORDO-CRAWFORD-DALLAS-EMMET-FRANKLIN-GREENE-GRUNDY- GUTHRIE-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-MARSHALL- PALO ALTO-POCAHONTAS-POLK-POWESHIEK-SAC-STORY-TAMA-WEBSTER- WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...REV LONG TERM...FAB AVIATION...REV  FXUS63 KDMX 241008 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 508 AM CDT MON JUN 24 2013 .SHORT TERM.../TODAY /... ISSUED AT 332 AM CDT MON JUN 24 2013 ONGOING CONVECTION WILL CONTINUE ACROSS THE I-80 CORRIDOR AND NORTH THIS MORNING. WARM CLOUD DEPTHS ARE AROUND 15KFT SO LARGE HAIL NOT MUCH OF A THREAT. WE COULD NOT GET MORE THAN HALF INCH HAIL FROM STORMS ALL NIGHT BUT RAINFALL RATES OF 2 TO 3 INCHES AN HOUR WERE COMMON. WE ARE IN FOR SEVERAL ROUNDS OF STORMS TODAY. CURRENT CONVECTION IS A RESULT MODERATE INSTABILITY AS A SHORTWAVE LIFTS ACROSS THE AREA. CURRENT CONVECTION WILL LIKELY WEAKEN OR DISSIPATE BY LATE MORNING BUT ANOTHER AREA OF STORMS OVER EASTERN NEBRASKA IS MOVING EAST AND OTHER STORMS AHEAD OF THIS LINE ARE STARTING TO DEVELOP AND SHOULD MOVE ACROSS THE I-80 CORRIDOR. I HAVE ISSUED A FLASH FLOOD WATCH FOR THE I80 TO HIGHWAY 20 CORRIDOR THROUGH 4 PM FOR THIS CONVECTION. IN ADDITION...ADDITIONAL SHORTWAVES WILL MOVE ACROSS THE AREA TODAY WITH THE FRONTAL BOUNDARY OVER THE AREA EXPECTED TO RETREAT BACK NORTH AS A WARM FRONT. SHEAR IS SUFFICIENT FOR STRONG/SEVERE STORMS FROM EARLY AFTERNOON AND BEYOND. THIS AFTERNOON SHOULD SEE ACTIVE WEATHER WITH POTENTIAL FOR SEVERE AND HEAVY RAIN. AS THE FRONT SHIFTS NORTH LATER THIS AFTERNOON...THE THREAT FOR HEAVY RAIN WILL FOLLOW SO A FLASH FLOOD WATCH IS ALSO POSTED NORTH OF HIGHWAY 20 FOR LATER AFTERNOON AND TONIGHT. .LONG TERM.../TONIGHT THROUGH SUNDAY/... ISSUED AT 332 AM CDT MON JUN 24 2013 MORE OF THE SAME FOR TONIGHT THROUGH TUESDAY AS WE WILL CONTINUE TO CONTEND WITH A QUASI STATIONARY FRONTAL BOUNDARY...A LOW LEVEL JET AND SEVERAL SHORTWAVES TO CROSS THE STATE. STORMS WILL LIKELY BE ONGOING FROM THE AFTERNOON AND LIKELY RE-INTENSIFY BY MID EVENING ACROSS THE NORTH. IT WILL LIKELY START OUT WITH SOME SEVERE POTENTIAL THEN TRANSITION INTO ANOTHER HEAVY RAIN EVENT. BEYOND TUESDAY THERE HAS NOT BEEN MUCH CHANGE TO THE GOING FORECAST. UPPER LEVEL RIDGING WILL DEVELOP OVER THE ROCKIES PLACING IOWA IN NORTHWEST FLOW WITH A COUPLE OF SHORT WAVES PUSHING ACROSS THE FORECAST AREA. ONE SUCH WAVE WILL PUSH ACROSS NORTHERN/EASTERN IOWA WEDNESDAY THEN AGAIN THURSDAY NIGHT. BEYOND THAT CONFIDENCE IS TOO LOW TO INCLUDE ANY KIND OF POP. COOLER TEMPS IN STORE FOR THE WEEKEND AS A RESULT OF THE NORTHWEST FLOW. && .AVIATION...24/06Z ISSUED AT 1146 PM CDT SUN JUN 23 2013 VFR CONDITIONS EXPECTED THRU THE FCST PD. ISOLD TO SCT TSRA IS EXPECTED TO AFFECT MAINLY THE KDSM TERMINAL OVERNIGHT...AND POSSIBLY ALSO KALO...KFOD AND KOTM. ADDITIONAL TSRA IS POSSIBLE MONDAY EVENING INTO MONDAY NIGHT AFFECTING MAINLY THE KFOD...KALO AND KMCW TERMINALS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR ADAIR-AUDUBON-BOONE- CARROLL-CASS-CRAWFORD-DALLAS-GREENE-GUTHRIE-JASPER-MADISON- MARSHALL-POLK-POWESHIEK-STORY-TAMA. FLASH FLOOD WATCH FROM THIS AFTERNOON THROUGH TUESDAY MORNING FOR BREMER-BUTLER-CALHOUN-CERRO GORDO-EMMET-FRANKLIN-HAMILTON- HANCOCK-HUMBOLDT-KOSSUTH-PALO ALTO-POCAHONTAS-SAC-WEBSTER- WINNEBAGO-WORTH-WRIGHT. FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR BLACK HAWK-GRUNDY- HARDIN. && $$ SHORT TERM...BOKSA LONG TERM...BOKSA AVIATION...ZOGG  FXUS63 KDMX 250851 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 351 AM CDT TUE JUN 25 2013 .SHORT TERM.../TODAY/... ISSUED AT 350 AM CDT TUE JUN 25 2013 ALOFT THERE WILL BE A COUPLE OF SHORTWAVES PUSHING ACROSS THE STATE TODAY INTO TONIGHT. AT THE SURFACE...A LOW WILL PUSH ACROSS EASTERN NEBRASKA/SOUTH DAKOTA WITH A WARM FRONTAL BOUNDARY EXTENDING ACROSS THE HIGHWAY 20 CORRIDOR AND A COLD FRONT PUSHING ACROSS EASTERN NEBRASKA BY 21Z. THE CAVEAT FOR NOW IS WHAT THE MORNING CONVECTION WILL DO TO THE AIRMASS AS IT TRACKS ACROSS CENTRAL IOWA THROUGH THE MORNING. IT APPEARS THAT FOR MUCH OF THE DAY...AFTER THIS CONVECTION PASSES...WE WILL BE CAPPED THROUGH MUCH OF THE REST OF THE MORNING AND EARLY AFTERNOON. THE CAP WEAKENS/BREAKS LATER THIS AFTERNOON AND EVENING AND WITH CAPES OF 3K J/KG AND DEEP SHEAR OF 45 KTS...STORMS SHOULD DEVELOP ROBUSTLY BETWEEN 21Z-00Z ALONG THE WARM FRONT. ALL MODES OF SEVERE WEATHER WILL BE POSSIBLE THROUGH EARLY EVENING...EVEN AN ISOLATED TORNADO. THE HEAVY RAIN THREAT IS DISCUSSED IN THE HYDRO SECTION BUT WITH WARM CLOUD DEPTHS OF 14.5KFT THESE STORMS SHOULD ONCE AGAIN BE EFFICIENT RAINERS AND MOVE ROUGHLY OVER THE SAME AREAS AS YESTERDAY. TEMPS SHOULD BE A LITTLE WARMER TODAY THAN YESTERDAY...BASED ON THE EXPECTATION OF SOME CLEARING THIS AFTERNOON. IF CLOUDS/SHOWERS KEEP FESTERING OVER CENTRAL IOWA THEN TEMPS WILL BE COOLER THAN FORECAST...LIKELY LOWER 80S NOT MID TO UPPER 80S. .LONG TERM.../TONIGHT THROUGH MONDAY/... ISSUED AT 350 AM CDT TUE JUN 25 2013 TALE OF TWO REGIMES THROUGH THE PERIOD WITH A CHANGE IN SIGHT. INITIALLY MORE OF THE SAME WITH CONTINUED CONCERNS ABOUT CONVECTIVE TRENDS. ALTHOUGH NAM IS SOMEWHAT CONTAMINATED BY SERN MN DEVELOPMENT 18-21Z...MODEL CONSENSUS SUGGESTS WEAK N-S FRONTAL BOUNDARY WEST OF MO RIVER AT 00Z. AIRMASS WILL BE VERY UNSTABLE TO THE EAST WITH MLCAPES 4000 PLUS J/KG AND MORE THAN ADEQUATE DEEP SHEAR FOR SUPERCELLS. FORCING WITH CURRENT PACIFIC NW SHORT WAVE CROSSING THE NRN ROCKIES WILL ALSO REACH THE MO VALLEY EARLY THIS EVENING. FORECAST SOUNDINGS SUGGEST THERE MAY BE A WEAK CAP FROM 2-3KM LAYER OF WARM AIR...HOWEVER SHORT WAVE QG FORCING APPEARS SUFFICIENT TO EITHER ERODE THIS FOR SURFACE BASED DEVELOPMENT...OR QUICKLY FORM SLIGHTLY ELEVATED CONVECTION DURING THE EARLY EVENING BASED ON 310K ISENT LIFT...CONVERGENCE AND MOISTURE TRANSPORT. SEVERAL WRF RUNS POINT TOWARD THE LATTER MORE THAN THE FORMER WITH INITIAL DEVELOPMENT INTO IA...ALTHOUGH THERE IS LITTLE CONSENSUS ON LOCATION. ALL MODES OF SEVERE WEATHER APPEAR POSSIBLE. 0-1KM SHEAR STRENGTHENS WITH THE LOW LEVEL JET RESPONSE SO EITHER SUPERCELL OR QLCS TORNADOES ARE POSSIBLE BEFORE MOISTURE TRANSPORT VEERS AROUND 06Z. WHEREVER THE COMPLEX FORMS IT WILL LIKELY EXIT THE FORECAST AREA TO THE EAST BY EARLY WED WITH ONLY TOKEN LINGERING SLIGHTS FAR NE THROUGHOUT THE DAY. CONDITIONS DURING THE EVENING WILL AGAIN BE FAVORABLE FOR HEAVY RAINS WHERE HIGH PWATS AND WARM CLOUD DEPTHS WILL STILL EXIST. PATTERN WILL BEGIN TO CHANGE BY MIDWEEK LEADING TO DRIER...COOLER AND LESS HUMID CONDITIONS. PATTERN WILL AMPLIFY AS AFOREMENTIONED LATE TUE SHORT WAVE EVENTUALLY CARVES OUT DEEPER TROUGH INTO THE ERN GREAT LAKES. CORRESPONDING ROCKIES HEIGHT RISES WILL FLIP OUR UPPER FLOW TO NW AND EVENTUALLY NORTHERLY. SHORT WAVES RIDING THE FLOW ON THE BACK SIDE OF THE LONG WAVE TROUGH MAY COMBINE AT TIMES WITH FAVORABLE MLCAPE/CIN PROFILES FOR SOME WEAK CONVECTION. INSTABILITY WILL NOT BE GREAT FOR THE SEASON HOWEVER AND THERE LOOKS TO BE LITTLE CONVERGENCE IN THE SURFACE FLOW SO NOTHING MORE THAN PEAK HEATING SLIGHT CHANCES FOR NOW...UNLIKE OUR RECENT NOCTURNAL MAX. THERE IS ALSO A WEAK SIGNAL OF SUBTLE WARM ADVECTION WED OR THU NIGHTS. MOISTURE IS LIMITED HOWEVER SO NO POPS AS OF YET BEYOND HOLDING OVER PREVIOUS THU NIGHT SLIGHTS. TEMPERATURES AND DEWPOINTS WILL BE NOTICEABLY DIFFERENT AS WELL. FORECAST SOUNDINGS SUGGEST HIGHS WILL STRUGGLE TO GET TOO FAR BEYOND 80F SAT-MON...IF AT ALL...WITH AN AROUND 10F DROP IN DEWPOINTS FROM CURRENT OBS AS WELL. && .AVIATION...25/06Z ISSUED AT 1148 PM CDT MON JUN 24 2013 MAIN CONCERN IS TIMING AND LOCATION OF PRECIP EARLY TUESDAY MORNING AND AGAIN TUESDAY NIGHT. WEAK LINE OF THUNDERSTORMS IN NORTHEAST NEBRASKA MAY CLIP FOD AND POSSIBLY MCW DURING THE OVERNIGHT HOURS. HAVE VCTS MENTIONED PAST 09Z AND INTO THE MORNING. LOW CONFIDENCE WITH MENTION OF MVFR VIS OR CIGS ATTM...BUT CANNOT RULE OUT THE POTENTIAL FOR SHORT TIME PERIODS EARLY TUESDAY MORNING. OTHERWISE...GUSTY SOUTH WINDS ARE EXPECTED THROUGHOUT THE DAY. && .HYDROLOGY... ISSUED AT 350 AM CDT TUE JUN 25 2013 ADDITIONAL STORMS FORECAST FOR TODAY WILL ONCE AGAIN BE EFFICIENT RAIN PRODUCING STORMS. BECAUSE OF THE HEAVY RAINFALL ACROSS THE NORTH AND EAST OVER THE PAST COUPLE OF DAYS AND THE ALREADY SATURATED SOIL WITH CREEKS AND STREAMS AT OR NEAR BANKFULL AND THE SEVERAL LOCATIONS IN THE NORTHEAST STILL IN FLOOD...AN EXTENSION OF BOTH TIME AND AREAL COVERAGE WAS NEEDED TO THE FLASH FLOOD WATCH. ANY MORNING CONVECTION WILL PRIME AREAS NOT ALREADY THOROUGHLY SATURATED BUT THE MAIN EVENT WILL COME LATER TODAY THROUGH TONIGHT. I AM EXPECTING ANOTHER ONE TO TWO INCHES OF RAIN IN THE WATCH AREA WITH LOCALLY HIGHER AMOUNTS EXPECTED. THIS IS CLOSE TO FLASH FLOOD GUIDANCE AND HENCE IN NEED OF THE EXTENSION IS AREA. IF CONVECTION LASTS MUCH INTO THE OVERNIGHT HOURS THEN FURTHER EXTENSIONS MAY BE NEEDED. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR BLACK HAWK- BREMER-BUTLER-CALHOUN-CERRO GORDO-EMMET-FRANKLIN-GRUNDY-HAMILTON- HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-MARSHALL-PALO ALTO-POCAHONTAS- POWESHIEK-SAC-STORY-TAMA-WEBSTER-WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...BOKSA LONG TERM...SMALL AVIATION...PODRAZIK HYDROLOGY...BOKSA  FXUS63 KDMX 071959 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 259 PM CDT SUN JUL 7 2013 .SHORT TERM.../TONIGHT/... ISSUED AT 259 PM CDT SUN JUL 7 2013 POTENTIAL FOR CONVECTION REMAINS THE CHALLENGE FOR THE OVERNIGHT FORECAST. SFC LOW PRESSURE TROUGH IS BEGINNING TO LEAN INTO NORTHWEST IOWA THIS AFTERNOON WITH WINDS BECOMING LIGHT UNDER THE SYSTEM WITH LITTLE TO NO GOOD SFC CONVERGENCE IN THE VICINITY. THE BEST LOW LEVEL MOISTURE REMAINS POOLED ON THE NORTHWEST SIDE OF THE SYSTEM THROUGH WESTERN MINNESOTA AND THROUGH SOUTHEAST SOUTH DAKOTA. ON LONE THUNDERSTORM HAS BEEN MOVING ACROSS SOUTHWEST IOWA THIS AFTERNOON IN ADVANCE OF A SHORT WAVE MOVING INTO THAT PORTION OF THE STATE. A MORE SIGNIFICANT CLUSTER OF SHORT WAVE ENERGY IS MOVING THROUGH WESTERN AND INTO CENTRAL SOUTH DAKOTA. THIS REGION HAS HAD NEW THUNDERSTORM DEVELOPMENT OVER THE PAST FEW HOURS. MODEL GUIDANCE IS EXTREMELY ERRATIC WITH NO SINGLE SOLUTION HAVING A GOOD HANDLE ON THE SITUATION. THE MOST PROBABLE SOLUTION IS THE POTENTIAL FOR THUNDERSTORMS WILL INCREASE ACROSS THE WEST TO NORTHWEST AS THE WESTERN SHORT WAVE ENERGY ARRIVES AND OVERTOPS THE WEAK SFC BOUNDARY THAT WILL BE SINKING INTO IOWA. ANY ACTIVITY WILL BECOME MORE FOCUSED OVER THE SOUTHEAST HALF AFTER MIDNIGHT WHILE DRIER MID LEVEL AIR PUNCHES INTO THE NORTH AND ENDS PRECIPITATION CHANCES OVER THAT AREA. OVERALL CONFIDENCE IN AREAL CONVERGE REMAINS LOW BUT THE SETUP IS MORE PROMISING THAT SATURDAY NIGHT WITH DEEPER MOISTURE AND STRONGER FORCING ARRIVING. .LONG TERM.../MONDAY THROUGH SUNDAY/... ISSUED AT 259 PM CDT SUN JUL 7 2013 LONG TERM FCST PD IS HIGHLIGHTED BY LACK OF SIGNIFICANT CHANGES FROM PREVIOUS FCST AND LOWER THAN AVERAGE CONFIDENCE DUE TO VARIATIONS IN MODEL GUIDANCE. THUS WILL LEAN ON CONCEPTUAL MODELS WHERE GREATER VARIATIONS EXIST IN THE GUIDANCE. FCST PERIOD BEGINS AND ENDS WITH ACTIVE WX...AND RELATIVELY QUIET WX IN BETWEEN. QUASI-ZONAL FLOW ACROSS THE NORTHERN CONUS WILL BECOME MORE AMPLIFIED IN RESPONSE TO A SHORTWAVE IN THE PROCESS OF COMING ONSHORE IN THE PAC NW ATTM. ADDITIONAL AMPLIFICATION IS EXPECTED AS THE SHORTWAVE SKIRTS ALONG THE U.S.-CANADIAN BORDER INTO THE MIDDLE PART OF THE WEEK AND NEARLY PHASES WITH AN UPPER LEVEL LOW OVER SRN CANADA. ON MONDAY...NEARLY STATIONARY BOUNDARY WILL BE INVOF THE CWA. DESPITE SOME H5 RIDGING AND A SLIGHT CAP...CONVECTION WILL BE POSSIBLE GIVEN THE EXISTENCE OF THE BOUNDARY AND AMPLE ENERGY IN THE BOUNDARY LAYER. LARGE-SCALE ORGANIZED ACTIVITY IS NOT EXPECTED HOWEVER...DUE TO THE LACK OF SYNOPTIC FORCING AND SUPPORT. ANY STORMS THAT DO DEVELOP WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL...GIVEN FACTORS SUCH AS INCREASED PWATS...MEAN STORM FLOW VECTORS ROUGHLY PARALLEL TO THE BOUNDARY AND WEAK CORFIDI VECTORS. MORE ORGANIZED CONVECTION IS POSSIBLE MONDAY NIGHT INTO EARLY TUESDAY. BEFORE THE PAC NW SHORTWAVE ARRIVES...A LEAD SHORTWAVE WILL MOVE THROUGH THE FLOW DURING THIS TIME. THAT ENERGY...COMBINED WITH THE SURFACE BOUNDARY AND DECENT THETA-E ADVECTION...WILL LEAD TO INCREASED CHANCES FOR CONVECTION. AN MCS IS EXPECTED TO DEVELOP OVERNIGHT AND MOVE EAST. AGAIN...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. STRONG TO SEVERE STORMS WILL BE POSSIBLE AS WELL. PRIMARY SEVERE WEATHER THREATS IN ADDITION TO LOCALLY HEAVY RAINFALL WOULD BE HAIL AND GUSTY...DOWNBURST TYPE WINDS. ANY LINGERING CONVECTION ON TUESDAY MORNING IS EXPECTED TO MOVE OFF TO THE EAST AS THE LEAD SHORTWAVE DEPARTS. THEN THE STRONGER PAC NW SHORTWAVE IS EXPECTED TO MOVE THROUGH TUESDAY EVENING INTO EARLY WEDNESDAY MORNING. THIS SHORTWAVE WILL ALSO BRING A SURFACE COOL FRONT THROUGH THE FORECAST AREA DURING THIS TIME PERIOD. ALTHOUGH SOME RESIDUAL CLOUD DEBRIS IS POSSIBLE DURING THE DAY ON TUESDAY...ESPECIALLY THROUGH MIDDAY..THE BOUNDARY LAYER IS STILL EXPECTED TO BECOME QUITE UNSTABLE WITH SURFACE TEMPS AROUND 90 OR LOWER 90S AND DEWPOINTS IN THE LOWER TO MIDDLE 70S. THUS SOME SEVERE STORMS WILL BE POSSIBLE. FORECAST SOUNDINGS INDICATE THE POSSIBILITY FOR SUPERCELL AND MULTICELL STORMS INVOF THE ADVANCING BOUNDARY. ALTHOUGH THE TORNADO THREAT DOES NOT APPEAR TO BE SIGNIFICANT...STORMS WOULD STILL HAVE TO BE MONITORED FOR THAT THREAT...ESPECIALLY THOSE THAT ARE ISOLATED AND/OR NEAR SURFACE BOUNDARIES SUCH AS OUTFLOW BOUNDARIES FROM THE PRIOR NIGHTS CONVECTION. LOCALLY HEAVY RAINFALL WILL AGAIN BE POSSIBLE WITH DEEP WARM CLOUD DEPTHS...CORFIDI VECTORS EITHER SMALL IN MAGNITUDE OR NEARLY PARALLEL TO MEAN STORM MOTION...AND PWATS. BY TUESDAY AFTERNOON PWATS ARE EXPECTED TO BE IN THE 75 TO 99TH PERCENTILE RANGE FOR THIS TIME OF YEAR. LINGERING CONVECTION IS POSSIBLE INTO TUESDAY NIGHT ESPECIALLY ACROSS THE SOUTHERN CWA. ONCE THE FRONT CLEARS THE FORECAST AREA LATER TUESDAY NIGHT AND INTO WEDNESDAY...A COOLER AND DRIER PACIFIC AIRMASS WILL DOMINATE THE REGION. AN AMPLIFIED UPPER AIR PATTERN CONTINUES OVER THE REGION UNTIL LATE IN THE WEEK WHEN A SHORTWAVE HELPS TO FLATTEN THE RIDGE OVER THE NORTHERN U.S. CHANCES FOR PRECIP WILL INCREASE BY LATER FRIDAY INTO SATURDAY AS RETURN FLOW SETS UP...BRINGING ADDITIONAL MOISTURE TO INTERACT WITH THE INCREASED ENERGY APPROACHING FROM THE WEST. && .AVIATION...07/18Z ISSUED AT 1240 PM CDT SUN JUL 7 2013 VFR CONDITIONS FORECAST FOR ALL TAF SITES THROUGH MONDAY MORNING. EXPECT CU FIELD TO DEVELOP ESPECIALLY OVER NORTHERN IOWA WITH BASES AROUND 5000 FT. WINDS PRIMARILY FROM THE SOUTH TO SOUTHEAST AT AROUND 10 KT SUNDAY AFTERNOON. AFTER SUNSET...WINDS BECOMING LIGHT AND VARIABLE. KEEPING AN EYE FOR THE POSSIBILITY OF SCATTERED CONVECTION NEAR KDSM AND KOTM FROM 03Z TO 10Z MONDAY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...DONAVON LONG TERM...ZOGG AVIATION...KOTENBERG  FXUS63 KDMX 150819 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 319 AM CDT MON JUL 15 2013 .SHORT TERM.../TODAY /... ISSUED AT 316 AM CDT MON JUL 15 2013 FORECAST CONCERN FOR TODAY WILL BE PRECIPITATION CHANCES...MAINLY FOCUSED IN THE AFTERNOON HOURS. UPPER LEVEL LOW WILL CONTINUE TO PUSH WEST WARD THROUGH SOUTHERN PLAINS AS LARGE UPPER LEVEL HIGH BUILDS INTO THE NORTHEAST. BETWEEN THESE TWO FEATURES...MOISTURE WILL STREAM NORTHWARD INTO IOWA. LITTLE IN THE WAY OF FORCING HOWEVER...BUT GIVEN THE AMOUNT OF AVAILABLE MOISTURE AND CAPE VALUES AROUND 1500 J/KG BY THE AFTERNOON ANTICIPATE THUNDERSTORM DEVELOPMENT IN THE AFTERNOON. HOWEVER...STORMS WILL BE SCATTERED AND ISOLATED. PWAT VALUES NEAR 1.8 AND GOOD WARM CLOUD DEPTHS WILL ALSO ALLOW FOR ANY STORMS THAT DO DEVELOP TO HAVE THE POTENTIAL FOR HEAVY RAIN. SHEAR IS VERY LIMITED AND DO NOT ANTICIPATE SEVERE THUNDERSTORMS...ASIDE FROM HEAVY RAIN POTENTIAL. HAVE KEPT TEMPERATURES NEAR GOING...THOUGH AN INCREASE IN CLOUD COVER IN THE AFTERNOON MAY LIMIT WARMING. .LONG TERM.../TONIGHT THROUGH SUNDAY/... ISSUED AT 316 AM CDT MON JUL 15 2013 PATTERN CONTINUES TO SLOWLY RETROGRESS EARLY TODAY WITH STATIONARY FRONT SITUATED FROM EASTERN COLORADO NORTHEAST INTO SOUTH DAKOTA TO WESTERN MINNESOTA. ALOFT WE CONTINUE TO HAVE HIGH PRESSURE AT H850 CENTERED OVER MARYLAND WITH A LOW OVER NEW MEXICO. AS INDICATED YESTERDAY WATER VAPOR IMAGERY SHOWS MOISTURE PLUME NICELY EXTENDING FROM FLORIDA NORTHWEST TO SOUTHERN ILLINOIS AND INDIANA. LARGE POOL OF HIGH LEVEL MOISTURE IS TRAPPED UNDER THE HIGH FOR NOW. ANOTHER AREA OF HIGH MOISTURE FROM WESTERN KS TO NORTHERN MINNESOTA IS LINED UP ALONG THE REMNANTS OF THE UPPER LEVEL BOUNDARY NOW EXTENDING THROUGH THE BUILDING RIDGE. SOMEWHAT COMPLICATED FORECAST OVER THE NEXT FEW DAYS WITH BUILDING HIGH APPROACHING WITH MOISTURE. AS THE HIGH GETS CLOSER THE CHANCES OF AFTERNOON THUNDER WILL DIMINISH... THOUGH AFTERNOON CLOUDS WILL STILL RETURN EACH DAY DUE TO INSTABILITY. MODELS STILL AT ODDS FOR TUESDAY AFTERNOON WITH SOME POTENTIAL YET FOR AFTERNOON CONVECTION. WHAT MIGHT DEVELOP WILL BE SOLELY DUE TO DAYTIME HEATING AND SOME MINOR WARM AIR ADVECTION ON THE WESTERN FRINGES OF THE UPPER LEVEL RIDGE. BUFR SOUNDINGS SHOW LITTLE CAP BUT AT THE SAME TIME FAIRLY WEAK WINDS THROUGHOUT THE COLUMN. STEERING CURRENTS TUESDAY AFTERNOON ARE AGAIN RATHER WEAK SO ANY STORMS THAT DO DEVELOP MAY BE SLOW MOVERS WITH BRIEF HEAVY RAINFALL POSSIBLE. PRECIPITABLE WATER IS AGAIN EXPECTED TO REACH THE 1.5 INCH AND HIGHER LEVEL BY TUESDAY AFTERNOON. CURRENTLY THE GFS/EURO/GEM HAVE SOME AFTERNOON CONVECTION DEVELOPING TUESDAY WHILE THE NAM IS CURRENTLY DRY. COVERAGE REMAINS SPOTTY WITH THE THREE MODELS THAT DO DEVELOP CONVECTION...SO CHANCES STILL REMAIN LOW. HEIGHTS CONTINUE TO BUILD INTO WED AND THURSDAY AS THE RIDGE ALOFT BEGINS TO WEAKEN AND DRIFT BACK EAST AS AN APPROACHING COLD FRONT MOVES SOUTH FROM NORTHERN MN. MOST OF THE MODELS ARE SHOWING AN INCREASE IN THICKNESS AND H850 TEMPS OVER THE AREA JUST AHEAD OF THE FRONT ON FRIDAY. GIVEN SOME CONSENSUS FOR WARMER CONDITIONS...WILL RAISE MAXT FOR FRIDAY OVER MUCH OF THE SOUTH WHERE BOUNDARY WILL NOT YET HAVE AFFECTED. STILL A LACK OF CONSENSUS ON HOW ACTIVE THE BOUNDARY WILL BE WITH THE PASSAGE ON FRIDAY. GFS A BIT MORE CONFIDENT WITH THUNDER ALONG THE BOUNDARY WHILE THE 12Z SUN EURO IS TRENDING DRIER FOR NOW AS WELL AS THE 00Z MON EURO. FOR NOW...WILL USE A BLEND OF SOLUTIONS GIVEN SOME UNCERTAINTY...BUT THE TRENDS SEEM TO POINT TO LESS CONVERGENCE ALONG THE FRONT AS THE FRONT HEADS SOUTH INTO A WEAKENING UPPER LEVEL RIDGE. AFTER TUESDAY HIGHS WILL AGAIN BE WARM WITH READINGS IN THE UPPER 80S TO MID 90S AT TIMES. OVERNIGHT LOWS ARE LIKELY TO CREEP BACK INTO THE LOWER TO MID 70S. CURRENTLY HIGHER DEW POINTS HAVE POOLED EAST OF THE REGION AND SHOULD CONTINUE TO MIGRATE BACK INTO THE REGION. THEN WITH THE CONTINUED HEATING THE CROPS SHOULD ADD A FEW DEGREES TO DAILY DEW POINTS. FOLLOWING THE PASSAGE OF THE FRONT HIGH PRESSURE IS EXPECTED TO DROP SOUTHEAST FROM CANADA TOWARD THE GREAT LAKES FOR THE WEEKEND. ALREADY SOME CHANGES ARE BEING NOTED IN THE EVOLUTION OF THE PATTERN WITH BOTH THE GEM/EURO KEEPING THE HIGH FARTHER NORTHEAST AND EXITING THE REGION MORE QUICKLY. THIS IS LIKELY TO RESULT IN THE JUST EXITED BOUNDARY HANGING UP NEARER IOWA AND PERHAPS LIFTING NORTH MORE QUICKLY BACK INTO THE REGION FOR THE START OF THE FOLLOWING WEEK WITH WARMTH AND THUNDER RETURNING. && .AVIATION...15/06Z ISSUED AT 1115 PM CDT SUN JUL 14 2013 VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH MONDAY EVENING. CLEAR SKIES AND LIGHT TO CALM WINDS OVERNIGHT. CU FIELD WILL BEGIN TO DEVELOP AROUND 16Z MONDAY. WATCHING FOR THE POSSIBILITY OF ISOLATED TS AFTER 18Z IN CENTRAL TO SOUTHERN IOWA. CHANCES TOO LOW AT THIS TIME TO ADD TO TAFS. WINDS SHOULD BE FROM THE SOUTHEAST AT 5 TO 10 KTS MONDAY. SKIES TO CLEAR AFTER SUNSET MONDAY EVENING. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AWB LONG TERM...BEERENDS AVIATION...KOTENBERG  FXUS63 KDMX 200856 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 356 AM CDT SAT JUL 20 2013 .SHORT TERM.../TODAY /... ISSUED AT 354 AM CDT SAT JUL 20 2013 NO SIGNIFICANT CONCERNS TODAY...ALTHOUGH TEMPS AND PRECIP TRENDS WILL STILL NEED TO BE ADDRESSED. JET REMAINS ACROSS SRN CANADA...HOWEVER WATER VAPORY IMAGERY CONTINUES TO INDICATE WEAK SHORT WAVES CROSSING BORDER INTO NRN HIGH PLAINS AND GENERATING SMALL CONVECTIVE CLUSTERS. THIS WEAK AND PATCHY FORCING WILL CONTINUE TO ADVANCE INTO IA BY THIS AFTERNOON...BUT APPARENTLY NOT WITH ELEVATED INSTABILITY THAT CURRENTLY EXISTS W OF THE MO RIVER. THUS EXPECT SD MCS TO WEAKEN AS IT REACHES HERE. NAM MLCAPES DO INCREASE NORTH DURING PEAK HEATING WITH MINIMAL CINH...SO THERE IS SOME POTENTIAL FOR ADDITIONAL SURFACE BASED DEVELOPMENT...BUT WITH WEAK SURFACE FLOW CONVERGENCE MAY BE INSUFFICIENT TO DO MUCH. HAVE LOW END POPS TO ACCOUNT FOR EITHER POSSIBILITY. HAVE BOOSTED TEMPS SOME BASED ON FORECAST SOUNDINGS AND RECENT TENDENCY FOR MOS TO REFLECT A COOL BIAS. HIGHS ARE NOW IN THE MID/UPPER 80S AND 90F IN A FEW SPOTS...DES MOINES TEMP IS STILL 73 AT 08Z...BUT HAVE SOME CONCERN THAT THEY MAY STILL NOT BE WARM ENOUGH. FORECAST SOUNDINGS WITH PROJECTED MIXING ALSO SUGGEST DEWPOINTS WILL MIX DOWN INTO THE 50S WEST BY AFTERNOON...WHICH MAKES SENSE LOOKING AT FRI AFTERNOON IN THE SURFACE RIDGE. .LONG TERM.../TONIGHT THROUGH FRIDAY/... ISSUED AT 354 AM CDT SAT JUL 20 2013 MAIN FORECAST CONCERN IS WITH CHANCES OF RAIN TONIGHT AND INTO TOMORROW WITH ANOTHER ROUND OF THUNDERSTORMS MONDAY NIGHT INTO TUESDAY. GENERALLY COOLER TEMPERATURES IN STORE FOR MUCH OF THE WEEK WITH THE EXCEPTION OF MONDAY WHERE TEMPS LOOK TO REBOUND BACK INTO THE 90S ACROSS SOUTHERN IOWA. LEANED TOWARD A BLEND OF THE NAM/GFS/SREF/NAMDNG5 THROUGH SUNDAY...THEN MAINLY THE GFS MONDAY THROUGH THE REST OF THE WEEK. TONIGHT INTO SUNDAY...HAVE POPS CONFINED TO NORTHERN IOWA TONIGHT AS SOME WEAK VORTICITY STRETCHES ACROSS SOUTHERN MN/NORTHERN IA AHEAD OF SHORTWAVE TO MOVE ACROSS THE STATE ON SUNDAY. SOME DECENT PV ASSOCIATED WITH THE SHORTWAVE MOVES OVER SOUTHWEST IOWA DURING THE DAY SUNDAY AND HAVE BEST POPS IN THIS AREA TOMORROW MORNING. WEAK THETA-E ADVECTION AND MOISTURE TRANSPORT INTO THE STATE TONIGHT INTO SUNDAY...WHICH MATCHES UP WELL WITH THE BEST FORCING OVER SOUTHWEST IOWA BY SUNDAY MORNING. MAY SEE SOME LOCALLY HEAVY RAIN OVER SOUTHERN IOWA BY SUNDAY MORNING AS PRECIPITABLE WATER VALUES AROUND 1.5 INCHES AND WARM LAYER CLOUD DEPTHS CLOSE TO 14000 FEET. MONDAY AND TUESDAY...WEAK WAA SETS UP AHEAD OF A SHARP COLD FRONT TO MOVE ACROSS THE REGION MONDAY NIGHT. TWEAKED UP MAX TEMPS SLIGHTLY ON MONDAY WITH THE WAA. DECENT AMOUNT OF MOISTURE AND FRONTOGENETICAL FORCING ASSOCIATED WITH THE COLD FRONT...AND HAVE BEST POPS GOING DURING THE EVENING MONDAY AS THE FRONT ROLLS THROUGH THE FORECAST AREA. CUT BACK ON POPS ON TUESDAY AS THE FRONT SHOULD CLEAR THE FORECAST AREA BY 12Z. WEDNESDAY THROUGH FRIDAY...HIGH PRESSURE DOMINATES THE WEATHER PATTERN WEDNESDAY AND THURSDAY BEFORE A FAIRLY STRONG LOW PRESSURE AND MOISTURE TRANSPORT ENTER THE REGION THURSDAY NIGHT INTO FRIDAY. MAY CONSIDER INCREASING POPS BY FRIDAY WITH SYSTEM MOVING THROUGH THE REGION AND CLEARS THE AREA BY SATURDAY. GFS/ECMWF ARE IN GOOD AGREEMENT WITH TIMING AND LOCATION OF THE FRONT. && .AVIATION...20/06Z ISSUED AT 1153 PM CDT FRI JUL 19 2013 WEAK HIGH PRESSURE WILL BUILD INTO THE STATE TONIGHT AND SATURDAY. LIGHT NLY FLOW WILL BECOME NELY SAT AND SELY SAT NIGHT. ONLY MID AND HIGH CLOUDS EXPECTED THROUGH THE FORECAST PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SMALL LONG TERM...PODRAZIK AVIATION...MS JUL 13  FXUS63 KDMX 252104 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 404 PM CDT THU JUL 25 2013 .SHORT TERM.../TONIGHT /... ISSUED AT 316 PM CDT THU JUL 25 2013 FORECAST CONCERNS FOCUS AROUND PRECIPITATION TRENDS FOR THE EVENING AND OVERNIGHT. TWO FOCUSES FOR PRECIPITATION CURRENTLY ONGOING ACROSS SOUTHERN MINNESOTA AND WESTERN IOWA ALONG MISSOURI RIVER VALLEY ALONG BAND OF MOISTURE CONVERGENCE. ANTICIPATE THIS PRECIPITATION TO INCREASE AND SPREAD ACROSS THE WESTERN AND NORTHERN CWA THROUGHOUT THE EVENING HOURS. GOOD INSTABILITY ACROSS THE CWA...WITH AROUND 2000 J/KG CAPE NOTED IN MESO ANALYSIS DATA. ENOUGH SHEAR AS WELL TO ALLOW STORMS WHICH DEVELOP TO PERSIST...AND MAY BECOME SEVERE. WITH STEEP MID AND LOW LEVEL LAPS RATES ALSO IN PLACE...STORMS MAY PRODUCE LARGE HAIL AND DAMAGING WINDS. MAIN PRECIPITATION HOWEVER WILL COME WITH APPROACHING COLD FRONT CURRENTLY LOCATED IN SOUTHEASTERN SOUTH DAKOTA. THIS WILL BE THE FOCUS FOR PRECIPITATION THROUGHOUT THE OVERNIGHT HOURS WITH STRONG SHORT WAVE ALSO TRACKING WITH FRONT...AND LLJ INCREASING AHEAD OF BOUNDARY. AS MOISTURE INCREASES AND SOUNDINGS SATURATE...SEVERE THREAT DIMINISHES INTO THE OVERNIGHT HOURS. PRECIPITATION OVERNIGHT WILL LIKELY BE HEAVY AT TIMES WITH BUFR SOUNDINGS INDICATING PWAT VALUES AROUND 1.7. IN ADDITION...DEEP WARM CLOUD DEPTHS WILL ALLOW FOR EFFICIENT RAINFALL PRODUCING STORMS. GIVEN RELATIVELY DRY CONDITIONS ACROSS THE CWA HAVE OPTED TO NOT ISSUE A FLASH FLOOD. IN ADDITION...STORMS WILL BE PROGRESSIVE WITH SHORTWAVE PUSHING SOUTH THOUGH ANY TRAINING OF STORMS THAT DOES OCCUR MAY LEAD TO LOCALIZED FLOODING CONCERNS. HAVE LOWERED TEMPERATURES A FEW DEGREES ACROSS THE CWA...ESPECIALLY IN THE NORTH WITH FRONT PUSHING THROUGH OVERNIGHT. .LONG TERM.../FRIDAY THROUGH THURSDAY/... ISSUED AT 316 PM CDT THU JUL 25 2013 MAIN FORECAST CONCERN THROUGH SUNDAY IS THE UNSEASONABLY COOL TEMPS EXPECTED OVER THE WEEKEND...ESPECIALLY ACROSS THE NORTH. LOW PRESSURE DROPPING OUT OF CANADA AND DEEPENING OVER NORTHERN MN WILL BRING DOWN VERY COOL AIR WITH IT. LOWS WILL BE IN THE 50S WITH HIGHS ONLY IN THE MID 60S TO 70 NORTH AND MID TO UPPER 70S SOUTH. FOR SUNDAY NIGHT THROUGH TUESDAY A FAIRLY POTENT SHORT WAVE WILL SHIFT ACROSS THE AREA. WARM ADVECTION WILL BE IN PLACE AND DEPENDING ON THE MODEL...SOME FORCING SO THUNDERSTORM CHANCES RETURN...ESPECIALLY MONDAY LATE DAY INTO TUESDAY. BEYOND TUESDAY FORECAST IS A BIT MORE NEBULOUS AS MODELS DIFFER ON THE DEVELOPMENT AND PLACEMENT OF A SURFACE LOW AND FRONTAL BOUNDARY. THE MODELS DO BREAK DOWN A RIDGE AND BRING A SHORT WAVE ACROSS IN THE THURSDAY INTO FRIDAY TIME FRAME AND THERE WILL LIKELY BE AN MCS DEVELOP SOMEWHERE BUT DETAILS STILL ARE FAR FROM SETTLED. I KEPT GENERAL CHANCE POPS ACROSS THE FORECAST AREA DUE TO THE UNCERTAINTY. && .AVIATION...25/18Z ISSUED AT 1236 PM CDT THU JUL 25 2013 PRECIPITATION WILL CONTINUE TO SPREAD INTO SITES FROM NE/SD. HAVE PUSHED BACK ONSET OF VCTS AND TSRA AT SITES WITH DEVELOPMENT STILL WEST OF MO RIVER. ANTICIPATE PERIODS OF TSRA AT SITES WITH LINGERING SHRA. CEILINGS WILL PRIMARILY BE VFR...THOUGH CEILINGS AND VISIBILITIES MAY DROP TO MVFR OR LOWER AT TIMES OF HEAVIEST RAIN. WITH INCREASED MOISTURE MAY SEE MVFR CEILINGS AT SITES BEHIND PRECIPITATION...BUT HAVE NOT INCLUDED ATTM. WINDS WILL SHIFT TO THE NORTHWEST FOR END OF PERIOD BEHIND FRONTAL BOUNDARY...WHICH WILL PUSH SE ACROSS SITES BY END OF PERIOD. WINDS MAY BE GUSTY LATE IN PERIOD BEHIND BOUNDARY. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AWB LONG TERM...FAB AVIATION...AWB  FXUS63 KDMX 272046 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 346 PM CDT SAT JUL 27 2013 .SHORT TERM.../TONIGHT /... ISSUED AT 345 PM CDT SAT JUL 27 2013 LARGE AREA OF LOW PRESSURE LOCATED IN NORTHERN WISCONSIN WILL CONTINUE TO SLOWLY PUSH EASTWARD OVERNIGHT. WEAK VORT MAX ROTATING AROUND THE LOW HAS SPARKED SHOWERS PUSHING SE ACROSS CENTRAL MN. HOWEVER...THIS WILL TRACK JUST TO THE EAST OF THE AREA THROUGH THE LATE EVENING. A STRAY SHOWER MAY BRUSH THE FAR NORTHEASTERN PORTIONS OF THE CWA...BUT WITH LIMITED FORCING...HAVE LEFT THE FORECAST DRY. MAIN CONCERN FOR OVERNIGHT IS TEMPERATURES. HAVE KEPT TEMPERATURES A FEW DEGREES LOWER AS TEMPERATURES WERE NOT ABLE TO WARM UP SIGNIFICANTLY TODAY WITH BROAD AREA OF CLOUD COVER ACROSS THE CWA. CLOUDS ARE BEGINNING TO DIMINISH AND WILL CONTINUE TO DECREASE THROUGHOUT THE OVERNIGHT...THOUGH WILL LINGER IN THE NORTHEAST. WINDS WILL ALSO BE LIGHTER OVERNIGHT THAN LAST...AND COOLER TEMPERATURES ALOFT WILL ALSO PUSH IN NEAR CENTER OF THE LOW. COOLEST TEMPERATURES ALOFT WILL BE ACROSS THE NORTHEAST...THOUGH LINGERING CLOUDS WILL HELP TO KEEP TEMPERATURES A BIT WARMER. HOWEVER...LOWS WILL BE NEAR RECORD LOWS ACROSS MUCH OF THE AREA...AND ANTICIPATE SEVERAL LOCATIONS BREAKING RECORD LOWS OVERNIGHT. .LONG TERM.../SUNDAY THROUGH SATURDAY/... ISSUED AT 345 PM CDT SAT JUL 27 2013 MAIN FORECAST CONCERN IS WITH UNSEASONABLY COOL TEMPS OVER THE NEXT FEW DAYS AND PRECIP CHANCES PRECIP CHANCES MONDAY AND AGAIN MID TO LATE WEEK. SUNDAY THROUGH TUESDAY...LARGE UPPER LOW WILL CONTINUE TO SHIFT EAST WITH ANOTHER WEAK SHOT OF CAA EXPECTED DURING THE DAY TOMORROW. LIKELY TO HAVE A MID-LEVEL CLOUD DECK INCREASE WITH THE SUNSHINE...SIMILAR SET UP TO TODAY. TWEAKED UP CLOUD COVER TOMORROW AFTERNOON. MODELS IN AGREEMENT WITH BRINGING IN A DECENT AMOUNT OF THETA-E ADVECTION INTO SOUTHWEST IOWA MONDAY INTO MONDAY EVENING...AND POSSIBLY INTO EARLY TUESDAY MORNING. HOWEVER...THE GFS IS FURTHER NORTH THAN SREF/NAM/ECMWF WITH THE PRECIP AND WITH THE SURFACE HIGH SLOWLY MOVING EAST INTO ILLINOIS SUNDAY NIGHT INTO MONDAY...THERE SHOULD BE PLENTY OF DRY AIR TO OVERCOME BEFORE PRECIP DEVELOPS...MAINLY OVER CENTRAL TO NORTHERN IOWA. KEPT MUCH OF NORTHERN IOWA DRY THROUGH 00Z TUESDAY. CONFIDENT ENOUGH TO INCREASE POPS ACROSS SOUTHERN IOWA DURING THE DAY MONDAY WITH THE SURFACE LOW AND SHORTWAVE CUTTING ACROSS KANSAS AND MISSOURI. POTENTIAL FOR SOME HEAVY RAIN ALONG THE SOUTHERN BORDER WITH PRECIPITABLE WATER VALUES INCREASING TO 1.5 TO NEAR 2 INCHES BY 00Z TUESDAY OVER SOUTHERN IOWA. WARM LAYER CLOUD DEPTHS INCREASES TO 13000 TO 14000 FEET WITH GOOD MOISTURE TRANSPORT INTO SOUTHERN IOWA AND NORTHERN MISSOURI. WEDNESDAY THROUGH SATURDAY...GFS HAS A WEAK SHORTWAVE TO BRING ANOTHER ROUND OF PRECIP ON WEDNESDAY...WHILE THE LATEST ECMWF KEEPS MUCH OF THE STATE DRY AS IT PLACES THE SHORTWAVE FURTHER NORTH. BEST POPS ARE OVER NORTHERN IOWA ON WEDNESDAY BUT MAY NEED TO TREND DRIER IF ECMWF PROVES CORRECT. THE NEXT MAIN CONCERN IS WITH SURFACE LOW DEVELOPING OVER THE NORTHERN ROCKIES AND MOVING ACROSS THE PLAINS INTO THE UPPER MIDWEST LATE THURSDAY THROUGH FRIDAY. GFS IS STRONGER AND FASTER WITH THE MOISTURE TRANSPORT AND THETA-E ADVECTION THAN THE ECMWF...BUT BOTH AGREE A COLD FRONT MOVES THROUGH BY SATURDAY MORNING. && .AVIATION...27/18Z ISSUED AT 1203 PM CDT SAT JUL 27 2013 CEILINGS WILL REMAIN VFR THOUGH PERIOD...THOUGH LOW VFR CEILINGS WILL PERSIST THROUGH MUCH OF THE PERIOD...ESPECIALLY THROUGH THE DAY SATURDAY WITH CU FIELD ACROSS SITES. WINDS WILL REMAIN FROM THE NORTHWEST AND WILL BE GUSTY IN THE AFTERNOON HOURS...BEFORE DECREASING AFTER 00Z. CLOUDS WILL ALSO DECREASE AFTER SUNSET. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AWB LONG TERM...PODRAZIK AVIATION...AWB  FXUS63 KDMX 222052 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 352 PM CDT THU AUG 22 2013 .SHORT TERM.../TONIGHT /... ISSUED AT 352 PM CDT THU AUG 22 2013 NEARLY STATIONARY SURFACE FRONTAL BOUNDARY WILL SHIFT A BIT FURTHER SOUTH AND WEAKEN FURTHER...POSSIBLY WASHING OUT. SURFACE WIND ON EITHER SIDE OF THE BOUNDARY HAS BECOME LIGHT AND VARIABLE. THE FRONT ALOFT IS STILL IN SOUTHERN MN WHERE IT HAS RESIDED ALL DAY. DEWPOINTS OVER IOWA REMAIN IN THE 60S TO AROUND 70 WITH 40 AND 50 DEGREE DEWPOINTS AS CLOSE AS MSP. UNFORTUNATELY IT DOES NOT LOOK LIKE THOSE LOWER DEWPOINTS WILL MAKE IT THIS FAR SOUTH. DESPITE WEAK SHEAR WE DO HAVE SOME INSTABILITY ACROSS OUR SOUTH AND WEST SO AN ISOLATED SHOWER OR THUNDERSTORM CANNOT BE RULED OUT TONIGHT BUT THE SCENARIO IS SIMILAR TO THE LAST COUPLE OF NIGHTS. ACROSS THE NORTH WHERE THERE WAS SOME DECENT RAINFALL AND WHERE CLEARING IS TAKING PLACE THERE IS SOME POTENTIAL FOR FOG AS WELL. TIME HEIGHT CROSS SECTIONS DO SHOW SOME LOW LEVEL MOISTURE...THOUGH NOT VERY CLOSE TO THE GROUND. I DID NOT FEEL CONFIDENT ENOUGH TO PUT IT IN THE GRIDS FOR NOW BUT WILL ADVISE THE EVENING SHIFT OF THE POTENTIAL. I DID INCLUDE SOME LOW CLOUDS IN THE AVIATION FORECASTS AS EVEN NOW OBS ARE REPORTING DECKS BETWEEN 1KFT AND 3KFT. TEMPS ARE VERY DIFFICULT AS A RESULT OF THE STALLED BOUNDARY. NORTHERN IOWA SHOULD COOL CONSIDERABLY TONIGHT...ESPECIALLY FAR NORTH WHERE CLOUDS WILL LIKELY BE LACKING. ACROSS THE SOUTH WHERE CLOUDS SHOULD LINGER...TEMPS WILL BE WARMER AS WELL AS HAVING HIGHER DEWPOINTS. .LONG TERM.../FRIDAY THROUGH THURSDAY/... ISSUED AT 352 PM CDT THU AUG 22 2013 THE WARM FRONTAL BOUNDARY THAT WILL BE NEAR THE KANSAS AND NEBRASKA BORDER THIS EVENING WILL GRADUALLY LIFT NORTHEAST THROUGH SOUTHWEST IOWA ON FRIDAY. HIGH PRESSURE MOVING EAST INTO THE CENTRAL GREAT LAKES REGION WILL SLOW THE BOUNDARIES PROGRESS NORTHEAST. THIS SETUP WILL PLACE AN INSTABILITY AXIS ACROSS CENTRAL AND SOUTHWEST IOWA ON FRIDAY WITH THETA-E ADVECTION PASSING ACROSS THE AREA. THE REGION WILL HOWEVER BE DEVOID OF ANY FEASIBLE KINEMATIC SUPPORT WITH THE LOW LEVEL JET REESTABLISHING TO THE WEST AND A LACK OF SHORT WAVE ENERGY. EXPECT A FEW THUNDERSTORMS TO DEVELOP BUT THE AREAL COVERAGE SHOULD BE ISOLATED TO POSSIBLY SCATTERED. SLOW STORM MOVEMENTS...PWAT VALUES IN EXCESS OF 1.5 INCHES AND DEEPENING WARM CLOUD DEPTHS WILL PROVIDE A CONDUCIVE ENVIRONMENT FOR EFFICIENT RAINFALL. IT WILL BE LIKE PLAYING THE LOTTERY OVER THE RAIN STARVED SOUTHWEST FORECAST AREA. THE BOUNDARY WILL LIFT NORTH AS THE UPPER RIDGE/SUBTROPICAL HIGH BUILDS NORTH AND CENTERS JUST SOUTH OF IOWA. EXPECT HIGH TEMPERATURES WARMING THROUGH THE LOW TO MID 90S SATURDAY AND SUNDAY AND THAT IS BEFORE THE REAL HEAT ARRIVES. A SHORT WAVE MOVING ACROSS THE NORTHERN PLAINS EARLY NEXT WEEK WILL SUPPRESS THE THERMAL RIDGE TO THE SOUTHEAST AND RIGHT OVER IOWA. COMPARING THIS EVENT TO THE HEAT FROM 2012...THOUGH IT IS ARRIVING A FEW WEEKS LATER IN THE SUMMER THAN LAST YEAR. THE 12Z 925 MB AND 850 MB TEMPERATURES WILL BE QUITE SIMILAR TO THE DAYS JULY 2012 TOPPED 100 DEGREES OVER A LARGE PORTION OF THE STATE. WHILE A PORTION OF NORTHERN AND NORTHEAST IOWA HAS RECEIVED THE CENTRAL AND SOUTHERN PORTIONS HAVE BEEN QUITE DRY SINCE JULY 1ST. FOR EXAMPLE...THE DES MOINES AIRPORT HAS RECEIVED 2 INCHES OF RAIN SINCE THEN...NEARLY 5.3 INCHES BELOW NORMAL. THE GROUND IS QUITE CONDUCIVE TO HEATING. HIGH TEMPERATURES WILL BE IN THE MID TO UPPER 90S AND NEAR RECORD HIGHS. NOT OUT OF THE QUESTION FOR A FEW AREAS TO TOP 100 SOMETIME BETWEEN TUESDAY AND THURSDAY. DEW POINT VALUES SHOULD LAG A BIT AGAIN DUE TO THE DRY SOILS AND BE MORE MID 60S AS OPPOSED TO UPPER 60 AND LOWER 70S. THEREFORE HEAT INDEX VALUES WILL NOT STRAY TO FAR FROM ACTUAL AIR TEMPERATURES. LITTLE TO NO CHANCE FOR PRECIPITATION DURING THIS TIME. ANY DRY LOCATIONS WILL ONLY DETERIORATE FURTHER THROUGH THE END OF NEXT WEEK. && .AVIATION...22/18Z ISSUED AT 1247 PM CDT THU AUG 22 2013 SLOW MOVING COLD FRONT WILL CONTINUE TO MAKE ITS WAY SOUTH ACROSS THE FORECAST AREA AND TAF LOCATIONS. ANY UPPER LEVEL SUPPORT FOR SUSTAINED CONVECTION IS GONE FOR NOW BUT A COUPLE OF UPPER LEVEL DISTURBANCES WILL DRIFT ACROSS THE AREA TONIGHT AND FRIDAY KEEPING AT LEAST THE POTENTIAL FOR A SHOWER OR ISOLD THUNDERSTORM. CONFIDENCE IS NOT AT ALL HIGH ENOUGH TO MENTION ANYTHING MORE THAN A VCSH IN THE TAFS. UP NORTH WHERE RAINFALL HAS BEEN A BIT MORE PREVALENT WE COULD SEE SOME FOG TONIGHT WITH CLEARING SKIES AND LIGHT TO NO WIND. OTHER TAF SITES MAY SEE SOME SHALLOW GROUND FOG BRIEFLY UNTIL WINDS PICK UP AFTER SUNRISE. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...FAB LONG TERM...DONAVON AVIATION...FAB  FXUS63 KDMX 192111 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 411 PM CDT THU SEP 19 2013 .SHORT TERM.../TONIGHT /... ISSUED AT 409 PM CDT THU SEP 19 2013 LINE OF SEVERE THUNDERSTORMS WILL CONTINUE TO PROGRESS EAST ACROSS THE SOUTHERN SECTIONS OF THE FORECAST AREA. MODERATELY UNSTABLE ENVIRONMENTAL AS SURFACE CAPE RANGES FROM 2000-3000J/KG AND LAPSE RATES IN THE 7 TO 7.5 C/KM RANGE OVER THE SOUTHERN PORTIONS OF IOWA. THE MLCAPE HAVE INCREASED TO AROUND 2000 J/KG AND LCL CONTINUE TO LOWER TO NEAR 1000M AGL. THE SHARP COLD FRONT WILL CONTINUE TO PROGRESS SOUTHEAST AND BEST DEEP LAYER SHEAR IS ALONG THE BOUNDARY. LARGE HAIL AND DAMAGING WINDS LIKELY WILL CONTINUE THROUGH AT LEAST 00Z. GOOD MOISTURE TRANSPORT AND PRECIPITABLE WATER VALUES IN THE 1.5-1.7 INCH RANGE...AND WARM LAYER CLOUD DEPTHS AROUND 12000 FEET...SO HEAVY RAIN IS CERTAINLY POSSIBLE. EXPECTING THE STORMS TO DIMINISH MID EVENING WITH SOME STRATIFORM RAIN BEHIND THE MAIN LINE OF STORMS LINGERING TO AROUND 06Z FRIDAY. USED A BLEND OF THE NAM12 AND ECMWF FOR LOW TEMPS TONIGHT AS BOTH HAD A GOOD HANDLE OF SHARP TEMP GRADIENT. .LONG TERM.../FRIDAY THROUGH THURSDAY/... ISSUED AT 409 PM CDT THU SEP 19 2013 FRONTAL BOUNDARY WHICH BROUGHT SEVERE WEATHER TO PARTS OF CWA THURSDAY AFTERNOON AND EVENING TO CONTINUE SOUTHEASTWARD PUSH OUT OF IOWA BY 13Z FRIDAY...FOLLOWED BY VERY QUIET WEATHER THROUGH THIS WEEKEND. FOR FRIDAY...WX FROM MONTANA WILL BE ADVECTED INTO IOWA IN ADVANCE OF HIGH PRESSURE PROPAGATING EASTWARD THROUGH THE MIDWEST. MODELS IN FAIRLY GOOD AGREEMENT THROUGH THE WEEKEND IN TERMS OF THE OVERALL SYNOPTIC WEATHER PATTERN. GFS AND ECMWF MAY BE UNDERDOING CLOUD COVER...AS MORE CLOUDS PRESENTLY OVER MOUNTAIN WEST THAN BEING PICKED UP. NAM DOING BEST WITH CLOUD COVER...THEREFORE WILL TREND TEMPS TOWARDS NAM AND INCREASE CLOUDS VERSUS PREVIOUS FORECAST. 850 MB TEMPS DROP FROM AROUND 18C ON THURS TO AROUND 8C ON FRI...SO HIGH TEMPS WILL BE AT LEAST 10 TO 15 DEGREES COOLER FRIDAY AFTERNOON. FOR THIS WEEKEND...HIGH PRESSURE TO DOMINATE SATURDAY/S WEATHER. CWA WILL REMAIN IN NW FLOW WHICH WILL CONTINUE TO ADVECT COOL AIR INTO REGION. SOMEWHAT OF A NOTICEABLE TEMPERATURE GRADIENT ON SATURDAY AS 850 MB TEMPS DOWN TO AROUND 4C...OVER ONE STANDARD DEVIATION BELOW NORMAL...IN NORTHEASTERN IOWA. LIKELY NOT A CLOUD IN THE SKY FOR A MUCH OF THE DAY. LATE SUNDAY INTO TUESDAY...A STRONG THERMAL RIDGE WILL BEGIN TO BUILD OVER THE DAKOTAS TOWARDS SUNDAY. THIS RIDGE WILL BREAK DOWN AS IT SHIFTS EASTWARD INTO IOWA. HIGH PRESSURE TO MOVE TO THE EAST AND RETURN FLOW TO BRING SOME MOISTURE BACK TO REGION...BUT NOT ENOUGH TO GENERATE MUCH CONVECTION FOR THIS TIME OF YEAR. ADDITIONALLY...A WEAK SHORTWAVE TO PASS THROUGH UPPER MIDWEST MONDAY INTO TUESDAY MORNING...WEAKENING AS IT PROPAGATES EASTWARD. FOR DMX CWA...WEAK MOISTURE CONVERGENCE IN LOW LEVELS...DRY AIR ALOFT...FAIRLY NORMAL PWAT VALUES DIDN/T INSTILL MUCH CONFIDENCE IN WIDESPREAD PRECIPITATION. FAVORED ECMWF AS GFS SEEMS TO BE A LITTLE TOO AGGRESSIVE IN TERMS OF POPS. ULTIMATELY...KEPT POPS LOWER AND TO THE WEST ACROSS OUR CWA. WEDNESDAY INTO THURSDAY...AFOREMENTIONED THERMAL RIDGE TO REACH THROUGH IOWA. EDGE OF LOW LEVEL JET ALSO EXPECTED TO BE NEARBY. SOME SLIGHT DISAGREEMENT AMONGST MOS GUIDANCE AND THE EURO...MOS A LITTLE MORE AGGRESSIVE WITH SOUTHWESTERLY FLOW...WHEREAS EURO KEEPS MORE OF A SOUTHERLY COMPONENT TO FLOW AND SUBSEQUENTLY MORE FORCING TO THE WEST OF OUR CWA. FORECAST CAPE VALUES SUGGEST RANGE OF 500 TO 1000 J/KG DEPENDING ON MODEL...SO WILL SEE HOW SETUP EVOLVES OVER THE WEEKEND. MAY NEED TO INCREASE POPS. AT THE VERY LEAST...LOOKS LIKE TEMPS LIKELY TO RETURN TO THE LOW TO MID 80S ACROSS IOWA. && .AVIATION...19/18Z ISSUED AT 1239 PM CDT THU SEP 19 2013 A FEW SCATTERED THUNDERSTORMS HAVE DEVELOPED AHEAD OF MAIN COLD FRONT THAT HAS PUSHED INTO NORTHWEST IOWA. STORMS LOOK TO AFFECT FOD AND POSSIBLY MCW THROUGH THE EARLY AFTERNOON HOURS. STORMS WILL REMAIN JUST TO NORTH OF DSM ATTM. AS THE FRONT PROGRESSES SOUTHEAST THIS AFTERNOON...EXPECTING MORE WIDESPREAD THUNDERSTORM ACTIVITY TO AFFECT ALO/DSM AND A BIT LATER AT OTM. THE 19.12Z HOPWRF HAS A GOOD HANDLE OF CURRENT RADAR TRENDS AND ADDITIONAL DEVELOPMENT AND LEANED TOWARD THE TIMING WRT TO CONVECTION. OTHERWISE...CAA DEVELOPS TONIGHT AND INCREASES TOMORROW WITH A SECONDARY COLD FRONTAL PASSAGE. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...KOTENBERG AVIATION...PODRAZIK  FXUS63 KDMX 200506 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1206 AM CDT FRI SEP 20 2013 .SHORT TERM.../TONIGHT/... ISSUED AT 409 PM CDT THU SEP 19 2013 LINE OF SEVERE THUNDERSTORMS WILL CONTINUE TO PROGRESS EAST ACROSS THE SOUTHERN SECTIONS OF THE FORECAST AREA. MODERATELY UNSTABLE ENVIRONMENTAL AS SURFACE CAPE RANGES FROM 2000-3000J/KG AND LAPSE RATES IN THE 7 TO 7.5 C/KM RANGE OVER THE SOUTHERN PORTIONS OF IOWA. THE MLCAPE HAVE INCREASED TO AROUND 2000 J/KG AND LCL CONTINUE TO LOWER TO NEAR 1000M AGL. THE SHARP COLD FRONT WILL CONTINUE TO PROGRESS SOUTHEAST AND BEST DEEP LAYER SHEAR IS ALONG THE BOUNDARY. LARGE HAIL AND DAMAGING WINDS LIKELY WILL CONTINUE THROUGH AT LEAST 00Z. GOOD MOISTURE TRANSPORT AND PRECIPITABLE WATER VALUES IN THE 1.5-1.7 INCH RANGE...AND WARM LAYER CLOUD DEPTHS AROUND 12000 FEET...SO HEAVY RAIN IS CERTAINLY POSSIBLE. EXPECTING THE STORMS TO DIMINISH MID EVENING WITH SOME STRATIFORM RAIN BEHIND THE MAIN LINE OF STORMS LINGERING TO AROUND 06Z FRIDAY. USED A BLEND OF THE NAM12 AND ECMWF FOR LOW TEMPS TONIGHT AS BOTH HAD A GOOD HANDLE OF SHARP TEMP GRADIENT. .LONG TERM.../FRIDAY THROUGH THURSDAY/... ISSUED AT 409 PM CDT THU SEP 19 2013 FRONTAL BOUNDARY WHICH BROUGHT SEVERE WEATHER TO PARTS OF CWA THURSDAY AFTERNOON AND EVENING TO CONTINUE SOUTHEASTWARD PUSH OUT OF IOWA BY 13Z FRIDAY...FOLLOWED BY VERY QUIET WEATHER THROUGH THIS WEEKEND. FOR FRIDAY...WX FROM MONTANA WILL BE ADVECTED INTO IOWA IN ADVANCE OF HIGH PRESSURE PROPAGATING EASTWARD THROUGH THE MIDWEST. MODELS IN FAIRLY GOOD AGREEMENT THROUGH THE WEEKEND IN TERMS OF THE OVERALL SYNOPTIC WEATHER PATTERN. GFS AND ECMWF MAY BE UNDERDOING CLOUD COVER...AS MORE CLOUDS PRESENTLY OVER MOUNTAIN WEST THAN BEING PICKED UP. NAM DOING BEST WITH CLOUD COVER...THEREFORE WILL TREND TEMPS TOWARDS NAM AND INCREASE CLOUDS VERSUS PREVIOUS FORECAST. 850 MB TEMPS DROP FROM AROUND 18C ON THURS TO AROUND 8C ON FRI...SO HIGH TEMPS WILL BE AT LEAST 10 TO 15 DEGREES COOLER FRIDAY AFTERNOON. FOR THIS WEEKEND...HIGH PRESSURE TO DOMINATE SATURDAY/S WEATHER. CWA WILL REMAIN IN NW FLOW WHICH WILL CONTINUE TO ADVECT COOL AIR INTO REGION. SOMEWHAT OF A NOTICEABLE TEMPERATURE GRADIENT ON SATURDAY AS 850 MB TEMPS DOWN TO AROUND 4C...OVER ONE STANDARD DEVIATION BELOW NORMAL...IN NORTHEASTERN IOWA. LIKELY NOT A CLOUD IN THE SKY FOR A MUCH OF THE DAY. LATE SUNDAY INTO TUESDAY...A STRONG THERMAL RIDGE WILL BEGIN TO BUILD OVER THE DAKOTAS TOWARDS SUNDAY. THIS RIDGE WILL BREAK DOWN AS IT SHIFTS EASTWARD INTO IOWA. HIGH PRESSURE TO MOVE TO THE EAST AND RETURN FLOW TO BRING SOME MOISTURE BACK TO REGION...BUT NOT ENOUGH TO GENERATE MUCH CONVECTION FOR THIS TIME OF YEAR. ADDITIONALLY...A WEAK SHORTWAVE TO PASS THROUGH UPPER MIDWEST MONDAY INTO TUESDAY MORNING...WEAKENING AS IT PROPAGATES EASTWARD. FOR DMX CWA...WEAK MOISTURE CONVERGENCE IN LOW LEVELS...DRY AIR ALOFT...FAIRLY NORMAL PWAT VALUES DIDN/T INSTILL MUCH CONFIDENCE IN WIDESPREAD PRECIPITATION. FAVORED ECMWF AS GFS SEEMS TO BE A LITTLE TOO AGGRESSIVE IN TERMS OF POPS. ULTIMATELY...KEPT POPS LOWER AND TO THE WEST ACROSS OUR CWA. WEDNESDAY INTO THURSDAY...AFOREMENTIONED THERMAL RIDGE TO REACH THROUGH IOWA. EDGE OF LOW LEVEL JET ALSO EXPECTED TO BE NEARBY. SOME SLIGHT DISAGREEMENT AMONGST MOS GUIDANCE AND THE EURO...MOS A LITTLE MORE AGGRESSIVE WITH SOUTHWESTERLY FLOW...WHEREAS EURO KEEPS MORE OF A SOUTHERLY COMPONENT TO FLOW AND SUBSEQUENTLY MORE FORCING TO THE WEST OF OUR CWA. FORECAST CAPE VALUES SUGGEST RANGE OF 500 TO 1000 J/KG DEPENDING ON MODEL...SO WILL SEE HOW SETUP EVOLVES OVER THE WEEKEND. MAY NEED TO INCREASE POPS. AT THE VERY LEAST...LOOKS LIKE TEMPS LIKELY TO RETURN TO THE LOW TO MID 80S ACROSS IOWA. && .AVIATION...20/06Z ISSUED AT 1203 AM CDT THU SEP 19 2013 TWO CONCERNS ARE LINGERING CIG REDUCTIONS AROUND KOTM AND EVOLUTION OF DAKOTAS/MN MVFR CIGS. CIGS AROUND KOTM HAVE ACTUALLY LOWERED RECENTLY EVEN THOUGH THE RAIN HAS DEPARTED SO HAVE GRADUALLY IMPROVED CONDITIONS FROM LIFR TO VFR BEFORE DAYBREAK AS NW WINDS INCREASE. ALSO EXPECT UPSTREAM CIGS TO BRUSH NERN TAF SITES /KMCW/KALO/ IN THE MORNING AND THEN LIFT AND/OR DISSIPATE AS MIXING OCCURS LATER IN THE AFTERNOON. CIGS PROGRESSION SEEMS TO BE DEPICTED WELL BY HIGH RES MODELS. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...KOTENBERG AVIATION...SMALL  FXUS63 KDMX 032054 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 354 PM CDT THU OCT 3 2013 .SHORT TERM.../TONIGHT/... ISSUED AT 339 PM CDT THU OCT 3 2013 FORECAST CONCERN IS TIMING OF CONVECTION TO REDEVELOPING THIS EVENING INTO THE EARLY MORNING HOURS FRIDAY. WARM FRONT HAS SURGED INTO NORTHERN IOWA AND EXTENDS SOUTHWESTWARD INTO EAST-CENTRAL NEBRASKA AND LOOKS TO BECOME QUASI-STATIONARY THROUGH THE OVERNIGHT HOURS. SOME PARTIAL CLEARING OVER WEST-CENTRAL TO SOUTHWEST IOWA WILL HELP DESTABILIZE THE ATMOSHPERE THE REMAINDER OF THE AFTERNOON. RAP13 SHOWING SURFACE INSTABILITY INCREASING TO 1000-1500 J/KG BY 00Z FRIDAY AND MLCAPE TO 500-1000 J/KG OVER THE WESTERN PORTIONS OF THE FORECAST AREA...BUT REMAINS CAPPED AT THE MOMENT. THE HI-RES MODELS (03.15Z HOPWRF...03.12Z NMM-ARW-EAST WRF) DEPICTING CONVECTION TO REDEVELOP PAST 00Z FRIDAY OVER NORTHERN HALF OF IOWA...GENERALLY ALONG AND NORTH OF INTERSTATE 80. FAIRLY STEEP LOW LEVEL LAPSE RATES OVER THE WEST LATE THIS AFTERNOON/EARLY EVENING AND 0-1KM AND 0-3KM SHEAR VALUES INCREASE TO 15 KNOTS AND OVER 30 KNOTS RESPECTIVELY. POTENTIAL THERE FOR A SHORT WINDOW OF SURFACE BASED STORMS EARLY THIS EVENING OVER THE WESTERN SECTIONS OF THE FORECAST AREA. MOISTURE TRANSPORT CONTINUES TO INCREASE THIS EVENING ALONG WITH MID-LEVEL THETA-E ADVECTION AND LLJ. WARM LAYER CLOUD DEPTHS NEAR 12000 FEET AND PRECIPITABLE WATER VALUES AROUND 1.50 INCHES...SO HEAVY RAIN IS CERTAINLY POSSIBLE OVER NORTHERN SECTIONS OF THE FORECAST AREA. HAVE HIGHEST POPS GOING ACROSS NORTHERN PORTIONS OF THE FORECAST AREA TONIGHT. .LONG TERM.../FRIDAY THROUGH THURSDAY/... ISSUED AT 339 PM CDT THU OCT 3 2013 PRIMARY...AND REALLY ONLY...FOCUS THROUGH THIS PERIOD WILL BE SENSIBLE WEATHER REFLECTIONS OF APPROACHING ROCKIES LONG WAVE TROUGH. ONLY SLIGHTLY ELEVATED MCS...STILL ROOTED FAIRLY LOW...WILL LIKELY BE ONGOING SOMEWHERE OVER IA FRI MORNING DRIVEN BY H85/7 THETA-E ADVECTION. FORCING ALSO SHOWS UP WITH A FEW BAROCLINIC ZONES ALONG 305K ISENT SURFACE. HOW RESULTANT SYNOPTIC AND MESOSCALE BOUNDARIES PLAY OUT LATER AFTER TYPICAL DIURNAL WARM ADVECTION WEAKENING WILL BE KEY TO SEVERE WEATHER POTENTIAL LATER IN THE DAY. 12Z ECMWF AND GFS ARE BOTH NOW IN GOOD AGREEMENT WITH SURFACE LOW TRACK...BUT DIFFER ON LATITUDINAL EXTENT OF ASSOCIATED WARM FRONT. ECMWF STALLS FRONT ROUGHLY ALONG HIGHWAY 20 WHILE GFS...NAM AND SEVERAL HI RES MODELS SUGGEST IT WILL BE FARTHER NORTH TOWARD THE MN BORDER. RECENT CONVECTION ALLOWING HI RES RUNS /HOPWRF/HRRR/ SUGGEST OVERNIGHT CONVECTION MAY BE OVER CENTRAL/SRN IA WHICH WOULD SUPPORT MORE SLY ECMWF SOLUTION. HOWEVER THE 18Z NAM HAS THIS CONVECTION FARTHER SOUTH AS WELL BUT STILL ADVANCES FRONT NORTHWARD BY 00Z SO CONFIDENCE IS NOT GREAT IN LOCATION. ALTHOUGH LOCATION IS DIFFICULT TO PINDOWN...CONFIDENCE IN OCCURRENCE IS SOMEWHAT GREATER. NAM AND GFS BOTH DEPICT AT LEAST UNCAPPED 2-3K J/KG MLCAPES AHEAD OF TRIPLE POINT...NAM EVEN HIGHER AT TIMES. STRONG SHORT WAVE/PV ANOMALY CURRENTLY OVER UT SHOULD BE SOMEWHERE OVER NRN NE/SRN SD BY 00Z PROVIDING SUFFICIENT KINEMATIC FORCING AND LARGE SCALE LIFT TO OVERCOME MLCINH CONCERNS. UPPER LEVEL DIFFLUENCE AHEAD OF TROUGH LOOKS FAVORABLE AS WELL. NW IA FORECAST SOUNDINGS SHOW VERY FAVORABLE SUPERCELL TORNADO ENVIRONMENT WITH IMPRESSIVE DEEP AND SHALLOW SHEAR...20 TO 50 KTS FROM 500M TO 6KM. ATYPICAL EARLY FALL DEWPOINTS WELL INTO THE 60S AND LINGERING LOW LEVEL MOISTURE FROM THE MORNING MCS WILL ALSO KEEP LCLS LOW. FORECAST SOUNDINGS DO SHOW WARM AIR ALOFT AROUND 1-1.5KM...BUT FEEL KINEMATIC FORCING AND DEEP CONVERGENCE WOULD BE SUFFICIENT TO OVERCOME THIS. QUICK LOOK AT 15Z SREF SHOWS MEAN SIG TOR VALUES UP TO 4 OVER N CENTRAL IA REINFORCING CONFIDENCE THAT TORNADOES WILL OCCUR SOMEWHERE IN THE MOD RISK AREA...JUST A MATTER OF WHETHER IT IS WRN HIGHWAY 30 OR SRN MN. EVENT WILL NOT LAST LONG AS SQUALL LINE...WITH SUPERCELLS ON THE NORTH END...WILL LIKELY MOVE THROUGH FAIRLY QUICKLY. PRECIP MAY LINGER ACROSS ERN IA SAT MORNING WITH LOBE OF DEEP FORCING BUT SOMEWHAT LIMITED MOISTURE EXITING ERN IA. ADDITIONAL LIGHT PRECIP IS POSSIBLE SAT NIGHT INTO SUN OVER NRN IA INTO SUN. FORCING IS NEUTRAL BUT STILL FAIRLY DEEP MOISTURE. HAVE TRUNCATED POPS AT 18Z SUN...BUT WILL HAVE TO KEEP AN EYE ON THIS AS ECMWF IS MUCH SLOWER THAN THE GFS AND HOLDS THE POTENTIAL LONGER. LITTLE OF CONCERN IN THE LATER PERIODS. TEMPS WILL DROP 20-30F WITH THE FROPA...HIGHS MAINLY IN THE 50S OVER THE WEEKEND...BUT SHOULD REBOUND BACK TO NORMAL BY NEXT WEEK. TROUGH WILL RETURN TO THE WRN CONUS BUT ANY EFFECTS FROM THIS SYSTEM OUTSIDE OF WARMING TEMPS SHOULD HOLD OFF UNTIL BEYOND THE VALID PERIOD. && .AVIATION...03/18Z ISSUED AT 1238 PM CDT THU OCT 3 2013 INTERMITTENT LIFR STRATUS DECK WILL CONTINUE TO AFFECT MCW/ALO THROUGH 20-21Z...AND THEN VFR LATER THIS AFTERNOON. OTM CIGS SHOULD IMPROVE VFR BY 1830Z AT THE LATEST...SO WENT WITH VFR AT TAF ISSUANCE. OTHERWISE...EXPECTING CONVECTION TO REDEVELOP LATER TONIGHT INTO THE OVERNIGHT HOURS ALONG AND NORTH OF THE WARM FRONT IN NORTHERN IOWA. THUNDERSTORMS MAINLY LOOK TO AFFECT ALO/MCW/FOD PAST 03Z FRIDAY. POTENTIAL FOR DSM TO SEE SOME CONVECTION LATE THIS EVENING AND HAVE VCTS MENTIONED PAST 03Z. MOS GUIDANCE HINTING ON MVFR STRATUS OVERNIGHT...BUT MAINLY THINKING DUE TO CONVECTION AND HAVE MENTIONED ACROSS THE NORTH. STRONG WAA DEVELOPS FRIDAY MORNING AND INCREASED SOUTH WINDS BY AROUND 14Z. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...SMALL AVIATION...PODRAZIK  FXUS63 KDMX 112038 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 338 PM CDT FRI OCT 11 2013 .SHORT TERM.../TONIGHT/... ISSUED AT 337 PM CDT FRI OCT 11 2013 INITIAL TROUGH MOVING ACROSS THE STATE THIS AFTERNOON HAS PROVIDED A WEAK BAND OF SPRINKLES...BUT MAINLY SOME LOW TO MID LEVEL CLOUD DECK. BULK OF THE CLOUD DECK LOOKS TO CLEAR CENTRAL IOWA BY AROUND 00Z TONIGHT...AND THE EASTERN EDGE OF THE FORECAST AREA BY AROUND 03Z...POSSIBLY A BIT LATER IN THE FAR SOUTHEAST. THE 11.12Z ARW-EAST/NMM-EAST ARE BIT SLOWER AND DO NOT MOVE THE CLOUD DECK OUT OF THE FORECAST AREA UNTIL CLOSER TO 06Z. HOWEVER...THE 11.15Z HOPWRF SEEMS TO HAVE A GOOD HANDLE ON CURRENT SATELLITE TRENDS AND LEANED TOWARD THE FASTER SOLUTION. THERE IS VERY LITTLE MOISTURE AVAILABLE FOR THE COLD FRONT THIS EVENING AS IT SWINGS ACROSS THE STATE BEGINNING AROUND 00Z IN THE WEST AND CLEARING THE EAST CLOSE TO 05Z SATURDAY. HAVE KEPT SMALL POPS GOING UNDERNEATH THE STRATUS BAND THROUGH THE EVENING. NOT ANTICIPATING MUCH QPF WITH THE LACK OF MOISTURE. OTHERWISE...WINDY CONDITIONS WILL PERSIST THROUGH 00Z...ESPECIALLY BEHIND THE STRATUS DECK MOVING EAST TO ALLOW THE SUNSHINE TO ENHANCE THE GUSTS. .LONG TERM.../SATURDAY THROUGH FRIDAY/... ISSUED AT 337 PM CDT FRI OCT 11 2013 VERY TYPICAL FALL WEATHER THROUGH THE WEEKEND WITH ONLY CONCERN FROST POTENTIAL NORTH SUNDAY MORNING. SUBSIDENCE WILL QUICKLY SPREAD INTO IA BEHIND CURRENT SYSTEM FOLLOWED BY SURFACE HIGH PRESSURE ALLOWING FOR PLENTY OF SUNSHINE DURING THE DAY. THE HIGHS CENTER SHOULD BE RIGHT OVER NORTH CENTRAL SECTIONS BY DAYBREAK SUNDAY SO EXPECT GOOD RADIATIONAL COOLING CONDITIONS. SEE NO REASON NOT TO DROP LOWS DOWN TO MOS GUIDANCE WHICH WOULD SUGGEST MINS APPROACHING FREEZING. HAVE INTRODUCED FROST WORDING IN AREAS AOB 35F AND WILL ADD TO HWO AS WELL. ATTENTION THEN TURNS TO SYSTEM CURRENTLY OFF THE WA/BC COAST AS IT REACHES THE CENTRAL AND NRN PLAINS EARLY NEXT WEEK. MODELS HAVE BEEN FAIRLY CONSISTENT WITH THIS PROGRESSION. DEEP FORCING MOVES INTO IA WEST TO EAST DURING THE DAY MONDAY. MOST OF THE KINEMATIC MID LEVEL FORCING IS STILL TO OUR NORTH...HOWEVER 1-3KM THERMODYNAMIC FORCING INCREASES INTO THE EVENING...INCLUDING STRONG THETA-E ADVECTION AND DECENT FRONTOGENETICAL FORCING. EXAMINATION OF GFS/ECMWF 300-310K ISENT LAYER LIFT...MOISTURE AND MOISTURE TRANSPORT SUGGESTS PEAK PRECIP SHOULD BE MON NIGHT SO HAVE WIDESPREAD LIKELIES IN PLACE. ONLY LIGHT TO MODERATE RAINS ANTICIPATED HOWEVER WITH SEASONAL PWS AND FAIRLY LOW WARM CLOUD DEPTHS. BETTER FORCING SHOULD DEPART EASTERN SECTIONS EARLY TUESDAY MORNING WITH LITTLE MORE THAN LIGHT WRAP AROUND PRECIPITATION NORTH TUE NIGHT INTO EARLY WED...MORE DUE TO SATURATION THAN LIFT. CONFIDENCE REMAINS LOW FOR THE REMAINDER OF THE PERIOD. GFS CONTINUES TO BE THE MOST STABLE WITH A RATHER GENERIC LONG WAVE TROUGH THE CENTRAL CONUS AND NO DESCRIPT SHORT WAVES. 12Z ECMWF CONTINUES TO SHOW MORE SPLIT FLOW WITH BETTER EMPHASIS ON A CANADIAN SHORT WAVE AND WHAT WILL EVENTUALLY BECOME A SWRN CONUS CUTOFF LOW. WITH LOW CONFIDENCE AND NEITHER OF THESE SOLUTIONS SUGGESTING MUCH IN THE WAY OF PRECIP FOR DIFFERENT REASONS HAVE OPTED TO LEAVE WED NIGHT THROUGH FRI DRY. && .AVIATION...11/18Z ISSUED AT 1239 PM CDT FRI OCT 11 2013 WEAK LINE OF SHOWERS...BETTER YET SPRINKLES...MOVING ACROSS CENTRAL IOWA EARLY THIS AFTERNOON. POTENTIALLY COULD AFFECT MCW/DSM/FOD THROUGH 21Z...BUT THEY ARE SO FAR APART AND LIGHT IN NATURE...ANYTHING THAT DOES GO OVER AN AIRPORT WILL BE SHORT- LIVED. SO LEFT MENTION OUT OF TAFS ATTM. OTHER CONCERN IS WITH MVFR CIGS MOVING ACROSS WITH THIS INITIAL TROUGH AND HAVE MVFR CIGS MENTIONED AT FOD/MCW THROUGH 21Z TODAY. MAY SEE THESE MVFR CIGS MOVE THROUGH DSM FOR A SHORT STINT...BUT LOW CONFIDENCE IN MENTIONING ATTM DUE TO THE SHORT TIME FRAME. OTHERWISE...WIND SHIFT TONIGHT WITH COLD FRONT MOVING ACROSS THE STATE. MIXING DEVELOPS OUT OF THE WEST SATURDAY MORNING. && .DMX WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR EMMET-KOSSUTH-PALO ALTO-WINNEBAGO. && $$ SHORT TERM...PODRAZIK LONG TERM...SMALL AVIATION...PODRAZIK  FXUS63 KDMX 282101 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 401 PM CDT MON OCT 28 2013 .SHORT TERM /TONIGHT/... ISSUED AT 400 PM CDT MON OCT 28 2013 PRECIPITATION TRENDS WILL BE FORECAST CONCERN FOR OVERNIGHT. AREA OF LOW PRESSURE WILL BEGIN TO LIFT NE OVERNIGHT. RIBBON OF ISENTROPIC MOISTURE AHEAD OF SYSTEM HAS ALLOWED FOR SOME SATURATION IN NORTHERN IOWA...AND EXPECT LIGHT RAIN/DRIZZLE TO CONTINUE THROUGH THE EVENING HOURS THERE. HOWEVER...MID AND LOW LEVEL MOISTURE IS STILL LACKING IN MOST LOCATIONS...AND HAVE ONLY KEPT DZ IN FORECAST...AND EXPECT ANY PRECIPITATION TO BE VERY ISOLATED IN THE EARLY EVENING HOURS. BEST FORCING ARRIVE AHEAD OF SYSTEM NEAR 06Z IN WESTERN IOWA AS THETA-E ADVECTION INCREASES. MODELS HAVE CONTINUED TO SLOW ONSET OF PRECIPITATION...AND GIVEN STRENGTH OF MID LEVEL DRY AIR HAVE CONTINUED THIS SLOWER TREND FOR BEGINNING OF PRECIPITATION. AS FORCING PUSHES EASTWARD SO WILL PRECIPITATION. WEAK SHORTWAVE WILL ALSO DROP SOUTH FROM DAKOTAS. THIS WILL ALLOW FOR THE BEST FOCUS FOR PRECIPITATION TO BE BOTH ACROSS NORTHERN IOWA AND SOUTHERN IOWA BY 12Z. HAVE THEREFORE KEPT POPS HIGHER IN THESE AREAS. TEMPERATURES OVERNIGHT WILL BE TRICKY...WITH CLOUD COVER NOT AS WIDESPREAD AS ANTICIPATED THIS AFTERNOON...AND SLOWER PROGRESSION OF PRECIPITATION AND ADVANCEMENT OF CLOUDS...HAVE DROPPED TEMPERATURES A FEW DEGREES ACROSS THE NORTHEAST WHERE CAA WILL ALSO DOMINATE OVERNIGHT. HAVE KEPT TEMPERATURES WARMER IN THE WEST WITH ADDITIONAL CLOUDS AND WEAK WAA AHEAD OF SYSTEM. GIVEN SLIGHTLY LOWER TEMPERATURES IN THE NORTH...HAVE INCLUDED RN/SN MENTION FOR 09Z-12Z. SOUNDINGS INDICATE A DECENT WARM LAYER ALOFT...AND WILL BE HARD TO SEE MUCH IN THE WAY OF SNOW...BUT A FLAKE OR TWO CANNOT BE RULED OUT EVEN THOUGH ACCUMULATION IS UNLIKELY. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 400 PM CDT MON OCT 28 2013 MAIN CONCERN THROUGH THE PERIOD WILL BE PRECIP TRENDS INTO MIDWEEK. ALTHOUGH PARENT SYSTEM IS STILL ONLY OVER THE WRN CONUS...ITS LEADING EFFECTS WILL BE IN PROGRESS TUE. MID LEVEL FORCING AND MOISTURE IS INCONSEQUENTIAL UNTIL WED...HOWEVER WAVES OF MAINLY THERMODYNAMIC FORCING 3KM AND BELOW WILL PERSIST TUE AND TUE NIGHT. INTERMITTENT WARM/THETA-E ADVECTION WILL MOISTURE THE LOW LEVELS FROM SW-NE TUESDAY WITH STATIC CONDITIONS INTO THE NIGHT. EXAMINATION OF VARIOUS 290-305K ISENT SURFACES SHOW THIS NICELY WITH MORE THAN ADEQUATE MOISTURE TRANSPORT AND VERTICAL MOTION TO PRODUCE PERIODS OF LIGHT RAIN AND/OR DRIZZLE. THIS HIGH POP/LOW QPF EVENT WARRANTS HIGH END CHANCE POPS AND EVEN LIKELIES TUE NIGHT WITH ENHANCEMENT OF LOW LEVEL JET AND ISENTROPIC LIFT. MOISTURE DEPTH MAY DIMINISH SUFFICIENTLY TO END THIS THREAT EARLY WED MORNING BUT ATTENTION WILL QUICKLY TURN UPSTREAM WITH DIFFERENT SCENARIO LATER IN THE DAY. AIRMASS WILL BECOME MORE UNSTABLE WITH INITIAL WAVE OF MORE KINEMATICALLY DRIVEN FORCING. THIS WILL COINCIDE WITH APPROACHING SURFACE SYSTEM AND ASSOCIATED CONVERGENCE TO PRODUCE A FEW PERIODS OF CONVECTION. MUCAPES MAY EXCEED 1000 J/KG AND WITH EFFECTIVE SHEAR INCREASING WOULD NOT BE SURPRISED TO SEE A FEW SEVERE STORMS. WITH MOIST LOW LEVELS AND VERY SHALLOW LAYER OF STABILITY...HIGH WIND AND TORNADO POTENTIAL WILL BE REDUCED LOCALLY AND A BIT MORE FAVORABLE JUST SOUTH. HOWEVER WOULD NOT BE SURPRISED TO SEE A FEW SUPERCELLS AND INSTANCES OF LARGE HAIL. LOCALLY HEAVY RAIN WILL ALSO BE A CONCERN WITH UNSEASONALLY HIGH PRECIPITABLE WATER VALUES AND WARM CLOUD DEPTHS. PWS UP TO 1.5 INCHES WILL BE APPROACHING 3SD FOR LATE OCTOBER/EARLY NOVEMBER...AND WARM CLOUD DEPTHS WILL BE OVER 10K FT. STORM TOTAL RAINFALL AMOUNTS...MAINLY WED OR WED EVENING...COULD REACH ONE TO TWO INCHES ALONG AND SOUTH OF I80. DO NOT EXPECT MUCH IN THE WAY OF FLOODING HOWEVER DUE TO PERSISTENT DRY CONDITIONS AND FAIRLY FAST STORM MOTION. TEMPERATURES WILL BE SOMEWHAT PROBLEMATIC WITH VARIOUS SOLUTIONS IN RAW MODEL DATA AND ASSOCIATED MOS OUTPUT. ESTHERVILLE MOS HIGHS VARY UP TO 15 DEGREES TUE FOR INSTANCE. ESSENTIALLY TOOK A MIDDLE OF THE ROAD APPROACH TUE MIXING OUT MEAN 925 MB TEMPS WHICH SUGGESTS HIGHS IN THE UPPER 40S TO MIDDLE 50S. TEMPS SHOULD BE FAIRLY STEADY TUE NIGHT BEFORE WARMING QUITE A BIT WED. IT WILL FEEL QUITE SPRING-LIKE BY THEN WITH HIGHS IN THE 50S AND 60S AND DEWPOINTS TO AROUND 60F CENTRAL AND SOUTH. FRONT SHOULD BE NEAR OR OUT OF FORECAST AREA BY 12Z THU HOWEVER EVENTUALLY APPROACH OF PARENT WAVE AND ASSOCIATED KINEMATIC FORCING MAY BRING A LAST SHOT OF POST FRONTAL RAIN THROUGH THU SOUTHEAST. FAIR WEATHER IS EXPECTED INTO THE WEEKEND WITH PERSISTENT DRY NW FLOW FOLLOWED BY WEAK RIDGING LATE IN THE WEEKEND. NEXT PRECIP CHANCES ARE QUITE LOW AND ON MONDAY WITH THE PASSAGE OF ANOTHER COLD FRONT AHEAD OF ANOTHER ITERATION OF A WRN CONUS TROUGH. FORCING WITH THIS LOOKS RATHER WEAK THROUGH MONDAY HOWEVER SO ONLY SLIGHT CHANCES. && .AVIATION...28/18Z ISSUED AT 1232 PM CDT MON OCT 28 2013 AREA OF STRATUS ACROSS NORTHEASTERN IOWA WILL CONTINUE TO AFFECT KALO/KMCW. CEILINGS WILL REMAIN VFR AT OTHER SITES FOR BEGINNING OF PERIOD...WITH GUSTY NORTHWESTERLY WINDS. APPROACHING LOW PRESSURE SYSTEM WILL BRING LOW MVFR AND IFR CEILINGS TO SITES BEGINNING NEAR 12Z...WHICH WILL PERSIST THROUGH THE REMAINDER OF THE PERIOD AS LIGHT RAIN IS ALSO EXPECTED AT SITES. CONDITIONS MY DROP INTO LOW IFR OR LIFR AT TIMES...BUT HAVE ONLY TRENDED THIS WAY FOR NOW. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...AWB LONG TERM...SMALL AVIATION...AWB  FXUS63 KDMX 270900 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 400 AM CDT SUN APR 27 2014 .SHORT TERM /TODAY/... ISSUED AT 359 AM CDT SUN APR 27 2014 SEVERE WEATHER POTENTIAL WILL BE PRIMARY CONCERN TODAY WITH CONDITIONALITY OF EVENT SEEMING TO DIMINISH WITH TIME. CURRENT NARROW RIBBON OF ELEVATED CONVECTION ROOTED 2-3KM AND DRIVEN BY STRONG WARM/THETA-E ADVECTION ZONE WILL CONTINUE TO LIFT NORTH AND EAST OUT OF THE AREA EARLY THIS MORNING. 3HR MUCAPE CHANGES SUGGEST THAT AIRMASS ALOFT IS BECOMING INCREASINGLY UNSTABLE AS INSTABILITY SURGES NORTHWARD SO...WHILE STORMS HAVE REMAINED BELOW SEVERE LIMITS OVERNIGHT AND EFFECTIVE SHEAR IS MINIMAL...WOULD NOT BE SURPRISED TO SEE A FEW NUDGE ABOVE SEVERE BEFORE EXITING FORECAST AREA. ATTENTION THEN TURNS TO THE SOUTH AND WEST TOWARD APPROACHING PARENT LONG WAVE TROUGH AND ASSOCIATED POTENT SHORT WAVE/PV ANOMALY. BROAD WEAK/MODERATE QG FORCING AND UPPER LEVEL DIFFLUENCE IS ALREADY IN PLACE ACROSS THE MO VALLEY SO COULD SEE PRECURSOR CONVECTION DEVELOP AHEAD OF MAIN EVENT AT ANY TIME BEHIND EXITING THERMODYNAMIC ZONE. PRIMARY FOCUS WILL BE ON THE AFTERNOON HOURS. PV ANOMALY SHOULD BE OVER KS BY 18Z WITH DRY SLOT AND ATTENDANT LOBE OF FORCING LIFTING INTO SWRN IA. THIS MECHANICAL FORCING SHOULD HAVE NO PROBLEM DEVELOPING CONVECTION WITH NAM/GFS BOTH SHOWING LITTLE TO NO CINH AFTER 18Z. MLCAPES AROUND OR JUST SHY OF 1000 J/KG IN BOTH INSTANCES. EXAMINATION OF CONVECTIVE MODE POINTS SQUARELY AT LOW TOPPED SUPERCELLS AND TORNADO POTENTIAL. 0-6KM SHEAR IS 30-50KTS DEPENDING ON MODEL...0-3KM CAPES ARE 100 J/KG OR MORE WITH LOW LCLS...20-30KTS OF 1KM SHEAR AND 100-300 M2/S2 SRH. MUCH LIKE EXPECTED YESTERDAY THE SW THIRD OR SO OF IA APPEARS TO BE HIGHLIGHTED AND WOULD NOT BE SURPRISED AT ALL TO SEE FUTURE SPC DAY1 OUTLOOKS LIFT MOD RISK INTO PORTIONS OF SRN IA. HAVE ADDED SEVERE WORDING TO FORECAST IN THESE AREAS. INTERESTINGLY TWO OF THE TOP EIGHT CIPS ANALOG EVENTS ARE ANDOVER KS /26 APR 91/ AND THE 1995 IA MEMORIAL DAY WEEKEND TORNADO OUTBREAK /27 MAY 95/. SECONDARY CONCERN WILL BE STRONG GRADIENT WINDS IN POTENT ELY FLOW AHEAD OF STEADY OR SLIGHTLY DEEPENING LOW PRESSURE AREA. SEVERAL SITES ARE CURRENTLY AT ADVISORY CRITERIA...AND WHILE THERE MAY BE A MIDDAY LULL...EXPECT WINDS TO INCREASE ONCE AGAIN BY LATE AFTERNOON. ADVISORY WILL BE IN EFFECT THROUGH 02Z ALONG AND NORTH OF HIGHWAY 20. YET ANOTHER CONCERN WILL BE HEAVY RAIN POTENTIAL. PWS WILL BE 1.25 INCHES OR BETTER WITH VERY STRONG 1000-850MB MOISTURE TRANSPORT FEEDING MCS. PWS ARE PLUS 2-3SD AND LOW LCLS WILL INCREASE WARM CLOUD DEPTHS AND EFFICIENCY. PRECIP AMOUNTS WILL NOT BE TOO EXTREME THROUGH 00Z WITH CONVECTION FAIRLY TRANSIENT...BUT WOULD NOT BE SURPRISED TO SEE LOCAL AMOUNTS EXCEED AN INCH. HIGH TEMPS WILL VARY QUITE A BIT WITH 08Z SURFACE ANALYSIS SHOWING WHAT APPEARS TO BE A DUAL WARM FRONTAL STRUCTURE...ONE FROM NE INTO KS/MO AND ANOTHER THROUGH IA INTO IL. FORECAST SOUNDINGS SHOW SOME MINIMAL MIXING RESULTING IN AROUND A 15-20F REBOUND NORTH TO SOUTH...CLOSER TO THE WARMER END OF MOS GUIDANCE. .LONG TERM /TONIGHT THROUGH SATURDAY/... ISSUED AT 359 AM CDT SUN APR 27 2014 AFTERNOON AND EVENING STORMS...WITH SOME SEVERE WEATHER THREAT IN THE EVENING AS DISCUSSED IN THE SHORT TERM DISCUSSION ABOVE...WILL LIFT NORTHEAST ACROSS THE AREA THROUGH MIDNIGHT TONIGHT WITH SLOWLY DIMINISHING INTENSITY. WE SHOULD THEN SEE A DECREASE IN COVERAGE OF SHOWERS AND THUNDERSTORMS LATE TONIGHT AND MONDAY MORNING. HOWEVER...THE SURFACE WARM FRONT WILL SHARPEN SOMEWHERE ACROSS CENTRAL IOWA IN ADVANCE OF THE PARENT LOW PRESSURE SYSTEM APPROACHING FROM THE WEST...AND ON MONDAY AFTERNOON DIURNAL HEATING WILL ALLOW A ZONE OF LOW LEVEL INSTABILITY AND VORTICITY TO DEVELOP ALONG/NEAR THE FRONT. THIS IS REFLECTED BY NUMEROUS NUMERICAL MODELS AS WELL AS CLIMATOLOGY IN SUCH PATTERNS AND REFLECTS A THREAT FOR SEVERE WEATHER WITH LANDSPOUT TYPE TORNADOES POSSIBLE. A MORE PRECISE LOCATION OF THE WARM FRONT AND SEVERE WEATHER THREAT DURING THIS TIME WILL BE DETERMINED AFTER THE SUNDAY/SUNDAY NIGHT CONVECTION...BUT THIS SITUATION WILL NEED TO BE MONITORED AS WE HEAD INTO MONDAY. ON MONDAY NIGHT AS THE LARGE STACKED GYRE MOVES OVER CENTRAL IOWA ANY SEVERE WEATHER THREAT WILL QUICKLY DIMINISH AND SEVERAL DAYS OF COLD RAIN WILL BEGIN...PERSISTING AT LEAST THROUGH THURSDAY WITH FREQUENT BUT GENERALLY LIGHT RAIN...OVERNIGHT LOWS IN THE UPPER 30S TO MID 40S...AND DAYTIME HIGHS ONLY IN THE 40S AND 50S TO USHER IN THE MONTH OF MAY. NEAR THE END OF THE WORK WEEK RAIN CHANCES WILL DIMINISH...HOWEVER THE 500 MB FLOW WILL REMAIN CYCLONIC WITH NO SIGNIFICANT WARMING FORECAST THROUGH NEXT WEEKEND. && .AVIATION...27/06Z ISSUED AT 1201 AM CDT SUN APR 27 2014 WARM FRONT SOUTH OF IA WILL LIFT NORTH. THUNDERSTORMS AHEAD OF THE FRONT WILL LIFT NORTH TONIGHT AND CLEAR NORTH OF THE TAF SITES BY 15Z. AREAS OF MVFR CIGS LIKELY TO DEVELOP ON SUNDAY BEFORE NEXT ROUND OF STRONG CONVECTION DEVELOPS IN THE 21 TO 03Z TIMEFRAME. OUTLOOK...WIDESPREAD MVFR CIGS AND SOME IFR EXPECTED TO SPREAD SOUTHEAST GRADUALLY LATE SUNDAY NIGHT INTO MONDAY. && .HYDROLOGY... ISSUED AT 359 AM CDT SUN APR 27 2014 EVENT TOTAL QPF IS EXPECTED TO BE WIDESPREAD ONE TO THREE INCH RAINS...MAINLY TODAY INTO MONDAY...WITH HIGHEST AMOUNTS OVER THE NORTHEAST HALF OF THE FORECAST AREA. THIS AREA ALSO HAS THE RELATIVELY WETTEST SOILS...REMOVED FROM THE D1-D2 DROUGHT FARTHER SOUTH AND WEST. ENSEMBLE AND DETERMINISTIC QPF AND RESULTANT RIVER MODEL OUTPUT SUGGESTS IOWA AND CEDAR RIVER BASINS WOULD BE FAVORED TO SEE SIGNIFICANT WITHIN BANK RISES TO MINOR FLOODING. HIGHER END ENSEMBLE SOLUTIONS WOULD ALSO SUGGEST MODERATE FLOODING IN A FEW LOCATIONS. && .DMX WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR BLACK HAWK-BREMER- BUTLER-CALHOUN-CERRO GORDO-EMMET-FRANKLIN-GRUNDY-HAMILTON- HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-PALO ALTO-POCAHONTAS-SAC-WEBSTER- WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...SMALL LONG TERM...LEE AVIATION...MS APR 14 HYDROLOGY...SMALL  FXUS63 KDMX 110918 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 418 AM CDT SUN MAY 11 2014 .SHORT TERM /TODAY/... ISSUED AT 407 AM CDT SUN MAY 11 2014 WARM FRONT WILL LIFT NORTH INTO IOWA TODAY. DEEP MOISTURE TRANSPORT IS UNDERWAY AND IS EVIDENT ON THE 88D REFLECTIVITY PRODUCTS THIS MORNING. MODELS ARE IN REASONABLE AGREEMENT ON TWO SETS OF CONVECTION TODAY. THE FIRST KS EXPECTED TO DEVELOP TO THE SOUTHWEST AND PUSH ACROSS THE SOUTH CLOSE TO THE WARM FRONT. THIS FITS WELL WITH THE THETAE ADVECTION SHOWN IN THE MODELS. NEXT ROUND WILL BE DEPENDENT ON WHAT HAPPENS WITH THE FIRST. THE MORE CLEARING WE GET BEHIND THE FIRST SET THE MORE INSTABILITY WILL BE AVAILABLE. NEXT ROUND WILL BE CLOSER TO THE COLD FRONT AND LATE IN THE FIRST PERIOD. MOST WILL BE IN THE TONIGHT PERIOD. IN ADDITION TO SEVERE WEATHER...DEEPER MOISTURE AND THE POTENTIAL FOR TRAINING ECHOS WILL GIVE THE POSSIBILITY OF HEAVY RAINFALL AND LOCAL FLOODING. TEMPS TODAY WILL BE TRICKY AND VERY DEPENDENT ON MORNING CONVECTION WENT WITH THE IDEA OF ENOUGH CLEARING IN THE AFTERNOON TO ALLOW READINGS TO REACH 80 OR ABOVE OVER THE SOUTH. .LONG TERM /TONIGHT THROUGH SATURDAY/... ISSUED AT 407 AM CDT SUN MAY 11 2014 ONGOING SEVERE WEATHER AND HEAVY RAIN EVENT WAS THE PRIMARY FOCUS TONIGHT INTO MONDAY...THEN WITH THE FALL LIKE TEMPERATURES THROUGH THE REMAINDER OF THE EXTENDED PERIOD. STRONG AREA OF LOW PRESSURE AT THE SURFACE WILL DEVELOP OVER THE TX/OK PANHANDLES WITH THE INVERTED SURFACE TROUGH EXTENDING NORTHEAST INTO IOWA AND SOUTHERN MINNESOTA THIS EVENING. A DEEP 500MB TROUGH DIGS SOUTH INTO THE FOUR CORNERS REGION BY 00Z MONDAY AND THIS TROUGH LOOKS TO SLOWLY PROPAGATE EAST AND CLEAR THE STATE BY LATE MONDAY NIGHT...PLACING THE FORECAST AREA IN MUCH COLDER TEMPERATURES THROUGH THE REST OF THE WEEK. TONIGHT INTO MONDAY...BY AROUND 03Z MONDAY...THE WARM FRONT LOOKS TO BE LAID UP IN THE VICINITY OF THE I-80 TO HIGHWAY 20 CORRIDOR WITH THE MAIN BULGE AS FAR NORTH AS AMES OR FORT DODGE AREA. THERE IS TREMENDOUS INSTABILITY AVAILABLE ALONG AND SOUTH OF THIS BOUNDARY AS MUCAPE VALUES RANGE FROM 2000-4000 J/KG...WITH MUCH OF THIS INSTABILITY IN THE 0-1KM OR 0-3KM RANGE...VERY IMPRESSIVE TO SAY THE LEAST. THE 0-1KM AND 0-3KM BULK SHEAR ARE IN 30 TO 45 KNOT RANGE AND HODOGRAPHS (DSM/OTM/RDD) CONTINUE TO SHOW THE SICKLE SHAPE FEATURE INDICATING THE DEEP LAYER SHEAR PRESENT FOR LONG LIVED SUPERCELLS. STORMS LOOK TO TRACK FROM SW TO NE...IF AND WHEN ANY STORMS GET ROOTED WITH THE BOUNDARY WILL ONLY AID IN THE LOW LEVEL SHEAR AND HELICITY...ONLY INCREASING THE TORNADIC DEVELOPMENT POTENTIAL. HENCE...AGREE WITH SPC 10 PERCENT HATCHED AREA FOR TORNADIC RISK THROUGH TONIGHT. PLUS WITH THE SUSTAINABILITY OF THE UPDRAFTS...LARGE HAIL IS HIGHLY LIKELY AND EXPECTING SEVERE STORMS TO PERSIST WELL INTO THE LATE EVENING HOURS. KEPT SEVERE WORDING MENTION IN FORECAST THROUGH 05Z MONDAY. OTHER ISSUE...HEAVY RAIN. STRONG AND DEEP MOISTURE TRANSPORT CONTINUES TONIGHT INTO TOMORROW BEFORE THE MAIN COLD FRONT AND AFOREMENTIONED UPPER LEVEL TROUGH PUSH ACROSS THE STATE BY THE LATE AFTERNOON. WARM LAYER CLOUD DEPTHS ARE IN THE 12KFT TO 13KFT RANGE AND PRECIPITABLE WATER VALUES REMAIN AROUND 1.50" THROUGH MONDAY MORNING. SHOULD SEE SOME EFFICIENT HEAVY RAIN PRODUCERS LATE TONIGHT THROUGH THE MORNING HOURS AS THE LLJ CONTINUES TO PUMP MOISTURE INTO THE STATE KEEP CONVECTION GOING. PRECIP CHANCES DECREASES THROUGH THE AFTERNOON MONDAY WITH THE FRONT/TROUGH MOVING ACROSS THE STATE. STILL SOME SHOWER ACTIVITY POSSIBLE WITHIN THE CAA MONDAY NIGHT INTO EARLY TUESDAY MORNING. TUESDAY THROUGH SATURDAY...COLD PERIOD WILL PERSIST THROUGH THE EARLY PART OF THE WEEKEND AS A COUPLE OF REINFORCING SHOTS OF COLD AIR FILTERS INTO THE REGION. THE COLDEST NIGHT LOOKS TO BE THURSDAY NIGHT INTO FRIDAY...AND MAY SEE SOME AREAS OF FROST AND POSSIBLY A LATE SEASON FREEZE ACROSS NORTHERN IOWA BY FRIDAY MORNING AS THE SURFACE HIGH BUILDS INTO MINNESOTA. && .AVIATION...11/06Z ISSUED AT 1154 PM CDT SAT MAY 10 2014 A CLUSTER OF THUNDERSTORMS SHOULD APPROACH CENTRAL IOWA ONCE AGAIN JUST AFTER SUNRISE AND MOVE THROUGH THE FORECAST AREA BEFORE 18Z. HAVE SLOWED THE ONSET OF PRECIP SLIGHTLY IN THE MORNING COMPARED TO THE PREVIOUS TAF PACKAGE BASED ON THE LATEST HIGH RES GUIDANCE. SOUTHEASTERLY WINDS WILL INCREASE AS MIXING COMMENCES DURING THE AFTERNOON WITH GUSTS OVER 20 KTS IN SOME LOCATIONS. NEXT ROUND OF STRONG THUNDERSTORMS WILL FORM OVER WESTERN IOWA AND TRACK EASTWARD AFTER 23Z ON SUNDAY. && .HYDROLOGY... ISSUED AT 407 AM CDT SUN MAY 11 2014 RAINFALL RATES TONIGHT INTO MONDAY MORNING HAVE THE POTENTIAL TO EXCEED 2 TO 3 INCHES PER HOUR AT TIMES. CONCERNED ABOUT FLASH FLOODING AND MAY NEED TO CONSIDER A FLASH FLOOD WATCH TONIGHT THROUGH MONDAY MORNING...BUT HELD OFF DUE TO THE SEVERE WEATHER POTENTIAL. MAIN AREAS AFFECTED WILL BE URBAN AREAS...SMALL CREEKS/STREAMS RUNNING BANK FULL OR HIGHER THROUGH MONDAY MORNING DUE TO THE RAPID RAINFALL RATES. MOST OF THE MAIN STEAM RIVERS CAN HANDLE SOME WATER ATTM...AND ANY RESPONSE LOOKS TO BE LATER THIS WEEK. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...MS LONG TERM...PODRAZIK AVIATION...SKOW HYDROLOGY...PODRAZIK  FXUS63 KDMX 252032 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 332 PM CDT SUN MAY 25 2014 .SHORT TERM /TONIGHT/... ISSUED AT 326 PM CDT SUN MAY 25 2014 CONVECTIVE TRENDS WILL BE THE MAIN CONCERN INTO TONIGHT. PATTERN EXPECTED TO CHANGE LITTLE OVERNIGHT WITH CUTOFF LOW REMAINING ANCHORED OVER NM/CO AND IA IN DEEP BUT WEAK SLY/SWLY FLOW. THERE IS LITTLE IN THE WAY OF TOTAL QG FORCING NOTED TONIGHT ALTHOUGH THERE IS WEAK THETA-E ADVECTION. EXAMINATION OF VARIOUS MODEL 300/305K ISENT SURFACES NOTES LESS BAROCLINICITY THAN LAST NIGHT SO PRECIP CHANCES MAY BE DRIVEN MORE BY INSOLATION THAN YESTERDAY. AIRMASS OVER SW HALF OF IA IS UNCAPPED WITH 1000 PLUS J/KG MLCAPES. DEEP CONVERGENCE IS WEAK AND CENTERED OVER MO RIVER NEAR FAR SERN NE/NERN KS CLUSTER AND EXPECT THIS TO DRIFT SLOWLY NEWD INTO IA WITHIN ONLY 15KT MEAN WIND. H85 MOISTURE TRANSPORT IS MODERATE SO CORFIDI VECTORS MAY RESULT IN EVEN SLOWER CELL MOTION. EFFECTIVE SHEAR IS WEAK SO MAIN CONCERN WOULD BE LOCALLY HEAVY RAIN RATHER THAN SEVERE WITH DEEP WARM CLOUD DEPTHS AND PWS 1.5 OR JUST ABOVE. EXPECT WEAK CONVECTIVE CHANCES TO PERSIST ALL NIGHT...BUT LIKELY DIMINISH SOMEWHAT LATER IN THE EVENING WITH LOSS OF HEATING. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 326 PM CDT SUN MAY 25 2014 FORECAST CONCERNS WERE FOCUSED ON PERIODIC RAIN/THUNDER CHANCES MONDAY THROUGH THE END OF THE WORK AND TRENDED TOWARD A DRIER FORECAST WITH INCREASED MODEL CONSENSUS. MONDAY THROUGH WEDNESDAY...WEAK THETA-E ADVECTION PUSHES NORTHWARD ACROSS CENTRAL IOWA MONDAY AFTERNOON INTO THE EVENING HOURS AHEAD OF A VERY SLOW MOVING 500MB LOW PRESSURE CENTERED OVER THE SOUTHERN ROCKIES. NOT ANTICIPATING MUCH PRECIP UNTIL THE AFTERNOON HOURS MONDAY DURING PEAK HEATING TIME. CUT BACK ON POPS DURING THE MORNING HOURS MONDAY. THE AFOREMENTIONED LOW WILL EVENTUAL PUSH SOUTHEAST INTO LOUISIANA BEFORE DISSIPATING BY MID TO LATE WEEK. IN THE MEAN TIME...A COUPLE OF WEAK SHORTWAVES WILL CUT ACROSS THE STATE AND PROVIDE ADDITIONAL SHOWER AND THUNDERSTORM CHANCES ON TUESDAY INTO WEDNESDAY. THERE IS HIGHER CONFIDENCE IN SOUTHWEST IOWA THAT WILL BE DRY MUCH OF TUESDAY INTO TUESDAY NIGHT AS THE BETTER FORCING IS LOCATED OVER NORTHEAST IOWA. THE NEXT VORT MAX MOVES THROUGH WEDNESDAY BEFORE CLEARING THE FORECAST AREA WEDNESDAY NIGHT. LEANED TOWARDS A DRY PERIOD WEDNESDAY NIGHT. THURSDAY THROUGH SUNDAY...UPPER LEVEL RIDGE REMAINS IN PLACE THROUGH THE WEEKEND WITH MODELS LOOKING MORE DRY THURSDAY INTO SATURDAY. TRENDED TOWARD SLIGHT POPS OR LOW CHANCE POPS THURSDAY AND AGAIN FRIDAY. RIDGE LOOKS TO BREAK DOWN BY SATURDAY WITH A FAIRLY STRONG COLD FRONT/UPPER LEVEL TROUGH MOVING ACROSS THE REGION. && .AVIATION...25/18Z ISSUED AT 1252 PM CDT SUN MAY 25 2014 WIDESPREAD MVFR CIGS ARE IN PLACE ACROSS CENTRAL AND WRN IA AT 18Z...A FEW SPOTS IFR. THESE LOW CLOUDS ARE EXPECTED TO LIFT NORTHWARD AFFECTING KMCW SHORTLY. FARTHER SOUTH ATTENTION WILL TURN TO THUNDERSTORM POTENTIAL. SCT STORMS ARE ALREADY DEVELOPING ACROSS NERN KS WITH VISIBLE SATELLITE TRENDS AND INSTABILITY SUGGESTING OTHER DEVELOPMENT LIKELY INTO ERN MO AND EVENTUALLY MOVING INTO AT LEAST SRN IA. HAVE ADDED VCTS MENTION TO KDSM/KOTM FOR NOW...WITH STRONGER WORDING AND EXPANSION NORTHWARD POSSIBLE DEPENDING ON TRENDS. LINGERING LOW CLOUDS AND ADDITIONAL RAIN MAY LEAD TO MVFR OR LOWER CONDITIONS OVERNIGHT AS WELL. OTHER PRECIP IS POSSIBLE INTO MON...BUT CONFIDENCE NOT GREAT ENOUGH TO INCLUDE AS OF YET. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SMALL LONG TERM...PODRAZIK AVIATION...SMALL  FXUS63 KDMX 260853 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 353 AM CDT MON MAY 26 2014 .SHORT TERM /TODAY/... ISSUED AT 317 AM CDT MON MAY 26 2014 THE CHALLENGE FOR TODAY WILL BE PRECIPITATION TRENDS WITH TIMING AND AREAL COVERAGE. UPPER LOW CENTERED OVER NEW MEXICO EARLY THIS MORNING WILL SHIFT SLOWLY EAST TODAY. A COUPLE IMPULSES ARE LIFTING NORTHEAST ON THE EAST SIDE OF THE UPPER LOW THROUGH KANSAS AND THESE CAN BE SEEN WITH MODEST LOWERING IN PV 1.5 PRESSURE FIELD TO AROUND 350 MB. EARLY MORNING CONVECTIVE TRENDS HAVE BEEN OVERALL DECREASING ACROSS CENTRAL IA WITH THE EXCEPTION OF WEAK GUST FRONT INDUCED CONVECTION. CONVECTION HAS BEEN INCREASING A BIT MORE AHEAD OF THE APPROACHING PV ANOMALIES FROM NORTHWEST MISSOURI AND INTO SOUTHEAST NEBRASKA. THIS AREA OF PRECIPITATION IS ALSO BEING AIDED BY THETA-E ADVECTION LIFTING NORTHWARD AS WELL. EXPECT AN AREA OF PRECIPITATION TO PRIMARILY BE FOCUSED OVER THE SOUTHEAST HALF OF THE FORECAST AREA THIS MORNING WITH MORE ISOLATED ACTIVITY NORTHWEST. BY THIS AFTERNOON...DESTABILIZATION SHOULD BE ONGOING OVER THE NORTHWEST AS ANOTHER WAVE OF THETA-E ADVECTION LIFTS NORTH INTO THE AREA WITH LESS ACTIVITY TO THE SOUTH. PWATS TODAY STILL HOVER NEAR 1.5 INCHES WITH WARM CLOUD DEPTHS OVER 10 KFT. THIS IN ADDITION TO WEAK FLOW WILL YIELD EFFICIENT RAINFALL PRODUCING STORMS WITH SOME AREAS POSSIBLY GETTING 1 TO 2 INCHES OF RAIN WHILE OTHER AREAS GET LITTLE TO NO ACTIVITY THROUGH TODAY. ASSUMING SOME BREAKS IN THE CLOUDS TODAY...SHOULD HAVE HIGHS BACK IN THE UPPER 70S TO LOWER 80S. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 317 AM CDT MON MAY 26 2014 UPPER LEVEL LOW PRESSURE SYSTEM WHICH HAS IMPACTED WEATHER THROUGH THE WEEKEND WILL CONTINUE TO SLOWLY PUSH EASTWARD...CONTINUING TO INFLUENCE WEATHER FOR BEGINNING OF THE WEEK. MODELS REMAIN IN GOOD AGREEMENT WITH TIMING AND PLACEMENT OF THE SYSTEM...AND ARE IN BETTER AGREEMENT WITH PRECIPITATION CHANCES ACROSS IOWA. HOWEVER...GIVEN RELATIVELY WEAK LOW...AND VERY LIMITED MOISTURE AND FORCING NORTH OF LOW...STILL ANTICIPATE A FAIRLY SCATTERED NATURE OF SHOWERS AND THUNDERSTORMS THROUGH THE WEEK. HOWEVER...BEST CHANCES LOOK TO BE ACROSS NORTHERN IOWA TONIGHT AND TOMORROW AS A WEAK BOUNDARY...ASSOCIATED WITH ANOTHER LOW PRESSURE SYSTEM IN CANADA...WILL BEGIN TO PUSH INTO NORTHERN IOWA. THIS WEAK BOUNDARY WILL CONTINUE TO PUSH SOUTH THROUGHOUT THE DAY TUESDAY...AND HAVE BROUGHT POPS FURTHER SOUTH..ESPECIALLY IN THE EAST. GIVEN GOOD WARM CLOUD DEPTH AND PWAT VALUES OVER AN INCH...WILL LIKELY SEE MODERATE TO HEAVY RAIN WITH ANY PRECIPITATION THROUGH TUESDAY. CONFIDENCE IN PRECIPITATION DECREASES LATE TUESDAY AS SOUTHERN LOW SHIFTS INTO EASTERN TEXAS/LOUISIANA AND AMOUNT OF MOISTURE NORTH DIMINISHES. AS SYSTEMS PUSH EAST...RIDGE WILL BUILD INTO UPPER MIDWEST FOR LATE IN THE WEEK. THIS WILL HELP TO LIMIT PRECIPITATION CHANCES...AND HAVE KEPT POPS LIMITED FOR END OF WEEK. MODELS DO ATTEMPT TO LIFT SYSTEM INTO SOUTHERN IOWA FRIDAY...BEFORE LARGE LOW PRESSURE SYSTEM IN CANADA AND ASSOCIATED FRONTAL BOUNDARY SWING THROUGH RIDGE FOR WEEKEND...WITH ADDITIONAL CHANCES FOR PRECIPITATION. GIVEN UPPER LEVEL PATTERN...TEMPERATURES WILL REMAIN FAIRLY CONSISTENT THROUGH THE WEEK...SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE 80S AND LOWS IN THE 60S. WAA IN THE WEST WILL KEEP TEMPERATURES WARMER THERE THROUGH THE WEEK. && .AVIATION...26/06Z ISSUED AT 1133 PM CDT SUN MAY 25 2014 AREA OF SHOWERS HAS DIMINISHED OVER THE EAST WHILE NEW AREA OF SLOW MOVING SHOWERS/STORMS CROSSING INTO FAR WEST. HRRR SUGGESTS THAT SOME ACTIVITY MAY GRAZE KDSM AND KOTM BY 11-12Z. OTHERWISE VCSH AND PATCHY BR WILL BE MAIN ISSUES THROUGH 12Z. AFT 14Z AGAIN LOOKING FOR MORE ORGANIZED SHOWERS OR THUNDER TO DEVELOP INTO THE LATE MORNING OR EARLY AFTERNOON HOURS AS A WEAK WAVE TRACKS NORTH INTO IOWA FROM MISSOURI. TIMING BETWEEN 15Z AND 22Z FROM SOUTH TO NORTH. COVERAGE STILL IN QUESTION...SO WITH SOME UNCERTAINTY HAVE GONE VC FOR NOW. WILL NEED TO REFINE TIMING AND COVERAGE FOR NEXT PACKAGE. WINDS TO REMAIN LIGHT WITH MVFR CIGS AFT 08-09Z AS BR BEGINS TO DEVELOP./REV && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DONAVON LONG TERM...AWB AVIATION...REV  FXUS63 KDMX 272024 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 324 PM CDT TUE MAY 27 2014 .SHORT TERM /TONIGHT/... ISSUED AT 324 PM CDT TUE MAY 27 2014 PRIMARY CONCERN REMAINS PRECIP TRENDS INTO THE NIGHT. PARENT WAVE OF MEANDERING UPPER LEVEL LONG WAVE TROUGH CONTINUES TO DRIFT ALONG THE RED RIVER WHILE SEPARATE WEAKER WAVE INFLUENCES OUR WEATHER ALONG THE UPPER MS VALLEY. TWO CURRENT CLUSTERS OF CONVECTION ARE SUBTLELY FORCED BUT APPEAR TO BE MAINLY DRIVEN BY FORCING ATTENDANT TO THE AFOREMENTIONED SHORT WAVE AND WEAK CONVERGENCE ALONG DIFFICULT TO ANALYZE SW-NE WEAK FRONT/PRESSURE TROUGH. AIRMASS IS RATHER HOMOGENEOUS WITH ONLY WEAK DRYING BEHIND WIND SHIFT. SHORT WAVE SHOULD DRIFT DOWN THE IMMEDIATE UPPER MS RIVER VALLEY TONIGHT KEEPING CLOUDS IN THE FORECAST AND SOME POPS...ESPECIALLY EAST...WHICH SHOULD VERY GRADUALLY DIMINISH INTO THE NIGHT WITH LOSS OF INSOLATION. FARTHER SOUTH HI RES CONVECTION ALLOWING MODELS...ESPECIALLY THE HOPWRF ENSEMBLE WHICH HAS PERFORMED WELL RECENTLY...SUGGESTS THIS CLUSTER SHOULD DIMINISH AND/OR EXIT THE SRN FORECAST AREA THIS EVENING. FREEZING LEVELS HAVE LOWERED SOMEWHAT TODAY VS YESTERDAY SO THERMODYNAMIC ENVIRONMENT FOR HEAVY RAIN IS SLIGHTLY LESS FAVORABLE THIS AFTERNOON. HOWEVER ENVIRONMENT IMPROVES SOMEWHAT LATER THIS EVENING AS WARM CLOUD DEPTHS INCREASE WITH LOWERING LCLS...AND PWS BEGIN TO POOL IN THE VICINITY OF THE BOUNDARY. THE WINDOW FOR THIS TO BE REALIZED WILL BE SMALL HOWEVER WITH COINCIDENT LOSS OF HEATING. FUNNEL CLOUD ENVIRONMENT IS STILL SOMEWHAT ELEVATED INTO PEAK HEATING MAX WITH 0-3KM CAPES 150 J/KG OR MORE AND NON SUPERCELL TORNADO PARAMETER 2-3 SOUTH. WEAK SURFACE VORTICITY HAS LIKELY PRECLUDED ANY REPORTS AS OF YET BUT WILL HAVE TO MONITOR LOCAL OUTFLOW BOUNDARIES...WHICH MAY BE PREVALENT IN THIS LOW 0-6KM SHEAR SITUATION...FOR ISOLATED VORTICITY GENERATION IN NEW CELL DEVELOPMENT. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 324 PM CDT TUE MAY 27 2014 WEAK UPPER LEVEL SHORTWAVE EMBEDDED IN THE MAIN UPPER LEVEL FLOW TO SLOWLY DEEPEN A BIT AS IT DROPS SOUTHEASTWARD/SOUTHWARD THROUGH THE CWA WEDNESDAY INTO WEDNESDAY NIGHT. THIS WILL BRING A WEAK BACKDOOR COOL FRONT ALONG WITH IT...WITH SOME WEAK INSTABILITY IN PLACE ACROSS THE CWA RESULTING IN CHANCES FOR ISOLATED TO SCATTERED SHOWER/THUNDERSTORM DEVELOPMENT THROUGH THE DAY WEDNESDAY INTO WEDNESDAY NIGHT. THE UPPER RIDGING IN PLACE ACROSS THE CENTRAL US...WILL AMPLIFY LATE THIS WEEK...WITH THE AREA OF HIGH PRESSURE ACROSS THE HIGH PLAINS SLIDING NORTHEAST WITH RETURN FLOW SETTING UP ACROSS THE AREA BY THURSDAY INTO FRIDAY. THIS WILL ALLOW GULF MOISTURE TO STREAM BACK NORTHWARD BY LATE WEEK INTO THE WEEKEND...WITH THETA-E RIDGING BUILDING NORTHWARD THROUGH THE WESTERN/CENTRAL CWA. THEREFORE CHANCES FOR CONVECTION CREEP BACK INTO THE CWA. FROM WEST TO EAST BY LATE THIS WEEK. THE ACTIVE PATTERN CONTINUES INTO THE WEEKEND/EARLY NEXT WEEK AS AN UPPER TROUGH DIGS INTO THE WESTERN US...SETTING UP SOUTHWESTERLY UPPER LEVEL FLOW ACROSS THE CENTRAL US AND STRONGER FLOW OFF THE GULF. GFS/EC HAVE A SFC LOW EJECTING NORTHEASTWARD ACROSS THE CENTRAL PLAINS INTO THE ERN DAKOTAS/WRN MN AREA BY LATE MONDAY INTO TUESDAY. THIS SHOULD PUT THE DMX CWA IN THE WARM SECTOR WITH INCREASING CHANCES FOR CONVECTION SUNDAY INTO MONDAY AS THE ASSOCIATED WARM FRONT LIFTS THROUGH THE CWA AND A DRY LINE FEATURE SURGES THROUGH AS WELL. THIS SCENARIO WOULD LIKELY BRING A SEVERE WEATHER THREAT BACK TO THE CWA AS WELL AS INCREASING CHANCES FOR THUNDERSTORMS AND WIDESPREAD RAINFALL. AS FOR TEMPERATURES...H85 TEMPS IN THE MID TEENS THROUGHOUT MUCH OF THE WEEK AND INCREASE TOWARD THE UPPER TEENS BY THE WEEKEND INTO EARLY NEXT WEEK. THEREFORE EXPECT THE TREND OF NEAR AVERAGE TO SLIGHTLY ABOVE AVERAGE TEMPERATURES TO CONTINUE THROUGH THE MID/LONG RANGE. && .AVIATION...27/18Z ISSUED AT 1256 PM CDT TUE MAY 27 2014 CONVECTIVE TRENDS WILL BE THE MAIN CONCERN THIS PERIOD. MID/HIGH BASED VFR CIGS ARE IN PLACE OVER MOST OF IA WITH ISOLATED MVFR CONDITIONS NEAR STORMS. CONFIDENCE IN TIMING...OR OCCURRENCE...OF THUNDER AT ANY PARTICULAR LOCATION IS FAIRLY LOW OUTSIDE OF CURRENT ACTIVITY NEAR KMCW...SO NOTHING MORE THAN VCSH WORDING FOR A START. WILL INJECT STRONGER WORDING OR THUNDER AS NEEDED AND CONFIDENCE INCREASES. VFR CONDITIONS WILL CONTINUE INTO WED MORNING...ALTHOUGH PATCHY MVFR DUE TO VSBYS AND/OR CIGS MAY RETURN BRIEFLY JUST BEFORE SUNRISE. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SMALL LONG TERM...BEERENDS AVIATION...SMALL  FXUS63 KDMX 282024 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 324 PM CDT WED MAY 28 2014 .SHORT TERM /TONIGHT/... ISSUED AT 323 PM CDT WED MAY 28 2014 FEW ISOLATED STORMS HAVE MADE THEIR WAY INTO THE EASTERN CWA...BUT OVERALL COVERAGE HAS REMAINED LESS THAN ANTICIPATED AND STAYED EAST OF THE CWA. MAJORITY OF THE ACTIVITY CURRENTLY LINING UP WELL WITH AN AREA OF THETA-E ADVECTION ACROSS SOUTHEAST IOWA...WHICH SHOULD TRANSLATE SOUTH-SOUTHWESTWARD ACROSS EXTREME SOUTHERN AND SOUTHEASTERN IOWA THROUGH THE NIGHT. WITH DRIER AIR MOVING IN FROM THE NORTHEAST ASSOCIATED WITH LARGE SFC HIGH OVER THE NORTHERN GREAT LAKES REGION. THEREFORE HAVE CUT BACK ON POPS FOR LATE THIS AFTERNOON INTO THE EVENING HOURS WITH ACTIVITY EXPECTED TO BE CONFINED TO THE SOUTHEASTERN CWA IF IT MAKES IT INTO THE AREA. LATEST MESO DATA SUGGESTS DECENT INSTABILITY...BUT MAIN MOISTURE PUSH IS OFF TO THE SOUTHEAST AT THIS TIME. STILL HAVE DECENT LOW LEVEL CAPE AND SOME SFC VORTICITY WHICH IS ALLOWING THE NST PARAMETER TO BE PEGGED OFF TO THE SOUTH/EAST OF THE CWA. IT IS NUDGING INTO THE SOUTHEASTERN CWA...THEREFORE IF WE DO GET SOME STRONGER CELLS THERE EXISTS A SMALL CHANCE FOR AN ISOLATED FUNNEL CLOUD REPORT WITH A SIMILAR ENVIRONMENT TO TUESDAY AFTERNOON. OVERALL REGARDING TEMPS TONIGHT...WITH THE DRIER AIR PUSHING IN EXPECT TEMPS TO FALL A BIT MORE ACROSS THE AREA THAN IN PREVIOUS NIGHTS. HOWEVER MAJORITY OF SITES SHOULD REMAIN NEAR THE SEASONAL AVERAGES OR WARMER. MAY STILL SEE SOME LIGHT FOG AGAIN TONIGHT...BUT WITH THE DRIER AIR MOVING IN DID NOT MENTION IT IN THE GRIDS AT THIS TIME. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 323 PM CDT WED MAY 28 2014 OVER THE NEXT COUPLE OF DAYS WEAK FLOW ALOFT WILL STILL DOMINATE THE PATTERN ACROSS THE CENTRAL PLAINS. UPPER LOW WILL CONTINUE TO WEAKEN OVER IOWA BY THURSDAY AND SHOULD BE JUST SOUTH OF AREA BY THURSDAY EVENING. HOWEVER...WITH APPROACHING WAVE OVER THE NORTHERN PLAINS THE SUBTLE RETURN FLOW IS LIKELY TO DRAW SOME REMNANT MOISTURE BACK NORTHWEST AND KEEP CLOUDS AND HUMIDITY ON THE UPSWING THROUGH THE WEEKEND ESPECIALLY ACROSS THE WEST AND SOUTHWEST. MODELS CONTINUE TO DIFFER ON TIMING OF RETURN FLOW AND GFS HAS BEEN MOST AGGRESSIVE WITH CLOUD COVER AND SHOWERS ALREADY ON FRIDAY AND FRIDAY NIGHT. THE GFS APPEARS TO BE SOMEWHAT OVERDONE COMPARED TO THE REST OF THE MODELS TODAY AND WILL LEAN TOWARD A SLOWER RETURN AND LESS OVERALL COVERAGE OF MOISTURE THROUGH FRIDAY. THE CONSENSUS EVOLUTION OF THE WEEKEND SYSTEM SUGGESTS THAT FROM SATURDAY ONWARD...CHANCES FOR THUNDER WILL EXIST DUE TO A WARM UNSTABLE ATMOSPHERE AND PEAKING WITH DAYTIME HEATING. DAYTIME HIGHS WILL RANGE FROM THE UPPER 70S TO LOWER 80S EACH DAY WITH MINS IN THE 60S. AS THE UPPER LEVEL LOW OVER THE WEST BEGINS TO EJECT SOME SHORT WAVE ENERGY INTO THE PLAINS...FORCING FOR STORMS WILL ALSO BE ON THE INCREASE. BY MONDAY AND TUESDAY OF NEXT WEEK SEVERAL MODEST WAVES WILL TRACK ACROSS THE PLAINS WITH INCREASING CHANCES FOR THUNDERSTORMS AND AN INCREASED RISK FOR SEVERE STORMS EACH DAY. CURRENT PATTERN AND UPPER LEVEL WIND FORECASTS SUGGEST THAT NO SINGLE STRONG WAVE WILL WASH THROUGH THE FLOW...BUT RATHER A NUMBER OF WEAKER WAVES. WITH WIND FIELDS LOOKING TO BE MODEST...ITS MORE LIKELY THAT ANY SEVERE THREAT WILL BE BLENDED WITH A HEAVY RAINFALL THREAT OVER SEVERAL DAYS. THE 12Z EURO/12Z GFS MODEL RUN ACCUM PRECIP SHOWS ANYWHERE FROM 2 TO 4 INCHES DURING THE NEXT TEN DAYS WITH MOST OF THAT FALLING THROUGH LATE NEXT WEEK. THE GFS PWATS CONTINUE TO INCREASE INTO THIS WEEKEND WITH VALUES IN THE 1.5 TO 2 INCH RANGE FROM SUNDAY NIGHT THROUGH TUESDAY AND WARM CLOUD DEPTHS SUPPORT EFFICIENT RAINFALL RATES. FOLLOWING THE PASSAGE OF THE WAVE AND ASSOCIATED SURFACE LOW TUESDAY THERE MAY BE A BRIEF 12-24 HOUR BREAK PRIOR TO ANOTHER WAVE ARRIVING BY WED EVENING OR THURSDAY. TEMPS THROUGH THE PERIOD WILL REMAIN NEARLY STEADY WITH ZONAL FLOW AND LACK OF ANY STRONG TEMPERATURE ADVECTION EITHER FROM THE NORTHERN PLAINS OR SOUTHERN PLAINS. && .AVIATION...28/18Z ISSUED AT 1257 PM CDT WED MAY 28 2014 STRATUS DECK THAT HAS BEEN IN PLACE ACROSS MUCH OF THE CWA...IS BEGINNING TO LIFT AND BECOME MORE CELLULAR IN NATURE. THIS SHOULD ALLOW MAJORITY OF TAF SITES CIGS TO GO VFR THIS AFTERNOON AND REMAIN THERE THROUGH THE REMAINDER OF THE FORECAST PERIOD. SOME POP UP THUNDERSTORMS FORMING ACROSS SOUTHEAST IOWA...AND EXPECT SOME OF THESE TO IMPACT KALO AND KOTM THROUGH THE AFTERNOON HOURS. THEY MAY COME CLOSE TO KMCW AND KDSM...BUT HAVE LEFT DRY ATTM. OTHERWISE MAY SEE SOME LIGHT FOG DEVELOP AGAIN LATE TONIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BEERENDS LONG TERM...REV AVIATION...BEERENDS  FXUS63 KDMX 282340 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 640 PM CDT WED MAY 28 2014 ...UPDATED AVIATION DISCUSSION.. .SHORT TERM /TONIGHT/... ISSUED AT 323 PM CDT WED MAY 28 2014 FEW ISOLATED STORMS HAVE MADE THEIR WAY INTO THE EASTERN CWA...BUT OVERALL COVERAGE HAS REMAINED LESS THAN ANTICIPATED AND STAYED EAST OF THE CWA. MAJORITY OF THE ACTIVITY CURRENTLY LINING UP WELL WITH AN AREA OF THETA-E ADVECTION ACROSS SOUTHEAST IOWA...WHICH SHOULD TRANSLATE SOUTH-SOUTHWESTWARD ACROSS EXTREME SOUTHERN AND SOUTHEASTERN IOWA THROUGH THE NIGHT. WITH DRIER AIR MOVING IN FROM THE NORTHEAST ASSOCIATED WITH LARGE SFC HIGH OVER THE NORTHERN GREAT LAKES REGION. THEREFORE HAVE CUT BACK ON POPS FOR LATE THIS AFTERNOON INTO THE EVENING HOURS WITH ACTIVITY EXPECTED TO BE CONFINED TO THE SOUTHEASTERN CWA IF IT MAKES IT INTO THE AREA. LATEST MESO DATA SUGGESTS DECENT INSTABILITY...BUT MAIN MOISTURE PUSH IS OFF TO THE SOUTHEAST AT THIS TIME. STILL HAVE DECENT LOW LEVEL CAPE AND SOME SFC VORTICITY WHICH IS ALLOWING THE NST PARAMETER TO BE PEGGED OFF TO THE SOUTH/EAST OF THE CWA. IT IS NUDGING INTO THE SOUTHEASTERN CWA...THEREFORE IF WE DO GET SOME STRONGER CELLS THERE EXISTS A SMALL CHANCE FOR AN ISOLATED FUNNEL CLOUD REPORT WITH A SIMILAR ENVIRONMENT TO TUESDAY AFTERNOON. OVERALL REGARDING TEMPS TONIGHT...WITH THE DRIER AIR PUSHING IN EXPECT TEMPS TO FALL A BIT MORE ACROSS THE AREA THAN IN PREVIOUS NIGHTS. HOWEVER MAJORITY OF SITES SHOULD REMAIN NEAR THE SEASONAL AVERAGES OR WARMER. MAY STILL SEE SOME LIGHT FOG AGAIN TONIGHT...BUT WITH THE DRIER AIR MOVING IN DID NOT MENTION IT IN THE GRIDS AT THIS TIME. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 323 PM CDT WED MAY 28 2014 OVER THE NEXT COUPLE OF DAYS WEAK FLOW ALOFT WILL STILL DOMINATE THE PATTERN ACROSS THE CENTRAL PLAINS. UPPER LOW WILL CONTINUE TO WEAKEN OVER IOWA BY THURSDAY AND SHOULD BE JUST SOUTH OF AREA BY THURSDAY EVENING. HOWEVER...WITH APPROACHING WAVE OVER THE NORTHERN PLAINS THE SUBTLE RETURN FLOW IS LIKELY TO DRAW SOME REMNANT MOISTURE BACK NORTHWEST AND KEEP CLOUDS AND HUMIDITY ON THE UPSWING THROUGH THE WEEKEND ESPECIALLY ACROSS THE WEST AND SOUTHWEST. MODELS CONTINUE TO DIFFER ON TIMING OF RETURN FLOW AND GFS HAS BEEN MOST AGGRESSIVE WITH CLOUD COVER AND SHOWERS ALREADY ON FRIDAY AND FRIDAY NIGHT. THE GFS APPEARS TO BE SOMEWHAT OVERDONE COMPARED TO THE REST OF THE MODELS TODAY AND WILL LEAN TOWARD A SLOWER RETURN AND LESS OVERALL COVERAGE OF MOISTURE THROUGH FRIDAY. THE CONSENSUS EVOLUTION OF THE WEEKEND SYSTEM SUGGESTS THAT FROM SATURDAY ONWARD...CHANCES FOR THUNDER WILL EXIST DUE TO A WARM UNSTABLE ATMOSPHERE AND PEAKING WITH DAYTIME HEATING. DAYTIME HIGHS WILL RANGE FROM THE UPPER 70S TO LOWER 80S EACH DAY WITH MINS IN THE 60S. AS THE UPPER LEVEL LOW OVER THE WEST BEGINS TO EJECT SOME SHORT WAVE ENERGY INTO THE PLAINS...FORCING FOR STORMS WILL ALSO BE ON THE INCREASE. BY MONDAY AND TUESDAY OF NEXT WEEK SEVERAL MODEST WAVES WILL TRACK ACROSS THE PLAINS WITH INCREASING CHANCES FOR THUNDERSTORMS AND AN INCREASED RISK FOR SEVERE STORMS EACH DAY. CURRENT PATTERN AND UPPER LEVEL WIND FORECASTS SUGGEST THAT NO SINGLE STRONG WAVE WILL WASH THROUGH THE FLOW...BUT RATHER A NUMBER OF WEAKER WAVES. WITH WIND FIELDS LOOKING TO BE MODEST...ITS MORE LIKELY THAT ANY SEVERE THREAT WILL BE BLENDED WITH A HEAVY RAINFALL THREAT OVER SEVERAL DAYS. THE 12Z EURO/12Z GFS MODEL RUN ACCUM PRECIP SHOWS ANYWHERE FROM 2 TO 4 INCHES DURING THE NEXT TEN DAYS WITH MOST OF THAT FALLING THROUGH LATE NEXT WEEK. THE GFS PWATS CONTINUE TO INCREASE INTO THIS WEEKEND WITH VALUES IN THE 1.5 TO 2 INCH RANGE FROM SUNDAY NIGHT THROUGH TUESDAY AND WARM CLOUD DEPTHS SUPPORT EFFICIENT RAINFALL RATES. FOLLOWING THE PASSAGE OF THE WAVE AND ASSOCIATED SURFACE LOW TUESDAY THERE MAY BE A BRIEF 12-24 HOUR BREAK PRIOR TO ANOTHER WAVE ARRIVING BY WED EVENING OR THURSDAY. TEMPS THROUGH THE PERIOD WILL REMAIN NEARLY STEADY WITH ZONAL FLOW AND LACK OF ANY STRONG TEMPERATURE ADVECTION EITHER FROM THE NORTHERN PLAINS OR SOUTHERN PLAINS. && .AVIATION...29/00Z ISSUED AT 635 PM CDT WED MAY 28 2014 EXPECTING FOG TO DEVELOP AGAIN ACROSS THE CENTRAL TO SOUTHERN PART OF THE STATE BY EARLY THURSDAY MORNING. HAVE MVFR VIS MENTION AT DSM/ALO/OTM BY 09Z. LOWER CONFIDENCE AT ALO TO SEE FOG...BUT KEPT FOG MENTION WITH DEW POINTS STILL WELL INTO THE 50S AND LIGHT WINDS TONIGHT. HOWEVER...NORTHEAST WINDS WILL CONTINUING TO ADVECT IN DRIER AIR...POTENTIAL ALO MAY STAY VFR. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...BEERENDS LONG TERM...REV AVIATION...PODRAZIK  FXUS63 KDMX 290833 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 333 AM CDT THU MAY 29 2014 .SHORT TERM /TODAY/... ISSUED AT 333 AM CDT THU MAY 29 2014 MUCH DRIER AIR MOVED INTO NORTHERN IA OVERNIGHT...ORIGINATING FROM HIGH PRESSURE OVER THE GREAT LAKES. DEWPOINTS DROPPED INTO THE INTO THE 30S BRIEFLY BUT HAVE SINCE REBOUNDED TO THE MID 40S. IN CONTRAST...DEWPOINTS REMAINED IN THE LOW TO MID 60S OVER SOUTHERN IOWA. IOWA WILL BE IN EASTERLY FLOW TODAY THANKS TO THE HIGH PRESSURE SYSTEM. A PLUME OF MOISTURE WILL ROTATE AROUND ALONG THE SOUTHERN PERIPHERY OF THIS FLOW AND INTO SOUTHERN IOWA TODAY. THE RESULT INITIALLY WILL BE INCREASING CLOUDS AND SOME CUMULUS DEVELOPMENT. THE ATMOSPHERE ACROSS THE SOUTH WILL DESTABILIZE AS TEMPERATURES PUSH INTO THE MID 70S AND ABOVE RESULTING IN SFC BASED CAPE VALUES AROUND 1500 J/KG WITH LITTLE TO NO CONVECTIVE INHIBITION IN PLACE. STILL THERE WILL NOT BE MUCH FORCING AROUND TODAY TO TRIGGER WIDESPREAD CONVECTION. A WEAK SHORT WAVE MOVES FROM WEST TO EAST ACROSS THE STATE THIS MORNING ALONG WITH SOME MODEST THETA-E ADVECTION. BY THIS AFTERNOON...FORCING WILL BE VERY WEAK AT BEST. POSSIBLE FOR ISOLATED TO SCATTERED SHOWERS AND UNORGANIZED STORMS. WEAK FLOW AND INCREASING PWATS TO 1.4 INCHES AND HIGHER ALONG WITH WARM CLOUD DEPTHS IN EXCESS OF 12 KFT WILL LEAD TO THE POTENTIAL FOR EFFICIENT RAIN PRODUCING CELLS. THAT SAID...THE LACK OF DEEP LAYER SHEAR SHOULD RESULT IN SHORT LIFE CYCLES FOR ANYTHING THAT DEVELOPS. TEMPERATURES WILL BE SIMILAR TO THE PAST SEVERAL DAYS WITH HIGHS IN THE UPPER 70S TO MID 80S. .LONG TERM /TONIGHT THROUGH WEDNESDAY/... ISSUED AT 333 AM CDT THU MAY 29 2014 UPPER RIDGING WILL BE SLIDING ACROSS THE CENTRAL U.S. TONIGHT INTO FRIDAY WITH UPPER LOW ACROSS THE DEEP SOUTH RETROGRADING ON UNDERNEATH SIDE OF RIDGE. A WEAK SHORTWAVE WILL MOVE NORTHWEST INTO IOWA ALONG WITH INCREASING MOISTURE ON FRIDAY WITH THE THREAT OF ISOLATED TO SCATTERED STORMS IN THE SOUTH AND WEST BY AFTERNOON AND DIURNALLY DRIVEN. THEREFORE...ANTICIPATE THIS CONVECTION TO END QUICKLY ON FRIDAY EVENING WITH RELATIVELY QUITE CONDITION ON FRIDAY NIGHT. MOISTURE WILL CONTINUE TO INCREASE ON SATURDAY WITH PWATS FROM 1.50-2.00" ACROSS THE AREA BY AFTERNOON. ONCE AGAIN ANTICIPATE ISOLATED TO SCATTERED THUNDERSTORMS TO DEVELOP BY AFTERNOON WITH DAYTIME HEATING. SHEAR WILL REMAIN WEAK ON BOTH FRIDAY AND SATURDAY WITH STORMS DOMINATED BY COLD POOL OUTFLOW AND LITTLE SEVERE WEATHER THREAT. HOWEVER...GIVEN THE HIGH PWATS...LOCALIZED HEAVY RAINFALL APPEARS POSSIBLE WITH THESE STORMS. FOCUS FOR CONVECTION SHIFTS INTO THE NORTHERN PLAINS ON SATURDAY NIGHT INTO EARLY SUNDAY WITH MUCH OF IOWA AGAIN QUIET. HOWEVER... JET AXIS WILL BEGIN TO APPROACH IOWA FROM THE NORTHWEST ON SUNDAY INTO MONDAY WITH SURFACE BOUNDARY ENTERING THE STATE. THIS WILL PROVIDE A FOCUS FOR CONVECTION FROM LATE SUNDAY INTO TUESDAY BEFORE SURFACE WAVE PASSES. SHEAR REMAINS SOMEWHAT WEAK ALTHOUGH SOME INCREASE IS NOTED ON SOUNDINGS WITH THE APPROACH OF MID LEVEL SHORTWAVE AND BETTER FORCING. THEREFORE...THERE IS LIKELY TO BE AT LEAST A MARGINAL THREAT OF SEVERE WEATHER INTO EARLY NEXT WEEK. PWATS REMAIN RATHER HIGH DURING THIS TIME AS WELL WITH THE THREAT OF HEAVY RAINFALL PERSISTING. TIMING AND PLACEMENT DIFFERENCE BECOME RATHER SIGNIFICANT BY NEXT TUESDAY BETWEEN THE EURO AND GFS WITH LITTLE CONFIDENCE IN THE FORECAST BEYOND THAT POINT. TEMPERATURES FOR MUCH OF THE FORECAST PERIOD WILL BE AT OR ABOVE NORMAL AS JET AXIS REMAIN NORTH OF THE STATE THROUGH THE WEEKEND. && .AVIATION...29/06Z ISSUED AT 1127 PM CDT WED MAY 28 2014 VFR CONDITIONS WILL PREVAIL DURING THE ENTIRE TAF PERIOD. TOOK OUT MENTION OF MVFR FOG WITH DRIER AIR ADVECTING INTO THE STATE AND MID LEVEL CLOUD COVER OVER SOUTHERN IOWA. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...DONAVON LONG TERM...COGIL AVIATION...PODRAZIK  FXUS63 KDMX 302122 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 422 PM CDT FRI MAY 30 2014 .SHORT TERM /TONIGHT/... ISSUED AT 421 PM CDT FRI MAY 30 2014 LEANING HEAVILY ON PERSISTENCE FOR THIS SHORT TERM FORECAST. MUCH LIKE THE PREVIOUS DAYS THIS WEEK...CU FIELD DEVELOPING ACROSS CENTRAL IOWA. SUFFICIENT CAPE TO CONTINUE TO BUILD ACROSS THE CWA... WITH VALUES LIKELY REACHING 1500 TO 2000 J/KG. AS WITH THE PAST COUPLE OF DAYS...THE SHEAR FIELD IS VERY WEAK. THERE IS ALSO LACK OF A DECENT FOCUSING MECHANISM. LAPSE RATES ARE NOT TERRIBLY STEEP AS WELL. THIS GENERAL SETUP HAS BEEN IN PLACE THE PAST COUPLE OF DAYS ACROSS THE CWA...YIELDING SCATTERED...NON SEVERE...STORMS WHICH DIE OFF WITH LOSS OF DAYTIME HEATING. THEREFORE AM THINKING TODAY WILL BE SIMILAR...WITH GREATEST STORM CHANCES IN DMX CWA EXPECTED MAINLY WEST OF INTERSTATE 35. A QUICK TENTH TO QUARTER OF AN INCH WILL BE POSSIBLE WITH THESE STORMS. TEMPERATURES TO REMAIN ABOVE NORMAL THROUGH THE OVERNIGHT. AS OF EARLY FRIDAY AFTERNOON...TEMPS ALREADY IN THE LOW TO MID 80S ACROSS THE CWA...WITH DWPTS IN THE LOW TO MID 60S. SERLY FLOW WILL REINFORCE LOW LEVEL MOISTURE AND +2 TO +3 STD DEV PWAT VALUES OVERNIGHT. AS A RESULT...OVERNIGHT LOWS SHOULD ONCE AGAIN HEDGE CLOSE TO PERSISTENCE...BOTTOMING OUT GENERALLY IN THE MID 60S. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 421 PM CDT FRI MAY 30 2014 CONVECTIVE TRENDS THROUGH MONDAY THEN AGAIN MID NEXT WEEK ARE THE PRIMARY CHALLENGES FOR THE FORECAST. SIMILAR SITUATION ON SATURDAY AS TODAY WITH A CONVECTIVELY UNSTABLE AIRMASS IN PLACE THOUGH OVERALL FORCING WILL BE WEAK.SHOULD HAVE POPCORN TYP SHOWERS AND THUNDERSTORMS DEVELOPING BY LATE MORNING AND CONTINUE THROUGH THE AFTERNOON. INDIVIDUALLY THESE SINGLE CELL STORMS WILL SHORT LIVED IN THE VERY WEAK SHEAR ENVIRONMENT WITH THE DOWN DRAFT/COLD POOLS QUICKLY UNDERCUTTING UPDRAFTS...BUT COULD HAVE SOME SMALL HAIL AND GUSTY WINDS WITH THE STRONGER CELLS. THE UPPER RIDGE WILL BEGIN TO SHIFT EAST LATE SATURDAY AND INTO SUNDAY. MUCH OF SUNDAY WILL BE SIMILAR TO TODAY AND SATURDAY WITH THE CONVECTIVE TREND FOCUS SHIFTED A BIT FURTHER EAST. A FRONTAL BOUNDARY WILL SINK INTO THE NORTHWEST LATE SUNDAY INTO SUNDAY NIGHT IN ADVANCE OF AN APPROACHING UPPER SHORT WAVE. MOISTURE TRANSPORT WILL INCREASE DURING THIS PERIOD AS WELL WITH PWAT VALUES BALLOONING TO NEAR ONE AND THREE QUARTERS INCHES. SOME POTENTIAL FOR SEVERE WEATHER INITIALLY ESPECIALLY ACROSS THE NORTHWEST AND IN VICINITY OF THE APPROACHING BOUNDARY WITH MAINLY LARGE HAIL AND DAMAGING WINDS POSSIBLE. POTENTIAL FOR LOCALLY HEAVY RAINS DOES INCREASE OVERNIGHT WITH THE HIGHER PWAT VALUES AND GOOD WARM CLOUD DEPTHS IN PLACE. LIKELY WILL HAVE STORMS FIRE ACROSS NEBRASKA AND SHIFT EAST AS AN MCS OVERNIGHT. STORM CHANCES WILL CONTINUE THROUGH EARLY MONDAY THEN MUCH DRIER AIR MOVES INTO THE STATE. HAVE DECREASED POPS LATE MONDAY THROUGH TUESDAY WITH THE DRIER AIR MASS AND AN STRENGTHENING ELEVATED MIXED LAYER ARRIVING. LATEST GUIDANCE IS STARTING TO PHASE A LITTLE BETTER ON TIMING FOR THE MID WEEK SHORT WAVE THAT WILL BE ARRIVING LATE TUESDAY NIGHT INTO WEDNESDAY. STRONG MOISTURE ADVECTION WILL AGAIN DEVELOP AHEAD OF THE SYSTEM WITH PWATS RISING TO NEAR ONE AND ONE HALF INCHES BY WEDNESDAY RESULTING IN ADDITIONAL THUNDERSTORM CHANCES. THE ECMWF STILL TRYING TO DEEPEN THE UPPER LOW AND LINGER THE SYSTEM THE REMAINDER OF THE WEEK. PREFER THE MORE PROGRESSIVE SOLUTIONS OF THE GFS/GEM. && .AVIATION...30/18Z ISSUED AT 1233 PM CDT FRI MAY 30 2014 LEANED HEAVILY ON PERSISTENCE FOR THIS FORECAST. FRIDAY AFTERNOON WILL BE VERY SIMILAR TO THE PAST FEW DAYS IN THAT SCATTERED STORMS ARE EXPECTED TO DEVELOP ACROSS CENTRAL IOWA DURING THE PEAK OF DAYTIME HEATING. THESE STORMS SHOULD STAY BELOW SEVERE LEVELS AND DIMINISH AROUND SUNSET...AS SIMILAR TO THE PAST FEW DAYS. AS OF NOW...KFOD AND KDSM ARE THE TWO TAF SITES MOST LIKELY TO BE IMPACTED BY SCATTERED STORMS. WILL WATCH TO SEE IF KOTM NEEDS TO BE ADDED. LOTS OF MOISTURE IN LOW LEVELS OVERNIGHT. PUT BR IN FOR KOTM...MAY NEED TO TWEAK VSBYS. WITH SUN RISING AND RAPIDLY HEATING SFC...NO DENSE FOG EXPECTED TOMORROW MORNING. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KOTENBERG LONG TERM...DONAVON AVIATION...KOTENBERG  FXUS63 KDMX 312052 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 352 PM CDT SAT MAY 31 2014 .SHORT TERM /TONIGHT/... ISSUED AT 314 PM CDT SAT MAY 31 2014 CONVECTIVE TRENDS REMAIN THE PRIMARY CONCERN INTO TONIGHT. UPPER LEVEL RIDGE CONTINUES TO DRIFT EASTWARD WITH MUCAPE/K INDEX AXIS FOLLOWING INKIND. 1-2KM MOISTURE/THETA-E CONVERGENCE HAS ALSO MOVED ACROSS THE STATE TODAY AS WELL...POSSIBLY AIDED BY WEAK GRAVITY WAVE FROM PREVIOUS PLAINS CONVECTION. DEEP MOISTURE CONVERGENCE MAX IS PRESENTLY OVER ERN SECTIONS SO EXPECT THIS HALF OF THE FORECAST AREA NEAR INSTABILITY GRADIENT TO HAVE THE MOST COVERAGE INTO THE EARLY EVENING. EXPECT SIMILAR UNORGANIZED DIURNALLY DRIVEN CONVECTION WITH LACK OF DEEP SHEAR. OVERNIGHT ATTENTION WILL TURN UPSTREAM TO EVOLUTION OF CURRENT SIOUXLAND CONVECTION. 305K ISENT SURFACES SUGGEST SOMEWHAT MORE FAVORABLE ENVIRONMENT NW WITH WEAK BAROCLINIC ZONE LIFTING THROUGH NW IA OVERNIGHT AND ASSOCIATED MOISTURE TRANSPORT VECTORS SHIFTING FROM SELY TO A THERMODYNAMICALLY MORE FAVORABLE SWLY COMPONENT. THUS HAVE HIGH END CHANCE POPS NORTH. HEAVY RAINS AGAIN THE BIGGEST THREAT WITH SHEAR STILL WEAK. PWS SHOULD HOVER AROUND 1.5 WITH MEAN WIND AROUND 20KTS...NIL CORFIDI VECTORS AND DEEP WARM CLOUD DEPTHS. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 314 PM CDT SAT MAY 31 2014 MAY ALLOW FOR LINGERING PRECIPITATION IN THE MORNING HOURS SUNDAY...ESPECIALLY IN THE NORTH AND EAST. A SURFACE LOW PRESSURE SYSTEM WILL PUSH EASTWARD THROUGH THE BEGINNING OF THE WEEK...WHICH WILL BE THE MAIN FOCUS FOR PRECIPITATION CHANCES. ANTICIPATE CONVECTION TO BEGIN IN NEBRASKA BEFORE PUSHING EAST INTO IOWA LATE SUNDAY AND INTO THE OVERNIGHT HOURS. GOOD MOISTURE AHEAD OF SYSTEM...AND MAY SEE HEAVY RAIN WITH STORMS OVERNIGHT. IN ADDITION...THERE IS SOME UNCERTAINTY IN MODELS AS TO WHERE BEST PRECIPITATION CHANCES WILL BE...AND HAVE KEPT LIKELY POPS ACROSS CWA...THOUGH MODELS ARE ATTEMPTING TO PULL SYSTEM A BIT FURTHER SOUTH. LOW PRESSURE SYSTEM WILL BE QUICK MOVING...AND HAVE SPED UP TIMING A BIT ON POPS...WITH SYSTEM PUSHING EAST BY EARLY TUESDAY MORNING. TEMPERATURES WILL BE WARM...ESPECIALLY IN THE WEST...WITH WAA ACROSS THE AREA THROUGH MONDAY. HOWEVER...ANOTHER SYSTEM WILL MOVE IN QUICKLY FOR TUESDAY...WITH BOUNDARY EXPECTED TO BE ACROSS/NEAR SOUTHERN IOWA AS SURFACE LOW TRACKS EAST ACROSS KS/MO. THIS WILL BE BEST CHANCE FOR SEVERE WEATHER AND HEAVY RAIN IN THE EXTENDED. TIMING ON SYSTEM IS STILL UNCERTAIN...THOUGH WILL SEE MAXIMIZED THREAT NEAR BOUNDARY. MODELS AGAIN ARE DEVELOPING CONVECTION TO THE WEST...PUSHING ACROSS IOWA OVERNIGHT. HAVE THEREFORE KEPT BEST POPS TUESDAY CONFINED TO OVERNIGHT PERIOD. WITH OVERNIGHT CONVECTION...WILL SEE CHANCES FOR HEAVY RAIN WITH PWAT VALUES JUST BELOW 1.5 INCHES...SEASONABLY HIGH...AND GOOD MOISTURE TRANSPORT INTO SOUTHERN IOWA. WILL AGAIN SEE LINGERING PRECIPITATION INTO WEDNESDAY AS SYSTEM CONTINUES TO PUSH EAST. WEAK RIDGE THEN BUILDS IN FOR LATE IN THE WEEK...WITH FRONT SOUTH OF IOWA...WHICH WILL HELP TO LIMIT PRECIPITATION CHANCES...ESPECIALLY IN THE NORTH. HAVE LOW CONFIDENCE IN POPS FOR END OF WEEK...THOUGH MODELS DO KEEP BOUNDARY INTO NORTHERN MISSOURI AND MAY SEE A SHIFT FURTHER NORTH. TEMPERATURES WILL BE COOLER BEHIND BOUNDARY FOR END OF WEEK. && .AVIATION...31/18Z ISSUED AT 100 PM CDT SAT MAY 31 2014 VFR CONDITIONS ARE GENERALLY ANTICIPATED THROUGH THE PERIOD. EXPECT UNORGANIZED WIDELY SCATTERED DIURNALLY DRIVEN CONVECTION INTO THE EARLY EVENING...WITH THE POTENTIAL FOR ADDITIONAL CONVECTION ENTERING IA FROM THE NORTH AND WEST EARLY SUN MORNING. MVFR OR LOWER CONDITIONS ARE POSSIBLE FOR BRIEF DURATIONS...BUT TIMING AND LOCATION CONFIDENCE IS CERTAINLY NOT GREAT ENOUGH TO INCLUDE THAT MENTION OR THUNDER FOR THAT MATTER. MINIMAL POTENTIAL FOR MVFR FOG DEVELOPMENT EARLY SUN MORNING...BUT SIMILARLY CONFIDENCE NOT THERE FOR INCLUSION AS OF YET. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMALL LONG TERM...AWB AVIATION...SMALL  FXUS63 KDMX 012104 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 404 PM CDT SUN JUN 1 2014 .SHORT TERM /TONIGHT/... ISSUED AT 345 PM CDT SUN JUN 1 2014 PRIMARY CONCERN THIS AFTERNOON WILL OBVIOUSLY BE CONVECTIVE TRENDS. SEPARATE MCS CLUSTERS OVER NE AND SRN MN MERGED DURING THE AFTERNOON ALONG 0-1KM CONVERGENCE AXIS IN ENVIRONMENT OF INCREASING MLCAPES... 2000 J/KG...AND REDUCED CINH. RELATIVELY DEEP THERMODYNAMICALLY DOMINATE TORNADOES DEVELOPED DURING PEAK HEATING IN VERY WEAK SHEAR ENVIRONMENT OVER NRN IA NEAR BOUNDARY WITH 0-3KM CAPES J/KG AT TIMES. ESSENTIALLY VERY STRONG LANDSPOUTS WITH ROTATION NOTED ABOVE 10K FT ON RADAR. SEVERE POTENTIAL AND ONGOING WIND THREAT IN THE SIOUXLAND AREA SHOULD WEAKEN WITH TIME AS DEEP SHEAR DIMINISHES QUICKLY FARTHER EAST...BUT ATTENTION TURNING TO FLASH FLOODING AS NOTED BELOW. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 345 PM CDT SUN JUN 1 2014 FOR BEGINNING OF FORECAST PERIOD...ANTICIPATE OVERNIGHT CONVECTION TO BE CONTINUING TO PUSH EASTWARD ACROSS CWA...WITH LINGERING PRECIPITATION IN THE EAST. GIVEN AMOUNT OF MOISTURE PRESENT...MAY CONTINUE TO SEE CHANCES FOR HEAVY RAIN...HOWEVER...GIVEN BEST FORCING AND PRECIPITATION ANTICIPATED TO BE EAST OF THE AREA...WILL ALLOW FLASH FLOOD WATCH TO EXPIRE AT 12Z...THOUGH WILL NEED TO BE MONITORED BY NEXT SHIFT FOR POSSIBLE EXTENSION. WEAK SURFACE HIGH WILL THEN PUSH SOUTH FOR MONDAY WHICH WILL BRING COOLER TEMPERATURES...AND HAVE DROPPED LOWS A BIT MONDAY NIGHT WITH HIGH PUSHING SOUTH...HOWEVER BREAK WILL BE SHORT LIVED AS SECONDARY LOW PRESSURE SYSTEM BEGINS TO AFFECT THE REGION FOR TUESDAY. FORECAST FOR TUESDAY WILL BE THE MAIN CONCERN FOR THE EXTENDED. SURFACE LOW WILL PUSH EASTWARD ACROSS CENTRAL PLAINS WITH FRONTAL BOUNDARY EXTENDING INTO IOWA. HOWEVER...THERE IS STILL A GOOD AMOUNT OF UNCERTAINTY IN MODEL SOLUTIONS AS TO LOCATION OF THIS BOUNDARY AND TRACK OF THE LOW. LOCATION WILL BE CRITICAL TO FORECAST. NAM IS CURRENTLY FURTHEST NORTH SOLUTION...WITH OTHER MODELS ONLY SLIGHTLY FURTHER SOUTH. HOWEVER...GFS IS SOUTH ENOUGH TO KEEP BEST SEVERE WEATHER THREAT JUST SOUTH OF IOWA...HOWEVER THREAT SHOULD NOT BE DISCOUNTED GIVEN PROXIMITY TO FRONT...ESPECIALLY IN SOUTHERN IOWA...AS WELL AS SHEAR AND INSTABILITY PARAMETERS. SECONDARY CONCERN WITH SEVERE THREAT WILL BE LOCATION OF INITIATION...DEPENDENT ON LOCATION OF LOW. MODELS HAVE SLOWED PROGRESSION OF LOW SLIGHTLY...WITH CURRENT RUNS SUGGESTION INITIATION WEST OF IOWA...INTO NEBRASKA OR KANSAS CLOSER TO CENTER OF LOW. HOWEVER...COULD STILL SEE ENOUGH INSTABILITY AHEAD OF SYSTEM INTO IOWA TO ALLOW FOR THUNDERSTORM DEVELOPMENT IN AFTERNOON. HAVE THEREFORE KEPT POPS CONFINED TO WEST IN AFTERNOON. WITH SLOWER SOLUTION...SEEMS BEST THREAT FOR CENTRAL IOWA WILL BE MCS TRACKING ACROSS STATE OVERNIGHT. ONCE AGAIN...SEVERE THREAT CANNOT BE RULED OVER EVEN WITH OVERNIGHT PASSAGE AS SHEAR AND INSTABILITY REMAIN FAIRLY HIGH. ADDITIONAL CONCERN WILL BE WITH HEAVY RAINFALL...AS MOISTURE TRANSPORT REMAINS HIGH INTO CENTRAL IOWA AHEAD OF SYSTEM...AND PWAT VALUES ARE EXPECTED TO BE NEAR 1.8...WHICH IS SEASONLY HIGH. ANTICIPATE WIDESPREAD RAINFALL OVERNIGHT...AND HAVE SHIFTED SLIGHTLY FURTHER SOUTH GIVEN MODELS MORE SOUTHERLY TREND...AND HAVE INCREASED POPS AND QPF ACCORDINGLY. BEYOND TUESDAY... WEAK RIDGE WILL BUILD IN AHEAD OF ANOTHER LOW PRESSURE SYSTEM SET TO TRACK EASTWARD ACROSS CANADA. HAVE LOW CONFIDENCE IN POPS FOR THURSDAY AND FRIDAY HEAD OF THIS SYSTEM...THOUGH MAY SEE SCATTERED STORMS WITH ONLY WEAK HIGH TRACKING NEAR GREAT LAKES...AND HAVE LEFT SLIGHT CHANCE POPS. BEST CHANCES FOR ADDITIONAL PRECIPITATION WILL COME OVER THE WEEKEND AS FRONTAL BOUNDARY ASSOCIATED WITH CANADIAN LOW PRESSURE SYSTEM PUSHES INTO IOWA. TEMPERATURES WILL BE GENERALLY NEAR NORMAL THROUGH REMAINDER OF EXTENDED...WITH HIGHS IN THE 70S AND LOWS IN THE 50S AND 60S. && .HYDROLOGY... ISSUED AT 345 PM CDT SUN JUN 1 2014 AS MENTIONED ABOVE...EXPECT APPROACHING MCS TO WEAKEN SOMEWHAT WITH TIME INTO THE NIGHT WITH LOSS OF DAYTIME HEATING...INCREASED MLCINH...AND LACK OF DEEP SHEAR BUT MAINTAIN TO SOME EXTENT AS IT ENTERS IA AND STRONG LOW LEVEL MOISTURE TRANSPORT AND ASSOCIATED CONVERGENCE. PWS SHOULD PUSH TWO INCHES WITH WARM CLOUD DEPTHS TO 4KM AND NIL CORFIDI VECTORS...VERY FAVORABLE CONDITIONS FOR HEAVY RAIN. HAVE ISSUED A FLASH FLOOD WATCH WHERE PREVIOUS HEAVY RAINS FELL THIS AFTERNOON...BUT MAY HAVE TO BE EXPANDED SOUTHWARD DEPENDING ON MCS TRENDS. && .AVIATION...01/18Z ISSUED AT 345 PM CDT SUN JUN 1 2014 EXPECT VFR CONDITIONS THROUGH THE NIGHT OUTSIDE OF THUNDERSTORM TRENDS. HAVE THUNDER MENTIONED AT MORE LIKELY AREAS /KMCW/KFOD/ BUT WILL STAY WITH VCSH AT OTHER LOCATIONS DUE TO REDUCED TIMING CONFIDENCE...AVOIDING UNNECESSARY PROLONGED THUNDER MENTION. THERE IS ALSO THE POTENTIAL FOR MVFR OR LOWER FOG/STATUS OVERNIGHT...BUT CONFIDENCE IS NOT GREAT ENOUGH TO INCLUDE AT THE MOMENT. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH MONDAY MORNING FOR CERRO GORDO-EMMET- HANCOCK-KOSSUTH-PALO ALTO-POCAHONTAS-WINNEBAGO-WORTH. && $$ SHORT TERM...SMALL LONG TERM...AWB AVIATION...SMALL HYDROLOGY...SMALL  FXUS63 KDMX 022050 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 350 PM CDT MON JUN 2 2014 .SHORT TERM /TONIGHT/... ISSUED AT 315 PM CDT MON JUN 2 2014 LITTLE OF CONCERN TONIGHT. EFFECTS OF LONG WAVE TROUGH ARE WELL PAST IA WITH SUBSEQUENT SURFACE HIGH ENTERING STATE BY 12Z. CU SHOULD DISSIPATE TOWARD SUNSET WITH CLEAR SKIES AND WINDS BECOMING LIGHT NWLY OVERNIGHT. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 315 PM CDT MON JUN 2 2014 MAIN CONCERN FOR EXTENDED WILL REMAIN WITH TUESDAY SYSTEM. SYSTEM REMAINS HIGHLY DEPENDENT ON TRACK OF LOW PRESSURE SYSTEM...WHICH MODELS CONTINUE TO HAVE DISAGREEMENT ON...HOWEVER LATEST RUNS OF GFS/NAM COME INTO BETTER AGREEMENT WITH TRACK OF LOW EASTWARD NEAR KS/NE BOARDER...WITH ECMWF BECOMING THE FURTHER SOUTH SOLUTION. ANY MODEL AGREEMENT BREAKS DOWN BEYOND 00Z WEDNESDAY. OVERALL...ANTICIPATE STORMS TO DEVELOP IN NEBRASKA IN LATE AFTERNOON TUESDAY BEFORE LIKELY DEVELOPING LARGE MCS AND DROPPING SOUTHEAST ALONG INSTABILITY GRADIENT ACROSS IOWA. HOWEVER...LOCATION OF DEVELOPMENT...AND THEREFORE SOUTHEASTERLY TRACK INTO CENTRAL IOWA REMAINS UNCERTAIN. MODELS ATTEMPT TO DEVELOP SYSTEM NEAR TRIPLE POINT...IN NORTHERN NE NEAR SD BOARD. THIS WOULD PUSH SYSTEM THROUGH MUCH OF CENTRAL IOWA. DIFFERENT SOLUTION WOULD BE DEVELOPMENT OF THUNDERSTORMS ALONG BOUNDARY SOUTH OF LOW IN CENTRAL NEBRASKA...DEVELOPING INTO MCS WHICH WOULD LIKELY TRACK ACROSS EASTERN/CENTRAL IOWA OVERNIGHT. POTENTIAL FOR DEVELOPMENT IN BOTH LOCATIONS AS WELL. HAVE THEREFORE KEPT HIGH POPS ACROSS CENTRAL IOWA OVERNIGHT TUESDAY. FORCING WITH SYSTEM IS SIGNIFICANT WITH BEST FORCING ARRIVING IN CENTRAL IOWA NEAR 06Z. RIBBON OF THETA-E ADVECTION EXPECTED WITH 850MB WINDS TO BE STRONG...50-60KTS...TO HELP FUEL STORMS. IN ADDITION...MODELS INDICATING 1000-2000 J/KG SB CAPE BETWEEN 00-06Z IN SOUTHWESTERN IOWA...WHILE DECREASING BEYOND 06Z STILL REMAINING HIGH. SHEAR AND HELICITY VALUES ARE VERY HIGH AS WELL. NAM REMAINS MORE AGGRESSIVE ON CAPE WITH GFS MORE AGGRESSIVE ON SHEAR VALUES...BUT NET RESULT IS FOR SEVERE POTENTIAL ACROSS SOUTHERN IOWA OVERNIGHT TUESDAY AND HAVE KEPT MENTION IN FORECAST. NOT TO BE OVERLOOKED...THERE WILL ALSO BE A SIGNIFICANT THREAT FOR HEAVY RAIN. PWAT VALUES WILL BE BETWEEN 1.7 AND 2 INCHES...SEASONLY VERY HIGH...WITH GOOD WARM CLOUD DEPTHS AND GOOD MOISTURE TRANSPORT. POTENTIAL FOR VERY HIGH RAINFALL RATES...AND MAY BE WIDESPREAD. SYSTEM WILL BE VERY FAST MOVING...WHICH WILL HELP TO LIMIT FLOODING AND FLASH FLOODING POTENTIAL...THOUGH WIDESPREAD HEAVY RAINFALL MAY LEAD TO RISES ON STREAMS...AND HIGH RAINFALL RATES...ESPECIALLY OVER URBAN AREAS...COULD RESULT IN LOCALIZED FLOODING OVERNIGHT. MODEL DISAGREEMENTS CONTINUE BEYOND TUESDAY NIGHT WITH DIFFERENT SPEED/TRACK OF LOW. NAM IS OUTLIER...LIFTING LOW THROUGH CENTRAL IA WHILE OTHER MODELS CONTINUE A MORE EASTERLY TRACK TO LOW. HAVE TRENDED TOWARDS THE EASTERLY SOLUTION...WHICH WILL PUSH PRECIPITATION OUT OF CENTRAL IOWA QUICKER THAN NAM SOLUTION WHICH ATTEMPTS TO WRAP PRECIPITATION AROUND INTO NORTHERN IOWA WEDNESDAY. FOR REMAINDER OF EXTENDED...HIGH PRESSURE WILL BRIEFLY BUILD IN FOR THURSDAY AND FRIDAY BEFORE LOW PRESSURE SYSTEM TRACK EAST ACROSS CANADA...AND ASSOCIATED FRONTAL BOUNDARY DROPS INTO IOWA FOR WEEKEND. IN ADDITION...MODELS INDICATE SECONDARY LOW PRESSURE SYSTEM IN KANSAS TRACKING EAST FOR THE WEEKEND...WHICH WILL LEAD TO ADDITIONAL CHANCES FOR THUNDERSTORMS AND SEVERE WEATHER. TEMPERATURES WILL GENERALLY BE NEAR NORMAL FOR THE PERIOD BEYOND TUESDAY. && .AVIATION...02/18Z ISSUED AT 1255 PM CDT MON JUN 2 2014 VFR CONDITIONS ARE ANTICIPATED THROUGH THE PERIOD WITH DISSIPATED CUMULUS TODAY FOLLOWED BY MOSTLY CLEAR CONDITIONS INTO TUE MORNING. WESTERLY WINDS WITH MINOR GUSTS WILL PERSIST THROUGH SUNSET FOLLOWED BY LIGHTER WINDS BECOMING VARIABLE WITH HIGH PRESSURE PASSAGE 12-18Z. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMALL LONG TERM...AWB AVIATION...SMALL  FXUS63 KDMX 030907 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 407 AM CDT TUE JUN 3 2014 .SHORT TERM /TODAY/... ISSUED AT 407 AM CDT TUE JUN 3 2014 WEAK HIGH PRESSURE WILL TRAVERSE THE STATE TODAY WITH A QUITE DAY FOR THE MOST PART. AS THE AXIS PASSES EAST...MOISTURE RETURN WILL BE QUITE RAPID WITH THE RETURNING WARM FRONT WILL SLOW DOWN THE ONSET OF THUNDERSTORM DEVELOPMENT A LITTLE FROM THE PREVIOUS FORECAST WITH ONLY THE FAR WESTERN COUNTIES AFFECTED LATE THIS AFTERNOON. ONCE INITIATION TAKES PLACE...DEVELOPMENT AND SPREADING IS EXPECTED TO BE RAPID WITH THE POTENTIAL OF THE FIRST SEVERE WEATHER TAKING PLACE WITH AN HOUR OR SO OF INITIATION. WENT A LITTLE ABOVE MOS TEMPS AGAIN TODAY...FITTING WITH THE TREND OF THE PAST SEVERAL DAYS. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 407 AM CDT TUE JUN 3 2014 MAIN FORECAST CONCERN WAS FOCUSED ON HEAVY RAIN AND SEVERE WEATHER POTENTIAL TONIGHT INTO EARLY WEDNESDAY MORNING. THE 03.00Z MODEL RUNS ARE IN BETTER AGREEMENT WITH THE EXCEPTION OF THE NAM BEING THE FARTHEST NORTH WITH THE HEAVY PRECIP SHIELD TONIGHT. UTILIZED A GFS/ECMWF/SREF BLEND TONIGHT INTO WEDNESDAY AS THE 03.00Z NAM REMAINS THE OUTLIER. HOWEVER...THE 03.06Z HAS COME INTO A LITTLE BETTER AGREEMENT WITH THE 03.00Z GFS/ECMWF. TONIGHT THROUGH WEDNESDAY...STRONG 500MB SHORTWAVE WILL EJECT OUT OF THE CENTRAL ROCKIES AND QUICKLY PUSH EAST THROUGH THE CENTRAL PLAINS TODAY. THE ASSOCIATED SURFACE LOW WILL DEVELOP OVER WESTERN NE/WESTERN KS/EASTERN CO TODAY WITH A WARM FRONT EXTENDING FROM NORTHEAST NE THROUGH CENTRAL IOWA. CUT BACK ON TIMING OF POPS TONIGHT AS INITIATION LOOKS BE AROUND 21Z TO 00Z IN FAR NORTHEAST NE AND SOUTHEAST SD BUT WILL QUICKLY MOVE INTO WESTERN IOWA BETWEEN 00Z AND 03Z WEDNESDAY. PER 06Z SPC DISCUSSION...AGREE WITH THE MAIN SEVERE THREAT BEING DAMAGING WINDS AS STORMS LOOK TO EVOLVE INTO BOWING SEGMENTS AS THEY WILL FOLLOW THE INSTABILITY AXIS ORIENTED EAST-SOUTHEAST ACROSS CENTRAL TO SOUTHERN IOWA TONIGHT. 0-3KM SHEAR VALUES IN THE 40 TO 50 KNOT RANGE AND THE DEEP LAYER SHEAR FROM 50 TO NEAR 75 KNOTS BY LATE THIS EVENING. CERTAINLY LARGE HAIL WILL ACCOMPANY THIS STRONG WIND AND CANNOT RULE OUT THE TORNADO THREAT WITH THE HODOGRAPH DEPICTING THE CLASSIC SICKLE SHAPE BY AROUND 01Z TONIGHT AT CRL. HAVE SEVERE THREAT MENTIONED ALONG AND SOUTH OF I-80 THROUGH 06Z TONIGHT BEFORE STORMS TRANSITION INTO MORE OF A HEAVY RAIN THREAT AND CONFIDENCE DECREASES OVERNIGHT WITH THE SEVERE POTENTIAL. AS MENTIONED...IN ADDITION TO THE SEVERE WEATHER THREAT...VERY HEAVY RAIN IS HIGHLY LIKELY. IMPRESSIVE MOISTURE TRANSPORT AND ISENTROPIC UPGLIDE ALONG THE 305K TO 315K ISENTROPIC SURFACE TONIGHT INTO THE OVERNIGHT HOURS INTO CENTRAL IOWA. STRONG THETA-E ADVECTION BETWEEN THE SURFACE TO 700MB AND CORFIDI VECTORS WOULD SUGGEST TRAINING THUNDERSTORMS BY LATE THIS EVENING INTO EARLY WEDNESDAY MORNING. WARM LAYER CLOUD DEPTHS INCREASE TO 12500FT TO JUST OVER 13KFT SOUTH OF I-80 WITH PRECIPITABLE WATER IN THE 1.5 TO 2.25 INCHES. VERY EFFICIENT RAIN PRODUCERS ANTICIPATED TONIGHT INTO THE OVERNIGHT HOURS AND ISSUED FLASH FLOOD WATCH FOR THE SOUTHERN PORTIONS OF THE FORECAST AREA. THURSDAY THROUGH MONDAY...COOLER AND DRIER CONDITIONS EXPECTED ON THURSDAY AND FRIDAY BEFORE ANOTHER SHORTWAVE AND ASSOCIATED SURFACE LOW PUSH ACROSS THE CENTRAL U.S. ECMWF AND GFS ARE IN DECENT AGREEMENT WITH THE TIMING...BUT THE GFS IS A BIT FURTHER NORTH WITH SURFACE LOW TRACK. && .AVIATION...03/06Z ISSUED AT 1127 PM CDT MON JUN 2 2014 LITTLE CHANGE TO PREVIOUS THINKING. MOST OF PERIOD PRIOR TO 04/00Z WILL REMAIN QUIET ACROSS THE TAF NETWORK THOUGH SOME CONVECTION MAY BE APPROACHING KFOD TOWARD 00Z. CONSISTENCY IN RUN TO RUN MODEL DATA REMAINS HIGH THIS EVENING. AS LOW TRACKS EAST TO SOUTHEAST NEBRASKA BY 06Z STRONG FORCING FOCUSED OVER SOUTH HALF OF AREA SHOULD CONCENTRATE HEAVY RAIN AND SEVERE WIND POTENTIAL MOSTLY FROM KFOD SOUTHEAST THROUGH KDSM AND KOTM THROUGH REMAINDER OF PERIOD...EXTENDING TO NEAR 10-12Z FOR KOTM. RISK OF SIGNIFICANT WIND AND HEAVY RAINFALL DEVELOPS AFT 02Z NORTHWEST NEAR KFOD...03Z TO 07Z CENTRAL AND AFT 07Z FOR KOTM IN THE SOUTHEAST. APT MANAGERS WILL NEED TO MONITOR AND PLAN FOR EXPECTED IMPACTS TO OPS DURING THIS PERIOD ESPECIALLY FOR KDSM FROM NEAR 03Z TO 07Z AND DOWNSTREAM THROUGH 04/12Z. THOUGH DETAILS WILL BE REFINED...OVERALL TRENDS REMAIN CONSISTENT./REV && .HYDROLOGY... ISSUED AT 407 AM CDT TUE JUN 3 2014 PRECIPITATION RATES OF 3 TO 5 INCHES PER HOUR WILL BE WIDESPREAD ACROSS CENTRAL TO SOUTHERN IOWA LATE THIS EVENING. QPF AMOUNTS LOOK TO RANGE IN THE 2 TO 4 INCHES IN A SHORT TIME FRAME. COULD POSSIBLY SEE A FEW ISOLATED 5 INCH OR GREATER AMOUNTS AS WELL. THE FLASH FLOOD WATCH BEGINS AT 01Z WEDNESDAY AND ENDS AT 13Z WEDNESDAY. FROM 03Z TO 09Z IS THE PERIOD OF HIGHEST CONFIDENCE WHEN THE HEAVIEST RAINFALL WILL OCCUR. POTENTIALLY COULD SEE WIDESPREAD FLASH FLOODING ISSUES OVER CENTRAL TO SOUTHERN IOWA. SMALLER STREAMS AND CREEKS TYPICALLY PRONE TO FLASH FLOODING ARE LIKELY TO SEE MUCH OF THIS RAINFALL TONIGHT. ESPECIALLY IN THE DES MOINES AREA WHERE THE WALNUT CREEK AND FOURMILE CREEK HAVE HAD HISTORY OF RISING RAPIDLY. OTHER POTENTIAL SMALLER CREEKS/STREAMS WOULD INCLUDE THE MUCHAKINOCK CREEK...WHITE BREAST CREEK...EAST FORK 102 RIVER...THOMPSON RIVER...AND THE CHARITON RIVER TO NAME A FEW. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-CASS-CLARKE-DALLAS-DAVIS- DECATUR-GUTHRIE-JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE-POLK- POWESHIEK-RINGGOLD-TAYLOR-UNION-WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...MS LONG TERM...PODRAZIK AVIATION...REV HYDROLOGY...PODRAZIK  FXUS63 KDMX 032102 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 402 PM CDT TUE JUN 3 2014 .SHORT TERM /TONIGHT/... ISSUED AT 345 PM CDT TUE JUN 3 2014 SIGNIFICANT SEVERE WEATHER EVENT EXPECTED LATE THIS AFTERNOON THROUGH THE EARLY EVENING WITH AN INTENSE HP SUPERCELL MOVING ALONG THE INSTABILITY AXIS INTO IOWA. THE INSTABILITY AXIS HAS LIFTED FURTHER NORTH INTO IOWA AHEAD OF THIS STORM WHICH COULD LEAD TO ANOTHER EASTWARD SHIFT IN THE STORM MOTION SOON THAT COULD MOVE THIS CELL FURTHER INTO CENTRAL IOWA. IN COORDINATION WITH SPC...A HIGH RISK FOR SEVERE WEATHER HAS BEEN ISSUED IN ADVANCE OF THIS CELL. ADDITIONAL SUPERCELLS ARE LIKELY WITH THE ADVANCING THETA-E ADVECTION AND THE SFC BOUNDARY OVER SOUTHEAST NEBRASKA AND NORTHERN MISSOURI WHERE MIXED LAYER CAPE VALUES HAVE INCREASED TO OVER 2500 J/KG. EFFECTIVE DEEP LAYER SHEAR VALUES OF 50 TO 70 KTS WILL BE SUFFICIENT FOR THESE SUPERCELLS TO BE THE PRIMARY MODE INITIALLY. THIS INITIAL ROUND OF STORMS WILL PUSH THROUGH. EXPECT RATHER QUICK DESTABILIZATION AGAIN BEHIND THE STORMS AS THE LOW LEVEL JET OF 65+ KTS INCREASES THROUGH THE EVENING AND FOCUSES INTO IOWA. THE INSTABILITY AXIS WILL BE FOCUSED OVER THE STATE AS THE AREA OF LOW PRESSURE LIFTS NORTHEAST INTO SOUTHEAST NEBRASKA AND INTO SOUTHWEST IOWA. WILL KEEP A DAMAGING WIND THREAT WITH 50 TO 60 KTS OF WIND JUST OFF THE SFC. WITH SATURATING PROFILES THE HAIL THREAT WILL DECREASE HOWEVER EFFECTIVE SRH VALUES INCREASING TO EXTREMELY HIGH VALUES OF 300 TO 600 M2/S2 WILL INCREASE THE POTENTIAL OF MESOVORTICY DEVELOPMENT ALONG THE LEADING EDGE OF ANY COLD POOL DEVELOPMENT. CERTAINLY POTENTIAL FOR A QLCS DEVELOPING WITH DAMAGING WINDS AND A FEW TORNADOES POSSIBLE THROUGH 3 AM. INTENSE RAINFALL RATES REMAIN HIGHLY LIKELY OVERNIGHT WITH RAINFALL RATES APPROACHING 3 TO 5 INCHES PER HOUR WITH PWAT VALUES INCREASING TO NEAR 2 INCHES AND WARM CLOUD DEPTHS TO NEAR 13 KFT. SHOULD HAVE AN AREA WITH TRAINING ELEVATED CELLS JUST NORTH OF THE SFC BOUNDARY SOMEWHERE BETWEEN INTERSTATE 80 AND HIGHWAY 20 WITH POTENTIAL FOR WIDESPREAD 2 TO 4 INCHES AND MORE LOCALIZED HIGHER AMOUNTS. THESE AMOUNTS ALSO POSSIBLE SOUTH BUT WILL BE ASSOCIATED WITH MORE SURFACE BASED CONVECTION AND MORE INTENSE RAIN RATES. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 345 PM CDT TUE JUN 3 2014 ANTICIPATED OVERNIGHT CONVECTION WILL BE PUSHING EAST OF THE CWA BY THE BEGINNING OF THE FORECAST PERIOD. HAVE CONTINUED TO CUT BACK ON POPS THROUGH WEDNESDAY MORNING. BEHIND SYSTEM TEMPERATURES WILL BE MUCH COOLER...AND WILL REMAIN SO THROUGHOUT THE EXTENDED WITH TEMPERATURES NEAR OR SLIGHTLY BELOW NORMAL. HIGH PRESSURE WILL PUSH INTO THE STATE WITH A WEAK RIDGE...WHICH WILL HELP TO KEEP PRECIPITATION CHANCES SOUTH AND WEST OF THE AREA THROUGHOUT THE REMAINDER OF THE WEEK. WEEKEND WILL SEE ADDITIONAL CHANCES FOR PRECIPITATION HOWEVER AS A LOW PRESSURE SYSTEM TRACKS ACROSS CANADA AND ASSOCIATED FRONTAL BOUNDARY BEGINS TO AFFECT WESTERN IOWA BY SATURDAY. IN ADDITION...LOW PRESSURE SYSTEM WILL PUSH EAST ACROSS KS AND WILL BEGIN TO LIFT BOUNDARY INTO IOWA AS WELL BY SATURDAY. THEREFORE...HAVE KEPT ONGOING POPS THROUGHOUT THE WEEKEND. THOUGH WILL LIKELY SEE BEST CHANCES SATURDAY ACROSS SOUTHERN IOWA...WHILE BEST CHANCES ACROSS WEST AND NORTH WILL COME LATER. ANOTHER AREA OF HIGH PRESSURE WILL PUSH IN FOR MONDAY...THOUGH LITTLE MODEL AGREEMENT ON HOW LONG HIGH LINGERS BEFORE ANOTHER LOW PRESSURE SYSTEM TRACKS ACROSS NORTHERN US. && .AVIATION...03/18Z ISSUED AT 109 PM CDT TUE JUN 3 2014 PRIMARY AVIATION THREAT THROUGH THE PERIOD WILL BE THUNDERSTORM POTENTIAL AND LOCATIONS AND STRONG THUNDERSTORM WINDS OVER THE SOUTH. VFR CONDITIONS WILL PREVAIL THROUGH THIS AFTERNOON WITH THUNDERSTORMS BECOMING MORE WIDESPREAD THIS EVENING AND OVERNIGHT. POTENTIAL FOR MVFR/IFR STRATUS TO LINGER POST CONVECTION THROUGH WEDNESDAY MORNING. && .HYDROLOGY... ISSUED AT 345 PM CDT TUE JUN 3 2014 IN ADDITION TO THE HEAVY RAINFALL DISCUSSION IN THE SHORT TERM SECTION...THE INTENSE RAINFALL RATES ARE THE PRIMARY CONCERN LEADING TO HIGH RUNOFF RATES AS WELL. THIS WILL RESULT IN SIGNIFICANT PONDING INTO ADDITION TO RISES ALONG SMALLER STREAMS AND CREEKS. AREAS OF FLASH FLOODING IS EXPECTED ESPECIALLY IN URBAN AREAS AND LOW LYING AREAS. SMALLER STREAMS AND CREEKS TYPICALLY PRONE TO FLASH FLOODING ARE LIKELY TO SEE MUCH OF THIS RAINFALL TONIGHT. ESPECIALLY IN THE DES MOINES AREA WHERE THE WALNUT CREEK AND FOURMILE CREEK HAVE HAD HISTORY OF RISING RAPIDLY. OTHER POTENTIAL SMALLER CREEKS/STREAMS WOULD INCLUDE THE MUCHAKINOCK CREEK...WHITE BREAST CREEK...EAST FORK 102 RIVER...THOMPSON RIVER...AND THE CHARITON RIVER TO NAME A FEW. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 8 PM CDT THIS EVENING THROUGH WEDNESDAY MORNING FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BOONE-CALHOUN-CARROLL- CASS-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-GREENE-GRUNDY-GUTHRIE- HAMILTON-HARDIN-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL- MONROE-POCAHONTAS-POLK-POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR- UNION-WAPELLO-WARREN-WAYNE-WEBSTER. && $$ SHORT TERM...DONAVON LONG TERM...AWB AVIATION...DONAVON HYDROLOGY...DONAVON  FXUS63 KDMX 070838 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 338 AM CDT SAT JUN 7 2014 .SYNOPSIS... ISSUED AT 320 AM CDT SAT JUN 7 2014 COLD FRONT WILL SINK SOUTHEAST ACROSS THE STATE TODAY AS LOW PRESSURE MOVES OUT OF KS INTO IN BY SUNDAY MORNING. WEAK HIGH PRESSURE WILL BUILD INTO THE STATE FROM THE NORTHWEST SUNDAY. A SLOW MOVING UPPER LEVEL SYSTEM WILL MOVE OUT OF THE SOUTHWEST U.S. THIS WEEK AND KEEP WEATHER UNSETTLED THROUGH MUCH OF THE WEEK. && .SHORT TERM /TODAY/... ISSUED AT 320 AM CDT SAT JUN 7 2014 TWO AREAS OF FORCING TO CONTEND WITH TODAY...THE FIRST IS AN H500 WAVE TRACKING JUST SOUTH OF THE REGION AND DIGGING AS IT DOES THROUGH MISSOURI AND ILLINOIS AND A COLD FRONT DROPPING SOUTH THROUGH THE REGION FROM NORTHWEST IOWA. ALREADY EARLY TODAY SHOWERS AND THUNDERSTORMS ARE FORMING ALONG THE BOUNDARY AND SLOWLY MOVING NORTHEAST INTO NW IOWA. OVER KS AND SOUTHERN NE AN AREA OF STORMS IS MOVING TO THE EAST NORTHEAST. A WEAK RIDGE OF HIGH PRESSURE CONTINUES OVER THE AREA NOW...AND WILL SLOWLY DRIFT EAST THIS AFTERNOON. EARLY ON THE CONVECTION WILL BE SLOW TO MOVE ACROSS THE WEST AND REMAIN WITH THE AREA THROUGH MUCH OF THE AFTERNOON ...DIMINISHING FROM WEST TO EAST. TODAYS STORMS WILL BE RATHER SLOW MOVING WITH PWATS IN THE 1 TO 1.5 INCH RANGE. WARM CLOUD DEPTHS NEAR 10KFT AT TIMES THIS MORNING WITH THE SOUTH SEEING WARM CLOUD DEPTHS BETWEEN 10 AND 11KFT THIS AFTERNOON. BRIEF HEAVY DOWNPOURS WILL BE POSSIBLE WITH LOCALIZED RAIN TOTALS OF 1 TO 1.5 INCHES IN SOME OF THE HEAVIER DOWNPOURS...OTHERWISE GENERALLY 0.5 INCH TOTALS EXPECTED. FLASH FLOOD GUIDANCE REMAINS IN THE 1 TO 2 INCH RANGE OVER ROUGHLY THE SOUTH HALF...BUT OVERALL NOT EXPECTING ANY WIDESPREAD PROBLEMS TODAY. LOOKING OVER NST PARAMETERS THIS AFTERNOON...IT APPEARS THAT WE MAY HAVE A FEW HOURS OF FAVORABLE CONDITIONS FOR A FEW FUNNEL CLOUDS AS WELL ALONG THE BOUNDARY AS IT MOVES SOUTHEAST DURING THE DAY TODAY. WIND SHEAR REMAINS LIGHT AND 0-3KM CAPE MAY APPROACH 100-250 J/KG THIS AFTERNOON. WITH THAT IN MIND WILL MENTION IN HWO AND HAVE THE DAY CREW MONITOR DURING THE DAY. HIGHS WILL REACH THE MID TO UPPER 70S AND WINDS SHOULD REMAIN LIGHT MOST OF THE DAY. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 320 AM CDT SAT JUN 7 2014 AS THE COLD FRONT SINKS SOUTH THE CHANCE FOR RAIN WILL END TONIGHT AND SUNDAY FOR MOST OF THE STATE. ISOLATED THUNDERSTORMS WILL BE POSSIBLE OVER THE SOUTHEAST PART OF THE CWA. THE NEXT SYSTEM WILL MOVE INTO THE AREA OUT OF THE ROCKIES AND IS EXPECTED TO MOVE ONLY SLOWLY THROUGH MID WEEK. GFS AND THE ECMWF BOTH ARE IN AGREEMENT WITH MOST OF THE PRECIPITATION REMAINING OVER THE SOUTHEAST HALF OF THE STATE. THE WEEK WILL LIKELY AVERAGE NEAR TO A LITTLE BELOW NORMAL TEMPERATURE WISE WITH NOT BIG DEVIATION ONE WAY OR THE OTHER. ABOUT THE TIME THE UPPER LOW PULLS OUT OF THE AREA...THE UPPER RIDGE BEGINS TO BUILD IN WITH THE PATTERN REMAINING UNSETTLED WITH MORE OR A RING OF FIRE TYPE SETUP DEVELOPING TOWARD NEXT WEEKEND. && .AVIATION...07/06Z ISSUED AT 1141 PM CDT FRI JUN 6 2014 STILL LOOKING AT VFR CONDITIONS IN ALMOST ALL LOCATIONS OVERNIGHT. HOWEVER...A FEW ISOLATED STORMS IN THE WEST AND NORTH WILL HAVE MVFR TO IFR CONDITIONS IN AND AROUND THE STORMS. SURFACE WINDS WILL BE LIGHT FROM THE SOUTHEAST BUT AS A BOUNDARY PROGRESSES ACROSS THE STATE LATE TONIGHT AND SATURDAY...WINDS WILL BECOME NORTHERLY BEHIND THE FRONT. CONDITIONS ON SATURDAY WILL MAINLY BE VFR ALTHOUGH SCATTERED TO NUMEROUS SHOWERS AND STORMS ARE EXPECTED WITH MVFR TO IFR CONDITIONS MORE COMMON THAN LATE TONIGHT NEAR THE STORMS. CONDITIONS ARE EXPECTED TO IMPROVE INTO SATURDAY NIGHT AS THE SYSTEM DEPARTS TO THE EAST. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MS JUN 14 SHORT TERM...REV LONG TERM...MS JUN 14 AVIATION...COGIL  FXUS63 KDMX 122036 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 336 PM CDT THU JUN 12 2014 .SHORT TERM /TONIGHT/... ISSUED AT 333 PM CDT THU JUN 12 2014 BENIGN WEATHER FOR THE NEXT 36 HOURS. CIRRUS SHIELD FROM LAST NIGHTS MCS IS CURRENTLY PUSHING INTO EASTERN IOWA AND DIURNALLY DRIVEN CU FIELD WILL DISSIPATE IN THE NEXT COUPLE OF HOURS. HIGH PRESSURE WILL MOVE IN THIS EVENING AND THE WIND WILL DIMINISH BY EARLY EVENING. THE CLEAR SKY AND LIGHT WIND SHOULD ALLOW TEMPS TO BE RATHER COOL TONIGHT. DEWPOINTS ARE ALSO FORECAST TO FALL INTO THE LOWER TO MID 40S. I DROPPED LOWS BELOW GUIDANCE BY AT LEAST A DEGREE OR TWO...MORE SO ACROSS THE NORTH...AS A RESULT. TEMPS MAY STILL BE A TOUCH TOO WARM. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 333 PM CDT THU JUN 12 2014 MAIN FORECAST CONCERN WAS FOCUSED ON THE WEEKEND WITH THE THUNDERSTORM AND SEVERE WEATHER POTENTIAL. ACTIVE WEATHER PATTERN CONTINUES INTO NEXT WEEK. LEANED TOWARD THE BLEND THROUGH THE WEEKEND AND THEN WITH A ECMWF FROM MONDAY THROUGH THURSDAY. FRIDAY THROUGH SUNDAY...SURFACE RIDGE MOVES INTO THE STATE ON FRIDAY INTO FRIDAY NIGHT AND PROVIDES SOME COOL TRANQUIL WEATHER. RETURN FLOW DEVELOPS FRIDAY NIGHT AND INCREASES DURING THE DAY SATURDAY. A LARGE AREA OF THETA-E ADVECTION MOVES INTO WESTERN IOWA EARLY SATURDAY MORNING AND SLOWLY SHIFTS EAST INTO THE EVENING. TRIMMED BACK TIMING OF POPS IN THE EAST TO SOUTHEAST AS MOISTURE AND FORCING DO NOT MOVE INTO THIS AREA UNTIL PAST 00Z SUNDAY. TWEAKED SATURDAY MAX TEMPS UP IN THIS AREA AS WELL WITH THE GOOD WAA AHEAD OF THE SURFACE LOW AND UPPER LEVEL TROUGH MOVING ACROSS THE REGION. TREMENDOUS ISENTROPIC LIFT AND MOISTURE TRANSPORT INTO THE STATE ON SATURDAY INTO SATURDAY NIGHT WITH PRECIPITABLE WATER VALUES IN THE 1.5 TO 2.0 INCHES. WARM LAYER CLOUD DEPTH RANGES FROM 13500 TO NEAR 14KFT SATURDAY NIGHT WITH WEAK CORFIDI VECTORS AND STORM MOTION. HEAVY RAIN IS CERTAINLY THE MAIN ISSUE FOR MUCH OF THE FORECAST AREA BY SATURDAY NIGHT. DEEP LAYER SHEAR AND MUCAPE VALUES ARE SOMEWHAT FAVORABLE FOR HAIL AND DCAPE BY SATURDAY EVENING MARGINAL FOR DAMAGING WINDS. THE BETTER DYNAMICS LOOK TO BE IN THE NORTH TO NORTHWEST COINCIDING WITH THE DY3 SLIGHT RISK IN NORTHWEST IOWA. MCS LOOKS TO PERSIST INTO SUNDAY MORNING BEFORE THE 500MB TROUGH KICKS EAST OF THE STATE. MONDAY THROUGH THURSDAY...ECMWF AND GFS REMAIN OUT OF CONSENSUS AND LEANED TOWARD THE ECMWF AS SEEMS TO BE THE MOST CONSISTENT WITH ITS RESPECTIVE SOLUTION. THE ECMWF PEGS IOWA WITH AN ACTIVE WEATHER AND BEGINS THE SHORTWAVE TRAIN STARTS LATE SUNDAY NIGHT THROUGH MUCH OF THE WEEK. THE GFS IS MUCH QUICKER BRINGING THE LARGE SCALE UPPER TROUGH THROUGH THE STATE BY TUESDAY NIGHT INTO WEDNESDAY AND IS SHOWING SIGNS OF SEVERE WEATHER POTENTIAL. HOWEVER...THE GFS DOES HAVE A VERY STRONG CAP IN PLACE TUESDAY AFTERNOON. REGARDLESS...ONE THING THE EXTENDED MODELS AGREE ON IS THE WARMER TEMPS ON TUESDAY AND TWEAKED MAX TEMPS UP A COUPLE DEGREES. && .AVIATION...12/18Z ISSUED AT 1240 PM CDT THU JUN 12 2014 HIGH PRESSURE WILL BUILD INTO THE STATE PRODUCING CLEARING SKIES BY 00Z. SFC WIND WILL BE GUSTY OUT OF THE NW AT 15-25KTS BUT THAT WILL DROP OFF BY 01Z. THERE MAY ALSO BE PATCHES OF LOWER VFR CIGS AROUND 3500 FT THROUGH 21Z. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...FAB LONG TERM...PODRAZIK AVIATION...FAB  FXUS63 KDMX 130909 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 409 AM CDT FRI JUN 13 2014 .SHORT TERM /TODAY/... ISSUED AT 405 AM CDT FRI JUN 13 2014 IT WILL BE MILD AND QUIET TODAY WITH RESPLENDENT SUNSHINE AS A HIGH PRESSURE AREA MOVES ACROSS IOWA. LIGHT NORTHWEST BREEZES WILL TURN TO SOUTHEAST BY LATE IN THE DAY WITH HIGHS IN THE MID TO UPPER 70S. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 405 AM CDT FRI JUN 13 2014 WEATHER WILL CERTAINLY BECOME MORE ACTIVE THIS WEEKEND AND INTO NEXT WEEK. PATTERN CHANGES RESULTING INTO PERSISTENT SWLY UPPER LEVEL FLOW FOLLOWED BY CENTRAL CONUS RIDGING TO SOME DEGREE. RETURN FLOW WILL ALREADY BE IN PROGRESS AT BEGINNING OF THE PERIOD WITH UPPER LEVEL RIDGE PASSING THROUGH MS VALLEY TONIGHT. THETA-E ADVECTION AND 1-3KM FORCING WILL MATURE INTO SAT WITH PATCHY ELEVATED CONVECTION DRIFTING FARTHER SOUTH AND EAST INTO THE FORECAST AREA DURING THE DAY. THIS WILL DO LITTLE TO REDUCE OUR SIGNIFICANT CONVECTIVE POTENTIAL HOWEVER WITH DEWPOINTS WELL INTO THE 60S SURGING TO ALONG AND WEST OF THE MO RIVER. SURFACE THETA-E AXIS INTO ERN NE WILL STILL RESULT IN 3000-4000 J/KG MLCAPES AHEAD OF SURFACE CONVERGENCE. SOME MLCINH IS NOTED BUT DEEP SYNOPTIC SCALE FORCING AHEAD OF SHORT WAVE WILL BE MORE THAN SUFFICIENT FOR WIDESPREAD CONVECTION TO ERUPT DURING PEAK HEATING. ALL MODES OF SEVERE WEATHER ARE POSSIBLE...WITH SOME UNCERTAINTY REGARDING HOW LONG SUPERCELLS WILL PERSIST VERSUS TRANSITION TO MORE LINEAR QLCS. DEEP AND SHALLOW SHEAR ARE BOTH MODERATE TO STRONG INTO THE NIGHT WITH STRENGTHENING LOW LEVEL JET SO THERE COULD VERY WELL BE A NOCTURNAL TORNADO THREAT...EITHER DISCRETE OR ASSOCIATED WITH QLCS. 0-6 AND 0-3KM SHEAR MAGNITUDES AND ORTHOGONAL ORIENTATION WITH RESPECT TO UPSTREAM NEARLY NORTH-SOUTH CONVERGENCE BOTH SUGGEST SUPERCELLS OR QLCS TORNADOES RESPECTIVELY. ALTHOUGH THE GFS SUGGESTS MORE LOW LEVEL STABILIZATION AND REDUCED SURFACE BASED POTENTIAL THAN THE NAM INTO THE NIGHT...BOTH SHOW STRONG SUPPORT FOR MCS SUSTAINING ITSELF OVERNIGHT WITH 40-50KTS OF FLOW ALONG 310K ISENT SURFACE AND SOME DEGREE OF BAROCLINICITY. THERE IS A HEAVY RAIN POTENTIAL AS WELL WITH PWS AROUND 2 INCHES...4KM WARM CLOUD DEPTHS AND K INDEX AROUND 40. MEAN WIND IS 40-50KTS BUT CORFIDI VECTORS ARE QUITE LOW DUE TO STRONG LOW LEVEL JET SO HAVE ADDED SEVERE AND HEAVY RAIN MENTION WEST ALIGNED WITH HIGHER DAY 2 OUTLOOK PROBABILITIES. FORCING LINGERS INTO THE DAY SUNDAY...SO EVEN THOUGH MCS SEVERITY WILL LIKELY WANE BY DAYBREAK PRECIP COULD VERY WELL CONTINUE DURING THE DAY...ENDING WEST TO EAST. THERE SHOULD THEN BE A LULL SUN NIGHT BEFORE A PROLONGED PERIOD OF CHANCES RETURN LATER INTO THE NEXT WORK WEEK. MODELS ARE FAIRLY CONSISTENT WITH ANOTHER WEAKER SHORT WAVE PASSAGE MON NIGHT WITH ASSOCIATED ELEVATED NOCTURNAL EVENT. SURFACE POTENTIAL RETURNS AGAIN LATE TUE AND WED...BUT MODELS ARE NOT IN AGREEMENT WITH WEAK BOUNDARY PLACEMENT SO CONFIDENCE IS NOT HIGH. CONFIDENCE DECREASES FURTHER TO END THE PERIOD WITH ECMWF MORE AGGRESSIVE BUILDING UPPER LEVEL RIDGE VS GFS. ECMWF EVEN DEVELOPS AN INTERESTING SUBTLE TROPICAL FEATURE OVER MEXICO WHICH GETS PULLED NORTHWARD INTO THE RIDGE RIGHT INTO IA BY FRI. THIS WOULD HAVE THE POTENTIAL TO BE A PROLIFIC SHARS-LIKE HEAVY RAIN PRODUCER AND WILL NEED TO BE WATCHED...ALTHOUGH THIS PROGRESSION SEEMS SOMEWHAT UNLIKELY AT THE MOMENT. ALTHOUGH CONFIDENCE IN PRECIP TRENDS IS RATHER LOW AT THIS POINT...THE AIRMASS LOOKS MUCH MORE SUMMER-LIKE REGARDLESS WITH SEASONALLY HIGH HUMIDITIES...A BIG CHANGE FROM CURRENT CONDITIONS. && .AVIATION...13/06Z ISSUED AT 1146 PM CDT THU JUN 12 2014 HIGH PRESSURE WILL CONTINUE TO BRING VFR CONDITIONS TO SITES THROUGH PERIOD. WINDS WILL SHIFT TO THE SOUTH NEAR 18Z AND BEYOND AT SITES. WINDS WILL REMAIN LIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...LEE LONG TERM...SMALL AVIATION...AWB  FXUS63 KDMX 140905 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 405 AM CDT SAT JUN 14 2014 .SHORT TERM /TODAY/... ISSUED AT 405 AM CDT SAT JUN 14 2014 TODAY WILL BE WARMER AND BREEZY WITH INCREASING CHANCES FOR THUNDERSTORMS BY THIS AFTERNOON. THE SURFACE PRESSURE GRADIENT CONTINUES TO TIGHTEN AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM OVER THE WESTERN HIGH PLAINS...LEADING TO BRISK SOUTH SOUTHEAST WINDS THAT WILL INCREASE FURTHER WITH DAYTIME MIXING ESPECIALLY FROM LATE MORNING TO MID AFTERNOON. CLIMATOLOGY FAVORS WINDS STAYING BELOW ADVISORY CRITERIA GIVEN THE DIRECTION AND SEASON...HOWEVER IT IS WORTH NOTING THAT FORECAST SOUNDINGS INDICATE SPEEDS OF AROUND 40 KT AT THE TOP OF THE MIXED LAYER BY MIDDAY SO IT MAY BE CLOSE. MEANWHILE...LOW LEVEL MOISTURE WILL SURGE NORTHWARD INTO THE REGION AHEAD OF THE APPROACHING STORM SYSTEM...AND A SUBTLE 500 MB SHORTWAVE MOVING OVERHEAD WILL PROVIDE FOR THE GENERATION OF THUNDERSTORMS ACROSS PORTIONS OF THE AREA TODAY. REGIONAL RADAR IMAGERY CURRENTLY REVEALS A COUPLE OF STORM CLUSTERS MOVING FROM SOUTHEAST SOUTH DAKOTA INTO SOUTHWEST MINNESOTA AND MOST PROGNOSTIC MODELS FORECAST THUNDERSTORM COVERAGE TO INCREASE ACROSS WESTERN AND INTO CENTRAL IOWA BY THIS AFTERNOON AND EVENING. THIS IS CONSISTENT WITH A DESTABILIZING ATMOSPHERE AND RAPIDLY ERODING CAP AS INDICATED BY FORECAST SOUNDINGS...HOWEVER THERE ARE RESERVATIONS AS TO HOW FAR SOUTHEAST THE INFLUENCE OF THE FORCING ASSOCIATED WITH THE 500 MB SHORTWAVE WILL BE ABLE TO OVERCOME THESE MITIGATING FACTORS. THUS THUNDERSTORMS ARE MORE LIKELY IN THE NORTHWEST...WITH CONFIDENCE DECREASING HEADING FURTHER SOUTHEAST BUT CHANCE POPS INCLUDED AS THERE IS A REASONABLE POTENTIAL FOR CONVECTION REACHING EVEN DOWN TO THE I-80 CORRIDOR. THE GOOD NEWS IS THAT SEVERE WEATHER PARAMETERS ARE UNIMPRESSIVE DURING THE DAY...SO THAT THREAT SHOULD HOLD OFF UNTIL TONIGHT AS DISCUSSED IN THE LONG TERM SECTION BELOW. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 405 AM CDT SAT JUN 14 2014 AN ACTIVE MID JUNE PERIOD IS ON TAP THROUGH NEXT WEEK. IT BEGINS EARLY IN THE PERIOD AS AN INTENSE UPPER PV ANOMALY OVER CALIFORNIA EARLY THIS MORNING WILL SLING SHOT AROUND AN UPPER LOW TO ITS NORTH AND BE OVER NORTHWEST IOWA AND SOUTHEAST SOUTH DAKOTA BY 12Z SUNDAY. THE WAVES OF THETA-E ADVECTION WILL STILL BE ONGOING BY THIS EVENING AS THE LOW LEVEL JET INTENSIFIES TO 70+ KTS ACROSS EASTERN KANSAS. THE THREAT FOR SEVERE WEATHER WILL EXIST THROUGH THIS EVENING WITH A MODERATE RISK COVERING WEST CENTRAL AND SOUTHWEST IOWA. CONVECTION INITIATING ACROSS NEBRASKA THIS AFTERNOON SHOULD PUSH INTO WEST CENTRAL IOWA THIS EVENING. THESE STORMS SEVERE THREAT SHOULD EVOLVE INTO A DAMAGING WIND THREAT BY THE TIME THEY REACH THE AREA. THAT SAID...CERTAINLY CAN NOT RULE OUT A QLCS SYSTEM WITH A FEW ISOLATED TORNADOES POSSIBLE AS LOW LEVEL SRH VALUES EXCEED 300 M2/S2 THROUGH 09Z. HEAVY RAIN IS ALSO A THREAT WITH PWAT VALUES EXCEEDING 1.75 INCHES AT TIMES. THIS COMBINED WITH WARM CLOUD DEPTHS IN EXCESS OF 11 KFT WILL YIELD HIGH EFFICIENCY RAIN PRODUCING STORMS. THE POTENTIAL FOR 3 INCHES OR MORE OF RAIN IS POSSIBLE ESPECIALLY OVER THE NORTHWEST HALF OF THE AREA THROUGH EARLY SUNDAY. MUCH OF THAT REGION SHOULD BE ABLE TO HANDLE 3 INCHES OF RAIN GIVEN THE RECENT DRY WEATHER...GROWING CROPS AND OVERALL TOPOGRAPHY IN THE HIGHEST THREAT AREA. THE UPPER ANOMALY LIFTS RAPIDLY NORTH LATE SATURDAY NIGHT INTO SUNDAY MORNING WITH A STRONG DRY PUNCH LIFTING INTO CENTRAL IOWA. THIS SHOULD BRING AN END TO MUCH OF THE PRECIPITATION THOUGH SOME LATE MORNING REDEVELOPMENT OVER THE FAR SOUTHEAST MAY OCCUR. THE UPPER FLOW WILL QUICKLY BECOME SOUTHWESTERLY AS THE WEEKEND SYSTEM LIFTS NORTHEAST AND ANOTHER UPPER LOW DROPS INTO THE PACIFIC NORTHWEST. THIS WILL LEAD TO A MORE SUMMER LIKE AIR MASS LIFTING RAPIDLY NORTH THROUGH THE DAY ON MONDAY WITH PWAT VALUES AGAIN RISING WELL ABOVE 1.50 INCHES AS A MOISTURE SURGE RETURNS. EXPECT THUNDERSTORMS TO DEVELOP INTO SOUTHWEST IOWA DURING THE DAY AND MAY REACH CENTRAL IOWA BY MID TO LATE AFTERNOON. ANOTHER ROUND OF SEVERE STORMS AND HEAVY RAIN POTENTIAL WILL CONTINUE INTO MONDAY NIGHT WITH THE LOW LEVEL JET MORE FOCUSED INTO CENTRAL IOWA AND MUCAPES RISING TO NEAR 2500 J/KG. IN SOME REGARDS...THIS EVENT MAY HAVE MORE WIDESPREAD IMPLICATIONS FOR CENTRAL IOWA THAN THEN ONE ARRIVING TONIGHT BASED ON THE OVERALL FOCUS OF THE EVENT. THE REMAINDER OF THE PERIOD IS HIGHLIGHTED BY THE PACIFIC NORTHWEST UPPER LOW MOVING SLOWLY EAST INTO THE NORTHERN PLAINS TOWARDS THURSDAY AND FRIDAY. THIS WILL KEEP SOUTHWEST FLOW IN PLACE THROUGH AT LEAST THURSDAY AND 850 MB TEMPERATURES OF 20 C TO 24 C AND SFC DEWPOINTS IN THE MID 60S TO NEAR 70. ON TUESDAY...A STRONG ELEVATED MIXED LAYER SHOULD PROVIDE A SFC BASED CAP AND KEEP THE AREA MOSTLY DRY. HOWEVER...THIS TYPE OF AIRMASS AND PATTERN CAN BE A BIT TRICKY WITH QUICK MOVING EMBEDDED SHORT WAVES IN THE FLOW CAN EASILY TRIGGER THUNDERSTORMS ESPECIALLY WEDNESDAY AND BEYOND. && .AVIATION...14/06Z ISSUED AT 1126 PM CDT FRI JUN 13 2014 WINDS WILL INCREASE SATURDAY MORNING WITH PRESSURE GRADIENT AND MIXING AHEAD OF TROUGH ANTICIPATED TO MOVE ACROSS THE STATE SATURDAY NIGHT. INTRODUCED TS AT FOD/MCW WITH MVFR VIS. OTHERWISE...VCTS MENTIONED AT ALO AND DSM AND LEFT OTM DRY ATTM. CONFIDENCE IS FAIRLY HIGH HEAVY RAIN WILL AFFECT ALL TAF SITES SATURDAY NIGHT BUT LOOKS TO BE AFTER 02Z INTO THE LATER PART OF THE FORECAST. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...LEE LONG TERM...DONAVON AVIATION...PODRAZIK  FXUS63 KDMX 160913 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 413 AM CDT MON JUN 16 2014 .SHORT TERM /TODAY/... ISSUED AT 413 AM CDT MON JUN 16 2014 COMPLICATED CONVECTIVE FORECAST FOR TODAY AS THE SYNOPTIC PATTERN BECOMES MUCH MORE ACTIVE. CURRENTLY AN EFFECTIVE WARM FRONTAL ZONE...STAGGERED IN SEVERAL SUBTLE NEAR SURFACE BOUNDARIES...LIES ACROSS SOUTHERN IOWA...NORTHERN MISSOURI AND NEBRASKA AND IS SLOWLY MOVING NORTHWARD. MEANWHILE A 500 MB SHORTWAVE IS MOVING OFF THE ROCKIES AND WILL PROGRESS EAST NORTHEASTWARD ACROSS THE PLAINS AND MIDWEST BY LATER TODAY. ACROSS OUR AREA THE MORNING AND EARLY AFTERNOON SHOULD REMAIN FAIRLY QUIET AS THE FORCING ASSOCIATED WITH THE SHORTWAVE WILL NOT HAVE ARRIVED YET AND IT WILL TAKE SOME TIME...THOUGH NOT MUCH...FOR THE LOW LEVEL MOISTURE SURGE TO TRAVERSE THE AREA. HOWEVER...GIVEN THE HIGH DEGREE OF INSTABILITY WITH BOUNDARIES MOVING ACROSS THE AREA IT WILL TAKE VERY LITTLE TO INITIATE ISOLATED TO SCATTERED POPCORN STORMS...A FEW OF WHICH COULD BE STRONG TO SEVERE. THUS HAVE MAINTAINED 20 TO 40 POPS ACROSS MUCH OF THE FORECAST AREA FOR THE LATE MORNING INTO AFTERNOON HOURS. MEANWHILE...SATELLITE AND REGIONAL RADAR IMAGERY INDICATE THAT CLOUDS ARE ALREADY BUBBLING ACROSS WESTERN AND CENTRAL NEBRASKA WITH A FEW STORMS BEGINNING TO DEVELOP IN THE ASCENT AHEAD OF THE APPROACHING SHORTWAVE. EXPECT STORMS TO DEVELOP IN EARNEST AROUND SUNRISE IN THESE AREAS AND MOVE NORTHEASTWARD INTO SOUTH DAKOTA...WITH GRADUAL INTENSIFICATION DURING THE DAY...THEN TURN MORE EASTWARD INTO NORTHERN IOWA BY MID TO LATE AFTERNOON. LATE IN THE DAY INTO TONIGHT THIS GROWING COMPLEX OF STORMS WILL RESIDE IN AN INCREASINGLY FAVORABLE ENVIRONMENT FOR SEVERE WEATHER...AS OUTLINED IN SPC PRODUCTS...AND PROBABLE UPSCALE GROWTH INTO AN MCS ACROSS NORTHERN IOWA. HAVE THUS INCREASED POPS SUBSTANTIALLY IN THE LATE AFTERNOON ACROSS OUR NORTHERN AND NORTHWESTERN COUNTIES...BUT THE BULK OF THIS LATE ACTIVITY WILL BE CONFINED TO AND DISCUSSED IN THE TONIGHT PERIOD BELOW. ASIDE FROM CONVECTIVE/PRECIP CONCERNS FOR TODAY...ONLY OTHER SENSIBLE WEATHER OF NOTE WILL BE INCREASING SOUTHERLY BREEZES AND A NOTABLE WARMING/MOISTENING TREND THAT WILL RESULT IN MUGGY CONDITIONS BY LATE IN THE DAY. HAVE BUMPED UP HIGH TEMPERATURES JUST A BIT FURTHER...AND WITH DEWPOINTS NEARING 70 DEGREES THIS AFTERNOON THE HEAT INDEX MAY CLIMB INTO THE LOWER 90S FOR THE FIRST TIME IN A WHILE. THIS WILL ONLY BE A HARBINGER OF THE MUCH WARMER WEATHER TO COME ON TUESDAY AND WEDNESDAY AS DETAILED IN THE LONG TERM SECTION. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 413 AM CDT MON JUN 16 2014 CONVECTIVE TRENDS WILL BE THE CHALLENGE FOR THE FORECAST THROUGH MUCH OF THE PERIOD. SUBTROPICAL HIGH PRESSURE WILL BUILD INTO THE SOUTHEAST CONUS TONIGHT AND INTO TUESDAY WHILE A CLOSED UPPER LOW SHIFTS EAST FROM THE PACIFIC NORTHWEST INTO THE NORTHERN PLAINS THROUGH THURSDAY. THIS WILL RESULT IN A PROGRESSIVE SOUTHWEST FLOW WITH NUMEROUS EMBEDDED IMPULSES. THE EVOLUTION OF THE THUNDERSTORM ACTIVITY TONIGHT WILL BE CONTINGENT ON CONVECTIVE ACTIVITY TODAY AS THE SFC BOUNDARY LIFTS NORTH AND A HIGHLY UNSTABLE ENVIRONMENT ARRIVES. GENERALLY EXPECT THE FOCUS FOR THUNDERSTORM ACTIVITY TO BE OVER THE NORTHERN HALF OF IOWA AND INTO SOUTHERN MINNESOTA. CONVECTION MAY BE ONGOING AT THE BEGINNING OF THE PERIOD AND SHOULD BECOME MORE WIDESPREAD AS THE LOW LEVEL JET INCREASES AND FURTHER FUELS THE SYSTEM. THE INSTABILITY AXIS WILL BE FROM NORTHWEST AND NORTH CENTRAL INTO THE PERIOD. DEEP LAYER SHEAR VALUES OF 40 KTS OR GREATER WILL BE FAVORABLE FOR SUPERCELL STORMS EARLY IN THE PERIOD. STEEPENING MID LEVEL LAPSE RATES WILL YIELD FAT CAPE VALUES OVER THE AREA WITH THE POTENTIAL FOR INTENSE UPDRAFTS AND VERY LARGE HAIL POTENTIAL. THE TORNADIC POTENTIAL STILL CONDITIONAL ON THE LCL LEVELS WHICH CURRENTLY LOOK MARGINAL. STORMS SHOULD GROW UPSCALE AND EVOLVE INTO A DAMAGING WIND THREAT MID TO LATE EVENING AND RACE EASTWARD AND BE MOSTLY OUT OF COUNTY WARNING AREA BY MIDNIGHT. PWAT VALUES AROUND 1.75 INCHES AND WARM CLOUD DEPTHS OVER 12 KFT WILL BRING A THREAT FOR HEAVY RAINFALL. AT THIS TIME...HAVE NOT ISSUED A FLASH FLOOD WATCH DUE TO THE LACK OF RECENT RAINFALL THROUGH THE THREAT AREA. CERTAINLY VERY HEAVY RAINFALL RATES COULD CAUSE LOCALIZED ISSUES DESPITE THE DRIER CONDITIONS. A STRONG ELEVATED MIXED LAYER WILL MOVE OVER CENTRAL IOWA ON TUESDAY AND PROVIDE A CAPPING LAYER TO CONVECTIVE DEVELOPMENT. H7 TEMPERATURES AROUND 14 C WILL OVERSPREAD THE AREA BY MID AFTERNOON. AFTERNOON HIGH TEMPERATURES ARE EXPECTED TO BE WELL INTO THE UPPER 80S TO LOWER 90S WITH DEWPOINT VALUES IN THE LOWER 70S. THIS WILL PUSH HEAT INDEX VALUES TO NEAR 100 DEGREES. A LARGE CANADIAN SFC HIGH PRESSURE SYSTEM BUILDING SOUTH INTO THE GREAT LAKES REGION WILL HELP SUPPRESS THE WARM FRONT SOUTH TO NEAR THE IA/MN BORDER BY LATE TUESDAY. ANOTHER ROUND OF THUNDERSTORMS SHOULD DEVELOP OVER SOUTHERN MINNESOTA. THESE STORMS LIKELY WILL FORM AN OUTFLOW BOUNDARY THAT WILL DROP SOUTH INTO NORTHERN IOWA AND RIGHT INTO THE PEAK INSTABILITY AXIS WITH MUCAPES AROUND 4000 J/KG. SHOULD ADDITIONAL STORMS DEVELOP...THEY SHOULD PROPAGATE FURTHER SOUTH INTO THE INSTABILITY AXIS. THE MAIN CHALLENGE IS HOW FAR SOUTH THE CONVECTION WILL BE ABLE TO SUSTAIN. THE SURFACE BOUNDARY WILL RETURN NORTH ON WEDNESDAY AS A BACKDOOR COOL FRONT MOVES OFF THE GREAT LAKES AND INTO EASTERN IOWA. THE CLASH OF AIRMASSES SHOULD FIRE ANOTHER ROUND OF THUNDERSTORMS THAN MAY REACH INTO CENTRAL IOWA BY THE AFTERNOON. THE ACTIVITY MAY BECOME WIDESPREAD BY WEDNESDAY NIGHT INTO THURSDAY BEFORE A RELATIVELY QUIET FRIDAY. CONSIDERING THE AMOUNT OF INSTABILITY DURING THE PERIOD...SEVERE WEATHER WILL BE POSSIBLE THROUGHOUT THE PERIOD. THE PACIFIC UPPER LOW WILL TRANSITION INTO A AN UPPER TROUGH OVER THE AREA INTO THE WEEKEND AS AN UPPER RIDGE BUILDS TO THE WEST. THE SLOW MOVING PATTERN SHOULD KEEP THE AREA MOSTLY DRY WITH SFC HIGH PRESSURE NEAR BY UNDER THE RIDGE. && .AVIATION...16/06Z ISSUED AT 1154 PM CDT SUN JUN 15 2014 MAIN FORECAST ISSUE WAS TIMING OF CONVECTION LATE MONDAY AFTERNOON INTO MONDAY NIGHT...SPECIFICALLY ACROSS NORTHERN IOWA. MENTIONED MVFR VIS/CIGS FOR STORMS PAST 00Z TUESDAY. OTHERWISE...HAD LOW CONFIDENCE IN MENTION MVFR CONDITIONS ELSEWHERE WITH DSM/ALO/OTM STAYING IN THE WARM SECTOR AND REMAINING CAPPED OFF. STRONG SOUTHERLY FLOW WILL PERSIST THROUGH MUCH OF THE PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...LEE LONG TERM...DONAVON AVIATION...PODRAZIK  FXUS63 KDMX 172046 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 346 PM CDT TUE JUN 17 2014 .SHORT TERM /TONIGHT/... ISSUED AT 346 PM CDT TUE JUN 17 2014 ANOTHER ACTIVE NIGHT EXPECTED ACROSS THE STATE TONIGHT...WITH SOUTHWEST FLOW ALOFT AND ANOTHER IMPULSE OF ENERGY EVIDENT ON WATER VAPOR IMAGERY ACROSS THE CENTRAL PLAINS LIFTING NORTHEASTWARD TOWARD THE REGION. SFC LOW CENTERED ACROSS CENTRAL NE/KS...WITH AN ASSOCIATED WARM FRONT STRETCHING ACROSS NORTHERN IOWA FROM FAR NORTHWEST IA SOUTHEASTWARD INTO EAST CENTRAL IOWA. DECENT CU FIELD HAS DEVELOPED ACROSS THE CWA WITH STRONG INSTABILITY...HOWEVER DECENT CAP IN PLACE WITH H7 TEMPS IN THE +13C TO +14C ACROSS THE MAJORITY OF THE CWA. WARM FRONT IS EXPECTED TO LIFT NORTHWARD SOME...WITH STORM INITIATION EXPECTED IN VICINITY OF THE FRONT TOWARD VERY LATE AFTERNOON/EARLY EVENING TOWARD 00Z FURTHER NORTH ALONG THE MN/IA BORDER OR JUST NORTH. MOISTURE TRANSPORT REMAINS ORIENTED INTO THE STATE OVERNIGHT...WITH A STRENGTHENING LLJ THEREFORE EXPECT ACTIVITY TO DIVE SOUTH SOUTHEASTWARD THROUGH CENTRAL/EASTERN CWA BY LATE EVENING INTO THE EARLY OVERNIGHT HOURS. A SECONDARY ROUND OF STORMS FROM ACTIVITY OVER SD WILL POTENTIALLY PUSH SOUTHEASTWARD THROUGH THE CWA LATE TONIGHT. SEVERE PARAMETERS REMAIN FAVORABLE FOR ALL MODES OF SEVERE WEATHER...WITH DECENT TURNING IN THE HODOGRAPHS ACROSS NORTHERN IOWA WHICH IS STORMS ARE GOING EARLY ENOUGH COULD PRESENT A TORNADO THREAT/HAIL THREAT. AS THE EVENING WEARS ON...THREAT TRANSITIONS MORE TO A DAMAGING WIND AND HEAVY RAIN THREAT. WITH MUCH OF THE NORTHERN CWA HAVING RECEIVED HEAVY RAINFALL LAST NIGHT...AND POTENTIAL FOR ONE MAYBE TWO COMPLEXES PUSHING THROUGH THE AREA TONIGHT HAVE ISSUED ANOTHER FLASH FLOOD WATCH FOR THE NORTHERN/EASTERN THIRD TO HALF OF THE CWA. OVERALL DO NOT ANTICIPATE RAINFALL AMOUNTS QUITE AS HIGH IN SOME LOCATIONS AS IN THE PREVIOUS NIGHT...BUT WITH SOILS SATURATED FROM THE PREVIOUS RAINFALL IT WILL NOT TAKE MUCH TO CREATE ADDITIONAL FLOODING ISSUES. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 346 PM CDT TUE JUN 17 2014 CONTINUED ACTIVE PATTERN FOR NEXT SEVERAL DAYS...WITH SEVERE STORMS AND HEAVY RAINFALL|FLASH FLOODING POTENTIAL TO REMAIN HIGHER THAN NORMAL. PERSISTENT H500 TROUGH OVER THE WEST AND SUBTROPICAL HIGH ACROSS THE SOUTHEAST US CONTINUES TO FEED HIGH MOISTURE INTO THE CENTRAL PLAINS. SUBJECTIVE H850 ANALYSIS AT 12Z TUES SHOWED WIDE PLUME OF 15C DEW POINTS FROM SOUTH TEXAS NORTH TO EASTERN WYOMING. WITH LONG WAVE TROUGH IN PLACE...SEVERAL SHORT WAVES EXPECTED TO TRACK EAST. BY EARLY WED...DECAYING MCS FROM OVERNIGHT SHOULD BE OVER EASTERN IOWA. OVERNIGHT CONVECTION LIKELY TO KEEP WARM FRONT TRAPPED ACROSS CENTRAL IOWA. LEFTOVER DEBRIS CLOUDS AND MORNING OUTFLOW MAY KEEP BOUNDARY FIXED OVER THE AREA WITH RAPID HEATING OVER NEBRASKA AND SOUTHWEST IOWA SETTING THE STAGE FOR NEARLY A REPEAT OF THE PAST TWO DAYS. EXPECTING ANOTHER ROUND OF THUNDER TO DEVELOP BY LATE MORNING OR AFTERNOON OVER THE EAST/NORTHEAST... POTENTIALLY BACK BUILDING INTO CENTRAL AND SOUTHERN IOWA FROM 21- 06Z. MODELS CONTINUE TO DIFFER ON DETAILS WITH EURO BEING MORE CONSISTENT/STATIONARY AND GFS MORE PROGRESSIVE WITH EASTERLY MOVEMENT OF CONVECTION. AT THIS TIME...EURO SEEMS MORE CORRECT GIVEN POTENTIAL FOR MESO SCALE PROCESSES TO OVERTAKE THE SYNOPTIC FORCING WHICH WILL MAINTAIN THE BOUNDARY IN IOWA. CONSEQUENTLY...MORE ROUNDS OF SVR WEATHER AND HEAVY RAINFALL POSSIBLE AND WILL NEED TO EVALUATE POTENTIAL FOR ANY FLASH FLOODING AREAL COVERAGE AND TIMING FOR WEDNESDAY THROUGH THURSDAY. HIGHS WILL BE QUITE WARM TO HOT AGAIN SW SECTIONS WED...WITH WARM READINGS OVER THE NORTHEAST. UPPER LEVEL H500 WAVE WILL FINALLY LIFT NORTHEAST INTO SOUTHERN CANADA BY 00Z SATURDAY...ENDING THE WIDESPREAD THREAT FOR HEAVY RAIN AND SEVERE WEATHER. OVER THE NEXT 36 TO 48 HOURS...PRECIPITABLE WATER VALUES WILL CONTINUE 1.5 TO 2 INCH RANGE. WARM CLOUD DEPTHS ARE VERY FAVORABLE FOR HEAVY RAINFALL ONCE AGAIN WITH A LARGE PART OF IOWA CONTINUING BETWEEN 3500 AND 4000 METERS...11500 AND 13000 FEET IN DEPTH. CORFIDI VECTORS SUGGEST WEAK FORWARD PROPAGATION WEDNESDAY/WEDNESDAY NIGHT AND MAY SEE AN MCS OVER EASTERN IOWA LATE WEDNESDAY MORNING BACKBUILD ACROSS THE AREA THROUGH THE AFTERNOON AND EVENING HOURS. THE UNUSUAL COMBINATION OF FACTORS MAY LEAD TO HIGH RAINFALL RATES AND THE POTENTIAL FOR 2 TO 4 INCHES OF RAINFALL IN A SHORT PERIOD OF TIME. WIND FIELDS ALOFT ARE NOT APPRECIABLY STRONG WEDNESDAY...THOUGH SEVERE WEATHER WILL STILL BE POSSIBLE THE FOCUS MAY SHIFT TO A GREATER RISK OF HEAVY RAINFALL. BY THURSDAY... WIND FIELDS INCREASE ALOFT SHIFTING THE FOCUS BACK SLIGHTLY TOWARD SEVERE WEATHER. WARM AND HUMID WEATHER TO REMAIN THROUGH SATURDAY WITH HIGHS IN THE 80S AND LOWS IN THE 60S TO NEAR 70. SOME RELIEF IS EXPECTED LATER IN THE WEEKEND TO EARLY NEXT WEEK. GEM/EURO SUGGEST CANADIAN HIGH WILL IMPACT THE AREA BY LATE SUNDAY/MONDAY WITH DRIER WEATHER EXPECTED... AND COOLER TEMPERATURES. GFS MAY BE BRINGING STORMS AND RAINFALL BACK TOO QUICKLY. IF THE HIGH HOLDS A BREAK FROM THE ACTIVE WEATHER SHOULD LAST FOR SEVERAL DAYS. && .AVIATION...17/18Z ISSUED AT 1235 PM CDT TUE JUN 17 2014 CU FIELD TO FILL IN ACROSS THE AREA THIS AFTERNOON...WITH MAINLY LOW VFR CIGS. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE MN/IA BORDER TOWARD LATE AFTERNOON/EARLY EVENING AND SPREAD SOUTH/SOUTHEASTWARD THROUGH THE STATE THIS EVENING INTO THE OVERNIGHT HOURS. HAVE NARROWED DOWN THE BEST CHANCES FOR PRECIP AT THE TAF SITES WITH VCSH AT THE WESTERN TAF SITES WHICH WILL BE MORE ON THE WESTERN EDGE OF EXPECTED ACTIVITY AND KEPT MORE ROBUST VCTS WORDING AT KMCW AND KALO WHERE BEST CHANCES EXIST. ADDITIONAL THUNDERSTORM CHANCES ARE EXPECTED JUST BEYOND THE CURRENT TAF FORECAST PERIOD FOR WEDNESDAY. && .HYDROLOGY... ISSUED AT 346 PM CDT TUE JUN 17 2014 SEVERAL ROUNDS OF HEAVY RAINFALL WILL BE POSSIBLE THROUGH THE PERIOD. TONIGHTS CONVECTION WILL BE CONCENTRATED OVER NORTHERN IOWA AND PORTIONS OF NORTHEAST AND CENTRAL IOWA MAINLY ALONG AND NORTH OF US HIGHWAY 30. ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED LATE WEDNESDAY MORNING INTO THE AFTERNOON/EVENING HOURS...POSSIBLY BACK BUILDING ACROSS CENTRAL AND SOUTHERN IOWA DURING THE AFTERNOON. ADDITIONALLY...MORE RAIN IS POSSIBLE THURSDAY INTO THURSDAY NIGHT. FLASH FLOOD GUIDANCE CONTINUES TO LOWER WITH EACH RAIN EVENT. MOST OF THE NORTH TWO THIRDS OF THE AREA IS LOOKING AT 1 HOUR FFG OF 1.25 TO 1.75 INCHES WITH THE SOUTHERN THIRD 2 TO 2.5 INCHES. 3 HOUR GUIDANCE IS 1.88 TO ABOUT 3 INCHES. WITH THE POTENTIAL FOR 2 TO 4 INCHES IN A SHORT PERIOD OF TIME...FLASH FLOODING WILL BE A POSSIBILITY TONIGHT ACROSS THE NORTH AND POSSIBLY OVER MORE OF THE AREA WEDNESDAY. RECENT AND FORECAST RAINFALL HAVE RESULTED IN SIGNIFICANT RISES ON RIVERS IN THE NORTHERN CWA...WITH SOME RIVERS ALREADY ABOVE FLOOD STAGE. RIVER FLOOD WARNINGS CONTINUE FOR PORTIONS OF THE DES MOINES RIVER BASIN UNTIL FURTHER NOTICE. CONCERN IS THE IMPACT OF SUCCESSIVE RAINFALL EVENTS ON THE STREAMS...ESPECIALLY ACROSS THE NORTHERN HALF OF THE CWA. QPF ENSEMBLE HYDROGRAPHS SUGGEST THAT ADDITIONAL RAINFALL WILL LIKELY PROLONG THE FLOODING IN LOCATIONS ALREADY WARNED...AND MAY RESULT IN NEW FLOODING. FOR EXAMPLE...QPF ENSEMBLE HYDROGRAPHS SUGGEST THE POSSIBILITY OF MODERATE FLOODING IN THE NORTHERN DES MOINES RIVER BASIN...WITH MINOR FLOODING POSSIBLE DOWN TO SAYLORVILLE RESERVOIR. THEY SHOW MINOR TO LOW-END MODERATE FLOODING POSSIBLE ON OTHER STREAMS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH WEDNESDAY MORNING FOR BLACK HAWK-BREMER-BUTLER-CALHOUN-CERRO GORDO-EMMET- FRANKLIN-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH- MARSHALL-PALO ALTO-POCAHONTAS-SAC-STORY-TAMA-WEBSTER-WINNEBAGO- WORTH-WRIGHT. && $$ SHORT TERM...BEERENDS LONG TERM...REV AVIATION...BEERENDS HYDROLOGY...ZOGG/REV  FXUS63 KDMX 182052 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 352 PM CDT WED JUN 18 2014 .SHORT TERM /TONIGHT/... ISSUED AT 351 PM CDT WED JUN 18 2014 FORECAST CONCERNS FOCUSED ON SEVERE AND HEAVY RAIN POTENTIAL LATE TONIGHT INTO THURSDAY MORNING. CURRENTLY IN SOUTHWEST IOWA THE CAP IS BEGINNING TO ERODE OR HAS ERODED ALLOWING FOR SOME IMPRESSIVE CAPE VALUES THIS AFTERNOON. HOWEVER...THE EFFECTIVE SHEAR REMAIN LOW...ALBEIT IT HAS INCREASED TO AROUND 20 KNOTS BY 20Z. LEANED TOWARD THE 18.12Z NAM12/ECMWF TONIGHT AS SEEMED TO HAVE DECENT HANDLE ON OVERNIGHT CONVECTIVE TRENDS. ALTHOUGH THE GFS AND SREF ARE IN FAIR AGREEMENT WITH THE NAM/ECMWF THINKING AS WELL. FRONTAL BOUNDARY CURRENTLY EXTENDS FROM NORTHWEST IOWA TO SOUTHEAST IOWA BUT LOOKS TO SHIFT BACK NORTHWARD WITH THE LLJ DEVELOPING TONIGHT BUT STILL ORIENTED NW TO SE. TREMENDOUS MOISTURE TRANSPORT INTO THE STATE COMBINED WITH STRONG MOISTURE CONVERGENCE AND 1.5 TO NEAR 2.0 INCH PRECIPITABLE WATER VALUES. THE WARM LAYER CLOUD DEPTHS INCREASE TO 13KFT TO NEAR 14KFT BY LATE THIS EVENING WITH THE MEAN STORM MOTION REMAINING UNDER 20 KNOTS...SO SOME EFFICIENT RAIN PRODUCERS ARE LIKELY. PLUS WITH THE RAIN OVER THE PAST FEW DAYS...3- HR FFG RANGES FROM 1.5 TO 2 INCHES AND CONFIDENCE IS HIGH SOME PORTIONS OF CENTRAL TO NORTHERN IOWA WILL EXCEED GUIDANCE OVERNIGHT. HAVE ISSUED A FLASH FLOOD WATCH FOR COUNTIES ALONG AND NORTH OF HIGHWAY 30 TO THE MINNESOTA BORDER FROM LATE TONIGHT INTO THURSDAY MORNING. MAY NEED TO EXPAND WATCH AREA FURTHER WEST AND SOUTH DEPENDING ON IF CONVECTION HOLDS TOGETHER INTO THURSDAY MORNING. CANNOT RULE OUT SEVERE POTENTIAL TONIGHT INTO THE OVERNIGHT HOURS WITH THE AMOUNT OF INSTABILITY PRESENT AND WEAK AMOUNT OF LOW LEVEL SHEAR. SHORTWAVE MOVING ACROSS TONIGHT BRINGS SOME DECENT LARGE SCALE FORCING OVER NORTH-CENTRAL IOWA. BUT MORE CONFIDENT CONVECTION WILL QUICKLY TRANSITION INTO HEAVY RAIN PRODUCERS WITH THE INCREASING LLJ. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 351 PM CDT WED JUN 18 2014 SIMILAR CONCERNS REMAIN THROUGH FRIDAY MORNING WITH A BREAK FINALLY ARRIVING FOR 36 HOURS BEFORE ANOTHER PERIOD OF POTENTIALLY MODERATE TO HEAVY RAINFALL RETURNS TO THE AREA FOR LATE SATURDAY INTO MONDAY NIGHT. FOLLOWING THAT...POTENTIALLY A MORE PRONOUNCED PATTERN CHANGE RESULTING IN COOLER AND DRIER WEATHER...POSSIBLY LASTING THROUGH LATE FRIDAY OF NEXT WEEK. BY THURSDAY MORNING ANOTHER DECAYING MCS IS LIKELY TO BE MOVING THROUGH THE AREA...WITH RAINFALL CONTINUING OVER THE AREA. THE SHORT WAVE WILL PASS INTO THE REGION AND INCREASE RAINFALL ACROSS THE REGION INTO THE AFTERNOON HOURS. THE POTENTIAL FOR HEAVY RAINFALL WILL CONTINUE OVER THE AREA THROUGH THE AFTERNOON AND EVENING HOURS WITH SOME POTENTIAL FOR SEVERE WEATHER. COOLER HIGHS ARE EXPECTED ACROSS THE NORTH WITH WARM READINGS AGAIN AHEAD OF THE AFTERNOON CONVECTION IN THE SOUTH. BY LATE THURSDAY EVENING...A BREAK FROM THE HEAVY RAINS SHOULD OCCUR BETWEEN THE MORNING AND AFTERNOON ACTIVITY...BUT THE WINDOW MAY ONLY BE 4 TO 6 HOURS. WITH THE CONTINUED AIRMASS SHOWING HIGH PRECIPITABLE WATER AND WARM CLOUD DEPTHS TO 13000 FEET OR HIGHER THROUGH TOMORROW...THE FLASH FLOOD WATCH MAY BE EXTENDED OR EXPANDED FOR TOMORROW ACROSS THE REGION. FOR NOW...WILL SEE HOW TONIGHTS CONVECTION EVOLVES TO BETTER DEFINE THE AREA OF MOST CONCERN RATHER THAN JUST EXPANDING AND EXTENDING NOW TO AREAS THAT MAY NOT NEED A WATCH. RAINFALL AMOUNTS COULD AGAIN APPROACH THE 1 TO 3 INCH RANGE WITH SOME OF THE STORMS AND POTENTIAL FOR SOME TRAINING MCS. ONCE THE SHORT WAVE MOVES EAST FRIDAY NIGHT A WELCOMED BREAK FROM THE RAIN AND SLIGHTLY LOWER DEWPOINTS WILL REPLACE THE CURRENT CONDITIONS HERE. THE CONTINUED ZONAL FLOW WILL FAVOR ANOTHER LEE SIDE TROUGH DEVELOPING BY LATE SATURDAY NIGHT AND SUNDAY...WITH ANOTHER ROUND OF THUNDERSTORMS TO ARRIVE ACROSS THE REGION BY LATE SATURDAY NIGHT INTO MONDAY. UNFORTUNATELY THE TROUGH WILL DEEPEN AS IT TRACKS INTO THE PLAINS SUNDAY NIGHT AND MONDAY...SO MORE HEAVY RAIN WILL BE POSSIBLE. THIS TIME THE TRACK OF THE SHORT WAVE MAY FAVOR THE SOUTHEAST HALF OF THE FORECAST AREA WHERE AREAS HAVE BEEN GENERALLY MISSED THE PAST FEW DAYS. THIS WOULD HELP THE NORTH RECOVER GIVEN THE NEXT TWO DAYS OF EXPECTED RAINFALL. WITH THE SYSTEM PULLING OUT OF THE REGION BY TUESDAY...HIGH PRESSURE AND LESS CHANCES FOR ANY SIGNIFICANT RAIN SHOULD OCCUR FROM TUESDAY NIGHT THROUGH THE END OF THE PERIOD. THIS MAY LAST UNTIL LATE IN THE WEEK AS ANOTHER LARGE SCALE TROUGH MOVES INTO THE WESTERN CONUS AND A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE PLAINS. INITIALLY COOLER WEATHER WILL REPLACE THE WARM TEMPERATURES FOR WEDNESDAY AND THURSDAY THEN WARMING LATER IN THE WEEK. && .AVIATION...18/18Z ISSUED AT 1232 PM CDT WED JUN 18 2014 VFR CONDITIONS THIS AFTERNOON INTO THE EVENING BEFORE EXPECTED STORMS TO DEVELOP PAST 02Z INTO THE OVERNIGHT HOURS. HAVE MVFR VIS/CIGS MENTIONED B/T 07Z TO 10Z FROM NORTH TO SOUTH AND LASTING FOR SEVERAL HOURS INTO THURSDAY MORNING. POTENTIAL FOR IFR/LIFR CONDITIONS WITH HEAVY RAIN...BUT LOW CONFIDENCE IN TIMING AND DURATION ATTM TO MENTION. && .HYDROLOGY... ISSUED AT 351 PM CDT WED JUN 18 2014 ANOTHER ROUND OF POTENTIALLY HEAVY RAINS WILL OCCUR TONIGHT ACROSS THE FORECAST AREA. PRECIPITABLE WATER REMAINS HIGH WITH VALUES OF 1.5 TO 2.0 INCHES ACROSS THE REGION TONIGHT. THE MAIN FOCUS WILL BE ALONG AND NORTH OF THE WARM FRONT WHICH BISECTS THE STATE RIGHT NOW FROM NORTHWEST TO SOUTHEAST. WITH WARM CLOUD DEPTHS AGAIN FAVORING EFFICIENT RAINFALLS...SOME 1 TO 2 INCHES OR HIGHER AMOUNTS WILL BE POSSIBLE. SIMILAR CONDITIONS WILL CONTINUE ON THURSDAY FOR MOST OF THE AREA...THOUGH STORMS MAY BE FASTER MOVING IN THE AFTERNOON HOURS. AGAIN...1 TO 2 INCH RAINFALLS MAY OCCUR WITH THE PASSAGE OF THE TROUGH THROUGH THURSDAY EVENING. WILL NEED TO MONITOR AREA FOR ANY FLASH OR AREAL FLOODING THURSDAY AND ALSO EXPECT THAT RIVER LEVELS AND FORECASTS OF LEVELS WILL INCREASE GIVEN THE ADDITION OF MORE RAIN TONIGHT AND THURSDAY. THIS WILL LIKLEY IMPACT RIVER LEVELS THROUGH THE WEEKEND AND EARLY NEXT WEEK. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH THURSDAY MORNING FOR BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN-CERRO GORDO- EMMET-FRANKLIN-GREENE-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT- KOSSUTH-MARSHALL-PALO ALTO-POCAHONTAS-STORY-TAMA-WEBSTER- WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...PODRAZIK HYDROLOGY...REV  FXUS63 KDMX 192050 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 350 PM CDT THU JUN 19 2014 .SHORT TERM /TONIGHT/... ISSUED AT 331 PM CDT THU JUN 19 2014 SHORTWAVE TROUGH PER WATER VAPOR IMAGERY LIFTING NORTHEAST ACROSS THE NORTHERN PLAINS THIS AFTERNOON. THE UPPER TROUGH IS FORECAST TO LIFT NORTHEAST TONIGHT AND WEAKEN. THE TROUGH SHOULD PUSH UPWARD VERTICAL MOTION FIELDS EAST OF THE CENTRAL BY 06Z. A LINE OF STORMS DEVELOPED THIS AFTERNOON OVER WESTERN IOWA AHEAD OF A SURFACE TROUGH. THE STORMS SHOULD MOVE EAST THIS EVENING AND SLOWLY WEAKEN AS THE SHORTWAVE SUPPORT MOVES EAST AND THE LOSS OF SURFACE HEATING AND LACK OF LOW LEVEL JET SUPPORT. EXPECT ALL OF THE PRECIPITATION SHOULD BE OVER BY MIDNIGHT. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 331 PM CDT THU JUN 19 2014 FINALLY A BREAK ARRIVES BY FRIDAY AS SHORT WAVE TROUGH MOVES TO THE EAST OF THE REGION. WEAK BUBBLE OF HIGH PRESSURE WILL PASS ACROSS THE STATE TOMORROW...WITH LITTLE MIXING BUT WARM H850 TEMPS WILL CONTINUE. THIS SHOULD LEAD TO HIGHS IN THE MID TO UPPER 80S AND LIKELY SOME FAIR WX CU FOR THE DAY. THE NEAR TERM UNFORTUNATE REALITY IS THAT ZONAL FLOW CONTINUES THROUGH EARLY NEXT WEEK ACROSS THE CONUS. WITH THAT CONTINUING...LEE SIDE TROUGHS LIKELY TO FORM EAST OF THE ROCKIES RESULTING IN WAVES/LOW PRESSURE TRACKING INTO THE MID MISSISSIPPI RIVER VALLEY. BY LATE FRIDAY NIGHT MODELS SHOW LEE SIDE DEVELOPMENT OVER WESTERN NEBRASKA WITH SOME WARM AIR ADVECTION HEADING INTO NORTHWEST IOWA. FOR NOW...PREFER A SLIGHTLY SLOWER EURO SOLUTION BUT THE NORTHERN COUNTIES MAY BE CLIPPED BY SOME WEAKER CONVECTION BY LATE FRIDAY NIGHT/SATURDAY MORNING. TEMPS WILL REMAIN MILD FRI NIGHT AND THROUGH THE WEEKEND AS WELL. APPROACHING WARM FRONT SATURDAY AFTERNOON OVER SOUTHERN IOWA WILL LIKELY LEAD TO ENHANCED CONVECTION CHANCES OVER WESTERN/SOUTHERN SECTIONS. THERE IS SOME UNCERTAINTY ON LOCATION OF THE BOUNDARY BUT THE MODELS SUGGEST A SOUTHERN IOWA BOUNDARY BY LATE AFTERNOON. THIS SHOULD LIFT NORTHEAST INTO THE EVENING HOURS WITH THE FOCUS FOR CONVECTION SHIFTING TO THE NORTH HALF OF THE FORECAST AREA. PRESENT PRECIPITABLE WATER FORECAST FOR LATE SATURDAY SHOWS RAPID RECOVERY ONCE AGAIN WITH NEAR 1.5 INCHES AVAILABLE ACROSS THE REGION. WARM CLOUD DEPTHS AGAIN RAPIDLY INCREASE TO 11.5 KFT TO 13 KFT BY 06Z SUNDAY AND REMAIN HIGH THROUGH LATE MONDAY AFTERNOON OVER MUCH OF SOUTHERN IOWA. POTENTIAL FOR MORE HEAVY RAINFALL OVER THE REGION SUNDAY AND SPECIFICALLY OVER THE SOUTHERN THIRD. PWATS INCREASE TO 1.5 TO NEARLY 2.0 INCHES BY SUNDAY NIGHT AS WELL. INSTABILITY REMAINS MODEST...WHICH ALL POINT TO POTENTIAL FOR EFFICIENT AND POTENTIALLY HEAVY RAINFALL. THOUGH THERE IS SOME UNCERTAINTY IN THE TRACK OF THE WAVE THAT MOVES ACROSS EITHER SOUTHERN IOWA OR NORTHERN MISSOURI...THIS SYSTEM MAY END UP BRINGING IN EXCESS OF THREE INCHES OF RAIN FROM SUNDAY THROUGH EARLY MONDAY NEAR THE LOW TRACK. GIVEN THE CURRENT SITUATION ACROSS THE REGION...WILL NEED TO CLOSELY MONITOR THE POTENTIAL FOR SOUTHERN IOWA IN THE NEXT 2 DAYS. WITH THE CLOUDS AND EXPECTED RAINS...TEMPS WILL COOL SOMEWHAT FROM SATURDAY TO SUNDAY WITH HIGHS IN THE MID TO UPPER 80S SATURDAY TO THE LOWER 70S ON SUNDAY. FOLLOWING THE PASSAGE OF THE RATHER SPRINGLIKE SYSTEM MONDAY...THERE IS STILL A SIGNAL FOR A PERIOD OF DRYING INTO MID TO MID WEEK. TODAYS GEM/GFS ARE IN LINE WITH YESTERDAYS AND TODAYS 12Z EURO. GIVEN THAT SOME UNCERTAINTY EXISTS LATER IN THE WEEK SOME CHALLENGES REMAIN REGARDING THE POTENTIAL FOR ADDITIONAL ROUNDS OF RAIN AFTER WEDNESDAY OF NEXT WEEK. THE ONE CONSISTENCY IN THE MODELS REMAINS THAT THE STRONG SUBTROPICAL HIGH WILL REMAIN ANCHORED IN THE SOUTHEAST US THROUGH THE PERIOD. && .AVIATION...19/18Z ISSUED AT 1222 PM CDT THU JUN 19 2014 SHOWERS AND THUNDERSTORMS OVER EASTERN IOWA SHOULD CONTINUE TO IMPACT KALO/KOTW FOR THE NEXT FEW HOURS. EXPECT THUNDERSTORMS TO DEVELOP OVER WESTERN IOWA THIS AFTERNOON AND THEN MOVE THROUGH CENTRAL IOWA. DEPECTED TIMING AS TEMPO GROUPS IN TAFS. WEAK HIGH PRESSURE AND PLENTY OF BOUNDARY LAYER MOISTURE SUPPORTS MENTIONING FOG AROUND SUNRISE. && .HYDROLOGY... ISSUED AT 331 PM CDT THU JUN 19 2014 SHORT TERM...THUNDERSTORMS THIS EVENING SHOULD BE VERY EFFICIENT RAINFALL PRODUCERS WITH DEEP WARM CLOUD LAYER OF NEARLY 4000 METERS...HIGH PRECIPTABLE WATER VALUES...AND DEEP MOISTURE PER MODEL SOUNDINGS. WILL KEEP FLASH FLOOD WATCH GOING OVER NORTHERN IOWA THIS EVENING. LONG TERM...THE NEXT PERIOD OF POTENTIAL HEAVY RAINFALL ARRIVES LATER ON SATURDAY AND ESPECIALLY SUNDAY INTO MONDAY. AN UNUSUAL LATE SEASON SPRING LIKE SYNOPTIC STORM MAY DEVELOP OVER SOUTHERN IOWA OR NORTHERN MISSOURI. WITH A WARM FRONTAL BOUNDARY NEAR THE AREA AND SIGNIFICANT FORCING COMBINED WITH CONTINUED HIGH PWATS AND EFFICIENT RAINFALL POTENTIAL ONCE AGAIN...THE SOUTHEAST THIRD OF THE FORECAST AREA WILL HAVE TO BE WATCHED FOR POTENTIAL HYDRO ISSUES BOTH IN TERMS OF FLASH FLOODING AND RIVER FLOODING. BECAUSE OF THE UNCERTAINTY OF THE COVERAGE AND LOCATION OF THE WEEKEND EVENTS...IT IS TOO EARLY TO DETERMINE RIVER LEVELS AND ADDITIONAL RIVER FLOODING POTENTIAL AT THIS TIME. LATER FORECASTS WILL ADDRESS BOTH ISSUES AS CONFIDENCE IN THE EVOLUTION OF THE SYSTEM INCREASES. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 10 PM CDT THIS EVENING FOR BLACK HAWK- BOONE-BREMER-BUTLER-CALHOUN-CERRO GORDO-EMMET-FRANKLIN-GREENE- GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-MARSHALL-PALO ALTO-POCAHONTAS-STORY-TAMA-WEBSTER-WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...JOHNSON LONG TERM...REV AVIATION...JOHNSON HYDROLOGY...JOHNSON/REV  FXUS63 KDMX 202044 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 344 PM CDT FRI JUN 20 2014 .SHORT TERM /TONIGHT/... ISSUED AT 345 PM CDT FRI JUN 20 2014 WEAK AREA OF HIGH PRESSURE OVER CENTRAL IOWA AND MISSOURI PROVIDED TEMPORARY RELIEF FROM THE WET PATTERN. BY THIS AFTERNOON...MOISTURE HAD RETURNED NORTH ACROSS THE MISSOURI VALLEY AND THUNDERSTORMS HAD DEVELOPED OVER WESTERN IOWA. HARD TO TELL IF THERE IS ANY SHORTWAVE ENERGY TO WORK WITH TONIGHT LOOKING AT WATER VAPOR. HOWEVER...WE REMAIN ON THE SOUTHERN EDGE OF THE WESTERLIES AND THERE IS LIKELY WEAK SHORTWAVE ENERGY SUPPORT EXPANDING CONVECTION TO THE WEST. THUNDERSTORMS SHOULD BE SLOW TO SPREAD EAST INTO IOWA EARLY ON DUE TO RELATIVELY DRY AREA OVER THE STATE. WITH THAT SAID...WILL INCREASE POPS NORTHWEST THIS EVENING. EXPECT MCS TO MOVE INTO WESTERN IOWA OVERNIGHT TONIGHT. OVERALL...THE CONVECTION SHOULD WEAKEN AS IT MOVES EAST AWAY FROM THE INSTABILITY GRADIENT. NONE THE LESS...I INCREASED POPS ACROSS CENTRAL IOWA AFTER MIDNIGHT. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 345 PM CDT FRI JUN 20 2014 CHALLENGES AND CONCERNS ABOUT RAINFALL FOR THE REMAINDER OF THE WEEKEND AND EARLY NEXT WEEK BEFORE RAIN CHANCES LESSEN FOR A FEW DAYS. WARM FRONT OVER EASTERN NEBRASKA THIS AFTERNOON EXPECTED TO LIFT INTO IOWA SATURDAY WITH THUNDERSTORMS MOVING ALONG THE BOUNDARY. MCS AND THUNDERSTORMS OVER NE SHOULD BE ON THE DECREASE SATURDAY IN THE MORNING HOURS OVER OUR FORECAST AREA...BUT MAY AGAIN INTENSIFY DURING THE AFTERNOON AS DAYTIME HEATING INCREASES INSTABILITY. THE MOST FAVORED AREA WOULD BE ALONG THE RETREATING WARM FRONT. CHALLENGES REMAIN ON WHERE THE FRONT WILL BE DURING THE DAY TOMORROW. EXPECTATION IS THAT IT WILL MAKE IT NO FARTHER NORTH THAN ABOUT INTERSTATE 80 AT BEST SATURDAY...SO HAVE BROAD BRUSHED CHANCE POPS ACROSS MOST OF THE FORECAST AREA FOR THE DAY. THERE SHOULD BE A FAVORED AREA OF HIGHER POP...BUT THAT WILL NEED TO BE BETTER DEFINED IN THE NEXT 12 HOURS AS THE WARM FRONT LIFTS NORTH. UNFORTUNATELY THE MESO SCALE WILL DOMINATE THE WX AGAIN IN THE NEXT 48 HOURS...PRIOR TO THE MAIN SHORT WAVE ARRIVING BY LATE SUNDAY INTO MONDAY WHEN FORECASTING CHANCES AND COVERAGE OF PRECIPITATION IS BETTER DEFINED. THE MAIN THEME AGAIN OVER THE WEEKEND WILL BE THE POTENTIAL FOR HEAVY RAINFALL AND LESSER RISK OF SEVERE WEATHER. WITH ABUNDANT MOISTURE AND RELATIVELY WEAK TO MODEST SYNOPTIC WINDS FIELDS...THUNDERSTORM DEVELOPMENT IS MORE LIKELY TO FOLLOW DIURNAL TRENDS...BOTH OVERNIGHT AND EARLY MORNING AND AGAIN LATE AFTERNOON AND EVENING BUT WITH EXPECTED INSTABILITY MAY SEE CHANCES REMAIN ALL DAY LONG. CURRENTLY OUR SVR OUTLOOK IS SLIGHT AND FOCUSING ON LIMITED CHANCES FOR WIND AND HAIL...VERY LITTLE RISK OF ANY TORNADOS. OVER THE NEXT TWO DAYS...PRECIPITABLE WATER ONCE AGAIN RISES QUICKLY WITH VALUES OF 1 TO 1.75 INCHES OVER OUR AREA SATURDAY THROUGH MIDDAY SUNDAY. MUCAPE INSTABILITY VALUES DIFFER AMONG MODELS FOR TOMORROW WITH VALUES RANGING BETWEEN 2500-4000 J/KG IN THE GFS TO 1500 TO 2500 J/KG IN THE EURO. THE HIGHER IN BOTH CASES IS OVER THE SOUTHWEST NEARER THE WARM FRONT. WITH LITTLE CAP AT H700...EXPECT THAT CONVECTION MAY BUBBLE FOR MOST OF THE DAY KEEPING CLOUDS AROUND AND TEMPERATURES DOWN...ALONG AND NORTH OF THE BOUNDARY. THOUGH OUTFLOW BOUNDARIES MAY INHIBIT THE WARM FRONT FROM MOVING NORTH...WILL LEAN TOWARD SLIGHT NORTHWARD MIGRATION THROUGH SUNDAY WITH MORE SCT CONVECTION SATURDAY NIGHT/SUNDAY PRIOR TO MAIN WAVE ARRIVAL LATER ON SUNDAY WITH BETTER CHANCES ACROSS THE NORTH THAN SOUTH. WITH POTENTIAL FOR MORE WIDELY SCATTERED STORMS...WILL BE DIFFICULT TO ASCERTAIN AREAS MOST LIKELY TO SEE EXCESSIVE RAINFALL. FOR NOW...WILL NOT ENTERTAIN ANY HEADLINES INTO SUNDAY. HIGHS SATURDAY AND SUNDAY WILL BE MAINLY IN THE 80S WITH RATHER HIGH HUMIDITY AGAIN. AS THE MAIN LOW EJECTS INTO SOUTHEAST IOWA SUNDAY NIGHT THROUGH MONDAY MODELS SHOW A SLIGHTLY STRENGTHENING LOW WHICH SHOULD RESULT IN MORE WIDESPREAD HEAVY RAINFALL OVER THE SOUTHEAST HALF TO TWO THIRDS OF THE AREA. AT THIS TIME...GENERAL COVERAGE SHOULD RANGE FROM NEAR 1 TO 2 INCHES WITH LOCALLY HIGHER AMOUNTS LIKELY. PWATS AGAIN RANGE FROM 1.5 TO NEARLY 2 INCHES WITH WARM CLOUD DEPTHS FROM 11500 TO 13000 KFT PROMOTING RAINFALL RATES SIMILAR TO WHAT OCCURRED THURSDAY ACROSS THE FORECAST AREA... UP TO 3.5 INCHES PER HOUR. THUS...QUICK 1 TO 2 INCH AMOUNTS COULD OCCUR IN SOME LOCATIONS. THOUGH SOME PORTIONS OF THE SOUTH COULD PROBABLY HANDLE HIGHER RAINFALL AT THIS TIME...WILL NEED TO EVALUATE MORE CLOSELY IF ANY AREAS NEED HEADLINES FOR HEAVY RAINFALL. FOLLOWING THE STORM A ONE TO TWO DAY BREAK FROM ANY ORGANIZED RAIN IS EXPECTED. BY WEDNESDAY ANOTHER LEE SIDE TROUGH IS EXPECTED TO FORM WHICH MAY INCREASE CHANCES FOR CONVECTION BY MIDWEEK. LOW CONFIDENCE HAS RETURNED TO THE FORECAST FOR THE REMAINDER OF THE EXTENDED AS THE EURO HAS NOW TRENDING TOWARD A PERIOD OF MUCH WARMER WEATHER WHILE THE GEM AND GFS CONTINUE TO ADVERTISE NORTHWEST FLOW AND COOLER TEMPERATURES. WILL CONTINUE A BLEND TOWARD THE END OF THE PERIOD UNTIL TRENDS BECOME MORE CLEAR. && .AVIATION...20/18Z ISSUED AT 1226 PM CDT FRI JUN 20 2014 WEAK HIGH PRESSURE OVER CENTRAL IOWA TODAY WILL GIVE WAY TO RETURN SOUTHEAST FLOW BY THIS EVENING. THUNDERSTORMS OVER NEBRASKA WILL LIKELY PUSH INTO WESTERN IOWA TONIGHT AND SATURDAY MORNING. ADDED VCSH TO TAFS BUT NOT ENOUGH CONFIDENCE IN TIMING TO ADD THUNDER TO THE TAFS. FORECAST FOR VFR CLOUDS AT THIS TIME. && .HYDROLOGY... ISSUED AT 345 PM CDT FRI JUN 20 2014 THE NEXT PERIOD OF POTENTIAL HEAVY RAINFALL ARRIVES LATER ON SATURDAY ACROSS THE NORTH AND ESPECIALLY SUNDAY INTO MONDAY FOR THE SOUTHEASTERN HALF TO TWO THIRDS OF THE FORECAST AREA. AN UNUSUAL LATE SEASON SPRING LIKE SYNOPTIC STORM EXPECTED TO DEVELOP OVER SOUTHERN IOWA OR NORTHERN MISSOURI AND DEEPEN SLIGHTLY AS IT MOVES TO THE NORTHEAST MONDAY. WITH A WARM FRONTAL BOUNDARY NEAR THE AREA AND SIGNIFICANT FORCING COMBINED WITH CONTINUED HIGH PRECIPITABLE WATER VALUES AND EFFICIENT RAINFALL POTENTIAL ONCE AGAIN...THE SOUTHEAST TWO THIRDS OF THE FORECAST AREA WILL HAVE TO BE WATCHED FOR POTENTIAL HYDRO ISSUES BOTH IN TERMS OF FLASH FLOODING AND RIVER FLOODING. BECAUSE OF THE UNCERTAINTY OF THE COVERAGE AND LOCATION OF THE WEEKEND EVENTS...IT IS TOO EARLY TO DETERMINE RIVER LEVELS AND ADDITIONAL RIVER FLOODING POTENTIAL AT THIS TIME. LATER FORECASTS WILL ADDRESS BOTH ISSUES AS CONFIDENCE IN THE EVOLUTION OF THE SYSTEM INCREASES. FOR INFORMATION ABOUT POSSIBLE RAINFALL AMOUNTS DURING THE LATE WEEKEND...SEE THE REGULAR FORECAST DISCUSSION ABOVE. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JOHNSON LONG TERM...REV AVIATION...JOHNSON HYDROLOGY...REV  FXUS63 KDMX 212021 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 321 PM CDT SAT JUN 21 2014 .SHORT TERM /TONIGHT/... ISSUED AT 320 PM CDT SAT JUN 21 2014 CONVECTIVE TRENDS OVERNIGHT ARE THE PRIMARY FORECAST CHALLENGE OVERNIGHT. MCV SHIFTING EAST ACROSS SRN WISCONSIN AND NRN ILLINOIS HAS WRAPPED DRY MID LEVEL AIR IN TO CENTRAL AND EASTERN IOWA. THIS HAS HELPED STRENGTHEN THE CONVECTIVE INHIBITION ACROSS THE AREA. SFC FLOW OVER CENTRAL IOWA REMAINS NEARLY NON EXISTENT WITH THE OVERNIGHT OUTFLOW PUSHING THE WARM FRONT JUST SOUTH INTO KANSAS AND MISSOURI. A FEW STORMS HAVE BEEN TRYING TO INITIATE ALONG THIS BOUNDARY BUT HAVING A DIFFICULT TIME BECOMING ORGANIZED WITH A LACK OF DEEP LAYER SHEAR AND ANY GOOD FORCING TO AID IN SUSTAINING UPDRAFTS. THIS ACTIVITY SHOULD MOSTLY REMAIN SOUTH OF THE STATE BUT MAY CLIP THE SOUTHERN TIER OF COUNTIES THE NEXT FEW HOURS. FORCING REMAINS WEAK ACROSS CENTRAL IOWA THROUGH THIS EVENING. THE LOW LEVEL JET OF AROUND 35 KTS WILL AMPLIFY OVER THE MID MISSOURI VALLEY AND POINTS TO THE WEST HOWEVER ITS ORIENTATION WILL FAVOR THE FORCING AND CONVERGENCE ZONE ACROSS NEBRASKA AND SOUTH DAKOTA. A SHORT WAVE MOVING RAPIDLY ACROSS THE ROCKIES OVERNIGHT SHOULD SPREAD QG FORCING EAST INTO WESTERN IOWA LATE AND WILL HAVE PUSH ANY DEVELOPING MCS CLOSE TO THE STATE LATE. POSSIBLE A FEW STORMS DEVELOP OVER THE CENTRAL AND SOUTHWEST AS A COUPLE WAVES OF THETA-E ADVECTION LIFT NORTH AND GENERATE AN INSTABILITY AXIS THROUGH THAT REGION. A DISCONTINUITY BETWEEN FORCING AND MOISTURE AVAILABLE SHOULD PREVENT WIDESPREAD ACTIVITY AHEAD OF THE WESTERN MCS. THE THREAT FOR SEVERE WEATHER IS LOW THROUGH THE PERIOD THOUGH CAN NOT DISCOUNT A LOCALIZED EVENT. THE THREAT FOR HEAVY RAIN IS ALSO LOW THROUGH 12Z. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 320 PM CDT SAT JUN 21 2014 MAIN CONCERNS CONTINUE TO FOCUS ON POTENTIAL FOR HEAVY RAINFALL WITH NEXT UPSTREAM WAVE EXPECTED TO CROSS THE REGION SUNDAY INTO EARLY MONDAY. EXPECTING SOME LEFTOVER CONVECTION ONCE AGAIN EARLY SUNDAY MORNING TO DECAY DURING THE MORNING HOURS ACROSS THE NORTH. A SLIGHTLY WEAKER WAVE IS NOW EXPECTED CROSS THE REGION INTO MONDAY. PREVIOUS MODEL SOLUTIONS SUGGESTED A STRONGER WAVE TRACKING OVER SOUTHERN IOWA/NORTHERN MISSOURI BUT LAST 2 RUNS OF THE MODELS SHOW SOMEWHAT OF A SPLIT NORTHERN/SOUTHERN STREAM WAVE CROSSING THE REGION. THIS SHOULD RESULT IN A LESSER THREAT FOR WIDESPREAD HEAVY RAIN ACROSS THE SOUTHEAST TWO THIRDS OF THE AREA FOR SUNDAY THROUGH MONDAY...BUT INCREASE THE RISK OF RAINFALL AND SOME LOCALLY HEAVY RAIN OVER THE NORTHERN AREAS OF THE FORECAST AREA. BOTH THE 12Z GFS/NAM ARE NOW FAVORING THE NORTHERN STREAM ENERGY TO DOMINATE THE NEXT 24 TO 36 HOURS...WITH WARM AIR ADVECTION AND FRONTAL FORCING MAXIMIZED FROM NORTHWEST IOWA THROUGH SOUTHEAST MINNESOTA AND A SECONDARY WAVE WELL SOUTH OF THE AREA. THIS LEAVES THE BULK OF CENTRAL IOWA IN AN AREA OF LESS FAVORABLE CONVERGENCE AND FORCING. TODAYS 12Z GEM MODEL HAS ALSO SPLIT THE ENERGY IN A SIMILAR PATTERN...WITH SYNOPTIC DEVELOPMENT OF THE WAVES OVER NORTHERN IOWA AND IN THE SOUTHERN PLAINS. THIS WOULD FAVOR TWO AREAS OF HEAVIER RAINFALL...ONE OVER NORTHERN IOWA AND THE OTHER OVER MISSOURI SOUTH TO NEAR THE OKLAHOMA/ARKANSAS BORDER. WITH THE SUGGESTION OF SPLIT FLOW...THE PATTERN WOULD BE MORE PROGRESSIVE WITH A QUICKER EXIT OF THE FRONT BY LATE MONDAY MORNING RATHER THAN MONDAY NIGHT. OVERALL THIS SHOULD HELP LIMIT WIDESPREAD HEAVY RAINFALL. HOWEVER...WE CONTINUE HAVE HIGH PRECIPITABLE WATER VALUES OF 1.5 TO 1.75 WITH WARM CLOUD DEPTHS ONCE AGAIN RUNNING FROM 11500 TO 13000 FT. THERE MAY STILL BE LOCALLY HEAVY RAINFALL NEARER THE SFC LOW AS IT TRACKS ACROSS CENTRAL TO NORTHERN IOWA WITH MORE WIDELY SCATTERED POCKETS OF LOCALLY HEAVY RAINFALL IN THE CENTRAL AND SOUTH MAINLY DURING THE AFTERNOON AND EVENING HOURS. HIGHS SUNDAY WILL BE VERY WARM...BUT WITH CLOUD COVER AROUND PROBABLY HELD INTO THE LOWER TO MID 80S WITH A FEW UPPER 80S IN THE SOUTH. COOLER WEATHER WILL RETURN TOWARD MONDAY AND TUESDAY AS THE SYSTEM PULLS EAST. TUESDAY MORNING EITHER LOOKS TO BE A GREAT CANDIDATE FOR FOG OR A LOT OF DEW. WILL NEED TO TAKE A LOOK AT THIS IN THE NEXT PACKAGE OR TWO AS WINDS BECOME VERY LIGHT BY THAT TIME AND TEMPERATURES RADIATE BACK INTO THE LOWER 60S. THERE REMAINS A WEAK SIGNAL FOR SOME SHOWERS TUESDAY OR WEDNESDAY OVER THE NORTH AND WEDNESDAY OVER THE CENTRAL. FOR NOW...GREATER UNCERTAINTY ABOUT CHANCES FOR RETURN MOISTURE THAT SOON...AND THIS MAY CHANGE. BY MID TO LATE IN THE PERIOD A WEST SOUTHWEST FLOW WILL RETURN ALOFT. THIS WILL PROMOTE WARMER TEMPERATURES AND INCREASED CHANCES FOR THUNDERSTORMS. HIGHS THROUGH MIDWEEK WILL REMAIN IN THE LOWER 80S WITH LOWS IN THE 60S. BY LATE IN THE PERIOD MID 80S ARE MORE LIKELY WITH LOWS IN THE UPPER 60S TO LOWER 70S. AS TEMPS WARM ALOFT AT H700 TO ABOVE 10C...THUNDERSTORM CHANCES MAY BE CAPPED BUT UNCERTAINTY INCREASES TOWARD THE END OF THE EXTENDED FORECAST. && .AVIATION...21/18Z ISSUED AT 1236 PM CDT SAT JUN 21 2014 THUNDERSTORM CHANCES ARE THE PRIMARY FORECAST CONCERN THROUGH THE PERIOD. GENERALLY VFR CONDITIONS FOR MUCH OF THE AREA THROUGH 06Z. A FEW THUNDERSTORMS ARE POSSIBLE OVER THE FAR SOUTH THIS AFTERNOON THAT MAY REACH THE VICINITY OF KOTM. BEST POTENTIAL FOR ACTIVITY IS AFTER 06Z HOWEVER POTENTIAL AT ANY ONE LOCATION LOW ENOUGH TO EXCLUDE FROM THIS FORECAST. WINDS WILL BE LIGHT AT LESS THAN 10 MPH. && .HYDROLOGY... ISSUED AT 320 PM CDT SAT JUN 21 2014 ...TONIGHT THROUGH MONDAY NIGHT... SOME THUNDERSTORMS MAY AGAIN DEVELOP INTO THE EVENING HOURS ACROSS THE SOUTH. THE MAIN CONCERN LATE TONIGHT AND EARLY SUNDAY WILL BE MCS DEVELOPMENT OVER THE WESTERN PLAINS...MOVING EAST INTO NORTHWEST IOWA BY MORNING. THIS ACTIVITY SHOULD DECAY EARLY IN THE DAY BUT AS THE MAIN SHORTWAVE MOVES ACROSS THE AREA SUNDAY...THUNDERSTORMS WILL INCREASE IN COVERAGE. WITH PWATS CONTINUING HIGH AND WARM CLOUD DEPTHS FAVORING EFFICIENT RAINFALL PROCESSES...SOME AMOUNTS OF 1 TO 2 INCHES IN A SHORT PERIOD OF TIME WILL BE POSSIBLE SUNDAY INTO SUNDAY EVENING ESPECIALLY. MOST 1 AND 3 HOUR GRIDDED FLASH FLOOD GUIDANCE OVER THE REGION IS ABOUT 1 TO 2 INCHES...SO IF ANY STORMS WITH HIGH RAINFALL RATES DEVELOP...THERE WILL BE A POTENTIAL FOR SOME LOCALIZED FLOODING ISSUES. ONE LIMITING FACTOR SUNDAY WILL BE A SLIGHTLY MORE PROGRESSIVE WAVE AS THE MAIN SHORTWAVE TRACKS EAST. CONFIDENCE OF OVERALL COVERAGE AND LOCATION IS LOW ENOUGH TO LEAVE HEADLINES OUT FOR NOW. RIVER LEVELS WILL RESPOND AGAIN TO ANY ADDITIONAL RAINFALL OVER OUR FORECAST AREA SUNDAY AND SUNDAY EVENING. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DONAVON LONG TERM...REV AVIATION...DONAVON HYDROLOGY...REV  FXUS63 KDMX 212353 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 653 PM CDT SAT JUN 21 2014 .SHORT TERM /TONIGHT/... ISSUED AT 320 PM CDT SAT JUN 21 2014 CONVECTIVE TRENDS OVERNIGHT ARE THE PRIMARY FORECAST CHALLENGE OVERNIGHT. MCV SHIFTING EAST ACROSS SRN WISCONSIN AND NRN ILLINOIS HAS WRAPPED DRY MID LEVEL AIR IN TO CENTRAL AND EASTERN IOWA. THIS HAS HELPED STRENGTHEN THE CONVECTIVE INHIBITION ACROSS THE AREA. SFC FLOW OVER CENTRAL IOWA REMAINS NEARLY NON EXISTENT WITH THE OVERNIGHT OUTFLOW PUSHING THE WARM FRONT JUST SOUTH INTO KANSAS AND MISSOURI. A FEW STORMS HAVE BEEN TRYING TO INITIATE ALONG THIS BOUNDARY BUT HAVING A DIFFICULT TIME BECOMING ORGANIZED WITH A LACK OF DEEP LAYER SHEAR AND ANY GOOD FORCING TO AID IN SUSTAINING UPDRAFTS. THIS ACTIVITY SHOULD MOSTLY REMAIN SOUTH OF THE STATE BUT MAY CLIP THE SOUTHERN TIER OF COUNTIES THE NEXT FEW HOURS. FORCING REMAINS WEAK ACROSS CENTRAL IOWA THROUGH THIS EVENING. THE LOW LEVEL JET OF AROUND 35 KTS WILL AMPLIFY OVER THE MID MISSOURI VALLEY AND POINTS TO THE WEST HOWEVER ITS ORIENTATION WILL FAVOR THE FORCING AND CONVERGENCE ZONE ACROSS NEBRASKA AND SOUTH DAKOTA. A SHORT WAVE MOVING RAPIDLY ACROSS THE ROCKIES OVERNIGHT SHOULD SPREAD QG FORCING EAST INTO WESTERN IOWA LATE AND WILL HAVE PUSH ANY DEVELOPING MCS CLOSE TO THE STATE LATE. POSSIBLE A FEW STORMS DEVELOP OVER THE CENTRAL AND SOUTHWEST AS A COUPLE WAVES OF THETA-E ADVECTION LIFT NORTH AND GENERATE AN INSTABILITY AXIS THROUGH THAT REGION. A DISCONTINUITY BETWEEN FORCING AND MOISTURE AVAILABLE SHOULD PREVENT WIDESPREAD ACTIVITY AHEAD OF THE WESTERN MCS. THE THREAT FOR SEVERE WEATHER IS LOW THROUGH THE PERIOD THOUGH CAN NOT DISCOUNT A LOCALIZED EVENT. THE THREAT FOR HEAVY RAIN IS ALSO LOW THROUGH 12Z. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 320 PM CDT SAT JUN 21 2014 MAIN CONCERNS CONTINUE TO FOCUS ON POTENTIAL FOR HEAVY RAINFALL WITH NEXT UPSTREAM WAVE EXPECTED TO CROSS THE REGION SUNDAY INTO EARLY MONDAY. EXPECTING SOME LEFTOVER CONVECTION ONCE AGAIN EARLY SUNDAY MORNING TO DECAY DURING THE MORNING HOURS ACROSS THE NORTH. A SLIGHTLY WEAKER WAVE IS NOW EXPECTED CROSS THE REGION INTO MONDAY. PREVIOUS MODEL SOLUTIONS SUGGESTED A STRONGER WAVE TRACKING OVER SOUTHERN IOWA/NORTHERN MISSOURI BUT LAST 2 RUNS OF THE MODELS SHOW SOMEWHAT OF A SPLIT NORTHERN/SOUTHERN STREAM WAVE CROSSING THE REGION. THIS SHOULD RESULT IN A LESSER THREAT FOR WIDESPREAD HEAVY RAIN ACROSS THE SOUTHEAST TWO THIRDS OF THE AREA FOR SUNDAY THROUGH MONDAY...BUT INCREASE THE RISK OF RAINFALL AND SOME LOCALLY HEAVY RAIN OVER THE NORTHERN AREAS OF THE FORECAST AREA. BOTH THE 12Z GFS/NAM ARE NOW FAVORING THE NORTHERN STREAM ENERGY TO DOMINATE THE NEXT 24 TO 36 HOURS...WITH WARM AIR ADVECTION AND FRONTAL FORCING MAXIMIZED FROM NORTHWEST IOWA THROUGH SOUTHEAST MINNESOTA AND A SECONDARY WAVE WELL SOUTH OF THE AREA. THIS LEAVES THE BULK OF CENTRAL IOWA IN AN AREA OF LESS FAVORABLE CONVERGENCE AND FORCING. TODAYS 12Z GEM MODEL HAS ALSO SPLIT THE ENERGY IN A SIMILAR PATTERN...WITH SYNOPTIC DEVELOPMENT OF THE WAVES OVER NORTHERN IOWA AND IN THE SOUTHERN PLAINS. THIS WOULD FAVOR TWO AREAS OF HEAVIER RAINFALL...ONE OVER NORTHERN IOWA AND THE OTHER OVER MISSOURI SOUTH TO NEAR THE OKLAHOMA/ARKANSAS BORDER. WITH THE SUGGESTION OF SPLIT FLOW...THE PATTERN WOULD BE MORE PROGRESSIVE WITH A QUICKER EXIT OF THE FRONT BY LATE MONDAY MORNING RATHER THAN MONDAY NIGHT. OVERALL THIS SHOULD HELP LIMIT WIDESPREAD HEAVY RAINFALL. HOWEVER...WE CONTINUE HAVE HIGH PRECIPITABLE WATER VALUES OF 1.5 TO 1.75 WITH WARM CLOUD DEPTHS ONCE AGAIN RUNNING FROM 11500 TO 13000 FT. THERE MAY STILL BE LOCALLY HEAVY RAINFALL NEARER THE SFC LOW AS IT TRACKS ACROSS CENTRAL TO NORTHERN IOWA WITH MORE WIDELY SCATTERED POCKETS OF LOCALLY HEAVY RAINFALL IN THE CENTRAL AND SOUTH MAINLY DURING THE AFTERNOON AND EVENING HOURS. HIGHS SUNDAY WILL BE VERY WARM...BUT WITH CLOUD COVER AROUND PROBABLY HELD INTO THE LOWER TO MID 80S WITH A FEW UPPER 80S IN THE SOUTH. COOLER WEATHER WILL RETURN TOWARD MONDAY AND TUESDAY AS THE SYSTEM PULLS EAST. TUESDAY MORNING EITHER LOOKS TO BE A GREAT CANDIDATE FOR FOG OR A LOT OF DEW. WILL NEED TO TAKE A LOOK AT THIS IN THE NEXT PACKAGE OR TWO AS WINDS BECOME VERY LIGHT BY THAT TIME AND TEMPERATURES RADIATE BACK INTO THE LOWER 60S. THERE REMAINS A WEAK SIGNAL FOR SOME SHOWERS TUESDAY OR WEDNESDAY OVER THE NORTH AND WEDNESDAY OVER THE CENTRAL. FOR NOW...GREATER UNCERTAINTY ABOUT CHANCES FOR RETURN MOISTURE THAT SOON...AND THIS MAY CHANGE. BY MID TO LATE IN THE PERIOD A WEST SOUTHWEST FLOW WILL RETURN ALOFT. THIS WILL PROMOTE WARMER TEMPERATURES AND INCREASED CHANCES FOR THUNDERSTORMS. HIGHS THROUGH MIDWEEK WILL REMAIN IN THE LOWER 80S WITH LOWS IN THE 60S. BY LATE IN THE PERIOD MID 80S ARE MORE LIKELY WITH LOWS IN THE UPPER 60S TO LOWER 70S. AS TEMPS WARM ALOFT AT H700 TO ABOVE 10C...THUNDERSTORM CHANCES MAY BE CAPPED BUT UNCERTAINTY INCREASES TOWARD THE END OF THE EXTENDED FORECAST. && .AVIATION...22/00Z ISSUED AT 652 PM CDT SAT JUN 21 2014 VFR CONDITIONS ARE ANTICIPATED THROUGH THE EVENING WITH THE ATTENTION TURNING UPSTREAM OVERNIGHT AND INTO SUN FOR CONVECTIVE TRENDS. SHOWERS AND STORMS ARE POSSIBLE EARLY IN THE DAY AS LARGER SCALE FORCING CROSSES THE PLAINS...WITH SURFACE BASED CONVECTION ALSO POSSIBLE WEST LATER IN THE DAY. HAVE FAIRLY HIGH CONFIDENCE IN CONVECTION SOMETIME SUN...BUT TIMING AND LOCATIONS HAVE LITTLE PREDICTABILITY AT THIS POINT SO HAVE NOTHING MORE THAN PROLONGED VFR VCSH WORDING FOR NOW. && .HYDROLOGY... ISSUED AT 320 PM CDT SAT JUN 21 2014 ...TONIGHT THROUGH MONDAY NIGHT... THE MAIN CONCERN LATE TONIGHT AND EARLY SUNDAY WILL BE MCS DEVELOPMENT OVER THE WESTERN PLAINS...MOVING EAST INTO NORTHWEST IOWA BY MORNING. THIS ACTIVITY SHOULD DECAY EARLY IN THE DAY BUT AS THE MAIN SHORTWAVE MOVES ACROSS THE AREA SUNDAY...THUNDERSTORMS WILL INCREASE IN COVERAGE. WITH PWATS CONTINUING HIGH AND WARM CLOUD DEPTHS FAVORING EFFICIENT RAINFALL PROCESSES...SOME AMOUNTS OF 1 TO 2 INCHES IN A SHORT PERIOD OF TIME WILL BE POSSIBLE SUNDAY INTO SUNDAY EVENING ESPECIALLY. MOST 1 AND 3 HOUR GRIDDED FLASH FLOOD GUIDANCE OVER THE REGION IS ABOUT 1 TO 2 INCHES...SO IF ANY STORMS WITH HIGH RAINFALL RATES DEVELOP...THERE WILL BE A POTENTIAL FOR SOME LOCALIZED FLOODING ISSUES. ONE LIMITING FACTOR SUNDAY WILL BE A SLIGHTLY MORE PROGRESSIVE WAVE AS THE MAIN SHORTWAVE TRACKS EAST. CONFIDENCE OF OVERALL COVERAGE AND LOCATION IS LOW ENOUGH TO LEAVE HEADLINES OUT FOR NOW. RIVER LEVELS WILL RESPOND AGAIN TO ANY ADDITIONAL RAINFALL OVER OUR FORECAST AREA SUNDAY AND SUNDAY EVENING. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...DONAVON LONG TERM...REV AVIATION...SMALL HYDROLOGY...REV  FXUS63 KDMX 220216 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 916 PM CDT SAT JUN 21 2014 .UPDATE... ISSUED AT 916 PM CDT SAT JUN 21 2014 LITTLE CHANGE FROM PREVIOUS THINKING THIS EVENING. LARGE SCALE FORCING AHEAD OF APPROACHING CO/WY SHORT WAVES WILL KEEP SCATTERED CONVECTION GOING IN SOME FORM UPSTREAM OVERNIGHT. SD MCS IS MOST PRESSING CONCERN BUT SEVERE WEATHER POTENTIAL SEEMS LOW. ALTHOUGH A FEW CELLS HAVE ACCELERATED FASTER FOR THE MOMENT...COMPLEX IS CURRENTLY FOLLOWING CORFIDI VECTORS AS A WHOLE AND DRIFTING SE AT 15-20KTS. EXPECT THIS COMPLEX TO WEAKEN SOMEWHAT WITH DECREASE/INCREASE IN MLCAPE/CINH RESPECTIVELY INTO THE NIGHT AND JUST WEAK TO MODERATE EFFECTIVE SHEAR. HEAVY RAIN IS MORE OF A CONCERN THAN SEVERE WITH ELEVATED K INDEX/PW AXIS DRIFTING EWD INTO WRN IA COINCIDENT WITH LOW LEVEL MOISTURE FLUX AS IT MOVES EWD WITH OVERALL SYSTEM AND VEERS. 01Z RAP CORFIDI VECTORS/MEAN WIND ARE BOTH 15KTS OR LESS BY 09Z SO WHAT IS LEFT OF THE COMPLEX WILL LIKELY BE SLOW MOVING. AIRMASS WILL SUPPORT EFFICIENT RAINFALL RATES BUT PWS AND WARM CLOUD DEPTHS ARE NOT AS EXTREME AS RECENT EVENTS. && .SHORT TERM /TONIGHT/... ISSUED AT 320 PM CDT SAT JUN 21 2014 CONVECTIVE TRENDS OVERNIGHT ARE THE PRIMARY FORECAST CHALLENGE OVERNIGHT. MCV SHIFTING EAST ACROSS SRN WISCONSIN AND NRN ILLINOIS HAS WRAPPED DRY MID LEVEL AIR IN TO CENTRAL AND EASTERN IOWA. THIS HAS HELPED STRENGTHEN THE CONVECTIVE INHIBITION ACROSS THE AREA. SFC FLOW OVER CENTRAL IOWA REMAINS NEARLY NON EXISTENT WITH THE OVERNIGHT OUTFLOW PUSHING THE WARM FRONT JUST SOUTH INTO KANSAS AND MISSOURI. A FEW STORMS HAVE BEEN TRYING TO INITIATE ALONG THIS BOUNDARY BUT HAVING A DIFFICULT TIME BECOMING ORGANIZED WITH A LACK OF DEEP LAYER SHEAR AND ANY GOOD FORCING TO AID IN SUSTAINING UPDRAFTS. THIS ACTIVITY SHOULD MOSTLY REMAIN SOUTH OF THE STATE BUT MAY CLIP THE SOUTHERN TIER OF COUNTIES THE NEXT FEW HOURS. FORCING REMAINS WEAK ACROSS CENTRAL IOWA THROUGH THIS EVENING. THE LOW LEVEL JET OF AROUND 35 KTS WILL AMPLIFY OVER THE MID MISSOURI VALLEY AND POINTS TO THE WEST HOWEVER ITS ORIENTATION WILL FAVOR THE FORCING AND CONVERGENCE ZONE ACROSS NEBRASKA AND SOUTH DAKOTA. A SHORT WAVE MOVING RAPIDLY ACROSS THE ROCKIES OVERNIGHT SHOULD SPREAD QG FORCING EAST INTO WESTERN IOWA LATE AND WILL HAVE PUSH ANY DEVELOPING MCS CLOSE TO THE STATE LATE. POSSIBLE A FEW STORMS DEVELOP OVER THE CENTRAL AND SOUTHWEST AS A COUPLE WAVES OF THETA-E ADVECTION LIFT NORTH AND GENERATE AN INSTABILITY AXIS THROUGH THAT REGION. A DISCONTINUITY BETWEEN FORCING AND MOISTURE AVAILABLE SHOULD PREVENT WIDESPREAD ACTIVITY AHEAD OF THE WESTERN MCS. THE THREAT FOR SEVERE WEATHER IS LOW THROUGH THE PERIOD THOUGH CAN NOT DISCOUNT A LOCALIZED EVENT. THE THREAT FOR HEAVY RAIN IS ALSO LOW THROUGH 12Z. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 320 PM CDT SAT JUN 21 2014 MAIN CONCERNS CONTINUE TO FOCUS ON POTENTIAL FOR HEAVY RAINFALL WITH NEXT UPSTREAM WAVE EXPECTED TO CROSS THE REGION SUNDAY INTO EARLY MONDAY. EXPECTING SOME LEFTOVER CONVECTION ONCE AGAIN EARLY SUNDAY MORNING TO DECAY DURING THE MORNING HOURS ACROSS THE NORTH. A SLIGHTLY WEAKER WAVE IS NOW EXPECTED CROSS THE REGION INTO MONDAY. PREVIOUS MODEL SOLUTIONS SUGGESTED A STRONGER WAVE TRACKING OVER SOUTHERN IOWA/NORTHERN MISSOURI BUT LAST 2 RUNS OF THE MODELS SHOW SOMEWHAT OF A SPLIT NORTHERN/SOUTHERN STREAM WAVE CROSSING THE REGION. THIS SHOULD RESULT IN A LESSER THREAT FOR WIDESPREAD HEAVY RAIN ACROSS THE SOUTHEAST TWO THIRDS OF THE AREA FOR SUNDAY THROUGH MONDAY...BUT INCREASE THE RISK OF RAINFALL AND SOME LOCALLY HEAVY RAIN OVER THE NORTHERN AREAS OF THE FORECAST AREA. BOTH THE 12Z GFS/NAM ARE NOW FAVORING THE NORTHERN STREAM ENERGY TO DOMINATE THE NEXT 24 TO 36 HOURS...WITH WARM AIR ADVECTION AND FRONTAL FORCING MAXIMIZED FROM NORTHWEST IOWA THROUGH SOUTHEAST MINNESOTA AND A SECONDARY WAVE WELL SOUTH OF THE AREA. THIS LEAVES THE BULK OF CENTRAL IOWA IN AN AREA OF LESS FAVORABLE CONVERGENCE AND FORCING. TODAYS 12Z GEM MODEL HAS ALSO SPLIT THE ENERGY IN A SIMILAR PATTERN...WITH SYNOPTIC DEVELOPMENT OF THE WAVES OVER NORTHERN IOWA AND IN THE SOUTHERN PLAINS. THIS WOULD FAVOR TWO AREAS OF HEAVIER RAINFALL...ONE OVER NORTHERN IOWA AND THE OTHER OVER MISSOURI SOUTH TO NEAR THE OKLAHOMA/ARKANSAS BORDER. WITH THE SUGGESTION OF SPLIT FLOW...THE PATTERN WOULD BE MORE PROGRESSIVE WITH A QUICKER EXIT OF THE FRONT BY LATE MONDAY MORNING RATHER THAN MONDAY NIGHT. OVERALL THIS SHOULD HELP LIMIT WIDESPREAD HEAVY RAINFALL. HOWEVER...WE CONTINUE HAVE HIGH PRECIPITABLE WATER VALUES OF 1.5 TO 1.75 WITH WARM CLOUD DEPTHS ONCE AGAIN RUNNING FROM 11500 TO 13000 FT. THERE MAY STILL BE LOCALLY HEAVY RAINFALL NEARER THE SFC LOW AS IT TRACKS ACROSS CENTRAL TO NORTHERN IOWA WITH MORE WIDELY SCATTERED POCKETS OF LOCALLY HEAVY RAINFALL IN THE CENTRAL AND SOUTH MAINLY DURING THE AFTERNOON AND EVENING HOURS. HIGHS SUNDAY WILL BE VERY WARM...BUT WITH CLOUD COVER AROUND PROBABLY HELD INTO THE LOWER TO MID 80S WITH A FEW UPPER 80S IN THE SOUTH. COOLER WEATHER WILL RETURN TOWARD MONDAY AND TUESDAY AS THE SYSTEM PULLS EAST. TUESDAY MORNING EITHER LOOKS TO BE A GREAT CANDIDATE FOR FOG OR A LOT OF DEW. WILL NEED TO TAKE A LOOK AT THIS IN THE NEXT PACKAGE OR TWO AS WINDS BECOME VERY LIGHT BY THAT TIME AND TEMPERATURES RADIATE BACK INTO THE LOWER 60S. THERE REMAINS A WEAK SIGNAL FOR SOME SHOWERS TUESDAY OR WEDNESDAY OVER THE NORTH AND WEDNESDAY OVER THE CENTRAL. FOR NOW...GREATER UNCERTAINTY ABOUT CHANCES FOR RETURN MOISTURE THAT SOON...AND THIS MAY CHANGE. BY MID TO LATE IN THE PERIOD A WEST SOUTHWEST FLOW WILL RETURN ALOFT. THIS WILL PROMOTE WARMER TEMPERATURES AND INCREASED CHANCES FOR THUNDERSTORMS. HIGHS THROUGH MIDWEEK WILL REMAIN IN THE LOWER 80S WITH LOWS IN THE 60S. BY LATE IN THE PERIOD MID 80S ARE MORE LIKELY WITH LOWS IN THE UPPER 60S TO LOWER 70S. AS TEMPS WARM ALOFT AT H700 TO ABOVE 10C...THUNDERSTORM CHANCES MAY BE CAPPED BUT UNCERTAINTY INCREASES TOWARD THE END OF THE EXTENDED FORECAST. && .AVIATION...22/00Z ISSUED AT 652 PM CDT SAT JUN 21 2014 VFR CONDITIONS ARE ANTICIPATED THROUGH THE EVENING WITH THE ATTENTION TURNING UPSTREAM OVERNIGHT AND INTO SUN FOR CONVECTIVE TRENDS. SHOWERS AND STORMS ARE POSSIBLE EARLY IN THE DAY AS LARGER SCALE FORCING CROSSES THE PLAINS...WITH SURFACE BASED CONVECTION ALSO POSSIBLE WEST LATER IN THE DAY. HAVE FAIRLY HIGH CONFIDENCE IN CONVECTION SOMETIME SUN...BUT TIMING AND LOCATIONS HAVE LITTLE PREDICTABILITY AT THIS POINT SO HAVE NOTHING MORE THAN PROLONGED VFR VCSH WORDING FOR NOW. && .HYDROLOGY... ISSUED AT 320 PM CDT SAT JUN 21 2014 ...TONIGHT THROUGH MONDAY NIGHT... THE MAIN CONCERN LATE TONIGHT AND EARLY SUNDAY WILL BE MCS DEVELOPMENT OVER THE WESTERN PLAINS...MOVING EAST INTO NORTHWEST IOWA BY MORNING. THIS ACTIVITY SHOULD DECAY EARLY IN THE DAY BUT AS THE MAIN SHORTWAVE MOVES ACROSS THE AREA SUNDAY...THUNDERSTORMS WILL INCREASE IN COVERAGE. WITH PWATS CONTINUING HIGH AND WARM CLOUD DEPTHS FAVORING EFFICIENT RAINFALL PROCESSES...SOME AMOUNTS OF 1 TO 2 INCHES IN A SHORT PERIOD OF TIME WILL BE POSSIBLE SUNDAY INTO SUNDAY EVENING ESPECIALLY. MOST 1 AND 3 HOUR GRIDDED FLASH FLOOD GUIDANCE OVER THE REGION IS ABOUT 1 TO 2 INCHES...SO IF ANY STORMS WITH HIGH RAINFALL RATES DEVELOP...THERE WILL BE A POTENTIAL FOR SOME LOCALIZED FLOODING ISSUES. ONE LIMITING FACTOR SUNDAY WILL BE A SLIGHTLY MORE PROGRESSIVE WAVE AS THE MAIN SHORTWAVE TRACKS EAST. CONFIDENCE OF OVERALL COVERAGE AND LOCATION IS LOW ENOUGH TO LEAVE HEADLINES OUT FOR NOW. RIVER LEVELS WILL RESPOND AGAIN TO ANY ADDITIONAL RAINFALL OVER OUR FORECAST AREA SUNDAY AND SUNDAY EVENING. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SMALL SHORT TERM...DONAVON LONG TERM...REV AVIATION...SMALL HYDROLOGY...REV  FXUS63 KDMX 220509 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1209 AM CDT SUN JUN 22 2014 .UPDATE... ISSUED AT 916 PM CDT SAT JUN 21 2014 LITTLE CHANGE FROM PREVIOUS THINKING THIS EVENING. LARGE SCALE FORCING AHEAD OF APPROACHING CO/WY SHORT WAVES WILL KEEP SCATTERED CONVECTION GOING IN SOME FORM UPSTREAM OVERNIGHT. SD MCS IS MOST PRESSING CONCERN BUT SEVERE WEATHER POTENTIAL SEEMS LOW. ALTHOUGH A FEW CELLS HAVE ACCELERATED FASTER FOR THE MOMENT...COMPLEX IS CURRENTLY FOLLOWING CORFIDI VECTORS AS A WHOLE AND DRIFTING SE AT 15-20KTS. EXPECT THIS COMPLEX TO WEAKEN SOMEWHAT WITH DECREASE/INCREASE IN MLCAPE/CINH RESPECTIVELY INTO THE NIGHT AND JUST WEAK TO MODERATE EFFECTIVE SHEAR. HEAVY RAIN IS MORE OF A CONCERN THAN SEVERE WITH ELEVATED K INDEX/PW AXIS DRIFTING EWD INTO WRN IA COINCIDENT WITH LOW LEVEL MOISTURE FLUX AS IT MOVES EWD WITH OVERALL SYSTEM AND VEERS. 01Z RAP CORFIDI VECTORS/MEAN WIND ARE BOTH 15KTS OR LESS BY 09Z SO WHAT IS LEFT OF THE COMPLEX WILL LIKELY BE SLOW MOVING. AIRMASS WILL SUPPORT EFFICIENT RAINFALL RATES BUT PWS AND WARM CLOUD DEPTHS ARE NOT AS EXTREME AS RECENT EVENTS. && .SHORT TERM /TONIGHT/... ISSUED AT 320 PM CDT SAT JUN 21 2014 CONVECTIVE TRENDS OVERNIGHT ARE THE PRIMARY FORECAST CHALLENGE OVERNIGHT. MCV SHIFTING EAST ACROSS SRN WISCONSIN AND NRN ILLINOIS HAS WRAPPED DRY MID LEVEL AIR IN TO CENTRAL AND EASTERN IOWA. THIS HAS HELPED STRENGTHEN THE CONVECTIVE INHIBITION ACROSS THE AREA. SFC FLOW OVER CENTRAL IOWA REMAINS NEARLY NON EXISTENT WITH THE OVERNIGHT OUTFLOW PUSHING THE WARM FRONT JUST SOUTH INTO KANSAS AND MISSOURI. A FEW STORMS HAVE BEEN TRYING TO INITIATE ALONG THIS BOUNDARY BUT HAVING A DIFFICULT TIME BECOMING ORGANIZED WITH A LACK OF DEEP LAYER SHEAR AND ANY GOOD FORCING TO AID IN SUSTAINING UPDRAFTS. THIS ACTIVITY SHOULD MOSTLY REMAIN SOUTH OF THE STATE BUT MAY CLIP THE SOUTHERN TIER OF COUNTIES THE NEXT FEW HOURS. FORCING REMAINS WEAK ACROSS CENTRAL IOWA THROUGH THIS EVENING. THE LOW LEVEL JET OF AROUND 35 KTS WILL AMPLIFY OVER THE MID MISSOURI VALLEY AND POINTS TO THE WEST HOWEVER ITS ORIENTATION WILL FAVOR THE FORCING AND CONVERGENCE ZONE ACROSS NEBRASKA AND SOUTH DAKOTA. A SHORT WAVE MOVING RAPIDLY ACROSS THE ROCKIES OVERNIGHT SHOULD SPREAD QG FORCING EAST INTO WESTERN IOWA LATE AND WILL HAVE PUSH ANY DEVELOPING MCS CLOSE TO THE STATE LATE. POSSIBLE A FEW STORMS DEVELOP OVER THE CENTRAL AND SOUTHWEST AS A COUPLE WAVES OF THETA-E ADVECTION LIFT NORTH AND GENERATE AN INSTABILITY AXIS THROUGH THAT REGION. A DISCONTINUITY BETWEEN FORCING AND MOISTURE AVAILABLE SHOULD PREVENT WIDESPREAD ACTIVITY AHEAD OF THE WESTERN MCS. THE THREAT FOR SEVERE WEATHER IS LOW THROUGH THE PERIOD THOUGH CAN NOT DISCOUNT A LOCALIZED EVENT. THE THREAT FOR HEAVY RAIN IS ALSO LOW THROUGH 12Z. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 320 PM CDT SAT JUN 21 2014 MAIN CONCERNS CONTINUE TO FOCUS ON POTENTIAL FOR HEAVY RAINFALL WITH NEXT UPSTREAM WAVE EXPECTED TO CROSS THE REGION SUNDAY INTO EARLY MONDAY. EXPECTING SOME LEFTOVER CONVECTION ONCE AGAIN EARLY SUNDAY MORNING TO DECAY DURING THE MORNING HOURS ACROSS THE NORTH. A SLIGHTLY WEAKER WAVE IS NOW EXPECTED CROSS THE REGION INTO MONDAY. PREVIOUS MODEL SOLUTIONS SUGGESTED A STRONGER WAVE TRACKING OVER SOUTHERN IOWA/NORTHERN MISSOURI BUT LAST 2 RUNS OF THE MODELS SHOW SOMEWHAT OF A SPLIT NORTHERN/SOUTHERN STREAM WAVE CROSSING THE REGION. THIS SHOULD RESULT IN A LESSER THREAT FOR WIDESPREAD HEAVY RAIN ACROSS THE SOUTHEAST TWO THIRDS OF THE AREA FOR SUNDAY THROUGH MONDAY...BUT INCREASE THE RISK OF RAINFALL AND SOME LOCALLY HEAVY RAIN OVER THE NORTHERN AREAS OF THE FORECAST AREA. BOTH THE 12Z GFS/NAM ARE NOW FAVORING THE NORTHERN STREAM ENERGY TO DOMINATE THE NEXT 24 TO 36 HOURS...WITH WARM AIR ADVECTION AND FRONTAL FORCING MAXIMIZED FROM NORTHWEST IOWA THROUGH SOUTHEAST MINNESOTA AND A SECONDARY WAVE WELL SOUTH OF THE AREA. THIS LEAVES THE BULK OF CENTRAL IOWA IN AN AREA OF LESS FAVORABLE CONVERGENCE AND FORCING. TODAYS 12Z GEM MODEL HAS ALSO SPLIT THE ENERGY IN A SIMILAR PATTERN...WITH SYNOPTIC DEVELOPMENT OF THE WAVES OVER NORTHERN IOWA AND IN THE SOUTHERN PLAINS. THIS WOULD FAVOR TWO AREAS OF HEAVIER RAINFALL...ONE OVER NORTHERN IOWA AND THE OTHER OVER MISSOURI SOUTH TO NEAR THE OKLAHOMA/ARKANSAS BORDER. WITH THE SUGGESTION OF SPLIT FLOW...THE PATTERN WOULD BE MORE PROGRESSIVE WITH A QUICKER EXIT OF THE FRONT BY LATE MONDAY MORNING RATHER THAN MONDAY NIGHT. OVERALL THIS SHOULD HELP LIMIT WIDESPREAD HEAVY RAINFALL. HOWEVER...WE CONTINUE HAVE HIGH PRECIPITABLE WATER VALUES OF 1.5 TO 1.75 WITH WARM CLOUD DEPTHS ONCE AGAIN RUNNING FROM 11500 TO 13000 FT. THERE MAY STILL BE LOCALLY HEAVY RAINFALL NEARER THE SFC LOW AS IT TRACKS ACROSS CENTRAL TO NORTHERN IOWA WITH MORE WIDELY SCATTERED POCKETS OF LOCALLY HEAVY RAINFALL IN THE CENTRAL AND SOUTH MAINLY DURING THE AFTERNOON AND EVENING HOURS. HIGHS SUNDAY WILL BE VERY WARM...BUT WITH CLOUD COVER AROUND PROBABLY HELD INTO THE LOWER TO MID 80S WITH A FEW UPPER 80S IN THE SOUTH. COOLER WEATHER WILL RETURN TOWARD MONDAY AND TUESDAY AS THE SYSTEM PULLS EAST. TUESDAY MORNING EITHER LOOKS TO BE A GREAT CANDIDATE FOR FOG OR A LOT OF DEW. WILL NEED TO TAKE A LOOK AT THIS IN THE NEXT PACKAGE OR TWO AS WINDS BECOME VERY LIGHT BY THAT TIME AND TEMPERATURES RADIATE BACK INTO THE LOWER 60S. THERE REMAINS A WEAK SIGNAL FOR SOME SHOWERS TUESDAY OR WEDNESDAY OVER THE NORTH AND WEDNESDAY OVER THE CENTRAL. FOR NOW...GREATER UNCERTAINTY ABOUT CHANCES FOR RETURN MOISTURE THAT SOON...AND THIS MAY CHANGE. BY MID TO LATE IN THE PERIOD A WEST SOUTHWEST FLOW WILL RETURN ALOFT. THIS WILL PROMOTE WARMER TEMPERATURES AND INCREASED CHANCES FOR THUNDERSTORMS. HIGHS THROUGH MIDWEEK WILL REMAIN IN THE LOWER 80S WITH LOWS IN THE 60S. BY LATE IN THE PERIOD MID 80S ARE MORE LIKELY WITH LOWS IN THE UPPER 60S TO LOWER 70S. AS TEMPS WARM ALOFT AT H700 TO ABOVE 10C...THUNDERSTORM CHANCES MAY BE CAPPED BUT UNCERTAINTY INCREASES TOWARD THE END OF THE EXTENDED FORECAST. && .AVIATION...22/06Z ISSUED AT 1209 AM CDT SUN JUN 22 2014 VFR CONDITIONS ARE ANTICIPATED INTO SUN MORNING WITH ATTENTION TURNING UPSTREAM INTO SD FOR CONVECTIVE TRENDS. SHOWERS AND STORMS ARE POSSIBLE FOR A PERIOD BEFORE DAYBREAK...WITH BETTER LIKELIHOOD NW VS SE. RESTRICTIONS ARE POSSIBLE WITH HEAVIER RAIN SHOWERS BUT LIKELIHOOD AT ANY PARTICULAR TAF SITES IS QUITE LOW. SURFACE BASED CONVECTION IS ALSO POSSIBLE LATER IN THE DAY. HAVE FAIRLY HIGH CONFIDENCE IN PRECIP SOMETIME SUN MIDDAY INTO THE EVENING...BUT TIMING AND LOCATIONS HAVE LITTLE PREDICTABILITY AT THIS POINT SO HAVE NOTHING MORE THAN PROLONGED VFR VCSH WORDING FOR NOW. && .HYDROLOGY... ISSUED AT 320 PM CDT SAT JUN 21 2014 TONIGHT THROUGH MONDAY NIGHT THE MAIN CONCERN LATE TONIGHT AND EARLY SUNDAY WILL BE MCS DEVELOPMENT OVER THE WESTERN PLAINS...MOVING EAST INTO NORTHWEST IOWA BY MORNING. THIS ACTIVITY SHOULD DECAY EARLY IN THE DAY BUT AS THE MAIN SHORTWAVE MOVES ACROSS THE AREA SUNDAY...THUNDERSTORMS WILL INCREASE IN COVERAGE. WITH PWATS CONTINUING HIGH AND WARM CLOUD DEPTHS FAVORING EFFICIENT RAINFALL PROCESSES...SOME AMOUNTS OF 1 TO 2 INCHES IN A SHORT PERIOD OF TIME WILL BE POSSIBLE SUNDAY INTO SUNDAY EVENING ESPECIALLY. MOST 1 AND 3 HOUR GRIDDED FLASH FLOOD GUIDANCE OVER THE REGION IS ABOUT 1 TO 2 INCHES...SO IF ANY STORMS WITH HIGH RAINFALL RATES DEVELOP...THERE WILL BE A POTENTIAL FOR SOME LOCALIZED FLOODING ISSUES. ONE LIMITING FACTOR SUNDAY WILL BE A SLIGHTLY MORE PROGRESSIVE WAVE AS THE MAIN SHORTWAVE TRACKS EAST. CONFIDENCE OF OVERALL COVERAGE AND LOCATION IS LOW ENOUGH TO LEAVE HEADLINES OUT FOR NOW. RIVER LEVELS WILL RESPOND AGAIN TO ANY ADDITIONAL RAINFALL OVER OUR FORECAST AREA SUNDAY AND SUNDAY EVENING. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SMALL SHORT TERM...DONAVON LONG TERM...REV AVIATION...SMALL HYDROLOGY...REV  FXUS63 KDMX 222044 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 344 PM CDT SUN JUN 22 2014 .SHORT TERM /TONIGHT/... ISSUED AT 344 PM CDT SUN JUN 22 2014 UPPER LEVEL SHORT WAVE NOW MOVING INTO NORTHWEST IOWA WITH CURRENT GREATEST INSTABILITY AND FORCING NOW OVER SOUTHEAST IOWA. THE POTENTIAL FOR SEVERE WEATHER WILL BE DIMINISHING QUICKLY AFTER 4 PM AS THE ACTIVITY SHIFTS TO THE EAST. THE HEAVY RAIN POTENTIAL ACROSS THE FLASH FLOOD WATCH AREA HAS DIMINISHED AND WILL BE DROPPING IT WITH THIS FORECAST ISSUANCE. WHILE A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS CENTRAL AND NORTHWEST IOWA OVER THE NEXT FEW HOURS...THE LACK OF INSTABILITY AND FOCUSED FORCING WILL LIMIT ACTIVITY ORGANIZED ENOUGH TO PRODUCE HEAVY RAINFALL. DRIER AIR WILL CONTINUE TO MOVE INTO FROM THE EAST THIS EVENING AND BRING AN END TO THE PRECIPITATION FROM THE WEST. WINDS WILL BECOME LIGHT FROM THE NORTHWEST AS WELL WITH DRIER DEWPOINTS ARRIVING. THIS SHOULD ALLOW TEMPERATURES TO COOL INTO THE 60S BY MORNING. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 344 PM CDT SUN JUN 22 2014 CONDITIONS QUIET DOWN EARLY MONDAY AS THE NORTHERN STREAM WAVE MOVES EAST OF THE AREA THIS EVENING. THE SOUTHERN STREAM WAVE OVER THE SOUTHERN PLAINS WILL DRIFT NORTHEAST AND MAY CLIP THE FAR SOUTHERN COUNTIES WITH SOME RAIN AND THUNDERSTORMS TODAY AND THIS EVENING. OTHERWISE...WEAK HIGH PRESSURE WILL BUILD ACROSS THE REMAINDER OF IOWA FOR MONDAY...AND MOST OF TUESDAY. A SHORT WAVE CURRENTLY OVER SOUTHERN CANADA IS EXPECTED TO PUSH A COOL FRONT SOUTH TO NEAR THE IOWA...WISCONSIN...ILLINOIS BORDER BY 00Z WEDNESDAY. THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS ALONG THE BOUNDARY OVER THE FAR NORTHEAST LATE TUESDAY AFTERNOON. WITH MUCH LESS MOISTURE AVAILABLE OVER THE AREA AT THAT TIME...THERE WILL BE LITTLE THREAT FOR ANY HEAVY RAIN AND LIMITED THREAT FOR ANY SEVERE WEATHER. THE FRONT IS EXPECTED TO WEAKEN DURING THE OVERNIGHT HOURS BUT REMAIN A WEAK WIND SHIFT ACROSS THE REGION BY WEDNESDAY AFTERNOON. BY WEDNESDAY AFTERNOON ANOTHER LEE SIDE TROUGH IS EXPECTED TO DEVELOP OVER NEBRASKA. AS A WARM FRONT DEVELOPS EAST INTO IOWA WHERE THE DECAYING TROUGH IS EXPECTED TO BE...WARM AIR ADVECTION OVER KANSAS WILL AID IN THE DEVELOPMENT OF THUNDERSTORMS BY MID TO LATE AFTERNOON. WITH DAYTIME HEATING IN PLACE...THERE WILL BE AN INCREASED THREAT AGAIN FOR SOME SEVERE STORMS. THE 12Z GFS IS FORECASTING PRECIPITABLE WATER TO AGAIN INCREASE TO 1.5 INCHES OVER THE AREA WITH WARM CLOUD DEPTHS ONCE AGAIN ABOVE 11KFT. THIS SHOULD PROMOTE EFFICIENT RAINFALL FROM ANY STORMS THAT DEVELOP WEDNESDAY AFTERNOON AND EVENING. THE THREAT FOR THUNDERSTORMS CONTINUES INTO THE OVERNIGHT HOURS WEDNESDAY NIGHT. ONCE AGAIN...THE MESOSCALE APPEARS TO BE DOMINATING THE SYNOPTIC SCALE OVER OUR AREA SO CONFIDENCE ABOUT RAINFALL CHANCES AND AMOUNTS WILL BE TENUOUS AT BEST. THE REMAINDER OF THE EXTENDED PERIOD IS STILL FAVORING WET AND WARM CONDITIONS OVER COOL AND DRY AS ZONAL TO WEST SOUTHWEST FLOW ALOFT IS EXPECTED TO PERSIST. THERE IS A HINT THAT THE STRONGER WESTERLIES MAY REMAIN ACROSS MINNESOTA RESULTING IN FURTHER H700 WAVES DEVELOPING DOWNSTREAM OF THE ROCKIES AND CREATING ADDITIONAL MCS OVER THE NORTHERN AND CENTRAL PLAINS. THIS IN ITSELF BRINGS LOW CONFIDENCE TO DAILY HIGHS AND LOWS...AND TIMING OF PRECIPITATION. WILL TAKE A BLENDED APPROACH FOR DAYS 4 THROUGH 7 WITH CHALLENGING FORECAST AHEAD. AT THIS TIME THE BEST CHANCES FOR ANY MODERATE OR HEAVIER RAINFALL WILL BE LATE WEDNESDAY INTO EARLY THURSDAY AS WELL AS FRIDAY INTO FRIDAY NIGHT. THE MODELS ARE HAVING A VERY DIFFICULT TIME RESOLVING THE PATTERN TOWARD FRIDAY AND THE WEEKEND. SOME SOLUTIONS IN THE PAST 2 DAYS ARE FAVORING A WARM FRONT TO MOVE NORTH OF THE AREA...CAPPING CONVECTION WITH SUMMER LIKE HEAT WHILE OTHER SOLUTIONS ARE SHOWING A BOUNDARY OVER MISSOURI OR IOWA FAVORING MORE CONVECTION. && .AVIATION...22/18Z ISSUED AT 1248 PM CDT SUN JUN 22 2014 SCATTERED THUNDERSTORMS WILL IMPACT THE AREA THROUGH THIS AFTERNOON WITH THE MAIN FOCUS EAST OF INTERSTATE 35. HEAVY DOWNPOURS CREATING REDUCED VISIBILITIES AND GUSTY WINDS WILL BE THE MAIN ISSUES. LOCALIZED MVFR CIGS MAY ALSO OCCUR. THE PRECIPITATION WILL END FROM WEST TO EAST LATE AFTERNOON AND INTO THE EVENING. POTENTIAL FOR SOME FOG OVERNIGHT WITH THE BEST POTENTIAL VICINITY OF KALO/KOTM. ERRATIC WIND DIRECTIONS TODAY BECOMING WEST TO NORTHWEST OVERNIGHT AND INTO MONDAY MORNING. && .HYDROLOGY... ISSUED AT 344 PM CDT SUN JUN 22 2014 OVERALL THE WORST OF IT LOOKS TO BE BEHIND US FOR NOW. UPDATED RAINFALL FORECASTS THROUGH MIDDAY MONDAY SUGGEST THAT RAINFALL AMOUNTS ACROSS THE NORTHERN CWA WILL BE LESS THAN PREVIOUSLY THOUGHT. PRESENT WEATHER AND RADAR TRENDS SUPPORT THIS THINKING...AND SUGGEST THAT THE HEAVIEST RAINFALL THROUGH MIDDAY MONDAY WILL ACTUALLY BE ACROSS THE FAR SOUTHEASTERN CWA INSTEAD. THUS...RIVER FORECASTS HAVE BEEN ADJUSTED ACCORDINGLY FOR STREAMS IN THE DES MOINES...RACCOON...SKUNK AND CEDAR RIVER BASINS. WHILE THIS MORNING/S RIVER FORECASTS INDICATED A SECONDARY CREST AT MANY LOCATIONS...UPDATED RIVER FORECASTS NOW EITHER REMOVE THIS SECONDARY CREST OR SUGGEST THAT IT WILL BE LOWER THAN THE ONES THAT HAVE ALREADY OCCURRED OR WILL OCCUR SHORTLY. IN RESPONSE TO THE LOWER RIVER FORECASTS...SAYLORVILLE RESERVOIR IS NOT EXPECTED TO CREST AS HIGH AS THIS MORNING/S USACE FORECAST INDICATED...WHICH SHOWED IT CRESTING JUST OVER 880 FT MSL THIS WEEK. SINCE THE UPDATED DES MOINES MAINSTEM FORECAST HAS ESSENTIALLY REVERTED BACK TO SATURDAY/S FORECAST...LATEST THINKING IS THAT SAYLORVILLE WILL NOW CREST CLOSER TO WHAT INDICATED BY THE SATURDAY FORECAST /AROUND 865 FT MSL/. WILL HAVE TO CONTINUE MONITORING RIVERS FOR IMPACTS RELATED TO POTENTIAL MODERATE TO HEAVY RAINFALL LATER THIS WEEK. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DONAVON LONG TERM...REV AVIATION...DONAVON HYDROLOGY...REV/ZOGG  FXUS63 KDMX 250837 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 337 AM CDT WED JUN 25 2014 .SYNOPSIS... ISSUED AT 318 AM CDT WED JUN 25 2014 WEAK FRONTAL BOUNDARY WILL SINK SOUTH ACROSS THE CWA TODAY THEN LIFT NORTH TONIGHT AS A WARM FRONT. THE FRONT LIFTS NORTH OF THE CWA ON THU WITH A SOUTHERLY FLOW BECOMING ESTABLISHED. THE NEXT COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREAS MONDAY AFTERNOON AND NIGHT. && .SHORT TERM /TODAY/... ISSUED AT 318 AM CDT WED JUN 25 2014 THERE ARE A LOT OF SUBTLE FEATURES TO CONTEND WITH TODAY THAT PROBABLY WILL NOT AMOUNT TO MUCH BUT WILL BEAR WATCHING. FIRST...THE WEAK BOUNDARY THAT MOVES ACROSS THE STATE YESTERDAY AND OVERNIGHT WILL SETTLE INTO NORTHERN MISSOURI. MEANWHILE A SHORTWAVE WILL DROP THROUGH THE NORTHERN PLAINS AND ACROSS MAINLY NORTHERN IOWA. INSTABILITY THIS MORNING WILL NOT BE MUCH TO SPEAK OF BUT WILL INCREASE THIS AFTERNOON...ESPECIALLY WEST. SHEAR IS NEGLIGIBLE TODAY SO ONCE AGAIN WE WILL FIND OURSELVES MAINLY WITH AFTERNOON OR LATE DAY SHOWERS OR AN ISOLATED THUNDERSTORM ACROSS THE NORTHEAST AS THE SHORTWAVE EXITS. ACROSS THE SOUTH...NEAR THE FRONTAL BOUNDARY SITTING IN MISSOURI...WARM ADVECTION WILL BE INCREASING IN THE AFTERNOON AND THE NAM DOES SHOW A VERY SUBTLE WAVE CROSSING ACROSS SOUTHWEST IOWA INTO WEST CENTRAL ILLINOIS. THIS COULD BE RESPONSIBLE FOR THE DEVELOPMENT OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY SOUTH AND WEST WHICH WOULD DRIFT INTO FAR SOUTHERN IOWA. WE STILL HAVE NEXT TO NO SHEAR AND PWATS OF AROUND AN INCH SO NOT REALLY LOOKING AT ANY SEVERE THREAT OR HEAVY RAIN THREAT WITH ANY STORMS. TEMPS WILL BE SIMILAR TO YESTERDAY...MAYBE A DEGREE OR TWO WARMER. .LONG TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 318 AM CDT WED JUN 25 2014 THE DYNAMICS ARE WEAK TONIGHT WITH THE FRONT TONIGHT. EVEN SO...EXPECTED TO SEE AT LEAST SOME SCATTERED THUNDERSTORM ACTIVITY WITH VERY LITTLE CIN BY LATER TONIGHT. EVEN WITH THE FRONT MOVING NORTH...THE PATTERN WILL REMAIN UNSETTLED WITH A STRONG SOUTHWEST FLOW ALOFT AHEAD OF THE APPROACHING NEGATIVE TILT TROUGH. THAT WILL KEEP THE CHANCES UP FOR THUNDERSTORMS. ALSO THERE IS NOT A WELL ESTABLISHED EML...SO CAPPING IS NOT LIKELY TO HOLD THINGS BACK EITHER THE NEXT COLD FRONT FOR MON COMES THROUGH AFTER THE WINDS ALOFT HAVE BECOME WESTERLY. MUCH OF THE RAIN WILL BE OUT OF THE AREA BY SOMETIME MONDAY NIGHT. THE OTHER CONSIDERATION WILL BE FOR THE MONDAY/MONDAY NIGHT TIMEFRAME WITH RESPECT TO HEAVY RAINFALL. PWAT VALUES ARE FORECAST TO MOVE THE 2 INCH MARK...WHICH WOULD BE NEARLY 3 SIGMA ABOVE CLIMO. THAT COMBINED WITH A WARM CLOUD DEPTH OF 4400 TO 4600 METERS LENDS ITSELF TO THE POTENTIAL FOR HEAVY RAINFALL IN AREAS THAT ARE ALREADY SATURATED. && .AVIATION...25/06Z ISSUED AT 1118 PM CDT TUE JUN 24 2014 LITTLE CHANGE FROM PREVIOUS THINKING...EVENING CONVECTION HAS ENDED AND WEAK BOUNDARY WILL DRIFT SOUTH TOWARD NORTHERN BORDER BY 12Z WITH SLIGHT CHANCE FOR SOME SHOWERS GENERALLY NEAR KMCW BY 12Z. IN THE SOUTHWEST...LESS FORCING ANTICIPATED AND NOT EXPECTING MUCH IN TERMS OF MID LEVEL CLOUDS. AFT 18Z WED INSTABILITY INCREASE BUT COVERAGE MAY BE LIMITED DUE TO LACK OF WELL DEFINED BOUNDARY OR FORCING ACROSS THE AREA. FOR NOW...RATHER THAN GO CATEGORICAL SHOWERS OR THUNDER...HAVE ADDED VCSH AFT 20-21Z MOST SITES. WINDS REMAIN GENERALLY LIGHT THROUGH THE PERIOD. /REV && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MS JUN 14 SHORT TERM...FAB LONG TERM...MS JUN 14 AVIATION...REV  FXUS63 KDMX 252054 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 354 PM CDT WED JUN 25 2014 .SHORT TERM /TONIGHT/... ISSUED AT 354 PM CDT WED JUN 25 2014 FAIRLY QUIET WEATHER IS EXPECTED THROUGH TONIGHT IN A LIGHT FLOW REGIME. CLASSIC SUMMERTIME CUMULUS FIELD HAS DEVELOPED THIS AFTERNOON IN AN UNSTABLE ATMOSPHERE...HOWEVER WE ARE LACKING LARGE SCALE FORCING AND A FOCUS MECHANISM SO THUS FAR ONLY A COUPLE OF TINY STORMS HAVE FORMED IN IOWA. EXPECT MORE OF THESE STORMS TO FORM IN THE NEXT FEW HOURS...WITH AN EYE TOWARD A WEAK SURFACE BOUNDARY CREEPING SOUTHWARD AROUND THE HIGHWAY 20 CORRIDOR...BUT SEVERE WEATHER IS NOT ANTICIPATED AND ONLY A VERY SMALL PERCENTAGE OF THE AREA WILL BE AFFECTED. VERY ISOLATED STORMS WILL PROBABLY PERSIST AT INTERVALS THROUGH TONIGHT AS A MODEST LOW LEVEL JET KICKS IN AND THE BOUNDARY/IES WOBBLE AROUND AND EVENTUALLY MOVE BACK NORTHWARD. HAVE MAINTAINED 20 POPS ACROSS MUCH OF THE AREA IN ORDER TO KEEP ISOLATED WORDING...BUT IN REALITY LESS THAN 20 PERCENT OF THE AREA WILL RECEIVE RAINFALL. OTHERWISE THE FORECAST IS STRAIGHTFORWARD WITH OVERNIGHT LOWS SIMILAR TO LAST NIGHT AND PARTLY CLOUDY SKIES. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 354 PM CDT WED JUN 25 2014 PRECIP TRENDS WILL BE THE ONLY CONCERN OF NOTE THROUGH THE PERIOD AS SEASONAL TEMPERATURES CONTINUE. THE PATTERN CAN ESSENTIALLY BE BROKEN INTO THREE REGIMES INTO NEXT WEEK WITH GRADUALLY INCREASING INSTABILITY BUT LITTLE FORCING TO END THE WORK WEEK...INCREASED SYNOPTIC SCALE FORCING INTO THE WEEKEND AND EARLY NEXT WEEK...AND A RETURN TO MORE TRANQUIL WEATHER FOR THE LAST FEW DAYS OF THE EXTENDED. THU AND FRI WILL BE VERY MUCH LIKE TODAY BUT WITH THERMODYNAMIC CONDITIONS SLOWLY BECOMING MORE FAVORABLE AS LOW LEVEL FLOW SLOWLY VEERS AND INCREASES. SURFACE CONVERGENCE WILL STILL BE WELL TO OUR WEST BY 00Z SAT HOWEVER...BACK INTO THE DAKOTAS AND NE...SO ANY CONVECTION THAT DEVELOPS WOULD BE SOMEWHAT RANDOM AND UNORGANIZED WITH WEAK SHEAR. HEADING INTO THE WEEKEND THE SHORT WAVE CURRENTLY OFF THE CA/OR COAST WILL REACH THE MO VALLEY WITH THE ASSOCIATED INCREASE IN FORCING COINCIDENT WITH BUILDING SHEAR AND INSTABILITY. DETAILS ARE CERTAINLY DIFFICULT TO PIN DOWN THIS FAR OUT...BUT SEVERE WEATHER CHANCES WILL INCREASE EVEN THOUGH LOW LEVEL CONVERGENCE WILL STILL BE DIFFICULT TO COME BY. HOWEVER BY SUN NIGHT MATURATION OF THE UPPER LOW OVER SRN CANADA WILL RESULT IN BETTER DEVELOPED SURFACE FEATURES INTO THE CENTRAL AND NRN PLAINS WITH FRONT PASSING THROUGH IA INTO MONDAY. ALTHOUGH THE PATTERN IS NOT IDEALISTIC FOR HEAVY RAIN WITH LITTLE BAROCLINICITY...THE AIRMASS WILL BECOME FOR FAVORABLE IN GENERAL WITH A FEW PERIODS OF ELEVATED PWS AND WARM CLOUD DEPTHS AND THE MEAN WIND PARALLEL TO THE LOW LEVEL JET RESULTING IN SLOW CELL MOVEMENT /CORFIDI VECTORS/. CHANCES FOR CONVECTION WILL LINGER MAINLY SE MONDAY NIGHT...BUT THERE SHOULD BE LITTLE FORCING OR INSTABILITY IN SUBSIDENT NW FLOW FOR TUE AND WED WITH BROAD CYCLONIC SURFACE FLOW BRINGING IN A DRIER AIRMASS AFTER SEVERAL DAYS OF HUMID CONDITIONS. && .AVIATION...25/18Z ISSUED AT 1223 PM CDT WED JUN 25 2014 VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. ISOLATED SHRA/TSRA ARE POSSIBLE AT TIMES...BUT PROBABILITY OF AFFECTING A GIVEN TERMINAL TOO LOW FOR INCLUSION. LIKEWISE LIGHT MVFR BR MAY DEVELOP TOWARD SUNRISE THURSDAY...BUT DURATION AND PROBABILITY TOO LOW TO MENTION IN THE TAFS. EXPECT INCREASING CLOUDS BY THURSDAY MORNING...WITH MORE SCATTERED SHRA/TSRA POSSIBLE TOWARD THE END OF THE TAF PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...LEE LONG TERM...SMALL AVIATION...LEE  FXUS63 KDMX 270909 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 409 AM CDT FRI JUN 27 2014 .SYNOPSIS... ISSUED AT 326 AM CDT FRI JUN 27 2014 WEAK WARM FRONT REMAINS TO THE SOUTH OF IOWA AND WILL LIFT NORTH OVER THE NEXT 36 HOURS. A SERIES OF UPPER LEVEL DISTURBANCES WILL AFFECT THE AREA. A SIGNIFICANT NEG TILT TROUGH WILL SWING THROUGH THE STATE SATURDAY NIGHT. A SECOND UPPER AIR DISTURBANCE AND ALSO THE COLD FRONT WILL MOVE THROUGH SUNDAY NIGHT AND MON. HIGH PRESSURE WILL BUILD INTO THE STATE MON AND TUE FOLLOWED BY HIGH PRESSURE FOR MID WEEK. && .SHORT TERM /TODAY/... ISSUED AT 326 AM CDT FRI JUN 27 2014 WEAK MCV IN SOUTHWEST IOWA WILL BRING THE NEXT ROUND OF SHOWERS/THUNDERSTORMS ACROSS THE CENTRAL PORTION OF THE FORECAST THROUGH 15Z. THERE ARE A FEW POCKETS OF HEAVIER RAIN ON THE LEADING EDGE OF THIS CLUSTER MOVING NORTHWARD...BUT MAINLY STRATIFORM PRECIP TRAILS BEHIND. 500MB SHORTWAVE TROUGH AND VORT MAX WILL TRANSITION EAST TO NORTHEAST THROUGH MIDDAY/EARLY AFTERNOON AND EXPECTING THE SOUTHWEST TO DRY OUT PAST 18Z. HAVE THE HIGHER POPS THIS AFTERNOON ACROSS THE NORTHEAST AS THE DEEPER FORCING MOVES INTO EASTERN IOWA WITH THE STRONGER SHORTWAVE. NO SHORTAGE OF MOISTURE TRANSPORT INTO THE STATE AND IS EVIDENT THE DEEP LAYER OF MOISTURE REMAINS PRESENT PER FORECAST SOUNDINGS AT DSM. WARM LAYER CLOUD DEPTHS RANGING AROUND 12KFT TO NEAR 13KFT AND THE PRECIPITABLE WATER VALUES IN THE 1.50 TO 1.75 INCH RANGE...SO STILL LOOKING AT ANOTHER ROUND OF POTENTIAL EFFICIENT RAIN PRODUCERS TODAY AS GENERALLY THE 1 TO NEAR 3 INCH PER HOUR RATES ARE POSSIBLE. HOWEVER...THE STORM PROGRESSION LOOKS TO BE AROUND 15-20 KNOTS TODAY PER CORFIDI VECTORS...SO THE HEAVY RAIN OVER ONE AREA SHOULD BE SHORT-LIVED UNLESS BACK-BUILDING OCCURS LIKE THURSDAY. THE 27.05Z HRRR HAS A DECENT HANDLE ON CURRENT CONVECTIVE TRENDS...ALBEIT ROUGHLY TWO HOURS TOO FAST...BUT LEANED TOWARD THE HRRR THROUGH THE MORNING HOURS FOR POP/WX TRENDS. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 326 AM CDT FRI JUN 27 2014 MUCH OF THE ACTIVITY TONIGHT WILL REMAIN TO THE WEST OF IA WHERE THERE IS STRONGER FORCING. NEGATIVE TILT TROUGH WILL BRING A GOOD CHANCE FOR WIDESPREAD THUNDERSTORM ACTIVITY SAT AND SAT NIGHT. SEVERE WEATHER IS LIKELY TO REMAIN TO THE WEST OF IA. THE COLD FRONT IN COMBINATION WITH THE STGRENGTHENING JET STREAM...OVER 80 KTS, WILL BRING A CHANCE FOR SEVERE WEATHER FOR LATE SUNDAY INTO SUNDAY NIGHT. WILL MENTION BOTH SEVERE AND HEAVY RAIN IN THE BODY OF THE ZONES. DEEP WARM CLOUD LAYER THICKNESS...OVER 4 KM AND PWAT VALUES NEAR 2 INCHES. THE SEVERE POTENTIAL IS PRETTY HIGH WITH STEEP LAPSE RATES AND CAPE NEAR 5000 J/KG. THOUGH NOT PERFECT, THE HODOGRAPHS ARE FAVORABLE WITH DECENT SHEAR...BOTH SPEED AND DIRECTION...IN PLACE. COOLER AND DRIER WEATHER IS ON TAP FROM THE BEGINNING OF NEXT WEEK ON. THE COLDEST AIR WILL MISS IA TO THE NORTHEAST AND THE COOLING TREND DOESN'T LOOK LIKE IT WILL LAST ALL THAT LONG EITHER. DON'T EXPECT TO SEE MORE THAN TWO OR THREE DAYS BELOW NORMAL. && .AVIATION...27/06Z ISSUED AT 1204 AM CDT FRI JUN 27 2014 LITTLE CHANGE IN THINKING SINCE 00Z ISSUANCE. VFR CONDITIONS ARE IN PLACE ACROSS MUCH OF IA ALTHOUGH LOCALLY DEGRADED NEAR HEAVIER RAINFALL. CONVECTION HAS SHOWN LITTLE PREDICTABILITY OUTSIDE OF SHORT TERM TRENDS HOWEVER SO HAVE ONLY ACCOUNTED FOR PRECIP IN THE FIRST HALF OF THE FORECAST TO VARIED DEGREES DEPENDING ON CONFIDENCE. CONVECTION IS POSSIBLE THROUGH THE ENTIRE PERIOD INTO FRI EVENING...BUT WILL ADDRESS THAT ONCE CONFIDENCE INCREASES. MAY ALSO SEE MVFR FOG DEVELOP EARLY THIS MORNING...ESPECIALLY NEAR AREAS THAT HAVE SEEN APPRECIABLE RAIN. && .HYDROLOGY... ISSUED AT 326 AM CDT FRI JUN 27 2014 WITH HIGH PWATS AND SLOW MOVEMENT OF WEATHER SYSTEM...THE POTENTIAL FOR FLOODING IS FAIRLY HIGH. RAINFALL OF THE PAST DAY OR SO HAS MOISTENED SOILS SO THE FFG IS DOWN TO AROUND AN INCH IN SEVERAL LOCATIONS. THE BEST POTENTIAL WILL COME SUNDAY NIGHT...THOUGH THE CURRENT PATTERN GIVES AT LEAST SOME RISK TO THE ENTIRE CWA THROUGH THE NEXT THREE DAYS. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MS JUN 14 SHORT TERM...PODRAZIK LONG TERM...MS JUN 14 AVIATION...SMALL HYDROLOGY...MS JUN 14  FXUS63 KDMX 280826 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 326 AM CDT SAT JUN 28 2014 .SHORT TERM /TODAY/... ISSUED AT 325 AM CDT SAT JUN 28 2014 EASTWARD PUSH FROM THE CONVECTION IN EASTERN NEBRASKA CONTINUES AND EXPECT THAT THE GRAVITY IMPULSE ASSOCIATED WITH THE COOL POOL WILL CONTINUE TO PUSH EAST. SCATTERED THUNDERSTORMS COULD BUBBLE UP ABOUT ANYWHERE...BUT THE BETTER CHANCES WILL LIKELY COME AFTER WE SEE SOME HEATING. WENT FOR FAIRLY HIGH POPS FOR THE AFTERNOON...NOT THAT IT WILL RAIN ALL AFTERNOON BUT MOST PLACES WILL AT LEAST SEE MEASURABLE. TEMPERATURES ARE TRICKY WITH THE EXTENSIVE CLOUD COVER. OTHER THAN THE KDSM HEAT ISLAND EFFECT...WILL GENERALLY SIDE WITH THE COOLER GUIDANCE VALUES. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 325 AM CDT SAT JUN 28 2014 EXPECTING ONGOING CONVECTION EARLY IN THE PERIOD AS SHORT WAVE/WARM FRONT CURRENTLY OVER THE SOUTH CENTRAL PLAINS CONTINUES PUSHING THROUGH THE AREA THIS EVENING AS THIS LIFTS NORTHEAST OF THE AREA EARLY SUNDAY. WARM CLOUD DEPTHS ALREADY 10 TO 13KFT THIS EVENING OVER THE AREA AND WITH THE LIFTING WARM FRONT PRECIPITABLE WATER WILL BE NEARING 2 INCHES ONCE AGAIN FROM 00Z THROUGH 06Z TONIGHT AND THEN DROPS BY MORNING AS A WEAK TROUGH MOVES ACROSS THE REGION TAKING SOME OF THE HIGH PWAT AIR WITH IT...FOR ONLY A SHORT PERIOD OF TIME. STORMS THIS EVENING SHOULD BECOME MORE PROGRESSIVE BUT WILL STILL BE CAPABLE OF DROPPING 1-2 INCHES OF RAINFALL IN A SHORT PERIOD OF TIME AS THE LINE MOVES THROUGH CENTRAL IOWA THIS EVENING. THOUGH SEVERE WEATHER WILL BE POSSIBLE...EVENING STORMS SHOULD BE LIMITED TO WIND. CURRENT FLASH FLOOD GUIDANCE CONTINUES RATHER LOW GIVEN PAST 2 DAYS OF RAIN OVER CENTRAL SECTIONS OF THE FORECAST AREA. OVER A GOOD SHARE OF THE US20 TO HIGHWAY 92 CORRIDOR...1 AND 3 HOUR GUIDANCE IS ABOUT BETWEEN 1 TO 2 INCHES OF RAINFALL. SOUTH OF THERE CONDITIONS ARE SLIGHTLY BETTER AND COULD HANDLE MORE RAINFALL. TONIGHT WILL BE WARM AND HUMID WITH A RAPID RETURN OF WARM AIR AND MOISTURE SUNDAY THROUGH SUNDAY AFTERNOON. BY EARLY SUNDAY MORNING A STRONG ZONAL FLOW WILL BEGIN TO IMPACT THE CENTRAL AND NORTHERN PLAINS. A QUICK RETURN OF VERY WARM AND UNSTABLE AIR COUPLED WITH A SHORT WAVE MOVING EAST OUT OF THE CENTRAL ROCKIES SHOULD RESULT IN MORE WIDESPREAD SEVERE POTENTIAL SUNDAY AFTERNOON AND NIGHT. PRECIPITABLE WATER RECOVERS QUICKLY SUNDAY AFTERNOON AND REACHES VALUES OF 1.75 TO 2 INCHES BY LATE DAY. AGAIN WARM CLOUD DEPTHS INCREASE TO 12 TO 14KFT DURING THE EVENING. WITH FORWARD PROPAGATING STORM MOTION APPROACHING 35 TO 40KTS...EXPECTING POSSIBILITY OF BOTH HEAVY RAINFALL AND DAMAGING WINDS SUNDAY NIGHT. UNFORTUNATELY THERE IS LITTLE CHANGE INTO MONDAY AS THE MAIN TROUGH IS STILL WEST OF THE AREA...WITH HOT DOME BUILDING IN THE STERN PLAINS AND IOWA ON THE SOUTHERN EDGE OF THE MEAN STRONG WESTERLIES AT H500 TO H300. THOUGH SOME DIFFERENCES ARE STILL EVIDENT IN THE VARIOUS MODEL OUTPUTS... ADDITIONAL STORM INITIATION APPEARS QUICKLY OVER NORTHWEST IOWA AS A STRONG SHORT WAVE APPROACHES AT H500 AND EITHER THE STORMS MOVE EAST OR EAST SOUTHEAST WITH TIME DURING THE AFTERNOON HOURS. GIVEN THE DYNAMICS AND INSTABILITY...ANOTHER ROUND OF STRONG THUNDERSTORM WINDS AND HEAVY RAIN IS LOOKING MORE PROBABLE. CIPS ANALOGS SHOW THE FORECAST RESEMBLING A NUMBER OF PAST VERY STRONG WIND EVENTS OVER THE REGION. WILL NEED TO EVALUATE THIS AGAIN AS MONDAY NEARS... THOUGH PLENTY OF CHALLENGES UNTIL THEN. HIGHS SUNDAY SHOULD REACH THE MID TO UPPER 80S WITH DEW POINTS IN THE LOWER TO MID 70S BY MID TO LATE AFTERNOON. MONDAY LIKELY TO BE A FEW DEGREES COOLER WITH LEFTOVER CONVECTION IN THE AREA. FOLLOWING THE ACTIVE TROUGH... CONSENSUS FORECASTS SUGGEST THAT WE FINALLY GET A BREAK FOR A FEW DAYS. THOUGH THERE MAY BE SOME RESIDUAL ISO THUNDER NORTH ON TUESDAY WITH THE PASSAGE OF A SECONDARY COLD FRONT...NORTHWESTERLY FLOW TAKES OVER FROM TUESDAY THROUGH THURSDAY BEFORE WARM AIR RETURNS FOR NEXT WEEKEND. BY LATE IN THE PERIOD WE MAY BE APPROACHING THE 85 TO 90 DEGREE MARK AS HEAT AND HUMIDITY RETURN. && .AVIATION...28/06Z ISSUED AT 1153 PM CDT FRI JUN 27 2014 AREA OF SHRA/TSRA IN NEBRASKA WILL PUSH EAST INTO SITES BY 12Z...THOUGH WILL DIMINISH SOMEWHAT. ADDITIONAL CHANCES FOR TSRA/SHRA WILL RETURN IN THE AFTERNOON AND PERSIST THROUGH MUCH OF THE EVENING AND POSSIBLY INTO THE OVERNIGHT. CONDITIONS WILL PRIMARILY BE VFR...THOUGH SOME MVFR CEILINGS AND VISIBILITIES WILL BE POSSIBLE NEAR 12Z WITH BR/FG. IN ADDITION...MVFR OR LOWER CONDITIONS WILL BE POSSIBLE IN PRECIPITATION AFFECTING SITES...THOUGH HAVE ONLY TRENDED THIS WAY FOR NOW. WINDS WILL BE PRIMARILY SOUTHEASTERLY...THOUGH WILL INCREASE AND BECOME GUSTY DURING THE DAY. && .HYDROLOGY... ISSUED AT 325 AM CDT SAT JUN 28 2014 LITTLE CHANGE TO PREVIOUS HYDRO OUTLOOK. WITH ADDITIONAL PERIODS OF HEAVY RAINFALL POSSIBLE THROUGH THE WEEKEND INTO MONDAY...CHANCES FOR SOME ADDITIONAL FLOODING WILL CONTINUE. HIGH PRECIPITABLE WATER AND DEEP WARM CLOUD DEPTHS SUGGEST TROPICAL RAIN ENVIRONMENT ONCE AGAIN...SIMILAR TO THE PAST TWO DAYS. STORMS MAY BE MORE PROGRESSIVE TONIGHT AND SUNDAY/MONDAY...BUT GIVEN THE INCREASED DYNAMICS AND AVAILABLE MOISTURE...RAINFALL EFFICIENCY WILL BE VERY HIGH. THE MORE ORGANIZED EVENTS APPEAR TO BE SUNDAY INTO SUNDAY NIGHT...AND POSSIBLY AGAIN ON MONDAY AS WIND FIELDS ALOFT BOTH DAYS WILL SUPPORT MORE WIDESPREAD CONVECTION. FROM PREVIOUS DISCUSSION... EXISTING RIVER FORECASTS INCORPORATE ONLY 24 HRS OF QPF. THE QPF ENSEMBLE FORECAST HYDROGRAPHS SHOW A RANGE OF POTENTIAL RESPONSES TO DIFFERING AMOUNTS OF QPF THIS WEEKEND...WHICH INDICATE THAT THE HYDROLOGIC SYSTEM IS SENSITIVE TO FUTURE RAINFALL AMOUNTS. POTENTIAL RESPONSES WITHIN THE DES MOINES...RACCOON...SKUNK...CEDAR AND IOWA BASINS RANGE FROM SLOWING THE FALL OF THE STREAMS TO NEW CRESTS WHICH MAY EQUAL OR EXCEED THOSE SEEN EARLIER. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...MS LONG TERM...REV AVIATION...AWB HYDROLOGY...REV  FXUS63 KDMX 052012 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 312 PM CDT SAT JUL 5 2014 .SHORT TERM /TONIGHT/... ISSUED AT 312 PM CDT SAT JUL 5 2014 MCV/MCS CURRENTLY EXITING THE AREA TO THE SOUTHEAST THIS AFTERNOON. TEMPS HAVE BEEN HELD BACK BUT ARE RECOVERING ACROSS THE WEST. WARM FRONT OVER NORTHERN MO THIS MORNING HAS BEEN REINFORCED BY OUTFLOW BOUNDARY FROM MESOSCALE SYSTEM...BUT SHOULD BEGIN TO LIFT NORTH DURING THE NIGHTTIME HOURS. MODELS AT ODDS ABOUT CONVECTION COVERAGE TONIGHT...BUT HINTING AT SOME DEVELOPMENT ALONG THE EDGE OF THE RETREATING WARM FRONT/OUTFLOW BOUNDARY THROUGH IOWA OVERNIGHT. WEAKEST PORTION OF THE H700 CAP FAVORS THE EASTERN AND SOUTHERN SECTIONS. HRRR REFLECTS SOME DEVELOPMENT WITH A BAND OF STORMS FORMING AFT 04Z NEAR I80 CORRIDOR...VARIOUS OTHER SOLUTIONS ALSO FAVOR SOME DEVELOPMENT OVER THE EAST OR ALONG THE IOWA/MO BORDER BETWEEN 00 AND 06Z AS NOCTURNAL LOW LEVEL JET INCREASES AND IMPINGES ALONG THE WARM FRONT/OUTFLOW BOUNDARY. WILL INCREASE POPS AGAIN BY MID TO LATE EVENING OVER THE EAST AND SOUTH...WEAK STEERING CURRENTS SUGGEST SOME SOUTHEASTERLY DRIFT ALONG THE BOUNDARY OVERNIGHT. ONCE AGAIN...IF CONVECTION GETS A BIT MORE ORGANIZED COULD SEE A QUICK INCH OR TWO TOTAL FROM ANY STRONGER CELLS THAT DEVELOP. WARM CLOUD DEPTHS PUSHING 13-14KFT AND PRECIPITABLE WATER STILL RUNNING 1.5 INCHES OVER THE SOUTHEAST THIRD. FOR NOW WILL NOT ISSUE HEADLINES AS COVERAGE IS EXPECTED TO BE LIMITED. AFTER LAST NIGHTS/THIS MORNING RAINFALL... GRIDDED FLASH FLOOD GUIDANCE HAS LOWERED TO 1 TO 1.5 INCHES OVER A GOOD SHARE OF THE SOUTH WITH 3 HOURLY GUIDANCE NEARING 2 INCHES OVER THE SAME LOCATIONS. THE SOUTHERN TWO TIER COUNTIES CONTINUE HIGHER...WITH 2 INCH VALUES FOR 1 HOUR AND 2 TO 3 INCH VALUES FOR 3 HOUR GUIDANCE. NEEDLESS TO SAY...NOT MUCH CAPACITY LEFT IN SOIL FOR ADDITIONAL RAINFALL OVER THE NEXT FEW DAYS. LOWS WILL CREEP UP TONIGHT. DESPITE THE LACK OF MUCH SUNSHINE THIS AFTERNOON...LOWS WILL REMAIN IN THE MID TO UPPER 60S AS DEW POINTS HAVE RISEN WITH THE RETURN OF MOISTURE TO THE AREA. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 312 PM CDT SAT JUL 5 2014 LONG TERM FORECAST PERIOD WILL FEATURE RATHER ACTIVE WX AND AN OVERALL UPPER AIR PATTERN OF WESTERLIES INVOF OF IOWA...EVOLVING FROM BROAD NORTHWEST FLOW TO BROAD CYCLONIC FLOW. MAIN CHALLENGES EARLY IN THE PERIOD WILL BE TSRA CHANCES SUNDAY AFTN/EVE AS WELL AS LATE MONDAY INTO TUE. FCST PERIOD BEGINS WITH IOWA SOUTH OF THE WESTERLIES. SUNDAY IS EXPECTED TO BE MORE SUMMER-LIKE...WITH THERMAL RIDGING AND MOISTURE TRANSPORT RESULTING IN SEASONALLY HOT AND HUMID CONDITIONS. TEMPS RANGING FROM THE UPPER 80S TO MIDDLE 90S ALONG WITH DEWPOINTS IN THE 70S ARE EXPECTED. AN IMPULSE WILL SWEEP A COOL FRONT INTO THE STATE ON SUNDAY. QUESTION IS HOW FAR WEST ALONG THE FRONT WILL THE TSRA DEVELOP. ALTHOUGH INSTABILITY IS PROGGED TO BE RESPECTABLE...CAPPING WILL INCREASE TOWARD THE WEST ACROSS THE STATE. BEST CHANCES OF TSRA WILL BE IN EASTERN IOWA...WHERE THE CAP WILL BE WEAKER AND UPPER-LEVEL FORCING WILL BE STRONGER. LOW- LEVEL JET WILL INCREASE MOISTURE TRANSPORT BY LATE EVENING...SO HAVE BROUGHT CHANCE POPS ALONG THE SOUTHERN BORDER OF THE STAGE BY THAT TIME. FRONT IS EXPECTED TO BECOME QUASI-STATIONARY INVOF THE IA-MO BORDER BY LATE SUNDAY NIGHT. STRONGER H5 SHORTWAVE WILL BRING ANOTHER CHANCE OF TSRA BY LATE MON. BOTH THERMODYNAMIC AND KINEMATIC FORCING WILL BE STRONGER WITH THIS SYSTEM THAN THE ONE ON LATE SUN. THIS SHORTWAVE WILL PUSH ANOTHER COOL FRONT SOUTH THROUGH IOWA...EVENTUALLY OVERTAKING THE QUASI-STATIONARY BOUNDARY INVOF THE IA-MO BORDER. AMPLE INSTABILITY AHEAD OF THE ADVANCING FRONT IS EXPECTED TO PROMOTE SFC-BASED TSRA DEVELOPMENT. SHEAR PARAMETERS SUGGEST A FEW SUPERCELLS POSSIBLE EARLY WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS...BUT CANNOT RULE OUT AN ISOLATED TORNADO. THE CONVECTION IS EXPECTED TO GROW UPSCALE INTO AN MCS AND PUSH SOUTHEAST INTO THE EVENING. AFTER THE FROPA MONDAY NIGHT/TUE MORNING...CYCLONIC WESTERLIES WILL DOMINATE THE WX INTO LATER IN THE WEEK. NEXT CHANCE OF PCPN WILL ARRIVE THURSDAY INTO THURSDAY NIGHT AS A WEAK IMPULSE PASSES OVER THE REGION. THE 12Z ECMWF IS ADVERTISING A STRONGER SHORTWAVE BRINGING ANOTHER BOUNDARY THROUGH THE CWA ON SATURDAY. THE 12Z RUN WAS CONSISTENT IN THIS REGARD WITH THE 00Z RUN. THIS SOLUTION IS ADMITTEDLY DIFFERENT THAN LAST NIGHT/S LONG TERM PACKAGE WHICH KEPT THE ACTIVITY NORTH OF THE CWA. SHRA/TSRA WILL BE POSSIBLE WITH THIS BOUNDARY AS IT SWEEPS THROUGH THE CWA. THIS BOUNDARY WILL BRING A SLIGHTLY COOLER AIR MASS OVER THE CWA TO END THE WEEKEND. && .AVIATION...05/18Z ISSUED AT 104 PM CDT SAT JUL 5 2014 MAIN CONCERNS WILL BE CIGS AND POTENTIAL FOR FOG OVERNIGHT. OLD MCV/MCS MOVING TO THE SOUTHEAST...WITH POCKETS OF IFR CIG STILL EVIDENT ACROSS THE REGION AT 100 PM...GRADUALLY THE CIGS SHOULD LIFT A BIT TO MVFR/VFR CONDITIONS AS THE CONVECTION PULLS AWAY. OVERNIGHT TONIGHT SOME HINT AT STORM REDEVELOPMENT OVER THE SOUTHEAST/SOUTH CENTRAL...SIGNAL NOT ALL THAT STRONG RIGHT NOW. BR WILL RETURN TOWARD 09Z WITH POTENTIAL 2-5SM VSBY FOR SEVERAL HOURS EITHER SIDE 12Z. EXPECT WINDS TO PICK UP FROM SW WITH IMPROVING CONDITIONS BY 15Z AS CAP ALOFT WILL KEEP CONVECTION DOWN UNTIL FRONT APPROACHES AFT 18Z ACROSS THE NORTH. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...ZOGG AVIATION...REV  FXUS63 KDMX 072023 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 323 PM CDT MON JUL 7 2014 .SHORT TERM /TONIGHT/... ISSUED AT 323 PM CDT MON JUL 7 2014 MAIN CONCERNS WILL BE SVR CHANCES AND HEAVY RAINFALL POTENTIAL TONIGHT. RATHER COMPLICATED MESOSCALE SITUATION AGAIN TODAY WITH MAIN COOL FRONT OVER SOUTH CENTRAL MN. OLD CONVECTION OVER NORTHEAST NEBRASKA HAS LEFT AN OUTFLOW BOUNDARY OVER SOUTHERN NEBRASKA WHICH IS BEGINNING TO LINE UP WITH YESTERDAYS PRESSURE TROUGH/OLD COOL FRONT THAT MOVED ACROSS THE REGION SUNDAY EVENING. LEFTOVER CONVECTION IN NORTHEAST NEBRASKA HAS WEAKENED SOMEWHAT AS IT HEADS TO THE EAST FOR NOW. MUCH OF THE AREA TODAY IS SEEING AMPLE SUNSHINE AND ALREADY SBCAPE OVER WESTERN SECTIONS HAS RISEN TO 3000 J/KG AT 19Z. CURRENTLY BULK SHEAR IS 35 TO 55KTS OVER WEST IOWA WITH 50 TO 60KTS ACROSS NEBRASKA AND SOUTH DAKOTA. WATER VAPOR IMAGERY HAS IMPRESSIVE SPEED MAX MOVING INTO NORTH CENTRAL SOUTH DAKOTA. THE INCREASE IN THE WINDS ALOFT AND ASSOCIATED MID LEVEL SHORTWAVE WILL ARRIVE MID EVENING AND CONTINUE TO IMPACT THE AREA THROUGH 12Z. ONE AREA OF STRONG FORCING WILL BE FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST AREA THIS EVENING FROM 00-01Z THROUGH 08Z. ANOTHER AREA OF FORCING WILL BE CLOSER TO THE BOUNDARY OVER SOUTHERN MN THIS EVENING. THERE MAY BE A SMALL CORRIDOR IN CENTRAL IOWA WHERE SLIGHTLY LESS CONVECTION OCCURS...BUT OVERALL MOST OF AREA WILL SEE THUNDER THOUGH AT LEAST 06Z. AS THE OLD CONVECTION IN NEBRASKA GETS CLOSER TO THE BETTER INSTABILITY AXIS OVER WESTERN IOWA AND SOUTHEAST NEBRASKA YET LATE THIS AFTERNOON...CONVECTION SHOULD INTENSIFY AND BEGIN TO MOVE EAST SOUTHEAST THIS EVENING. CURRENT OUTLOOK FOR MORE WIND...HAIL ACROSS THE SOUTH...AND SMALLER POTENTIAL FOR TORNADOES OVER THE REGION LOOKS ON TRACK. EMPHASIS FOR NEBRASKA/SOUTHERN IOWA CONVECTION TO DRIFT INTO MISSOURI ALSO LOOKS ON TRACK. MODELS CONTINUE TO SHOW AXIS OF HEAVY RAINFALL BRUSHING SOUTHERN IOWA OVERNIGHT WITH MORE OF THE FOCUS IN MISSOURI. WILL LEAVE FFA OUTLINE AS IS...GIVEN THE CURRENT TRENDS AND SOME UNCERTAINTIES. MOST OF THE AREA WILL SEE CLEARING BETWEEN 06-09Z AS THE FRONT IS FORCED SOUTHEAST BY THE STRONG UPPER LEVEL SHORTWAVE THIS EVENING. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 323 PM CDT MON JUL 7 2014 BROAD CYCLONIC UPPER FLOW IS EXPECTED FROM TUESDAY INTO WEDNESDAY AS SURFACE RIDGING PASSES THROUGH THE REGION. LIKELY SEE EXTENSIVE CU FIELD DEVELOP WITH DAYTIME HEATING ON BOTH DAYS AND MAY ACTUALLY SEE SOME ISOLATED SHOWER IN THE AFTERNOON. OTHERWISE...QUIET WEATHER WITH BELOW NORMAL TEMPERATURES IS FORECAST DURING THIS TIME AS A CANADIAN AIRMASS MOVES ACROSS THE STATE. WARM ADVECTION WILL BEGIN ON THURSDAY WITH INCREASING THETA-E ADVECTION THURSDAY NIGHT INTO FRIDAY. AS INSTABILITY INCREASES ALONG WITH FORCING...THUNDERSTORMS ARE EXPECTED TO DEVELOP AND OVERSPREAD THE FORECAST AREA ON THURSDAY NIGHT INTO FRIDAY. HEAVY RAIN WILL BE THE MAIN THREAT WITH THIS SYSTEM ALTHOUGH SOME ISOLD SEVERE WEATHER WILL REMAIN POSSIBLE. THE EURO CONTINUES ITS TREND OF PUSHING A SURFACE FRONT THROUGH THE STATE ON FRIDAY WITH FAIRLY TRANQUIL WEATHER INTO NEXT WEEKEND. GFS IS MUCH MORE BULLISH ON PRECIPITATION AS THE SURFACE FRONT LINGERS NEAR THE STATE WITH ONGOING CHANCES OF STORMS THROUGH THE WEEKEND. HAVE CONTINUED TO MENTION SOME THREAT OF STORMS FOR NEXT WEEKEND BUT FEEL IT SHOULD BE DRY MOST OF THE TIME PER EURO SOLUTION. && .AVIATION...07/18Z ISSUED AT 1248 PM CDT MON JUL 7 2014 MAIN CONCERNS THIS PERIOD WILL BE CONVECTIVE TRENDS AND WINDS FOR TUESDAY FOLLOWING THE FRONTAL PASSAGE. AIRMASS AHEAD OF THE MAIN SYSTEM CONTINUES TO DESTABILIZE...WEAKENING AREA OF CONVECTION OVER NW IOWA WILL SHOULD BE NO MORE THAN A FEW SHOWERS AS IT CROSSES THE AREA THERE THROUGH 20Z. MODELS INCREASE UPPER LEVEL FORCING TOWARD 00Z WITH CURRENT AREA OF CONVECTION OVER NORTHEAST NEBRASKA MOVING TOWARD WESTERN TAF SITES KFOD...KDSM AT THAT TIME. SVR CONCERNS THIS AFTERNOON WITH POTENTIAL FOR WIND AND SOME HAIL OVER THE AREA...WILL UPDATE AS NEEDED ONCE LINE BECOMES MORE WELL DEFINED AND CONVECTIVE TRENDS MORE APPARENT. STORMS WILL MOVE QUICKLY ESE THIS EVENING...WITH THE COLD FRONT HANGING UP OVER NORTHERN MO THROUGH 09Z. THIS WILL ALLOW FOR CONTINUED CONVECTION AND LOW CIGS ACROSS THE THROUGH 09Z SOUTHEAST AT KOTM...SOME UNCERTAINTY AS TO HOW QUICKLY THE AREA WILL TRANSITION SOUTH OF THE BORDER...AND MAY HAVE TO DELAY ENDING OF CONVECTION NEARER KOTM. OTHERWISE...WINDS INCREASE WITH MIXING AFT 15Z TUESDAY WITH NORTHWEST 13 GUST 24KTS THROUGH END OF TAF PERIOD. && .HYDROLOGY... ISSUED AT 323 PM CDT MON JUL 7 2014 POTENTIAL FOR HEAVY RAINFALL WILL CONTINUE OVER THE SOUTHERN COUNTIES THIS EVENING...THOUGH THE BEST FORCING MAY DEVELOP SLIGHTLY MORE SOUTH AS CONVECTION FIRES OVER SOUTHERN NEBRASKA AND THEN DRIFTS TO THE EAST SOUTHEAST WITH TIME THIS EVENING. OVERALL STILL LOOKING AT PRECIPITABLE WATER VALUES OF 1.5 INCHES OVER THE REGION THIS EVENING...WITH WARM CLOUD DEPTHS AGAIN SUPPORTING EFFICIENT RAINFALL RATES OVER THE AREA. WILL MAINTAIN THE WATCH ACROSS THE SOUTHERN COUNTIES THROUGH THE OVERNIGHT HOURS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH TUESDAY MORNING FOR ADAIR-ADAMS-APPANOOSE-CASS-CLARKE-DAVIS-DECATUR- LUCAS-RINGGOLD-TAYLOR-UNION-WAYNE. && $$ SHORT TERM...REV LONG TERM...COGIL AVIATION...REV HYDROLOGY...REV  FXUS63 KDMX 092036 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 336 PM CDT WED JUL 9 2014 .SHORT TERM /TONIGHT/... ISSUED AT 335 PM CDT WED JUL 9 2014 QUIET WEATHER IS EXPECTED TO CONTINUE OVERNIGHT AS SURFACE RIDGING SLIDES ACROSS THE AREA AND EAST INTO THE GREAT LAKES AREA BY MORNING. INITIALLY...WILL SEE SMOKE PLUME FROM CANADIAN FIRES CONTINUE TO MOVE OVERHEAD INTO TONIGHT WHICH MAY PROVIDE A COLORFUL SUNSET. IN ADDITION...SOME HAZY CONDITIONS MAY BE POSSIBLE OVERNIGHT AS PARTICULATE MATTER INCREASES IN THE LOW LEVELS. OTHERWISE...THE SMOKE SHOULD HAVE LITTLE INFLUENCE ON OVERNIGHT TEMPERATURES WITH READINGS FALLING BELOW NORMAL ONCE AGAIN WITH LIGHT WINDS REMAINING AND RELATIVELY CLEAR SKIES. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 335 PM CDT WED JUL 9 2014 MAIN FORECAST CONCERN WAS FOCUSED ON SYSTEM THURSDAY NIGHT INTO FRIDAY...SECONDARY SYSTEM ON SATURDAY...AND THEN WITH THE COOL DOWN NEXT WEEK. LEANED TOWARD A NAM12/SREF BLEND THURSDAY INTO FRIDAY...THEN SLIGHTLY MORE TOWARDS THE ECMWF OVER THE WEEKEND INTO NEXT WEEK. THURSDAY AND FRIDAY...SURFACE RIDGE SHIFTS EAST AND ALLOWS RETURN FLOW TO DEVELOP THROUGHOUT THE DAY THURSDAY. MOISTURE TRANSPORT AND THETA-E ADVECTION INCREASE ACROSS WESTERN IOWA BY 00Z FRIDAY AND SPREADS SLOWLY EAST DURING THE EVENING THURSDAY. CUT BACK ON TIMING OF POPS EAST OF I-35 FROM 00-06Z FRIDAY AND EVEN COULD GO COMPLETELY DRY ACROSS THE EAST AS THE DEEPER FORCING LOOKS TO MOVE THROUGH OVERNIGHT INTO FRIDAY MORNING. CONTINUED WITH THE HIGHEST POPS FROM 06-12Z FRIDAY AS THE STRONGEST FORCING AND BEST MOISTURE MOVE ACROSS THE FORECAST AREA DURING THIS TIME FRAME. HAVE SOME LINGERING LIKELY POPS EAST OF I-35 FRIDAY MORNING DUE TO THE MODELS TRENDING SLOWER WITH THIS SYSTEM. SATURDAY THROUGH MONDAY...BOUNDARY SETS UP ACROSS IOWA FROM WEST TO EAST FRIDAY NIGHT INTO SATURDAY WITH THE ASSOCIATED SURFACE LOW DEVELOPING OVER THE WESTERN PLAINS. A FEW SMALL VORT MAXES TRACK ACROSS THE STATE FRIDAY NIGHT THROUGH SUNDAY MORNING AND TIMING THESE WILL BE DIFFICULT. HOWEVER...BOTH THE GFS AND ECMWF WANT TO BRING IN A DECENT AMOUNT OF PRECIPITATION OVER THE WEEKEND...WITH THE FIRST ROUND LATE FRIDAY NIGHT INTO SATURDAY MORNING AND THE NEXT SATURDAY NIGHT INTO SUNDAY...COINCIDING WHEN THE LLJ STRENGTHENS. TWEAKED UP QPF/POPS DURING THE AFOREMENTIONED TIME. SEVERE POTENTIAL LOOKS LIMITED WITH MINIMAL INSTABILITY AND SHEAR PRESENT WITH THIS SYSTEM OVER THE WEEKEND. HEAVY RAIN IS MORE LIKELY THE GREATER THREAT WITH PRECIPITABLE WATER VALUES REACHING 2 INCHES AND THE WARM LAYER CLOUD DEPTHS TOPPING 13KFT TO 14KFT BY SATURDAY. WEAK CORFIDI VECTORS AND STRONG MOISTURE TRANSPORT AND DECENT CONVERGENCE ACROSS STATE ON LATE FRIDAY NIGHT INTO SATURDAY. NO MENTION OF HEAVY RAIN ATTM DUE TO UNCERTAINTY OF WHERE THE BOUNDARY LOCATION AND TIMING OF SHORTWAVE ON SATURDAY. ANOTHER SHOT OF COOL CANADIAN AIR WILL FILTER INTO THE REGION BY MONDAY AS A LARGE UPPER TROUGH MOVES INTO THE CENTRAL U.S. GFS IS SLIGHTLY STRONGER WITH THE 500MB LOW...BUT THE EXTENDED MODELS ARE IN FAIR AGREEMENT WITH TIMING AND LOCATION OF THE LOW. COOLED TEMPS DOWN A LITTLE ON TUESDAY. && .AVIATION...09/18Z ISSUED AT 1241 PM CDT WED JUL 9 2014 RELATIVELY QUIET AVIATION WEATHER FOR THE DURATION OF THE FORECAST PERIOD. MAIN CONCERN IS SMOKE DRIFTING SOUTHEAST TOWARD THE STATE FROM CANADIAN WILDFIRES. THIS MAY PRODUCE SOME REDUCTION IN VISIBILITY THIS EVENING INTO THE OVERNIGHT AND HAVE PUT IN SOME HAZE FOR THE POTENTIAL. OTHERWISE...CEILINGS WILL REMAIN VFR WITH LIGHT AND VARIABLE WINDS THROUGH TONIGHT BECOMING SOUTHEAST ON THURSDAY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...COGIL LONG TERM...PODRAZIK AVIATION...COGIL  FXUS63 KDMX 112100 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 400 PM CDT FRI JUL 11 2014 .SHORT TERM /TONIGHT/... ISSUED AT 355 PM CDT FRI JUL 11 2014 FORECAST ISSUE DEALT WITH THUNDERSTORM DEVELOPMENT LATE THIS EVENING INTO SATURDAY MORNING OVER THE CENTRAL TO NORTHERN SECTIONS OF THE FORECAST AREA. LEANED TOWARD A BLEND OF THE 11.12Z HIRES ARW/NMM EAST...11.17Z HRRR...11.12Z 4KM WRF AND NAM12/ECMWF FOR POPS AND TIMING OF CONVECTION. HENCE...MODELS WERE IN GOOD AGREEMENT THROUGH TOMORROW MORNING. GOOD MOISTURE TRANSPORT AND THETA-E ADVECTION ALONG WITH MODERATELY UNSTABLE ENVIRONMENT TONIGHT INTO SATURDAY MORNING ACROSS CENTRAL TO NORTHERN IOWA WILL LEAD TO THE POTENTIAL FOR HEAVY RAIN. THE STRONGEST MOISTURE CONVERGENCE SETS UP WEST-TO-EAST BETWEEN INTERSTATE 80 TO HIGHWAY 18 CORRIDORS WITH THE BEST FORCING FROM THE NEXT SHORTWAVE MOVING ACROSS THE STATE AFTER 07Z SATURDAY. THE LLJ MAX REMAINS IN SOUTH-CENTRAL NEBRASKA OVERNIGHT BUT THE NOSE EXTENDS FAR ENOUGH EAST TO ALLOW FOR DECENT DIVERGENCE ALOFT TO AID IN LONGEVITY OF CONVECTION OVERNIGHT. WARM LAYER CLOUD DEPTHS DEEPEN TO AROUND 13KFT BY 03Z-06Z SATURDAY WITH PRECIPITABLE WATER VALUES IN THE 1.5-2.0 INCH RANGE. HAVE MENTION OF HEAVY RAIN PAST 06Z TONIGHT ALONG AND NORTH OF INTERSTATE 80 AND INCREASED QPF AMOUNTS FROM 06Z- 12Z SATURDAY. WENT SLIGHTLY COOLER THAN THE NAM/GFS/SREF FOR MINIMUM TEMPERATURES TONIGHT WITH MUCH OF THE AREA LIKELY TO BE RAIN COOLED. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 355 PM CDT FRI JUL 11 2014 TWO PRIMARY CONCERNS WILL BE CONVECTIVE TRENDS SAT AND SAT NIGHT... AND COOLER TEMPERATURES EARLY NEXT WEEK. MCS IS EXPECTED TO BE IN PROGRESS AT THE BEGINNING OF THE PERIOD /12Z/ INTO AT LEAST WRN IA DRIVEN BY EVENTUALLY COMBINED FORCING ASSOCIATED WITH CURRENT NOTED UT/WY SHORT WAVE/PV ANOMALY AND NRN STREAM SHORT WAVE ALONG WRN U.S./CANADIAN BORDER. ALTHOUGH THERE MAY VERY WELL BE A TYPICAL BREAK OR LULL BETWEEN OVERNIGHT NOCTURNAL MCS AND LATE AFTERNOON REDEVELOPMENT...PHASED ASCENT GENERATED BY THE TWO FEATURES SHOULD AGAIN INCREASE PEAK HEATING SURFACE BASED CONVECTION DURING THE LATE AFTERNOON AND EARLY EVENING HOURS. DIFFERENTIAL HEATING ALONG MORNING MCS OUTFLOW AND/OR CONVERGENCE OF THE SYNOPTIC SCALE BOUNDARY SHOULD PROVIDE THE FOCUS. NAM/GFS MLCAPES SUGGEST VALUES WELL OVER 2K J/KG TOWARD 00Z WITH LITTLE CINH DUE TO MID LEVEL FORCING AND HIGH SURFACE THETA-E VALUES. HI RES CONVECTION ALLOWING MODELS ARE IN GOOD AGREEMENT WITH UPSTREAM SIOUXLAND CONVECTION MERGING WITH NEW DEVELOPMENT ALONG THE BOUNDARY 21-00Z AND THEN EXITING SERN SECTIONS AROUND 09Z. DEEP SHEAR IS MORE THAN ADEQUATE FOR ORGANIZATION AND POTENTIAL SUPERCELLS...AND LOW LEVEL SHEAR IS ADEQUATE AS WELL SO ALL MODELS OF SEVERE WEATHER ARE POSSIBLE. SPC SSEO DOES DEPICT INCREASING UPDRAFT HELICITY TOWARD 00Z. HEAVY RAIN PARAMETERS ARE EVEN MORE IMPRESSIVE WITH PWS AT OR ABOVE 2 INCHES...WARM CLOUD DEPTHS OVER 4KM AND K INDICES AROUND 40. EXPECT LOCALLY HEAVY RAINS...BUT HOPEFULLY PROGRESSIVE ENOUGH TO SOMEWHAT REDUCE FLASH FLOODING POTENTIAL AS MEAN WIND...CORFIDI VECTORS AND BUNKERS SUPERCELL MOTION WOULD SUGGEST SUFFICIENT SEWD MOVEMENT. SIGNIFICANT CONVECTIVE POTENTIAL SHOULD THEN END INTO SUN WITH DEPARTING INSTABILITY AXIS. WEAKER CONVECTION MAY DRIFT N-S THROUGH IA SUN AND THEN AGAIN MORE SO MON WITH MORE SIGNIFICANT MID LEVEL FORCING AND APPROACH OF LONG WAVE TROUGH AXIS. THIS WILL CHANGE OUR SENSIBLE WEATHER TO A COOL AND DRY REGIME WITH POPS ENDING BY MON NIGHT. GEFS/NAEFS TEMP ANOMALIES ARE SIGNIFICANTLY NEGATIVE...BELOW 4 SDS AT TIMES...SO CURRENT NEAR RECORD TEMP WORDING WILL STAY INTACT AND THE FORECAST COULD VERY WELL NOT BE AGGRESSIVE ENOUGH CONSIDERING THE MAGNITUDE OF THE ANOMALIES. REMAINDER OF THE EXTENDED WILL REMAIN COOL AND DRY WITH RELATIVELY INACTIVE NW FLOW AND LITTLE FORCING. THERE MAY BE A FEW WINDOWS OF WEAK PEAK HEATING CONVECTION...BUT WITH LITTLE CONVERGENCE DID NOT FEEL IT WAS JUSTIFIED TO MENTION YET. && .AVIATION...11/18Z ISSUED AT 1236 PM CDT FRI JUL 11 2014 GENERALLY VFR CONDITIONS FORECAST TONIGHT INTO SATURDAY BUT WITH RAIN/TSTMS DEVELOPING LATE TONIGHT HAVE MVFR CIGS/VIS MENTIONED AT MCW/FOD/ALO AS HIGHER CONFIDENCE IN THESE LOCATIONS THAT WILL RECEIVE AN EXTENDED PERIOD OF RAIN OVERNIGHT. DSM/OTM MAY SEE RAIN BY SATURDAY MORNING AND THERE IS POTENTIAL FOR MVFR AND EVEN IFR CONDITIONS...BUT LOW CONFIDENCE IN TIMING AND DURATION. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...SMALL AVIATION...PODRAZIK  FXUS63 KDMX 122030 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 330 PM CDT SAT JUL 12 2014 .SHORT TERM /TONIGHT/... ISSUED AT 326 PM CDT SAT JUL 12 2014 MAIN CHALLENGE THIS PERIOD WILL BE EXTENT OF CONVECTION AND SEVERE THREAT. MOST OF THE SYNOPTIC SCALE MODELS CONTINUE TO INDICATE CONVERGENCE AND INSTABILITY SHOULD BE SUFFICIENT TO INITIATE CONVECTION BETWEEN 3 TO 5 PM OVER CENTRAL IOWA BETWEEN US 20 AND US 30 THIS AFTERNOON...THEN SWINGING ACTIVITY OVER THE REMAINDER OF THE AREA BETWEEN 5 PM AND 3 AM. SOME OF THE MESO MODELS AT ODDS WITH MORE FOCUS ON BANDING SHOWERS/ISO THUNDER NORTH OF US 20 AND SOME ADDITIONAL DEVELOPMENT OVER THE FAR SOUTH... ESPECIALLY NEARER 06Z ALONG THE IA/MO BORDER WHEN LOW LEVEL JET INCREASES ACROSS EXITING BOUNDARY. CURRENT MESO ANALYSIS SHOWS THE SOUTH HALF NEARLY UNCAPPED WITH 3000 TO 3500 J/KG SBCAPE AND INCREASING SFC CONVERGENCE ALONG BOUNDARY DRIFTING SOUTH AND CURRENTLY LOCATED FROM EAST OF MASON CITY SOUTHWEST TO ABOUT OMAHA. H700 TEMPS SUGGEST WEAK CAP OF 10C AT THAT LEVEL FOR NOW...BUT EXPECT THAT TO WEAKEN YET BY LATE AFTERNOON. EFFECTIVE BULK SHEAR SUFFICIENT FOR SUPERCELL DEVELOPMENT. SOUNDINGS ACROSS THE SOUTH SHOW SOME DRYING AROUND H700 SO EXPECT THAT WIND WILL REMAIN THE GREATER THREAT THIS AFTERNOON/EVENING ALONG WITH AN ISOLATED TORNADO. 0-3KM CAPE ALREADY NEAR 125 J/KG WITH LCL HTS NEAR 1000 TO 1250 M OVER THE SOUTH AS WELL. WITH WARM CLOUD DEPTHS APPROACHING 15 KFT AND PRECIPITABLE WATER QUITE HIGH AT 2 TO 2.25 INCHES AVAILABLE THROUGH THE EVENING SOUTH HALF THERE WILL BE A POTENTIAL FOR A QUICK RAINFALL TOTAL OF +2 INCHES WITH ANY OF THE STRONGER STORMS. ALONG WITH THAT...A POTENTIAL FOR LOCALIZED WATER ISSUES AND POSSIBLE FLASH FLOODING REMAINS. CONFIDENCE ON WIDESPREAD HEAVY RAINFALL COVERAGE REMAINS TOO LOW FOR A FLASH FLOOD WATCH. WITH RATHER WEAK CONVERGENCE AND THUNDERSTORM DEVELOPMENT CONDITIONAL ON CAP BREAKING...WILL KEEP THUNDER CHANCES AT SLIGHT/CHANCE CATEGORY THROUGH MID AFTERNOON SOUTH AND THEN INCREASE POP THROUGH 23-03Z TIME FRAME. ACROSS THE NORTH ACTIVITY SHOULD BE NEARING AN END AROUND 00Z-02Z. LOOKING AT ALL THE DATA...FEEL THE HRRR AND HOP WRF MAY BE TOO PESSIMISTIC WITH LACK OF THUNDER DEVELOPMENT ACROSS THE WARM SECTOR. LATEST 4 KM WRF SHOWS INCREASING COVERAGE FROM US 20 SOUTH THIS AFTERNOON...MATCHING UP BETTER WITH THE SYNOPTIC SCALE SOLUTIONS. LOWS TONIGHT WILL DROP TO NEAR 60 NORTH AND IN THE UPPER 60S SOUTH AS COOLER AIR FILTERS INTO THE REGION BY SUNDAY MORNING. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 326 PM CDT SAT JUL 12 2014 MAIN CONCERN REMAINS FOCUSED ON UNSEASONABLY COLD TEMPERATURES TO FILTER INTO THE STATE MONDAY THROUGH WEDNESDAY...AND THEN MILD AND DRY CONDITIONS THROUGH THE END OF THE WORK WEEK. SUNDAY INTO MONDAY...SECONDARY TROUGH/COLD FRONT LOOKS TO PUSH ACROSS THE STATE ON SUNDAY AND MAY BRING A FEW LIGHT SHOWERS AND AN ISOLATED THUNDERSTORMS IN THE AFTERNOON WITH SOME MARGINAL INSTABILITY RECOVERING FROM CONVECTION TONIGHT. SURFACE DEWPOINTS LOOK TO BE ABOUT 10 DEGREES LESS THAN TODAY BUT ENOUGH MOISTURE AVAILABLE COMBINED WITH WEAK FORCING WITH BOUNDARY MOVING THROUGH...SO KEPT SLIGHT POPS GOING IN THE AFTERNOON SUNDAY. ANOTHER STRONGER COLD FRONT TO BRING THE WELL ANTICIPATED UNSEASONABLY COOL TEMPERATURES WILL PUSH THROUGH THE STATE DURING THE DAY MONDAY. GOOD MIXING BEHIND THE FRONT BY THE AFTERNOON AND TWEAKED UP WINDS SLIGHTLY. LOW CONFIDENCE WITH MENTION THE NON- DIURNAL TEMP TREND ON MONDAY WITH THE CAA AS SUN ANGLE STILL HIGH ENOUGH TO WARM TEMPS UP IN THE AFTERNOON. TUESDAY THROUGH SATURDAY...VERY COLD AIRMASS FOR THIS TIME OF YEAR TO FILTER INTO THE STATE AS 850MB TEMPS DROP TO +5C TO +6C BY EARLY TUESDAY MORNING. KEPT MENTION OF NEAR RECORD LOWS FOR TUESDAY MORNING AS SURFACE RIDGE LOOKS TO BE CENTERED OVER EASTERN IOWA INTO THE WESTERN GREAT LAKES BY 12Z TUESDAY AND EXPECTING DECENT RADIATIONAL COOLING TO DEVELOP. SURFACE DEWPOINTS DROP TO AROUND 50F BY TUESDAY MORNING AND WITH THE RADIATION COOLING EVENT...COULD SEE SOME SHALLOW FOG DEVELOP IF WINDS DROP OFF ENTIRELY. SOMETHING TO CONSIDER WITH NEXT FORECAST PACKAGE. COOL AIRMASS REMAINS IN PLACE THROUGH MUCH OF THE WORK WEEK BEFORE IT BEGINS MODERATE BACK TO NORMAL TEMPERATURES BY FRIDAY INTO SATURDAY OF NEXT WEEK. NO SIGNIFICANT SYSTEM TO BRING PRECIPITATION TO CENTRAL IOWA FROM MID TO LATE WEEK NEXT WEEK. && .AVIATION...12/18Z ISSUED AT 105 PM CDT SAT JUL 12 2014 FRONTAL BOUNDARY DRIFTING SOUTH THIS AFTERNOON AND EVENING. SHRA CONTINUE ALONG THE BOUNDARY OVER NORTHERN IOWA WITH GENERALLY UNSTABLE CONDITIONS DEVELOPING ACROSS THE SOUTH. EXPECTING LINE OF SHOWERS TO BECOME MORE CONVECTIVE THIS AFTERNOON WITH POTENTIAL FOR BRIEF PERIOD OF HEAVIER RAINFALL AND MVFR VSBY. TIMING FOR NORTHERN AREAS BETWEEN 19 AND 00Z...FROM US 20 SOUTH TO HIGHWAY 30...22Z THROUGH 03Z AND SOUTH OF HIGHWAY 30 FROM 23Z THROUGH 06Z. BEST CHANCES FOR SVR CONVECTION WILL BE FOR KDSM AND KOTM AS MAX INSTABILITY EXPECTED THERE FROM 21Z THROUGH 03Z. SVR THREAT MOST LIKELY WIND GUSTS ABOVE 45 TO 50 KTS. HAVE NOT ADDED TO TAFS AT THIS TIME...DUE TO TIMING/UNCERTAINTY CONSIDERATIONS...BUT WILL MONITOR/ADD AS NEEDED WHEN TRENDS BECOME MORE EVIDENT. AFT 06Z MOST AREA WILL BE VFR WITH LIGHT NW WINDS BECOMING 10-15KTS AFT 15Z SUNDAY... ESPECIALLY NORTH HALF. /REV && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...REV LONG TERM...PODRAZIK AVIATION...REV  FXUS63 KDMX 201751 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1151 AM CST TUE JAN 20 2015 ...UPDATED FOR 18Z AVIATION FORECAST DISCUSSION... .SHORT TERM /TODAY/... ISSUED AT 313 AM CST TUE JAN 20 2015 THE FIRST SHORTWAVE THAT AFFECTED IOWA YESTERDAY INTO THE OVERNIGHT IS PUSHING OFF TO THE EAST. THERE WERE PATCHES OF A LIGHT WINTRY MIX OF PRECIP WITH THIS FIRST WAVE AND SOME LOWER CLOUD COVER IN ITS WAKE BUT LITTLE ELSE TO SPEAK OF. THE CLOUD COVER HELPED TO MAINTAIN TEMPERATURES ACROSS THE NORTH. THE NEXT WAVE IS POISED TO SWEEP ACROSS MAINLY NORTHERN AND EASTERN IOWA LATER THIS AFTERNOON AND TONIGHT. THE BEST MID LEVEL FORCING WILL ENTER NORTHERN IOWA AROUND OR SHORTLY AFTER 12Z THEN PUSH SOUTHEAST THROUGH 18Z. WEAKER FORCING WILL FOLLOW THROUGH THE REMAINDER OF THE DAY OVER NORTHERN AND EASTERN IOWA. BETTER LOW LEVEL FORCING BRUSHES THE FAR NORTHEAST LATER THIS AFTERNOON AND TONIGHT. LOOKING AT SOUNDINGS...LOW LEVEL MOISTURE IS QUITE SUFFICIENT AND DEEPER MOISTURE TRIES TO OCCUR AS SOUNDINGS TRY TO SATURATE THROUGH THE MORNING. MASON CITY LOOKED MORE IMPRESSIVE WITH TRYING TO SATURATE THAN OTHER FORECAST SOUNDINGS ACROSS THE NORTH BUT THE PROBLEM IS THAT THERE IS NO ICE INTRODUCTION UNTIL WE GET INTO LATE AFTERNOON AND ESPECIALLY THIS EVENING. GIVEN THE FORCING INVOLVED THE LOW LEVEL MOISTURE IN PLACE LIGHT PRECIP IS EXPECTED. HOWEVER THE SCENARIO LOOKS MORE LIKE ONE OF DRIZZLE OR FREEZING DRIZZLE AT LEAST INITIALLY. THEN THERE MAY BE BRIEF PERIODS OF RAIN OR FREEZING RAIN BUT TEMPERATURES HAVE STABILIZED UP THERE IN THE MID 30S AND ARE NOT EXPECTED TO FALL MUCH AND FOR VERY LONG. ALL THE SHORT TERM AND HI-RES MODELS ONLY SUGGEST TOKEN QPF ACROSS THE NORTH AND MAINLY DURING THE LATE AFTERNOON ALTHOUGH THEY ALSO HINT AT VERY LIGHT HIT OR MISS PRECIP FROM MID MORNING THROUGH THE EARLY AFTERNOON. AS A RESULT OF TEMPS BEING BRIEFLY NEAR FREEZING AND ONLY VERY LIGHT QPF...WE ARE NOT LOOKING AT MUCH IF ANY ICING TO OCCUR THROUGH THE MORNING. BY LATE MORNING OR AFTERNOON TEMPS WILL JUST BE TOO WARM SO LIQUID PRECIP IS ALL THAT IS EXPECTED. SOMETIME AFTER 21Z AS THE COLUMN SATURATES AND BEGINS TO COOL WE WILL START GETTING ICE INTRODUCTION WHICH WILL LEAD TO SOME SNOW DEVELOPMENT THAT WILL BECOME MORE PREVALENT TONIGHT. EXPECTED SNOWFALL THROUGH THE AFTERNOON WILL NOT BE MORE THAN A COUPLE OF TENTHS OF AN INCH. THE BETTER ACCUMULATIONS WILL OCCUR TONIGHT. I DO EXPECT MORE CLOUD COVER TO EXPAND ACROSS CENTRAL IOWA THROUGH THE DAY SO TEMPS WILL NOT BE AS WARM AS WE HAVE SEEN THE LAST FEW DAYS BUT ABOVE FREEZING NONETHELESS. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 313 AM CST TUE JAN 20 2015 LOW PRESSURE WILL TRACK SOUTHEAST CROSS THE NERN PART OF THE CWA TONIGHT...LEAVING MUCH OF IA IN THE PACIFIC AIR WITH LITTLE CHANCE FOR PRECIPITATION. WILL GO WITH LIKELY POPS OVER THE NEAR ZONES WITH AN INCH OR SO SNOW EXPECTED NORTH OF THE LOW PRESSURE TRACK. HIGH PRESSURE MOVES IN FOR THE LAST PART OF THE WEEK WITH PACIFIC AIR REMAINING DOMINANT. TEMPS WILL REMAIN ABOVE NORMAL...ESPECIALLY OVER THE SNOW FREE SOUTHWEST COUNTIES. THE NEXT CLIPPER TYPE SYSTEM WILL MOVE INTO THE UPPER MIDWEST THIS WEEKEND. THE ASSOCIATED WAVE IS STRONGER THEN THE CURRENT WAVES IN THE SERIES. THE ECMWF IS MORE AGGRESSIVE WITH THE PRECIP AREA WITH THIS SYSTEM. FEELING IS WITH CONSISTENCY IN THE MODELS BEING THAT THE UPPER LOW WILL ATTEMPT TO CLOSE OFF...THE CHANCE FOR SNOW WILL NEED TO BE INCREASED. IF IT APPEARS THIS CONSISTENCY REMAINS...WOULD EXPECT THE CHANCES OVER NORTHEAST IA ARE AT LEAST IN THE LIKELY CATEGORY WITH THE REST OF THE STATE LIKELY TO HAVE A BETTER CHANCE AS WELL. NO REAL BIG COOLING IN THE OFFING FOR RIGHT NOW...THOUGH IT WILL GRADUALLY COOL AFTER THE MILD HIGHS ON FRI AND SAT. MUCH OF THE REAL COLD AIR IS LIKELY TO BE SHUNTED OFF UNTIL WE GET TOWARD THE MIDDLE OF NEXT WEEK. THOUGH COLDER...SIGNIFICANT SPLITS REMAIN IN THE JET STREAM...ENOUGH TO KEEP A ALL OUT SHIFT INTO ARCTIC AIR. && .AVIATION...20/18Z ISSUED AT 1139 AM CST TUE JAN 20 2015 PERFORMED MAJOR OVERHAUL OF TAFS FROM 12Z PACKAGE. KMCW...KALO...AND KFOD ARE TAF SITES TO WATCH AS WEAK SFC LOW SLATED TO MOVE ACROSS MN/IA/WI BORDER...IMPACTING SITES MAINLY FROM 00Z TO 12Z TIMEFRAME. CLOUDS BASES TO LOWER DURING THIS TIME. FOR NOW...HAVE KEPT MVFR THROUGH KMCW AND KFOD. KALO IN BRIEF IFR AS LOW NEARS. CLOUD THICKNESS ONLY REACHING 7000FT OR SO WHICH WILL HELP KEEP PRECIP LIGHT. WILL KEEP PRECIP ON -RA TO -RASN BEFORE 03Z AS ICE INTRODUCTION VERY WEEK THROUGH THIS TIME. FROM 03Z UNTIL AROUND 12Z EXPECT LIGHT -RASN TO -SN. VSBYS WILL HAVE TO BE WATCHED AS WELL. WITH WINDS AROUND 5 TO 7 KTS AND PRECIP INTENSITY EXPECTED TO BE LIGHT...HAVE VSBY REDUCED TO 2 TO 3 MILES. KEEPING MVFR THROUGH END OF TAF PERIOD AS ST DECK LOOKS VERY LIKELY INTO THURSDAY. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...FAB LONG TERM...MS JAN 15 AVIATION...KOTENBERG  FXUS63 KDMX 202151 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 351 PM CST TUE JAN 20 2015 .SHORT TERM /TONIGHT/... ISSUED AT 351 PM CST TUE JAN 20 2015 MAIN DRIVER OF SHORT TERM WX IS A WEAK CYCLONE WHICH IS SLATED TO CONTINUE TO PROPAGATE SOUTHEASTWARD FROM THE DAKOTAS THROUGH SOUTHERN MINNESOTA AND MAKE IT ACROSS NORTHEASTERN IA BY 12Z TONIGHT. 925MB HEIGHT FIELD PICKS UP THIS FEATURE VERY WELL. MODELS IN GOOD AGREEMENT WITH PROGRESSION OF THIS SYSTEM. THEY ALL SHOW A BROAD AREA OF MID LEVEL Q-VECTOR CONVERGENCE PROVIDE SOME LIFT ALOFT. CLOSER TO THE SFC IS WHERE SYSTEM LOSES SUPPORT. LOW LEVEL FRONTOGENESIS IS LITTLE TO NONE. FCST SOUNDINGS SHOW CLOUD DEPTHS OF LESS THAN 5000FT BEFORE 22Z WED...WHICH WOULD KEEP ANY PRECIP AS LIGHT DRIZZLE. CLOUD THICKNESS TO INCREASE TO AROUND 7500FT AFTER 00Z...WHICH WOULD HELP INCREASE DROPLET SIZE PAST DRIZZLE. TEMPS WILL PLAY A HUGE FACTOR IN P-TYPES TODAY AND TONIGHT. LOOKING AT INITIALIZATION...THE GFS IS WAY UNDER-DOING MOISTURE IN THE LOW LEVELS OF THE ATMOS. THIS UNDER-EVALUATION CARRIES ITSELF THROUGH THE SHORT TERM AND IS REFLECTED IN THE GFS FCST SOUNDINGS. THEREFORE...HAVE HEAVILY LEANED AWAY FROM THE GFS AND TOWARDS THE RUC AND NAM FCST SOUNDINGS...WHICH HAVE SEEMED TO HANDLE ST DECK EVOLUTION AND TEMPS COMPARATIVELY BETTER THROUGH THIS AFTERNOON. AT THE EARLIEST...KMCW AND KALO FCST SOUNDINGS NOT SHOWING ICE INTRODUCTION UNTIL AROUND 00Z-03Z TONIGHT. PUTTING IT ALL TOGETHER...AM EXPECTING P-TYPE TO START ON THE -RA SIDE OF THE -RASN SPECTRUM AT AROUND FROM 00Z TO 03Z ACROSS OUR FAR NORTH. SFC TEMPS SHOULD BECOME COOL ENOUGH FROM 04Z-10Z OR SO TO TRANSITION TO A MORE -SN P-TYPE ALONG HIGHWAY 30...WITH A -RASN MIX REMAINING THROUGH KMIW. ROEBBER SNOW RATIOS POINTING TOWARDS 14:1 TO 13:1 FOR KMCW AND KALO AND HAVE LEANED TOWARDS THESE VALUES. IMPACTS SHOULD BE ON THE LIGHTER SIDE AS WINDS SHOULD NOT BE STRONG DURING PERIODS OF SNOW...KEEPING VSBYS IN THE 2 TO 3 SM RANGE. THEREFORE HEADLINES NOT WARRANTED AT THIS TIME. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 351 PM CST TUE JAN 20 2015 LIGHT NORTHWEST FLOW WILL PERSIST ON WEDNESDAY AND WEDNESDAY NIGHT AS ONE LAST WEAK LOBE MOVES THROUGH THE DEPARTING 500 MB TROUGH. FORECAST SOUNDINGS INDICATE SHALLOW MOISTURE SUFFICIENT TO GENERATE LIGHT PRECIPITATION GIVEN THE WEAK LIFT ASSOCIATED WITH THIS FEATURE. TEMPERATURE FORECAST DURING THIS PERIOD IS TRICKY WITH STRATUS IN PLACE AND ONLY WEAK COLD AIR ADVECTION...BUT SOME MIX OF RAIN AND SNOW IS LIKELY WITH SNOW THE PREDOMINANT P-TYPE ACROSS OUR NORTHERN COUNTIES AND PERIODS OF DRIZZLE OR FREEZING DRIZZLE POSSIBLE. IN ANY EVENT ACCUMULATIONS WILL BE LIGHT WITH AROUND AN INCH OR SO IN THE NORTH TAPERING TO NOTHING FURTHER SOUTH...AND WINDS WILL BE LIGHT SO LITTLE IMPACT IS ANTICIPATED AS LONG AS ROAD ICING IS AVOIDED. FROM THURSDAY INTO FRIDAY A BRIEF SPELL OF RIDGING WILL OCCUR...LEAVING TO WARMER TEMPERATURES BY FRIDAY AFTERNOON THOUGH THIS WILL BE TEMPERATED BY A RELATIVE LACK OF WARM AIR ALOFT TO MIX DOWN. EVEN SO...HIGHS SHOULD GET INTO THE 40S ACROSS MOST OR ALL OF THE AREA BEFORE A WEAK SURFACE TROUGH MOVES THROUGH AROUND FRIDAY EVENING. BY SATURDAY IOWA WILL RESIDE BENEATH NORTHWESTERLY 500 MB FLOW ON THE WESTERN FLANK OF A DEEP TROUGH LYING ALONG THE APPALACHIANS. A COMPACT BUT VERY ENERGETIC SHORTWAVE WILL THEN ROCKET DOWN THIS FLOW FROM CANADA ACROSS MINNESOTA AND OVER IOWA SOMETIME SATURDAY NIGHT OR SUNDAY. ALL INDICATIONS ARE THAT THIS FEATURE...REFLECTED IN A QUICKLY DEVELOPING SURFACE LOW PRESSURE CENTER...WILL PRODUCE A LOW CLOUD AND PRECIPITATION SHIELD ESPECIALLY ON THE EASTERN HALF OF ITS CIRCULATION. HOWEVER...THERE ARE STILL UNCERTAINTIES REGARDING HOW FAR EAST OR WEST THIS LOW WILL TRACK AND WHAT PERIOD WILL BE MOST LIKELY TO SEE PRECIP...SO HAVE HELD ONTO CHANCE POPS FOR NOW. IT WILL ALSO BE A MIXED PRECIPITATION SYSTEM...LIKELY STARTING AS RAIN ACROSS OUR FORECAST AREA BEFORE TURNING TO SNOW AFTER THE LOW MOVES OVER. THE DETAILS OF TIMING THIS RAIN TO SNOW CHANCE AND RESULTING SNOW AMOUNTS WILL LIKELY NOT BE CLEAR FOR A FEW DAYS YET. LOOKING INTO EARLY NEXT WEEK...IT IS PROBABLE THAT A SURFACE HIGH WILL MOVE THROUGH IN THE WAKE OF THE SUNDAY LOW PRESSURE SYSTEM...WHILE NORTHWEST FLOW IS MAINTAINED ALOFT. THIS SHOULD RESULT IN SOMEWHAT COOLER WEATHER ESPECIALLY IF ANY SNOW COVER IS ESTABLISHED WITH THE SUNDAY SYSTEM...BUT IF THE STORM TRACK IS A BIT FURTHER EAST OR WE MISS OUT ON ACCUMULATING SNOWFALL THEN ANY COOL DOWN WILL BE SIGIFICANTLY MODERATED. && .AVIATION...20/18Z ISSUED AT 1139 AM CST TUE JAN 20 2015 PERFORMED MAJOR OVERHAUL OF TAFS FROM 12Z PACKAGE. KMCW...KALO...AND KFOD ARE TAF SITES TO WATCH AS WEAK SFC LOW SLATED TO MOVE ACROSS MN/IA/WI BORDER...IMPACTING SITES MAINLY FROM 00Z TO 12Z TIMEFRAME. CLOUDS BASES TO LOWER DURING THIS TIME. FOR NOW...HAVE KEPT MVFR THROUGH KMCW AND KFOD. KALO IN BRIEF IFR AS LOW NEARS. CLOUD THICKNESS ONLY REACHING 7000FT OR SO WHICH WILL HELP KEEP PRECIP LIGHT. WILL KEEP PRECIP ON -RA TO -RASN BEFORE 03Z AS ICE INTRODUCTION VERY WEEK THROUGH THIS TIME. FROM 03Z UNTIL AROUND 12Z EXPECT LIGHT -RASN TO -SN. VSBYS WILL HAVE TO BE WATCHED AS WELL. WITH WINDS AROUND 5 TO 7 KTS AND PRECIP INTENSITY EXPECTED TO BE LIGHT...HAVE VSBY REDUCED TO 2 TO 3 MILES. KEEPING MVFR THROUGH END OF TAF PERIOD AS ST DECK LOOKS VERY LIKELY INTO THURSDAY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...KOTENBERG LONG TERM...LEE AVIATION...KOTENBERG  FXUS63 KDMX 202343 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 543 PM CST TUE JAN 20 2015 .SHORT TERM /TONIGHT/... ISSUED AT 351 PM CST TUE JAN 20 2015 MAIN DRIVER OF SHORT TERM WX IS A WEAK CYCLONE WHICH IS SLATED TO CONTINUE TO PROPAGATE SOUTHEASTWARD FROM THE DAKOTAS THROUGH SOUTHERN MINNESOTA AND MAKE IT ACROSS NORTHEASTERN IA BY 12Z TONIGHT. 925MB HEIGHT FIELD PICKS UP THIS FEATURE VERY WELL. MODELS IN GOOD AGREEMENT WITH PROGRESSION OF THIS SYSTEM. THEY ALL SHOW A BROAD AREA OF MID LEVEL Q-VECTOR CONVERGENCE PROVIDE SOME LIFT ALOFT. CLOSER TO THE SFC IS WHERE SYSTEM LOSES SUPPORT. LOW LEVEL FRONTOGENESIS IS LITTLE TO NONE. FCST SOUNDINGS SHOW CLOUD DEPTHS OF LESS THAN 5000FT BEFORE 22Z WED...WHICH WOULD KEEP ANY PRECIP AS LIGHT DRIZZLE. CLOUD THICKNESS TO INCREASE TO AROUND 7500FT AFTER 00Z...WHICH WOULD HELP INCREASE DROPLET SIZE PAST DRIZZLE. TEMPS WILL PLAY A HUGE FACTOR IN P-TYPES TODAY AND TONIGHT. LOOKING AT INITIALIZATION...THE GFS IS WAY UNDER-DOING MOISTURE IN THE LOW LEVELS OF THE ATMOS. THIS UNDER-EVALUATION CARRIES ITSELF THROUGH THE SHORT TERM AND IS REFLECTED IN THE GFS FCST SOUNDINGS. THEREFORE...HAVE HEAVILY LEANED AWAY FROM THE GFS AND TOWARDS THE RUC AND NAM FCST SOUNDINGS...WHICH HAVE SEEMED TO HANDLE ST DECK EVOLUTION AND TEMPS COMPARATIVELY BETTER THROUGH THIS AFTERNOON. AT THE EARLIEST...KMCW AND KALO FCST SOUNDINGS NOT SHOWING ICE INTRODUCTION UNTIL AROUND 00Z-03Z TONIGHT. PUTTING IT ALL TOGETHER...AM EXPECTING P-TYPE TO START ON THE -RA SIDE OF THE -RASN SPECTRUM AT AROUND FROM 00Z TO 03Z ACROSS OUR FAR NORTH. SFC TEMPS SHOULD BECOME COOL ENOUGH FROM 04Z-10Z OR SO TO TRANSITION TO A MORE -SN P-TYPE ALONG HIGHWAY 30...WITH A -RASN MIX REMAINING THROUGH KMIW. ROEBBER SNOW RATIOS POINTING TOWARDS 14:1 TO 13:1 FOR KMCW AND KALO AND HAVE LEANED TOWARDS THESE VALUES. IMPACTS SHOULD BE ON THE LIGHTER SIDE AS WINDS SHOULD NOT BE STRONG DURING PERIODS OF SNOW...KEEPING VSBYS IN THE 2 TO 3 SM RANGE. THEREFORE HEADLINES NOT WARRANTED AT THIS TIME. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 351 PM CST TUE JAN 20 2015 LIGHT NORTHWEST FLOW WILL PERSIST ON WEDNESDAY AND WEDNESDAY NIGHT AS ONE LAST WEAK LOBE MOVES THROUGH THE DEPARTING 500 MB TROUGH. FORECAST SOUNDINGS INDICATE SHALLOW MOISTURE SUFFICIENT TO GENERATE LIGHT PRECIPITATION GIVEN THE WEAK LIFT ASSOCIATED WITH THIS FEATURE. TEMPERATURE FORECAST DURING THIS PERIOD IS TRICKY WITH STRATUS IN PLACE AND ONLY WEAK COLD AIR ADVECTION...BUT SOME MIX OF RAIN AND SNOW IS LIKELY WITH SNOW THE PREDOMINANT P-TYPE ACROSS OUR NORTHERN COUNTIES AND PERIODS OF DRIZZLE OR FREEZING DRIZZLE POSSIBLE. IN ANY EVENT ACCUMULATIONS WILL BE LIGHT WITH AROUND AN INCH OR SO IN THE NORTH TAPERING TO NOTHING FURTHER SOUTH...AND WINDS WILL BE LIGHT SO LITTLE IMPACT IS ANTICIPATED AS LONG AS ROAD ICING IS AVOIDED. FROM THURSDAY INTO FRIDAY A BRIEF SPELL OF RIDGING WILL OCCUR...LEAVING TO WARMER TEMPERATURES BY FRIDAY AFTERNOON THOUGH THIS WILL BE TEMPERATED BY A RELATIVE LACK OF WARM AIR ALOFT TO MIX DOWN. EVEN SO...HIGHS SHOULD GET INTO THE 40S ACROSS MOST OR ALL OF THE AREA BEFORE A WEAK SURFACE TROUGH MOVES THROUGH AROUND FRIDAY EVENING. BY SATURDAY IOWA WILL RESIDE BENEATH NORTHWESTERLY 500 MB FLOW ON THE WESTERN FLANK OF A DEEP TROUGH LYING ALONG THE APPALACHIANS. A COMPACT BUT VERY ENERGETIC SHORTWAVE WILL THEN ROCKET DOWN THIS FLOW FROM CANADA ACROSS MINNESOTA AND OVER IOWA SOMETIME SATURDAY NIGHT OR SUNDAY. ALL INDICATIONS ARE THAT THIS FEATURE...REFLECTED IN A QUICKLY DEVELOPING SURFACE LOW PRESSURE CENTER...WILL PRODUCE A LOW CLOUD AND PRECIPITATION SHIELD ESPECIALLY ON THE EASTERN HALF OF ITS CIRCULATION. HOWEVER...THERE ARE STILL UNCERTAINTIES REGARDING HOW FAR EAST OR WEST THIS LOW WILL TRACK AND WHAT PERIOD WILL BE MOST LIKELY TO SEE PRECIP...SO HAVE HELD ONTO CHANCE POPS FOR NOW. IT WILL ALSO BE A MIXED PRECIPITATION SYSTEM...LIKELY STARTING AS RAIN ACROSS OUR FORECAST AREA BEFORE TURNING TO SNOW AFTER THE LOW MOVES OVER. THE DETAILS OF TIMING THIS RAIN TO SNOW CHANCE AND RESULTING SNOW AMOUNTS WILL LIKELY NOT BE CLEAR FOR A FEW DAYS YET. LOOKING INTO EARLY NEXT WEEK...IT IS PROBABLE THAT A SURFACE HIGH WILL MOVE THROUGH IN THE WAKE OF THE SUNDAY LOW PRESSURE SYSTEM...WHILE NORTHWEST FLOW IS MAINTAINED ALOFT. THIS SHOULD RESULT IN SOMEWHAT COOLER WEATHER ESPECIALLY IF ANY SNOW COVER IS ESTABLISHED WITH THE SUNDAY SYSTEM...BUT IF THE STORM TRACK IS A BIT FURTHER EAST OR WE MISS OUT ON ACCUMULATING SNOWFALL THEN ANY COOL DOWN WILL BE SIGNIFICANTLY MODERATED. && .AVIATION...21/00Z ISSUED AT 542 PM CST TUE JAN 20 2015 CIGS WILL CONTINUE TO LOWER OVERNIGHT AS A SYSTEM MOVES IN FROM THE NORTHWEST. CIGS WILL BE WIDESPREAD IFR TO MVFR AFT 06Z WITH POTENTIAL TO REACH LIFR LATE. PRECIPITATION WILL ALSO INCREASE WITH DRIZZLE POSSIBLE EARLY THEN TRANSITIONING TO LIGHT SNOW OVERNIGHT WITH THE MOST WIDESPREAD ACTIVITY IMPACTING NORTHERN SITES. STRATUS SHIELD IS EXPECTED TO PERSIST MUCH OF WEDNESDAY. LIGHT WESTERLY WINDS EARLY WILL BECOME NORTHWEST AND BREEZY AT TIMES. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KOTENBERG LONG TERM...LEE AVIATION...DONAVON  FXUS63 KDMX 210541 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1141 PM CST TUE JAN 20 2015 .SHORT TERM /TONIGHT/... ISSUED AT 351 PM CST TUE JAN 20 2015 MAIN DRIVER OF SHORT TERM WX IS A WEAK CYCLONE WHICH IS SLATED TO CONTINUE TO PROPAGATE SOUTHEASTWARD FROM THE DAKOTAS THROUGH SOUTHERN MINNESOTA AND MAKE IT ACROSS NORTHEASTERN IA BY 12Z TONIGHT. 925MB HEIGHT FIELD PICKS UP THIS FEATURE VERY WELL. MODELS IN GOOD AGREEMENT WITH PROGRESSION OF THIS SYSTEM. THEY ALL SHOW A BROAD AREA OF MID LEVEL Q-VECTOR CONVERGENCE PROVIDE SOME LIFT ALOFT. CLOSER TO THE SFC IS WHERE SYSTEM LOSES SUPPORT. LOW LEVEL FRONTOGENESIS IS LITTLE TO NONE. FCST SOUNDINGS SHOW CLOUD DEPTHS OF LESS THAN 5000FT BEFORE 22Z WED...WHICH WOULD KEEP ANY PRECIP AS LIGHT DRIZZLE. CLOUD THICKNESS TO INCREASE TO AROUND 7500FT AFTER 00Z...WHICH WOULD HELP INCREASE DROPLET SIZE PAST DRIZZLE. TEMPS WILL PLAY A HUGE FACTOR IN P-TYPES TODAY AND TONIGHT. LOOKING AT INITIALIZATION...THE GFS IS WAY UNDER-DOING MOISTURE IN THE LOW LEVELS OF THE ATMOS. THIS UNDER-EVALUATION CARRIES ITSELF THROUGH THE SHORT TERM AND IS REFLECTED IN THE GFS FCST SOUNDINGS. THEREFORE...HAVE HEAVILY LEANED AWAY FROM THE GFS AND TOWARDS THE RUC AND NAM FCST SOUNDINGS...WHICH HAVE SEEMED TO HANDLE ST DECK EVOLUTION AND TEMPS COMPARATIVELY BETTER THROUGH THIS AFTERNOON. AT THE EARLIEST...KMCW AND KALO FCST SOUNDINGS NOT SHOWING ICE INTRODUCTION UNTIL AROUND 00Z-03Z TONIGHT. PUTTING IT ALL TOGETHER...AM EXPECTING P-TYPE TO START ON THE -RA SIDE OF THE -RASN SPECTRUM AT AROUND FROM 00Z TO 03Z ACROSS OUR FAR NORTH. SFC TEMPS SHOULD BECOME COOL ENOUGH FROM 04Z-10Z OR SO TO TRANSITION TO A MORE -SN P-TYPE ALONG HIGHWAY 30...WITH A -RASN MIX REMAINING THROUGH KMIW. ROEBBER SNOW RATIOS POINTING TOWARDS 14:1 TO 13:1 FOR KMCW AND KALO AND HAVE LEANED TOWARDS THESE VALUES. IMPACTS SHOULD BE ON THE LIGHTER SIDE AS WINDS SHOULD NOT BE STRONG DURING PERIODS OF SNOW...KEEPING VSBYS IN THE 2 TO 3 SM RANGE. THEREFORE HEADLINES NOT WARRANTED AT THIS TIME. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 351 PM CST TUE JAN 20 2015 LIGHT NORTHWEST FLOW WILL PERSIST ON WEDNESDAY AND WEDNESDAY NIGHT AS ONE LAST WEAK LOBE MOVES THROUGH THE DEPARTING 500 MB TROUGH. FORECAST SOUNDINGS INDICATE SHALLOW MOISTURE SUFFICIENT TO GENERATE LIGHT PRECIPITATION GIVEN THE WEAK LIFT ASSOCIATED WITH THIS FEATURE. TEMPERATURE FORECAST DURING THIS PERIOD IS TRICKY WITH STRATUS IN PLACE AND ONLY WEAK COLD AIR ADVECTION...BUT SOME MIX OF RAIN AND SNOW IS LIKELY WITH SNOW THE PREDOMINANT P-TYPE ACROSS OUR NORTHERN COUNTIES AND PERIODS OF DRIZZLE OR FREEZING DRIZZLE POSSIBLE. IN ANY EVENT ACCUMULATIONS WILL BE LIGHT WITH AROUND AN INCH OR SO IN THE NORTH TAPERING TO NOTHING FURTHER SOUTH...AND WINDS WILL BE LIGHT SO LITTLE IMPACT IS ANTICIPATED AS LONG AS ROAD ICING IS AVOIDED. FROM THURSDAY INTO FRIDAY A BRIEF SPELL OF RIDGING WILL OCCUR...LEAVING TO WARMER TEMPERATURES BY FRIDAY AFTERNOON THOUGH THIS WILL BE TEMPERATED BY A RELATIVE LACK OF WARM AIR ALOFT TO MIX DOWN. EVEN SO...HIGHS SHOULD GET INTO THE 40S ACROSS MOST OR ALL OF THE AREA BEFORE A WEAK SURFACE TROUGH MOVES THROUGH AROUND FRIDAY EVENING. BY SATURDAY IOWA WILL RESIDE BENEATH NORTHWESTERLY 500 MB FLOW ON THE WESTERN FLANK OF A DEEP TROUGH LYING ALONG THE APPALACHIANS. A COMPACT BUT VERY ENERGETIC SHORTWAVE WILL THEN ROCKET DOWN THIS FLOW FROM CANADA ACROSS MINNESOTA AND OVER IOWA SOMETIME SATURDAY NIGHT OR SUNDAY. ALL INDICATIONS ARE THAT THIS FEATURE...REFLECTED IN A QUICKLY DEVELOPING SURFACE LOW PRESSURE CENTER...WILL PRODUCE A LOW CLOUD AND PRECIPITATION SHIELD ESPECIALLY ON THE EASTERN HALF OF ITS CIRCULATION. HOWEVER...THERE ARE STILL UNCERTAINTIES REGARDING HOW FAR EAST OR WEST THIS LOW WILL TRACK AND WHAT PERIOD WILL BE MOST LIKELY TO SEE PRECIP...SO HAVE HELD ONTO CHANCE POPS FOR NOW. IT WILL ALSO BE A MIXED PRECIPITATION SYSTEM...LIKELY STARTING AS RAIN ACROSS OUR FORECAST AREA BEFORE TURNING TO SNOW AFTER THE LOW MOVES OVER. THE DETAILS OF TIMING THIS RAIN TO SNOW CHANCE AND RESULTING SNOW AMOUNTS WILL LIKELY NOT BE CLEAR FOR A FEW DAYS YET. LOOKING INTO EARLY NEXT WEEK...IT IS PROBABLE THAT A SURFACE HIGH WILL MOVE THROUGH IN THE WAKE OF THE SUNDAY LOW PRESSURE SYSTEM...WHILE NORTHWEST FLOW IS MAINTAINED ALOFT. THIS SHOULD RESULT IN SOMEWHAT COOLER WEATHER ESPECIALLY IF ANY SNOW COVER IS ESTABLISHED WITH THE SUNDAY SYSTEM...BUT IF THE STORM TRACK IS A BIT FURTHER EAST OR WE MISS OUT ON ACCUMULATING SNOWFALL THEN ANY COOL DOWN WILL BE SIGNIFICANTLY MODERATED. && .AVIATION...21/06Z ISSUED AT 1139 PM CST TUE JAN 20 2015 LIGHT SNOW WILL MOVE THROUGH THE NORTHERN SITES OVERNIGHT AND MAY LINGER ACROSS KMCW/KALO WELL INTO WEDNESDAY. BORDERLINE IFR/LIFR CIGS CURRENTLY OVER SOUTHERN MN AND WILL MOVE THROUGH THE NORTH WHILE LOWEST CIGS GENERALLY MVFR OVER THE SOUTH. GUSTY NORTHWEST WINDS AT KDSM/KOTM OVERNIGHT. WIDESPREAD MVFR OR LESS CIGS EXPECTED TO PERSIST THROUGH MUCH OF WEDNESDAY. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KOTENBERG LONG TERM...LEE AVIATION...DONAVON  FXUS63 KDMX 082112 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 312 PM CST SUN FEB 8 2015 .SHORT TERM /TONIGHT/... ISSUED AT 311 PM CST SUN FEB 8 2015 LATE THIS AFTERNOON SOME LIGHT SHOWERS OR DRIZZLE WILL CONTINUE TO MOVE SOUTHEAST INTO THE SOUTH CENTRAL COUNTIES PRIOR TO 00Z. A COUPLE OF CONCERNS TONIGHT WITH REGARD TO COLDER AIR ENTERING THE AREA OVERNIGHT. FIRST LOWER STRATUS NORTHWEST OF REGION SHOULD EXPAND SOMEWHAT AS COLDER AIR MOVES IN LATE TONIGHT. TO OUR WEST ANOTHER WEAK LOW AND SURFACE BOUNDARY ARE BOTH FOCUSING MORE CLOUD COVER INTO THE REGION TONIGHT AS WELL. BOUNDARY LAYER MOISTURE REMAINS FAIRLY HIGH...SO THE PATCHY FOG SHOULD REMAIN OVER THE REGION DURING THE OVERNIGHT HOURS. ACROSS THE FAR NORTH A SECOND ARCTIC BOUNDARY CURRENTLY OVER MN WILL DROP SOUTH INTO NORTHERN IOWA BY 12Z WITH SOME WEAK LIFT ALOFT. ALONG THE BOUNDARY THICKER FOG SHOULD DEVELOP. ALONG WITH THE WEAK LIFT ALOFT...BUFR SOUNDINGS OVER FAR NORTHERN IA INDICATE A LACK OF ICE INTRODUCTION SO HAVE ADDED SOME PATCHY FREEZING DRIZZLE MAINLY IN THE NORTHWEST SECTIONS OF THE FORECAST AREA NEARER THE BOUNDARY. TEMPERATURES WILL COOL BACK DOWN INTO THE LOWER TO MID 20S BY MORNING. WITH A WEAK PRESSURE GRADIENT ONLY LIGHT NORTH NORTHEAST WINDS ARE EXPECTED AS WELL. THIS MAY AID IN SOME LIGHT FROST DEVELOPMENT ON AREA ROADS OR BRIDGES DUE TO MOISTURE DEPOSITION OF TODAYS RELATIVELY HIGH BOUNDARY LAYER MOISTURE AND THE BIGGER DROP IN OVERNIGHT LOWS BY MORNING. THOUGH CURRENT METRO ROADCAST IS NOT SHOWING MUCH IN TERMS OF FROST EARLY MONDAY...AREA TRAVELERS MAY STILL NEED TO WATCH FOR PATCHY FROST ON ROADS EARLY MONDAY MORNING. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 311 PM CST SUN FEB 8 2015 A SURFACE HIGH PRESSURE RIDGE WILL SLOWLY SLIDE ACROSS IOWA ON MONDAY. THIS WILL ENABLE OVERNIGHT FOG AND FREEZING DRIZZLE IN THE NORTHWEST...AS DETAILED IN THE SHORT TERM DISCUSSION ABOVE...TO PERSIST INTO THE MORNING BEFORE GRADUALLY IMPROVING. THE CLOUDS WILL LIKELY REMAIN FOR MOST OR ALL OF THE DAY AND WITH LITTLE SURFACE FLOW IT WILL BE DIFFICULT TO WARM MUCH. THUS HAVE HELD MONDAY HIGHS ABOUT 8 TO 10 DEGREES ABOVE MORNING LOWS...AND IF SKIES DO REMAIN OVERCAST THEN THAT MAY EVEN BE A BIT GENEROUS. AS THE SURFACE RIDGE DEPARTS TO THE EAST ON MONDAY NIGHT WE WILL SEE A RETURN OF SOUTHEASTERLY LOW LEVEL WINDS AHEAD OF A DEVELOPING LOW PRESSURE CENTER APPROACHING FROM SOUTH DAKOTA. THE COMBINATION OF GRADUALLY INCREASING BREEZES/LOW LEVEL MOISTURE AND PERSISTENT CLOUDS WILL KEEP TEMPERATURES FROM FALLING TOO FAR ON MONDAY NIGHT...WITH LOWS GENERALLY IN THE UPPER TEENS TO MID 20S. THE PRIMARY FORECAST CHALLENGE IN THE LONG TERM FORECAST PERIOD IS THE EVOLUTION OF THE AFOREMENTIONED SURFACE LOW MOVING ACROSS SOUTH DAKOTA ON MONDAY NIGHT...ITS ASSOCIATED PRECIPITATION FIELDS...AND THE COLD FRONT MOVING THROUGH IN ITS WAKE. PROGNOSTIC MODELS ARE UNANIMOUS IN TRACKING THE LOW PRESSURE CENTER EAST NORTHEASTWARD ACROSS SOUTHERN MINNESOTA ON TUESDAY AND INTO NORTHERN WISCONSIN ON TUESDAY NIGHT. THE LOW WILL BE SURROUNDED BY A LARGE SHIELD OF LOW CLOUDS AND PRECIPITATION...HOWEVER THE INITIAL BAROCLINIC ZONE ATTENDANT TO THE LEADING FLANK OF THE SYSTEM WILL BE WELL NORTH OF IOWA...AND THE MID LEVEL TROUGH FORCING THE SURFACE RESPONSE WILL LIKEWISE MOVE EAST NORTHEASTWARD WELL TO OUR NORTH. THE RESULT IS FORECAST SOUNDINGS AROUND ESTHERVILLE AND MASON CITY THAT PREDICT A DECIDED LACK OF MOISTURE ABOVE A RELATIVELY SHALLOW NEAR SURFACE CLOUD LAYER...AS WELL AS ONLY MODEST ATMOSPHERIC LIFT THAT IS GENERALLY CENTERED ABOVE THIS CLOUD LAYER. PROFILE TEMPERATURES SHOW THAT FOR MUCH OF THE TUESDAY INTO TUESDAY NIGHT TIME FRAME THE LOW LEVEL CLOUDS WILL EXIST BELOW THE ICE INTRODUCTION LAYER...LEADING TO A FORECAST OF PRIMARILY LIGHT FREEZING RAIN AND PERHAPS PERIODS OF LIGHT SNOW/SLEET UP TOWARD THE MINNESOTA BORDER. FURTHER SOUTH TOWARD CENTRAL IOWA THE CLOUD DEPTHS DO NOT ATTAIN A DEPTH SUFFICIENT TO GENERATE PRECIPITATION...AND THERE IS VERY LITTLE IN THE WAY OF FORCING TO ACCOMPLISH THIS EITHER. THUS POPS HAVE BEEN INCREASED INTO THE HIGH CHANCE RANGE ACROSS OUR NORTHERN COUNTIES BUT REMAIN DRY TOWARD HIGHWAY 30 AND SOUTHWARD. PRECIPITATION TYPE WILL BE A MIXED BAG BUT WITH A DEFINITE POTENTIAL FOR SOME LIGHT ICING...ESPECIALLY DURING THE DAY ON TUESDAY WHEN FORECAST SOUNDINGS ARE PARTICULARLY FAVORABLE WITH WARM CLOUD DEPTHS OF 7 TO 9 KFT ALL AT TEMPERATURES OF ABOUT -9C OR HIGHER AND HIGH TEMPERATURES FORECAST TO BE AROUND FREEZING OR BELOW. ANY ACCUMULATIONS WILL BE VERY LIGHT...BUT GIVEN THE EXPECTED TEMPERATURES HEADING INTO THE PRECIPITATION TIMES IT IS LIKELY THAT ROADS WILL BE BELOW FREEZING AND ANY ICE ACCRUAL WILL LEAD TO HAZARDOUS TRAVEL. AN ADVISORY MAY BECOME WARRANTED FOR PARTS OF OUR NORTH AS THIS SYSTEM APPROACHES. AS THE LOW PRESSURE SYSTEM MOVES INTO WISCONSIN LATE TUESDAY NIGHT IT WILL SWEEP AN ATTENDANT COLD FRONT ACROSS IOWA...CLEARING OUR AREA TO THE SOUTHEAST BY MID MORNING WEDNESDAY. THIS WILL BRING COLDER AIR INTO THE REGION...REINFORCED FURTHER WEDNESDAY NIGHT AS THE LARGE HIGH PRESSURE AREA BEHIND THE FRONT REALLY BUILDS DOWN TOWARD IOWA. THE GRADIENT BETWEEN THE DEPARTING LOW AND APPROACHING HIGH...AS WELL AS EFFICIENT LOW LEVEL MIXING AND COLD AIR ADVECTION...WILL ALSO RESULT IN BREEZY CONDITIONS FROM WEDNESDAY INTO WEDNESDAY NIGHT...AND POSSIBLY STRATUS CLOUDS THAT WILL HELP TO HOLD DOWN TEMPERATURES ON WEDNESDAY. THE GENERAL PATTERN OF THE FIRST HALF OF THE WEEK WILL REPEAT ITSELF IN THE SECOND HALF AS PERSISTENT NORTHWESTERLY 500 MB FLOW RESULTS IN AN ALTERNATING SERIES OF SURFACE LOW AND HIGH PRESSURE SYSTEMS. AS THE FORECAST GETS FURTHER INTO THE FUTURE THE TIMING AND DETAILS OF THESE SUCCESSIVE SYSTEMS BECOMES MURKIER...BUT AT THIS TIME NO SIGNIFICANT PRECIPITATION OR STRONG STORM SYSTEMS ARE APPARENT FROM THURSDAY THROUGH NEXT WEEKEND. && .AVIATION...08/18Z ISSUED AT 1126 AM CST SUN FEB 8 2015 WITH ONE SYSTEM DEPARTING AND ANOTHER ONE ARRIVING FROM THE NORTHWEST THIS EVENING...CLOUDS AND LOWER VSBY WILL REMAIN. UPPER LEVEL FLOW CONTINUES FROM THE NORTHWEST WITH CYCLONIC FLOW OVERNIGHT. AS BOUNDARY LAYER COOLS...LOWER MVFR/IFR STRATUS TO THE NORTH SHOULD EXPAND OVER THE AREA...ESPECIALLY THE NORTHERN SECTIONS OF THE REGION FOR KMCW...KFOD...KALO AND AM EXPECTING THIS TO OCCUR GENERALLY AFT 03-04Z. ALONG WITH THAT VSBY WILL MOST LIKELY REMAIN MVFR WITH OCNL IFR VSBY THROUGH 12Z. SOME IMPROVEMENT SHOULD OCCUR AFT 13Z MON...BUT HAVE LIMITED CONFIDENCE ON TIMING...SO FOR NOW HAVE NOT ATTEMPTED TO DEFINE CONDITIONS AFT 13Z. /REV && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...LEE AVIATION...REV  FXUS63 KDMX 092128 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 328 PM CST MON FEB 9 2015 .SHORT TERM /TONIGHT/... ISSUED AT 328 PM CST MON FEB 9 2015 MAIN CONCERNS ARE CLOUD COVER AND APPROACHING WAVE FROM THE WEST. LOW STRATUS ERODING OVER THE NORTH MOMENTARILY BUT SHOULD BEGIN TO FILL BACK IN AFTER SUNSET. THE HRRR SHOWS THE CURRENT SETUP QUITE WELL WITH SOME THINNING OF THE CLOUD DECK OVER THE NORTH FOLLOWED BY CLOUDS FILLING IN ONCE AGAIN. THE UPSTREAM SHORT WAVE OVER MT WILL MOVE SOUTHEAST OVERNIGHT AND SHOULD BEGIN TO IMPACT THE NORTHWEST WITH PRECIPITATION CHANCES BETWEEN 09-12Z. BUFR SOUNDINGS OVER THE NORTHWEST SHOW LOWER LAYERS THICKENING TOWARD MORNING WITH SOME LIFT INCREASING TOWARD 12Z. WILL MAINTAIN LIGHT FREEZING DRIZZLE ACROSS THE NORTHWEST TRANSITIONING TO A CHANCE FOR LIGHT FREEZING DRIZZLE OR LIGHT FREEZING RAIN/ICE PELLET MIX BY 12Z. INITIALLY THERE IS NOT MUCH IN THE WAY OF ICE INTRODUCTION WHICH WOULD FAVOR SOME LIGHT FREEZING DRIZZLE. TEMPERATURES TONIGHT ARE CHALLENGING AS WELL. GUIDANCE DROPS VALUES INTO THE TEENS NORTH TO LOWER TO MID 20S MOST AREAS. LAST NIGHT MOIST BOUNDARY LAYER AND CLOUD COVER KEPT MINS IN THE LOWER 30S. THOUGH NOT EXPECTING IT TO BE THAT WARM TONIGHT THERE SHOULD BE A DECENT GRADIENT FROM EAST TO SOUTHWEST WITH UPPER TEENS EAST TO THE MID TO UPPER 20S OVER THE SOUTHWEST WHERE CLOUDS WILL HOLD. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 328 PM CST MON FEB 9 2015 LITTLE HAS CHANGED IN OVERALL FORECAST THINKING FROM PREVIOUS SHIFTS. A LOW PRESSURE SYSTEM WILL SPREAD PRECIPITATION ACROSS MOST OF MINNESOTA ON TUESDAY...WITH LIGHT PRECIPITATION AFFECTING NORTHERN IOWA...THEN PUSH A PRETTY STRONG COLD FRONT ACROSS IOWA ON TUESDAY NIGHT AND WEDNESDAY MORNING. THE PRECIPITATION ACROSS NORTHERN IOWA STILL LOOKS SPOTTY AND VERY LIGHT...WITH FORECAST SOUNDINGS SHOWING CLOUD DEPTHS WAVERING BETWEEN ABOUT 3000 AND 8000 FEET AND MAINLY LOCATED BENEATH BOTH THE ICE INTRODUCTION LAYER AND THE LIMITED FORCING ASSOCIATED WITH THE LOW PASSING BY TO THE NORTH. THIS SUPPORTS MOSTLY A DRIZZLE/LIGHT RAIN SCENARIO WITH TEMPERATURES NEAR OR A LITTLE BELOW FREEZING...LIKELY LEADING TO SOME LIGHT ICE ACCUMULATIONS OF PERHAPS A FEW HUNDREDTHS OF AN INCH. GIVEN THE RELATIVELY LOW CONFIDENCE IN ACCUMULATING PRECIPITATION OCCURRING IN OUR AREA...WITH ONLY 40 TO 50 POPS IN THE NORTH AND VERY LIGHT EXPECTED AMOUNTS...HAVE NOT ISSUED AN ADVISORY AT THIS TIME. HOWEVER...THIS WILL BE CLOSELY MONITORED TONIGHT AND TOMORROW AND ONE MAY YET BECOME WARRANTED IF THERE IS A MORE CONSISTENT SIGNAL FOR MEANINGFUL ICE ACCUMULATION/IMPACTS. THE LIGHT PRECIPITATION ACROSS THE NORTH WILL END ON TUESDAY NIGHT...THEN THE AFOREMENTIONED COLD FRONT WILL SWEEP RAPIDLY SOUTHEASTWARD ACROSS THE AREA. WINDS WILL SURGE SIGNIFICANTLY ON WEDNESDAY MORNING...THEN AGAIN ON WEDNESDAY EVENING AS ONE LAST 500 MB IMPULSE ROUNDS THE TROUGH AND IS REFLECTED BY A TIGHTENING SURFACE PRESSURE GRADIENT. FORECAST SOUNDINGS INDICATE WINDS AT THE TOP OF THE MIXED LAYER APPROACHING 40 KNOTS AT TIMES AND THERE IS AN INCREASING POSSIBILITY...ESPECIALLY GIVEN THE COLD AIR ADVECTION AND EFFICIENT MIXING EXPECTED...THAT A WIND ADVISORY MAY BECOME NECESSARY AT SOME POINT FOR WEDNESDAY INTO WEDNESDAY NIGHT. TEMPERATURES WILL LIKELY REMAIN STEADY OR FALL DURING THE DAY WEDNESDAY...THEN PLUMMET FURTHER WEDNESDAY NIGHT WITH WIND CHILLS OF AROUND 20 TO 25 BELOW FORECAST ACROSS NORTHERN IOWA BY THURSDAY MORNING. AS A SURFACE HIGH PRESSURE AREA CROSSES IOWA ON THURSDAY WINDS WILL LIGHTEN SUBSTANTIALLY BUT IT WILL REMAIN COLD...THEN WE WILL CONTINUE THIS SERIES OF ALTERNATING HIGHS AND LOW PRESSURE TROUGHS THROUGH THE WEEKEND. THIS WILL RESULT IN A MODEST WARM UP ON FRIDAY...ANOTHER FRONTAL PASSAGE LATE FRIDAY...MORE STRONG WINDS AROUND FRIDAY NIGHT INTO SATURDAY...MORE COLD ON SATURDAY AND SATURDAY NIGHT...ETC. IN A REPEAT OF THE PATTERN WE HAVE SEEN FOR THE LAST SEVERAL DAYS ALREADY. THERE IS SOME INDICATION IN THE PAST SEVERAL RUNS OF THE ECMWF AND GFS THAT THIS PATTERN COULD SHIFT A BIT FURTHER SOUTHWARD AROUND MONDAY OR TUESDAY OF NEXT WEEK AS A BROAD 500 MB TROUGH DIGS A BIT FURTHER DOWN INTO THE CENTRAL U.S. IF THIS VERIFIES THEN IT WOULD SPREAD THE BULK OF THE PRECIPITATION FROM THE ASSOCIATED SURFACE SYSTEM MORE ACROSS IOWA RATHER THAN FURTHER NORTH AS WE HAVE SEEN THUS FAR...HOWEVER AT THIS RANGE IT IS WAY TOO EARLY TO GET MUCH DETAIL OUT OF WHAT THIS WOULD MEAN FOR SENSIBLE WEATHER AND PRECIPITATION AMOUNTS ACROSS CENTRAL IOWA. && .AVIATION...09/18Z ISSUED AT 1153 AM CST MON FEB 9 2015 MAIN CONCERNS CONTINUE TO BE THE STRATUS DECK AND POTENTIAL FOR SOME LIGHT FREEZING RAIN EARLY TUESDAY THROUGH 18Z. CURRENT TRENDS SHOW SOME OCCASIONAL BREAKS IN THE CIGS OVER NORTH CENTRAL IA WITH SOME EXPANSION SOUTH TOWARD KFOD AND KMCW EXPECTED WITH A FEW HOURS OF VFR CONDITIONS EXPECTED PRIOR TO 00Z. ELSEWHERE CIGS BOUNCING BETWEEN MVFR/VFR OR REMAINING MVFR THROUGH 00Z. AFT 00Z EXPECT BOUNDARY LAYER TO LOWER WITH RETURN OF MVFR CIGS REGIONWIDE. OVER THE NORTH AT KFOD AND KMCW...SOME POTENTIAL FOR IFR CONDITIONS TO RETURN AFT 11Z WITH -FZRADZPL POSSIBLE. SOME UNCERTAINTY ON COVERAGE BUT HAVE CONFINED TO NORTHERN SITES AS MOST PROBABLE. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...LEE AVIATION...REV  FXUS63 KDMX 200904 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 404 AM CDT FRI MAR 20 2015 .SHORT TERM /TODAY/... ISSUED AT 400 AM CDT FRI MAR 20 2015 LOW CLOUDS HAVE BEEN SLOWLY BUT STEADILY CLEARING OUT OVERNIGHT AHEAD OF AN APPROACHING WEAK SURFACE TROUGH. AS SKIES HAVE CLEARED LIGHT WINDS HAVE ALLOWED FOR GOOD RADIATIVE COOLING CONDITIONS...RESULTING IN THE DEVELOPMENT OF SOME FOG ACROSS SOUTHERN IOWA. MOST VISIBILITIES ARE ABOVE 4 MILES...BUT A FEW LOCATIONS IN SOUTHWESTERN IOWA HAVE DIPPED BELOW 2 MILES. NO SUBSTANTIAL WIND CHANGE IS ANTICIPATED BEFORE SUNRISE...AND WILL NEED TO MONITOR OBSERVATIONS FOR THE POSSIBLE DEVELOPMENT OF LOCALIZED DENSE FOG...HOWEVER GIVEN THE DRY SURFACE CONDITIONS IN PLACE THE PROBABILITY DOES NOT SEEM HIGH AT THIS TIME. WHATEVER FOG IS THERE AT SUNRISE WILL BURN OFF AFTERWARD...WITH A MORE ORGANIZED SOUTHWEST FLOW DEVELOPING DURING THE DAY. THIS WILL LEAD TO CONSIDERABLY WARMER CONDITIONS ACROSS THE FORECAST AREA. GIVEN THE TEMPERATURES EXPERIENCED DURING THE WARM SPELL OF LAST WEEK...HAVE MAINTAINED A FORECAST ABOVE MOS GUIDANCE WITH MID TO UPPER 60S EXPECTED ACROSS ABOUT THE SOUTHWESTERN HALF OF OUR AREA. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 400 AM CDT FRI MAR 20 2015 PRIMARY CONCERN WILL BE A PERIOD OF ACTIVE WEATHER EARLY NEXT WEEK WITH LITTLE SENSIBLE WEATHER TO START...BUT SETTING THE STAGE INTO SUNDAY. AFTER MILD TEMPERATURES TODAY WEAK COLD FRONTAL PASSAGE WILL OCCUR TONIGHT DROPPING TEMPERATURES BACK CLOSER TO NORMAL. THERE IS A COUPLET OF THERMODYNAMIC FORCING JUST AHEAD OF THE SURFACE FEATURES BUT THIS WILL BE MOISTURE STARVED AND NOT AMOUNT TO ANYTHING. ASSOCIATED BAROCLINIC ZONE WILL THEN SETUP THROUGH THE MO VALLEY INTO SATURDAY WITH MID/HIGH LEVEL KINEMATIC FORCING SPREADING INTO THE NRN PLAINS AHEAD OF SHORT WAVE CURRENTLY APPROACHING THE PACIFIC NW. WARM/THETA-E ADVECTION WILL THEN MATURE LATE SATURDAY NIGHT WITH THERMODYNAMIC FORCING BECOMING QUITE STRONG. MOISTURE WILL REMAIN LIMITED HOWEVER SO PRECIP ONSET WILL LIKELY HOLD OFF UNTIL SUNDAY MORNING. DEEP THERMODYNAMIC AND KINEMATIC FORCING THEN DEVELOPS THROUGH THE DAY...MAINLY ORIENTED NW-SE UNTIL LOBE MATURES FARTHER SOUTH INTO IA AS PARENT SHORT WAVE CROSSES THE MO RIVER. ALTHOUGH THE GFS IS STILL ON THE COOL SIDE...MODEL CONSENSUS IS INCREASING WITH A WARMER FARTHER NORTH SOLUTION. THIS RESULTS IN A BRIEF WINTRY MIX INITIALLY...TRANSITIONING TO MAINLY RAIN WITH HIGHEST POPS NORTH. DEEP LIFT WITH AFOREMENTIONED SHORT WAVE EXITS BY LATE EVENING HOWEVER WITH MOISTURE RELEGATED TO 1.5-2KM OR BELOW. STILL EXPECT LIGHT PRECIP TO LINGER HOWEVER...ASSOCIATED WITH INVERTED SURFACE TROUGH PASSAGE. SOUNDINGS SHOW NICE VEERING AND WARM ADVECTION CENTERED AROUND 1KM AND NOTED IN FAIRLY SHALLOW 285K ISENT SURFACE. THIS WILL BE COINCIDENT WITH COOLING TEMPS AT NIGHT SO THERE MAY BE A PERIOD OF LIGHT FREEZING RAIN OR FREEZING DRIZZLE NORTHEAST LATE INTO EARLY MONDAY MORNING. DO NOT EXPECT ANYTHING SIGNIFICANT HOWEVER. LATE MARCH SUN AND HIGHS IN THE 40S SUNDAY SHOULD KEEP PAVEMENT TEMPERATURES RELATIVELY WARM INTO THE NIGHT WITH MOISTURE AND CLOUDS KEEPING THINGS INSULATED FROM MUCH RADIATIONAL COOLING. ANY ICING WOULD BE ONLY A FEW HUNDREDTHS AND MAINLY ON ELEVATED SURFACES. NEXT SYSTEM WILL FOLLOW QUICKLY ON ITS HEELS STARTING MON NIGHT AND LASTING INTO TUE NIGHT AND BE STRONGER...ASSOCIATED WITH DEEPER WAVE WHICH WILL EVENTUALLY ESTABLISH CENTRAL CONUS MEAN TROUGH INTO MIDWEEK. THIS SYSTEM WILL BE ALL LIQUID WITH PRECIP DRIVEN BY HIGHER BASED KINEMATIC FORCING AND FOLLOWED BY FAIRLY IMPRESSIVE ZONE OF ISENTROPIC LIFT AND THETA-E ADVECTION INTO TUE...ESPECIALLY IF THE GFS VERIFIES. PRECIP INTENSITY WILL NOT BE EXTREME...BUT THE HIGHEST WE HAVE SEEN IN A WHILE. NAEFS INTEGRATED WATER VAPOR TRANSPORT...PWS AND SPECIFIC HUMIDITIES ARE NOT OFF THE CHARTS BUT JUST INTO THE 90TH PERCENTILE WITH SEASONALLY HIGH WARM CLOUD DEPTHS AS WELL. WITH SOUNDINGS SHOWING ELEVATED CONVECTION POTENTIAL WOULD NOT BE SURPRISED TO SEE SOME RUMBLES OF THUNDER SOUTH. WOULD NOT BE SURPRISED TO SEE SOME INCH RAINFALL AMOUNTS. REMAINDER OF THE EXTENDED SHOULD BE DRY HOWEVER WITH IA SETTING UP ON THE COOLER BACK SIDE OF THE MEAN TROUGH. TEMPS WILL GRADUALLY COOL BUT STILL REMAIN CLOSE TO NORMAL. && .AVIATION...20/06Z ISSUED AT 1130 PM CDT THU MAR 19 2015 VFR CONDITIONS ARE EXPECTED THROUGH PERIOD. WEAK BOUNDARY WILL PUSH THROUGH BEFORE 12Z...WITH WINDS BECOMING NORTHWESTERLY. WINDS WILL SHIFT BACK TO THE WEST BEYOND 12Z...WITH GUSTS UP TO 15KTS NEAR/AFTER 18Z. WINDS WILL BECOME MORE SOUTHERLY FOR END OF THE PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...LEE LONG TERM...SMALL AVIATION...AWB  FXUS63 KDMX 310853 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 353 AM CDT TUE MAR 31 2015 .SYNOPSIS... ISSUED AT 321 AM CDT TUE MAR 31 2015 LOW PRESSURE EAST OF IA WILL PULL AWAY AS ITS ASSOCIATED COLD FRONT STALL TODAY...THEN BEGINS LIFTING NORTH AS A WARM FRONT. STRONGER LOW OVER ALBERTA WILL MOVE EAST WITH A COLD FRONT SWEEPING INTO IA LATE WEDNESDAY INTO EARLY THURSDAY. PACIFIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT. && .SHORT TERM /TODAY/... ISSUED AT 321 AM CDT TUE MAR 31 2015 A WEAK SURFACE LOW PASSES TO THE EAST OF IOWA OVERNIGHT DRAGGING A WEAK TROUGH AND WINDSHIFT ACROSS THE STATE. TODAY WEAK SURFACE HIGH PRESSURE WILL DRIFT ACROSS THE STATE AS THE FLOW ALOFT REMAINS OUT OF THE NORTHWEST. THE RESULT WILL BE A LIGHTER WIND OUT OF THE NORTHWEST AND WITH LIGHTER WIND AND LESS MIXING AND A WEAK NORTHWESTERLY FLOW...TEMPS WILL BE A FEW DEGREES COOLER TODAY. SOUNDINGS ARE DRY THOUGH AND THE SUN WILL BE BRIGHT TODAY AND TEMPS WILL STILL BE WELL ABOVE AVERAGE SO ANOTHER SUNNY WARM DAY IS EXPECTED. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 321 AM CDT TUE MAR 31 2015 STRONG WARM AIR ADVECTION WILL TAKE PLACE TONIGHT INTO WEDNESDAY. TEMPS WEDNESDAY ARE LIKELY TO BE CLOSEST TO THE WARMEST GUIDANCE SOLUTIONS WITH GOOD SOLAR INSOLATION THROUGH THE DAY. MODELS ARE IN GOOD AGREEMENT WITH THE COLD FRONT ENTERING THE NORTHWEST IN THE AFTERNOON. STRONG THETA-E ADVECTION WITH SURFACE DEW POINTS RISING INTO THE 50S WILL SET THE STAGE FOR THUNDERSTORM DEVELOPMENT DURING THE LATE AFTERNOON INTO THE OVERNIGHT. DECENT INSTABILITY WITH ABOUT 2000 J/KG AVAILABLE DURING PRIME TIME...THOUGH INSTABILITY IS LOST REASONABLY QUICKLY. WITH FRONT SLOWING DOWN AND H8 JET INCREASING TO AT LEAST 50 KTS...MOISTURE CONVERGENCE IS STRONG. WARM CLOUD DEPTHS INCREASE TO OVER 2500 METERS WITH PWAT VALUES IN IN THE 1.3 INCH RANGE...ABOUT 3 SIGMA ABOVE NORMAL FOR THIS TIME OF THE YEAR. THERE IS A SEVERE POTENTIAL ACROSS THE CWA...BUT AS THE NIGHT PROGRESSES EXPECT TO SEE MORE OF A LINEAR STRUCTURE WITH ISOLATED SEVERE AND HEAVY RAINFALL. AT THIS TIME DO NOT FEEL RAINFALL WILL BE ENOUGH TO CAUSE FLOODING...BUT THAT WILL NEED TO BE MONITORED. COOLER WEATHER OVERSPREAD THE AREA THURSDAY AFTER LINGERING SHOWERS END. COLD FRONT IS NOT LIKELY TO GET TOO FAR SOUTH OF THE STATE WITH THE SOUTHWEST FLOW ALOFT CONTINUING AND MEAN TROUGH POSITION OVER THE WESTERN U.S. RAIN WILL MOVE BACK INTO THE SOUTH ABOUT FRIDAY...AND OVER THE CWA FOR SUNDAY INTO EARLY NEXT WEEK. && .AVIATION...31/06Z ISSUED AT 1125 PM CDT MON MAR 30 2015 VFR CONDITIONS WILL PREVAIL THROUGH TUESDAY NIGHT. WEAK MIXING WILL DEVELOP LATE TUESDAY MORNING INTO THE AFTERNOON AND HAVE MENTION OF GUSTS TO 16 KNOTS. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MS MAR 15 SHORT TERM...FAB LONG TERM...MS MAR 15 AVIATION...PODRAZIK  FXUS63 KDMX 032045 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 345 PM CDT SUN MAY 3 2015 .SHORT TERM /TONIGHT/... ISSUED AT 345 PM CDT SUN MAY 3 2015 A MUCH MORE ACTIVE PATTERN FOR THE UPCOMING WEEK WILL MAKE THE WEATHER MORE INTERESTING IN BOTH THE NEAR AND EXTENDED FUTURE. WARM SECTOR HAS SPREAD ACROSS THE STATE TODAY WITH COLD FRONT APPROACHING NORTHERN IOWA THIS AFTERNOON. INSTABILITY HAS INCREASED RAPIDLY DURING THE DAY WITH MLCAPES OF 1500-2000J/KG ACROSS MUCH OF WESTERN IOWA. STILL SLIGHTLY CAP BUT THIS HAS BEEN ERODING AS TEMPERATURES HAVE RISEN IN THE LOW TO MID 80S. HOWEVER...ANTICIPATE INITIAL CONVECTIVE DEVELOPMENT NEAR THE FRONT TO BE IN MN AND FAR SE SD CLOSER TO THE SHORTWAVE AND COOLER AIR ALOFT. SOUNDINGS HAVE A SOMEWHAT INVERTED V DISPLAY WITH HIGH LCL AND LFCS BUT FAIRLY DECENT EFFECTIVE BULK SHEAR VALUES OF 30-45KTS. WITH THESE PARAMETER... GENERALLY ANTICIPATE LARGE HAIL AND DAMAGING WINDS WITH THESE STORMS AS THE MOVE INTO NORTHERN IOWA THIS EVENING. THE LINE WILL LIKELY EXTEND WESTWARD ACROSS THE STATE ALONG THE BOUNDARY TOWARD WEAK SURFACE LOW IN FAR EASTERN NEBRASKA. THE COMPLEX OF STORMS WILL SINK SOUTHWARD OVERNIGHT WITH THE FRONT AND ANTICIPATE THE STORMS TO WEAKEN WITH TIME...LIKELY AS OUTFLOW SURGES OUT AHEAD OF THE SYSTEM. TEMPERATURES WILL REMAIN QUITE WARM AHEAD OF THE BOUNDARY OVERNIGHT WITH READINGS NEAR 60 BUT A DECENT COOL PUSH FARTHER NORTH AND POSSIBLE CLEARING NEAR DAYBREAK SHOULD ALLOW VALUES TO THE UPPER 40S. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 345 PM CDT SUN MAY 3 2015 ACTIVE WEATHER PATTERN CONTINUES THROUGHOUT THE WEEK WITH MAIN CONCERN FOR SEVERE WEATHER POTENTIAL AND HEAVY RAIN MONDAY INTO MONDAY NIGHT. MODELS ARE IN FAIR AGREEMENT THROUGH TOMORROW NIGHT AND LEANED TOWARD A BLEND OF THE ECMWF/NAM AND THEN SLIGHTLY MORE WEIGHT TOWARDS THE ECMWF THROUGH THE REST OF THE WEEK. MONDAY INTO WEDNESDAY...BOUNDARY LAYS UP ALONG THE INTERSTATE 80 TO HIGHWAY 30 CORRIDOR TOMORROW MORNING AND THE FORECAST AREA LOOKS TO REMAIN BETWEEN SHORTWAVES WITH THE SHORTWAVE TONIGHT EXITING EASTERN IOWA BY 12Z. SOME LINGERING STORMS ARE POSSIBLE PRIOR TO 15Z...BUT THE 03.12Z SPCWRF KEEPS THE FORECAST AREA DRY UNTIL THE LATE AFTERNOON. A SECOND SHORTWAVE QUICKLY PUSHES INTO WESTERN IOWA MONDAY AFTERNOON AND SPAWNS THUNDERSTORMS IN SOUTHWEST IOWA BY AS EARLY AS 18Z. QUESTIONABLE WHETHER SURFACE BASED INSTABILITY RECOVERS ENOUGH PRIOR TO THE SHORTWAVE ENTERING THE FORECAST AREA BY MONDAY AFTERNOON...BUT ENOUGH ELEVATED CAPE AND STRONG 0-6KM SHEAR PRESENT TO SUSTAIN SOME UPDRAFTS. PLUS...THERE IS CERTAINLY ENOUGH LARGE SCALE FORCING WITH THE SHORTWAVE AND THE LOW TO MID-LEVEL LAPSE RATES ARE CONDITIONALLY UNSTABLE OVER SOUTHERN IOWA MONDAY AFTERNOON. EXPECTING MAIN CONCERN FOR HAIL TOMORROW AFTERNOON INTO EVENING WRT TO SEVERE THREAT. OTHER CONCERN IS LOCALLY HEAVY RAIN. PRECIPITABLE WATER VALUES RANGE RISE INTO THE 1.0 TO 1.5 INCH WHICH IS STILL IN THE 75 PERCENTILE FOR PW CLIMATOLOGY FOR MAY. STRONG CONVERGENCE AND MOISTURE TRANSPORT INCREASE MONDAY NIGHT AND DECENT WARM LAYER CLOUD DEPTHS TO SUPPORT EFFICIENT RAIN PRODUCERS. INCREASED QPF TOMORROW INTO TOMORROW NIGHT. SURFACE BOUNDARY SURGES NORTHWARD DURING THE EVENING MONDAY AND KEEPS THE BEST THUNDERSTORM POTENTIAL FOCUSED OVER NORTHERN PORTIONS OF THE FORECAST AREA PAST 06Z TUESDAY THROUGH 18Z TUESDAY. NAM AND ECMWF FURTHER NORTH PLACING THE BOUNDARY ALONG OR NORTH OF HIGHWAY 20 BY TUESDAY AFTERNOON AND HAVE LOW CONFIDENCE WITH STORM POTENTIAL SOUTH OF THIS LINE AFTER 18Z TUESDAY. HENCE...LOWERED POPS DURING THIS TIME. ALSO...CONTINUED TO GO DRY TUESDAY NIGHT INTO WEDNESDAY WITH STRONG SUBSIDENCE IN PLACE ACROSS CENTRAL IOWA. ECMWF/NAM SLOWER AND FURTHER WEST WITH 500MB TROUGH AND SURFACE LOW ENTERING IOWA WEDNESDAY THAN THE GFS. THINKING FORECAST AREA WILL BE DRY THROUGH AT LEAST 18Z WEDNESDAY WITH LACK OF ANY SIGNIFICANT FORCING AND MOISTURE UNTIL LATER IN THE DAY WEDNESDAY. CUT BACK ON POPS AND WENT COMPLETELY DRY GENERALLY EAST OF INTERSTATE 35 12-18Z WEDNESDAY. THURSDAY THROUGH SUNDAY...COLD FRONT AND SURFACE LOW TRACK ACROSS THE STATE BY THURSDAY PROVIDING ADDITIONAL THUNDERSTORM CHANCES DURING THIS TIME. LOOKS EARLY ENOUGH IN THE DAY TO LIMIT SEVERE POTENTIAL WITH THE LACK OF ANY SIGNIFICANT INSTABILITY. LATE IN THE WEEK...DIFFICULT TO TIME ANY SHORTWAVE TO PASS THROUGH THE STATE OVER THE WEEK...BUT AT LEAST MUCH OF THE AREA LOOKS POTENTIALLY DRIER BY SATURDAY. && .AVIATION...03/18Z ISSUED AT 1233 PM CDT SUN MAY 3 2015 VFR CONDITIONS WILL PERSIST THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. THIS FRONT WILL PUSH INTO IOWA TONIGHT WITH SHOWERS AND THUNDERSTORMS BECOMING NUMEROUS NEAR THE FRONT THIS EVENING IN NORTHERN IOWA WITH THE STORMS PROGRESSING SOUTHEAST OVERNIGHT. THE STORMS WILL AFFECT ALL TAF SITES BEFORE THE PRECIPITATION BEGINS TO DISSIPATE AND MOVE EAST BY MONDAY MORNING. SURFACE WINDS WILL BE SOUTHERLY TODAY AND VARIABLE NEAR THE FRONT. NORTHEAST WINDS ARE EXPECTED IN MOST LOCATIONS BY TOMORROW MORNING ON THE BACKSIDE OF THE BOUNDARY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...COGIL LONG TERM...PODRAZIK AVIATION...COGIL  FXUS63 KDMX 070902 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 402 AM CDT THU MAY 7 2015 .SYNOPSIS... ISSUED AT 339 AM CDT THU MAY 7 2015 FRONTAL BOUNDARY FROM ERN ND INTO THE TEXAS PANHANDLE WILL MOVE EAST AND REACH SOUTHEAST IOWA BY FRIDAY MORNING BEFORE STALLING. FRONT WILL BEGIN LIFTING NORTH SATURDAY AND SATURDAY NIGHT IN RESPONSE TO A STRONG S/WV LIFTING OUT OF THE WESTERN TROUGH. LOW WILL MOVE THROUGH NORTHWEST IOWA WITH TRAILING COLD FRONT SWEEPING THROUGH THE STATE BY MONDAY MORNING. COOL HIGH PRESSURE WILL DOMINATE THE FIRST PART OF NEXT WEEK. && .SHORT TERM /TODAY/... ISSUED AT 339 AM CDT THU MAY 7 2015 AREA OF WEAKENING CONVECTION OVER WESTERN IOWA THIS MORNING WITH LIGHTNING ASSOCIATED WITH THE ACTIVITY BECOMING MORE SPARSE OVERALL. ANOTHER WAVE OF THETA-E ADVECTION WILL LIFT INTO SOUTHERN IOWA BY EARLY THIS MORNING AND IS EXPECTED TO BE THE FOCUS FOR RENEWED SHOWERS AND THUNDERSTORMS AND LIFT NORTHEAST THROUGH THE STATE. HI RESOLUTION SOLUTIONS SUGGESTING A LULL IN THE ACTIVITY EARLY THIS AFTERNOON. A WEAKENING BOUNDARY WILL ENTER NORTHWEST IOWA AND WILL SHIFT VERY SLOWLY SOUTHEAST THROUGH THE DAY INTO TONIGHT. MOISTURE TRANSPORT REMAINS GOOD DURING THE DAY WITH THE LOW LEVEL JET OF 35 TO 40 KTS SHIFTING EAST OVER THE STATE. THIS WILL PUSH PWAT VALUES TO 1.25-1.50 INCHES. WARM CLOUD DEPTHS AT LESS THAN 10 KFT NOT FAVORABLE FOR HEAVY RAINFALL HOWEVER WITH PWATS CLIMATOLOGICALLY HIGH AND STORM MOTIONS FAVORABLE NEARLY PARALLEL TO THE INSTABILITY AXIS COULD LEAD TO NUMEROUS STORMS OVER THE SAME AREA AND INCREASE THE THREAT. BY MID TO LATE AFTERNOON...THUNDERSTORM CHANCES WILL BE GREATEST OVER THE FAR SOUTHEAST NEAR THE MOISTURE TRANSPORT AXIS AND TO THE NORTHWEST IN VICINITY OF THE SURFACE BOUNDARY. AN ISOLATED SEVERE STORM OR TWO AREA POSSIBLE. MELTING LEVEL HEIGHTS ARE RELATIVELY LOW WITH INCREASING CAPE VALUES IN THE -10C TO -30C LAYER. .LONG TERM /TONIGHT THROUGH WEDNESDAY/... ISSUED AT 339 AM CDT THU MAY 7 2015 THUNDERSTORMS FROM THE DAY WILL CONTINUE TO BE SQUEEZED EAST TONIGHT AS THE FRONTAL BOUNDARY MOVES EAST. WITH THE FRONT STALLING SOUTH OF THE STATE AND A NELY FLOW OF SOMEWHAT DRIER AIR...MOST OF THE ACTION WILL BE SOUTHEAST OF IOWA FRIDAY AND FRIDAY NIGHT. ATTENTION TURNS TO THE WEEKEND WELL ADVERTISED SITUATION WITH A CLOSED LOW LIFTING OUT OF THE SOUTHWEST U.S. SURFACE LOW IS SLATED TO MOVE THROUGH NORTHWEST IA SUNDAY NIGHT. ECMWF HAS BEEN CONSISTENT WITH THIS TRACK AND OTHER DETERMINISTIC MODELS ARE ON BOARD WITH A VERY SIMILAR TRACK THOUGH THERE ARE SOME SIGNIFICANT DIFFERENCES WITH THE SYSTEM THIS WEEKEND...LOOKING AT CIPS PRODUCTS INDICATE THE 05/27/95 EVENT IS QUITE SIMILAR IN MANY WAYS. ECMWF IS THE MOST AGGRESSIVE AND PRESENTS A CLASSIC TRIPLE POINT AND DRY LINE EVENT. SUNDAY AND SUNDAY EVENING IS LIKELY TO UNFOLD AS A SIGNIFICANT OUTBREAK DAY. CAPE VALUES ARE NOT TREMENDOUSLY HIGH...BUT OTHER KINEMATICS ARE CERTAINLY IN PLACE. ONCE THE LOW PASSES...A SHARP CHANGE TO COOLER WEATHER FOR THE FIRST PART OF NEXT WEEK. SHOWERY ON MONDAY YET...BUT MUCH COOLER WITH HIGHS IN THE 50S AND 60S FOR A COUPLE DAYS. && .AVIATION...07/06Z ISSUED AT 1157 PM CDT WED MAY 6 2015 AREA OF SHOWERS AND STORMS WILL PROGRESS INTO WESTERN IOWA OVERNIGHT AND EVENTUALLY ACROSS CENTRAL IOWA THROUGH THURSDAY MORNING. WHILE CONDITIONS WILL BE PRIMARILY VFR...LOCATIONS EXPERIENCING SHOWERS AND STORMS WILL SEE MVFR TO LOCALIZED IFR CONDITIONS WITH RESTRICTIONS TO CEILINGS AND VISIBILITIES. WILL SEE THE VFR CONDITIONS IN MOST LOCATIONS BY MIDDAY INTO THE AFTERNOON ON WEDNESDAY BEFORE MORE CONVECTION DEVELOPS IN THE AREA ON WEDNESDAY LATE AFTERNOON AND EVENING. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MS MAY 15 SHORT TERM...DONAVON LONG TERM...MS MAY 15 AVIATION...COGIL  FXUS63 KDMX 090905 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 405 AM CDT SAT MAY 9 2015 .SHORT TERM /TODAY/... ISSUED AT 310 AM CDT SAT MAY 9 2015 SFC BOUNDARY HAS MOVED SOUTH INTO MISSOURI WHILE CANADIAN HIGH PRESSURE HAS RIDGED INTO NORTHERN IOWA AND HAS DRIVEN DEWPOINTS DOWN INTO THE LOW TO MID 30S OVER THE NORTHWEST PORTION OF THE STATE. THE PRIMARY FORECAST CHALLENGE IS PRECIPITATION CHANCES THROUGH THE DAY. THE AFOREMENTIONED DRY AIR ENTERING THE STATE WILL HAVE A BIG IMPACT ON PRECIPITATION POTENTIAL. CENTRAL AND NORTHERN IOWA IS EXPECTED TO REMAIN DRY THROUGH 7 PM. MOISTURE TRANSPORT DOES BEGIN OVER THE SOUTHWEST LATE IN THE DAY WITH MODEST INSTABILITY DEVELOPING AS THE INCREASING THETA-E ADVECTION ARRIVES. OVERALL HAVE SIGNIFICANTLY CUT BACK POPS FOR TODAY AND HAVE CONFINED THEM TO THE FAR SOUTHWEST PORTION OF THE FORECAST AREA FOR LATE AFTERNOON. TEMPERATURES AGAIN WILL BE CONTINGENT ON CLOUD COVER. AN AREA OF STRATUS CONTINUES TO LINGER OVER EASTERN IOWA THIS MORNING. THE STRATUS SHOULD RETREAT TO THE EAST OF THE AREA FOR A PERIOD TODAY BEFORE THE STEERING FLOW WINDS BECOME MORE EASTERLY AGAIN THIS AFTERNOON AND BRING THE STRATUS BACK INTO THE NORTHEAST. WITH SOME PERIODS OF SUN...EXPECT HIGH TEMPERATURES TO RANGE FROM THE UPPER 60S TO MID 70S. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 310 AM CDT SAT MAY 9 2015 MAIN FORECAST CONCERN FOR EXTENDED WILL FOCUS ON AREA OF LOW PRESSURE SET TO LIFT NORTHEAST FROM NEAR FOUR CORNERS REGION. LOW WILL BEGIN TO LIFT NORTHEASTWARD TODAY...WITH UPPER LEVEL LOW REACHING SD LATE SUNDAY. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH TIMING AND PLACEMENT OF LOW...WITH ONLY SLIGHT VARIANCES. CURRENT FORECAST IS FOR SURFACE LOW TO BE LOCATED NEAR SD/NE/IA BOARDER BY 00Z MONDAY...THIS IS A BIT SLOWER THAN PREVIOUS RUNS. PRECIPITATION ASSOCIATED WITH THE LOW IS EXPECTED TO COME IN TWO MAIN TIME FRAMES...OVERNIGHT TONIGHT AND AGAIN SUNDAY AFTERNOON/OVERNIGHT. LATE TONIGHT WILL SEE INCREASING PRECIPITATION CHANCES AS BOUNDARY ASSOCIATED WITH LOW LIFTS THROUGH IOWA. WAA AND THETA-E ADVECTION ALONG BOUNDARY WILL LEAD TO PRECIPITATION CHANCES. HOWEVER...WITH SLIGHTLY SLOW MODEL SOLUTIONS HAVE BACKED OFF ON POPS THROUGH THE OVERNIGHT. SOUNDINGS INDICATE GOOD SATURATION THROUGH THE COLUMN AND DEEP WARM CLOUD DEPTHS WITH PWAT VALUES NEAR 1.2-1.4 INCHES WHICH IS SOMEWHAT HIGH FOR THE TIME OF YEAR...AND HEAVY RAIN WILL BE POSSIBLE WITH THUNDERSTORMS. IN ADDITION...CANNOT RULE OUT SEVERE POTENTIAL IN THE EARLY MORNING HOURS WITH MUCAPE VALUES NEAR 1000 J/KG AND INCREASING SHEAR THROUGH THE MORNING HOURS. AS BOUNDARY LIFTS NORTH EXPECT TO SEE PRECIPITATION GENERALLY END ACROSS THE AREA FOR THE LATE MORNING. FOCUS WILL THEN SHIFT TO POTENTIAL FOR THUNDERSTORMS AND SEVERE WEATHER IN THE AFTERNOON. MODELS CONTINUE TO KEEP WARM FRONT NEAR IA/MN BOARDER...AND MAY SEE CONTINUED DEVELOPMENT THERE THROUGH THE PERIOD...AND HAVE KEPT SOMEWHAT HIGHER POPS ACROSS THE NORTH. HOWEVER...MAIN CONCERN WILL COME IN THE AFTERNOON IN WESTERN IOWA WHERE DRY LINE IS EXPECTED TO BE. CONVECTIVE ALLOWING MODELS GENERALLY BEGIN PRECIPITATION IN THE WEST IN THE AFTERNOON/LATE AFTERNOON AND HAVE KEPT HIGHEST POPS CONFINED TO THE LATE AFTERNOON ACROSS THE CWA. SEVERE THUNDERSTORMS WILL BE POSSIBLE. NAM IS MOST AGGRESSIVE WITH SEVERE PARAMETERS...AND FEEL MAY BE TOO AGGRESSIVE. HOWEVER...GFS ALLOWS FOR CAPE VALUES NEAR 2000-2500 J/KG TO BUILD INTO CENTRAL IOWA. IN ADDITION...SHEAR WILL BE SUFFICIENT TO ALLOW FOR STORMS WHICH DEVELOP TO PERSIST...WITH ALL MODES OF SEVERE WEATHER POSSIBLE. SYSTEM WILL NEED TO CONTINUE TO BE MONITORED FOR FINE TUNING TIMING AND LOCATION OF BEST CHANCES FOR SEVERE WEATHER...THOUGH ATTM FEEL SPC ENHANCED RISK IS WELL PLACED...WITH BEST CHANCES IN THE LATE AFTERNOON HOURS ACROSS CENTRAL IOWA. STORMS WILL PUSH EAST THROUGHOUT THE EARLY EVENING HOURS...AGAIN WITH SOMEWHAT SLOWER MODEL PROGRESSION HAVE KEPT POPS LONGER THROUGH SUNDAY NIGHT. AS UPPER LEVEL LOW CONTINUES TO LIFT NORTH MAY SEE SOME WRAP AROUND PRECIPITATION IN THE NORTH MONDAY AND MONDAY NIGHT...THOUGH MODELS ARE NOT IN GOOD AGREEMENT WITH THE PLACEMENT OF THIS...AND HAVE KEPT GENERALLY SLIGHT CHANCE POPS GOING. BEHIND LOW MUCH COLDER AIR WILL PUSH IN...BRINGING COOLER TEMPERATURES FOR THE BEGINNING OF THE WEEK...AND WINDY CONDITIONS MONDAY AND TUESDAY AS LOW LIFTS NORTH. 850MB TEMPS WILL BE NEAR ZERO THROUGH WEDNESDAY BEFORE A RETURN TO SOUTHERLY SURFACE FLOW AND WAA. HAVE THEREFORE DROPPED TEMPERATURES A FEW DEGREES...WITH HIGHS EXPECTED TO BE NEAR 10 DEGREES BELOW NORMAL. FORECAST BECOMES LESS CERTAIN FOR MID WEEK THROUGH END OF PERIOD AS RIDGE BUILDS INTO IOWA AHEAD OF ANOTHER LOW PRESSURE SYSTEM. ECMWF KEEPS RIDGE A BIT STRONGER AND KEEPS PRECIPITATION GENERALLY WEST OF CWA FOR WEDNESDAY WHILE GFS BRINGS PRECIPITATION INTO NORTHERN IOWA WEDNESDAY. HAVE GENERALLY KEPT POPS BEGINNING THURSDAY WHEN MODELS ARE IN BETTER AGREEMENT WITH PRECIPITATION CHANCES...THOUGH STILL CONTINUE TO HANDLE SYSTEM DIFFERENTLY AND GENERALLY HAVE LOW CONFIDENCE IN PRECIPITATION CHANCES BEYOND WEDNESDAY. && .AVIATION...09/06Z ISSUED AT 1151 PM CDT FRI MAY 8 2015 LATEST MODEL GUIDANCE SUGGESTS A SLOWER TRANSITION TO SHOWERS AND POSSIBLE THUNDER SATURDAY...NEARER TO AFTER 00Z SUNDAY. OTHERWISE MAIN ISSUES REMAIN WITH MVFR CIGS NORTHEAST AND STRATUS REFORMING OVER KS MOVING NORTHEAST OVERNIGHT...MAY SPREAD BOTH MID AND HIGH CLOUDS AS WELL AS LOWER BKN035 ACROSS THE REGION TOWARD 12Z. OVER THE FAR NORTH...PATCHY 5SM BR POSSIBLE AT KMCW NEAR 12Z. WINDS REMAIN LIGHT NORTHWEST OVERNIGHT THEN BECOME EAST WITH TIME. MAIN SYSTEM TO ARRIVE NEAR END OF PERIOD BETWEEN 03Z AND BEYOND. /REV && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DONAVON LONG TERM...AWB AVIATION...REV  FXUS63 KDMX 132011 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 311 PM CDT WED MAY 13 2015 .SHORT TERM /TONIGHT/... ISSUED AT 310 PM CDT WED MAY 13 2015 HIGH PRESSURE HAS MOVED OFF TO THE EAST WITH AN AREA OF LOW PRESSURE APPROACHING FROM THE WEST. AN UPPER WAVE WILL LIFT OUT OF THE SOUTHERN HIGH PLAINS TONIGHT AND MOVE INTO NE/KS BY 12Z THURSDAY. A PIECE OF ENERGY WILL EJECT OUT AHEAD OF THE MAIN WAVE AND MOVE THROUGH ERN NE/WRN IA THIS EVENING. CLOUD COVER EXPECTED TO INCREASE AHEAD OF THESE TWO WAVES...WITH SOME LIGHT SPRINKLES OR SHOWERS POSSIBLE THIS EVENING WITH THE FIRST IMPULSE. THESE WILL MAINLY BE CONFINED TO WESTERN PORTIONS OF IOWA. ADDITIONALLY QUITE A BIT OF DRY AIR IN THE LOWER LEVELS WITH AN EASTERLY COMPONENT TO THE WIND USUALLY MEANS THAT PRECIP WILL HAVE A HARD TIME REACHING THE GROUND. THUS HAVE CUT BACK ON THE PROGRESSION OF POPS THIS EVENING. OTHERWISE STRONGER PUSH OF WAA AND THETA-E ADVECTION TO COME LATE TONIGHT...WITH BETTER PUSH OF MOISTURE INTO THE LOWER LEVELS AS THE STRONGER WAVE LIFTS NORTH/NORTHEASTWARD TOWARD THE REGION. TRAJECTORY OF THE LIFT ALOFT TO BE MORE NNE THAN NE AS IN PAST FORECASTS...SO HAVE BACKED OFF ON PRECIPITATION ACROSS THE EASTERN CWA LATE TONIGHT WITH DEEPER MOISTURE AND LOW LEVEL SATURATION NOTED ON THE SOUNDINGS/TIME HEIGHT SECTIONS ACROSS THE WESTERN CWA. THEREFORE HAVE HIGHEST LIKELY/CATEGORICAL POPS IN THAT AREA FOR LATE TONIGHT. MODELS CONTINUE TO SUGGEST LACK OF INSTABILITY...ALTHOUGH WITH THE STRENGTH OF FORCING AND GIVEN THE TIME OF YEAR WAS INCLINED TO STILL INCLUDE A MENTION OF ISOLATED THUNDER. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 310 PM CDT WED MAY 13 2015 RELATIVELY ACTIVE PERIOD EXPECTED THROUGH SUNDAY WITH SEVERAL WAVES APPROACHING FROM THE SOUTH AND SOUTHWEST. FIRST WAVE THIS WED MORNING CONTINUES OVER THE NM/TX AREA AND IS EXPECTED TO LIFT NNE WITH TIME BY TONIGHT. DRY SOUTHEAST FLOW CURRENTLY WILL GIVE WAY TO MORE SOUTHERLY FLOW AS RIDGE AXIS DEPARTS AREA BY 06Z TONIGHT. LOOKING AT ALL THE MODELS...SEE LITTLE IN TERMS OF INSTABILITY THROUGH 18Z THURSDAY SO HAVE TRIMMED BACK THUNDER TO SHRA AND LIMITED ANY CHANCE OF THUNDER TO AFTERNOON AS SECOND PUSH OF WARM AIR ADVECTION MOVES NORTHEAST INTO THE AREA TOWARD 00Z FRI. MODELS CONTINUE AT ODDS REGARDING THE POSITION OF THE TRAILING COOL FRONT BY FRIDAY MORNING THAT ACCOMPANIES THE FIRST SYSTEM WE EXPERIENCE TOMORROW. LATE THURSDAY EVENING SOME LIFT NORTH OF THE BOUNDARY AND NEAR THE EXITING SFC LOW IS EXPECTED SO WILL CONTINUE CHANCE SHOWERS/ISO THUNDER THERE...THEN BY 12Z OVER THE FAR SOUTH THERE WILL BE A CHANCE FOR RETURNING ISO THUNDER. THE FRONT IS EXPECTED TO RETREAT NORTH FRIDAY AFTERNOON AND EVENING...BRINGING ALONG WITH IT SUFFICIENT MOISTURE TO INCREASE DEW POINTS INTO THE LOWER 60S BY AFTERNOON. TEMPERATURES...ESPECIALLY SOUTH SHOULD HAVE LITTLE TROUBLE REACHING THE MID 70S BY EARLY AFTERNOON. INSTABILITY INCREASES ACCORDINGLY WITH PROGGED MUCAPE BETWEEN 1200-1800 J/KG (EURO) TO 2000-3500 J/KG (GFS) BY 00Z SATURDAY. WITH SECOND APPROACHING WAVE AND 0-6KM BULK SHEAR INCREASING TO 25 TO 30 KTS BY 00Z SAT...THERE COULD BE A CHANCE FOR A FEW SVR STORMS MAINLY WEST THIRD TO HALF BY LATE DAY. OTHERWISE... THROUGH FRIDAY NIGHT THE FRONT LIFTS NORTH AND BULK SHEAR LESSENING THERE WILL BE A CONTINUED CHANCE FOR THUNDER MOVING NORTH...BUT LESSENING CHANCES FOR SEVERE STORMS AFTER 06Z. SATURDAY AFTERNOON INTO EARLY SUNDAY MORNING WILL BE THE MORE LIKELY PERIOD OF SEEING ORGANIZED SEVERE STORMS. BY SATURDAY MODELS SHOW A DEVELOPING LEE SIDE SYSTEM OVER WESTERN KS BETWEEN 994-998MB FROM 18Z SATURDAY THROUGH 12Z SUNDAY. LITTLE ADDITIONAL SFC DEEPENING IS EXPECTED...BUT IMPRESSIVE UPPER LEVEL WIND FIELDS APPROACH EASTERN NE/WESTERN IA BY 00-06Z SUNDAY WITH INCREASING SFC PRESS GRADIENT AND WINDS ALOFT. THROUGH THE PERIOD WARM CLOUD DEPTHS REMAIN ABOVE 10KFT WHICH WILL PROMOTE EFFICIENT RAINFALL FROM THUNDERSTORMS...SO HEAVY DOWNPOURS WILL BE POSSIBLE WITH THE STORMS AS WELL. LATE AFTERNOON/EVENING MLCAPE INSTABILITY VARIES BETWEEN 600-1200 J/KG (EURO) TO 1400-2000 J/KG (GFS) DIMINISHING TOWARD 06-12Z. BULK SHEAR IS EXPECTED TO INCREASE TO 40 TO 55KTS OVER THE AREA BETWEEN 06 AND 12Z SUNDAY. THOUGH THE SFC WARM FRONT SHOULD BE NORTH OF IOWA AND THE MAIN SPEED MAX ANTICIPATED TO ARRIVE BETWEEN 06Z AND 12Z...A BIT LATER THAN MAX INSTABILITY...DYNAMICS REMAIN STRONG ENOUGH TO CONTINUE SVR CHANCES INTO THE LATE EVENING OR OVERNIGHT HOURS. WITH THE MAIN WAVE ALOFT MOVING EAST BY LATE SUNDAY AFTERNOON...DRY SLOT AND WARM READINGS WITH GUSTY WINDS MAY REACH THE AREA DURING THE AFTERNOON HOURS FOLLOWED BY ANOTHER SHOT OF COLDER AIR FOR MONDAY INTO MONDAY NIGHT AS HIGHS FALL BACK INTO THE 50S TO LOWER 60S OVER THE REGION...AFTER MID/UPPER 70S SAT AND SUNDAY. COOL TEMPERATURES WILL REMAIN TUESDAY WITH THE GFS MODEL SUGGESTING SHOWERS RETURNING BY WEDNESDAY...CLOUDS AND COOL TEMPERATURES. LOW CONFIDENCE OUT TO SEVEN DAYS AS EURO MAINTAINS COOLER NORTHWEST FLOW AND APPROACHING HIGH PRESSURE WITH DRY WEATHER. WILL NEED TO IRON OUT DETAILS OF SATURDAY NIGHT POTENTIAL SVR EVENT AS EVENT NEARS. && .AVIATION...13/18Z ISSUED AT 1233 PM CDT WED MAY 13 2015 SOUTHEASTERLY WINDS TO CONTINUE THROUGH PERIOD...LOSING THE GUSTINESS AND DIMINISHING SOME TONIGHT. INCREASING CLOUDS OVERNIGHT...EXPECTED TO LOWER INTO THURSDAY WITH RAIN MOVING IN. COULD BE SOME ISOLATED TO SCATTERED THUNDERSTORMS AS WELL. UNCERTAINTY IN LOCATION SO HAVE LEFT MENTION OUT. GREATEST CERTAINTY IN RAINFALL AT KFOD AND KDSM LATE IN THE PERIOD...SO HAVE MENTIONED WITH -SHRA...AND VCSH WHERE DRY AIR MAY WIN OUT WITH IT TAKING LONGER FOR PRECIP TO REACH THE GROUND. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BEERENDS LONG TERM...REV AVIATION...BEERENDS  FXUS63 KDMX 140452 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1152 PM CDT WED MAY 13 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TONIGHT/... ISSUED AT 310 PM CDT WED MAY 13 2015 HIGH PRESSURE HAS MOVED OFF TO THE EAST WITH AN AREA OF LOW PRESSURE APPROACHING FROM THE WEST. AN UPPER WAVE WILL LIFT OUT OF THE SOUTHERN HIGH PLAINS TONIGHT AND MOVE INTO NE/KS BY 12Z THURSDAY. A PIECE OF ENERGY WILL EJECT OUT AHEAD OF THE MAIN WAVE AND MOVE THROUGH ERN NE/WRN IA THIS EVENING. CLOUD COVER EXPECTED TO INCREASE AHEAD OF THESE TWO WAVES...WITH SOME LIGHT SPRINKLES OR SHOWERS POSSIBLE THIS EVENING WITH THE FIRST IMPULSE. THESE WILL MAINLY BE CONFINED TO WESTERN PORTIONS OF IOWA. ADDITIONALLY QUITE A BIT OF DRY AIR IN THE LOWER LEVELS WITH AN EASTERLY COMPONENT TO THE WIND USUALLY MEANS THAT PRECIP WILL HAVE A HARD TIME REACHING THE GROUND. THUS HAVE CUT BACK ON THE PROGRESSION OF POPS THIS EVENING. OTHERWISE STRONGER PUSH OF WAA AND THETA-E ADVECTION TO COME LATE TONIGHT...WITH BETTER PUSH OF MOISTURE INTO THE LOWER LEVELS AS THE STRONGER WAVE LIFTS NORTH/NORTHEASTWARD TOWARD THE REGION. TRAJECTORY OF THE LIFT ALOFT TO BE MORE NNE THAN NE AS IN PAST FORECASTS...SO HAVE BACKED OFF ON PRECIPITATION ACROSS THE EASTERN CWA LATE TONIGHT WITH DEEPER MOISTURE AND LOW LEVEL SATURATION NOTED ON THE SOUNDINGS/TIME HEIGHT SECTIONS ACROSS THE WESTERN CWA. THEREFORE HAVE HIGHEST LIKELY/CATEGORICAL POPS IN THAT AREA FOR LATE TONIGHT. MODELS CONTINUE TO SUGGEST LACK OF INSTABILITY...ALTHOUGH WITH THE STRENGTH OF FORCING AND GIVEN THE TIME OF YEAR WAS INCLINED TO STILL INCLUDE A MENTION OF ISOLATED THUNDER. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 310 PM CDT WED MAY 13 2015 RELATIVELY ACTIVE PERIOD EXPECTED THROUGH SUNDAY WITH SEVERAL WAVES APPROACHING FROM THE SOUTH AND SOUTHWEST. FIRST WAVE THIS WED MORNING CONTINUES OVER THE NM/TX AREA AND IS EXPECTED TO LIFT NNE WITH TIME BY TONIGHT. DRY SOUTHEAST FLOW CURRENTLY WILL GIVE WAY TO MORE SOUTHERLY FLOW AS RIDGE AXIS DEPARTS AREA BY 06Z TONIGHT. LOOKING AT ALL THE MODELS...SEE LITTLE IN TERMS OF INSTABILITY THROUGH 18Z THURSDAY SO HAVE TRIMMED BACK THUNDER TO SHRA AND LIMITED ANY CHANCE OF THUNDER TO AFTERNOON AS SECOND PUSH OF WARM AIR ADVECTION MOVES NORTHEAST INTO THE AREA TOWARD 00Z FRI. MODELS CONTINUE AT ODDS REGARDING THE POSITION OF THE TRAILING COOL FRONT BY FRIDAY MORNING THAT ACCOMPANIES THE FIRST SYSTEM WE EXPERIENCE TOMORROW. LATE THURSDAY EVENING SOME LIFT NORTH OF THE BOUNDARY AND NEAR THE EXITING SFC LOW IS EXPECTED SO WILL CONTINUE CHANCE SHOWERS/ISO THUNDER THERE...THEN BY 12Z OVER THE FAR SOUTH THERE WILL BE A CHANCE FOR RETURNING ISO THUNDER. THE FRONT IS EXPECTED TO RETREAT NORTH FRIDAY AFTERNOON AND EVENING...BRINGING ALONG WITH IT SUFFICIENT MOISTURE TO INCREASE DEW POINTS INTO THE LOWER 60S BY AFTERNOON. TEMPERATURES...ESPECIALLY SOUTH SHOULD HAVE LITTLE TROUBLE REACHING THE MID 70S BY EARLY AFTERNOON. INSTABILITY INCREASES ACCORDINGLY WITH PROGGED MUCAPE BETWEEN 1200-1800 J/KG (EURO) TO 2000-3500 J/KG (GFS) BY 00Z SATURDAY. WITH SECOND APPROACHING WAVE AND 0-6KM BULK SHEAR INCREASING TO 25 TO 30 KTS BY 00Z SAT...THERE COULD BE A CHANCE FOR A FEW SVR STORMS MAINLY WEST THIRD TO HALF BY LATE DAY. OTHERWISE... THROUGH FRIDAY NIGHT THE FRONT LIFTS NORTH AND BULK SHEAR LESSENING THERE WILL BE A CONTINUED CHANCE FOR THUNDER MOVING NORTH...BUT LESSENING CHANCES FOR SEVERE STORMS AFTER 06Z. SATURDAY AFTERNOON INTO EARLY SUNDAY MORNING WILL BE THE MORE LIKELY PERIOD OF SEEING ORGANIZED SEVERE STORMS. BY SATURDAY MODELS SHOW A DEVELOPING LEE SIDE SYSTEM OVER WESTERN KS BETWEEN 994-998MB FROM 18Z SATURDAY THROUGH 12Z SUNDAY. LITTLE ADDITIONAL SFC DEEPENING IS EXPECTED...BUT IMPRESSIVE UPPER LEVEL WIND FIELDS APPROACH EASTERN NE/WESTERN IA BY 00-06Z SUNDAY WITH INCREASING SFC PRESS GRADIENT AND WINDS ALOFT. THROUGH THE PERIOD WARM CLOUD DEPTHS REMAIN ABOVE 10KFT WHICH WILL PROMOTE EFFICIENT RAINFALL FROM THUNDERSTORMS...SO HEAVY DOWNPOURS WILL BE POSSIBLE WITH THE STORMS AS WELL. LATE AFTERNOON/EVENING MLCAPE INSTABILITY VARIES BETWEEN 600-1200 J/KG (EURO) TO 1400-2000 J/KG (GFS) DIMINISHING TOWARD 06-12Z. BULK SHEAR IS EXPECTED TO INCREASE TO 40 TO 55KTS OVER THE AREA BETWEEN 06 AND 12Z SUNDAY. THOUGH THE SFC WARM FRONT SHOULD BE NORTH OF IOWA AND THE MAIN SPEED MAX ANTICIPATED TO ARRIVE BETWEEN 06Z AND 12Z...A BIT LATER THAN MAX INSTABILITY...DYNAMICS REMAIN STRONG ENOUGH TO CONTINUE SVR CHANCES INTO THE LATE EVENING OR OVERNIGHT HOURS. WITH THE MAIN WAVE ALOFT MOVING EAST BY LATE SUNDAY AFTERNOON...DRY SLOT AND WARM READINGS WITH GUSTY WINDS MAY REACH THE AREA DURING THE AFTERNOON HOURS FOLLOWED BY ANOTHER SHOT OF COLDER AIR FOR MONDAY INTO MONDAY NIGHT AS HIGHS FALL BACK INTO THE 50S TO LOWER 60S OVER THE REGION...AFTER MID/UPPER 70S SAT AND SUNDAY. COOL TEMPERATURES WILL REMAIN TUESDAY WITH THE GFS MODEL SUGGESTING SHOWERS RETURNING BY WEDNESDAY...CLOUDS AND COOL TEMPERATURES. LOW CONFIDENCE OUT TO SEVEN DAYS AS EURO MAINTAINS COOLER NORTHWEST FLOW AND APPROACHING HIGH PRESSURE WITH DRY WEATHER. WILL NEED TO IRON OUT DETAILS OF SATURDAY NIGHT POTENTIAL SVR EVENT AS EVENT NEARS. && .AVIATION...14/06Z ISSUED AT 1146 PM CDT WED MAY 13 2015 MVFR TO IFR CONDITIONS WILL MOVE INTO THE FORECAST AREA OVERNIGHT INTO THURSDAY MORNING WITH A WIDESPREAD AREA OF RAIN. LOW CIGS WILL TEETER BETWEEN MVFR TO IFR THROUGHOUT THE DAY AND LOOKS LIKE LOW STRATUS IS EXPECTED TO PERSIST TOWARDS THE END OF THE TAF PERIOD. VIS LIKELY TO REMAIN GENERALLY MVFR WITH PERIODIC IFR AND EVEN POSSIBLY SHORT STINTS OF LIFR CONDITIONS WITH THE RAIN. LOW CONFIDENCE WITH TIMING THE LIFR CONDITIONS AND LEFT OUT MENTION ATTM. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...BEERENDS LONG TERM...REV AVIATION...PODRAZIK  FXUS63 KDMX 212050 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 350 PM CDT THU MAY 21 2015 .SHORT TERM /TONIGHT/... ISSUED AT 349 PM CDT THU MAY 21 2015 THE QUIET WEATHER TODAY WILL PERSIST INTO TONIGHT WITH WEAK SUBSIDENCE ACROSS THE STATE AS HIGH PRESSURE MOVES OVERHEAD. SKIES WILL REMAIN CLEAR WITH A DRY AIRMASS IN PLACE AND LIGHT WINDS ALLOWING READINGS TO DROP NICELY OVERNIGHT. HAVE LOWERED TEMPS SLIGHTLY IN FAVORED LOCATIONS IN THE NORTHEAST AND NISHNA VALLEYS WITH GOOD RADIATIONAL COOLING EXPECTED. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 349 PM CDT THU MAY 21 2015 HIGH PRESSURE WILL CONTINUE TO SHIFT EAST OF THE AREA ON FRIDAY WITH RETURN SOUTHERLY FLOW INCREASING THROUGH THE DAY. MOISTURE ADVECTION ALOFT AT 700 MB AND ABOVE WILL ARRIVE THROUGH THE AFTERNOON WITH INCREASING CLOUDS. SHORT WAVE ENERGY WILL ARRIVE DURING THE AFTERNOON AS WELL ALONG WITH GOOD KINEMATIC FORCING. THE ELEVATED FORCING OVER WESTERN IOWA CONTINUES TO LOOK BETTER AS THE PERIOD GETS CLOSER AND EXPECT SOME SHOWERS TO DEVELOP OVER FAR WEST TO SOUTHWEST IOWA. THE PRIMARY QUESTION IS IF IT WILL ARRIVE OVER THE FAR WESTERN FORECAST AREA DURING THE AFTERNOON. HAVE KEPT MOSTLY DRY FOR THE MOMENT BUT BECOMING LESS CONFIDENT IN A DRY SOLUTION AND LIKELY WILL NEED TO ADD POPS ACROSS THE WEST FOR FRIDAY AFTERNOON AND EVENING. HAVE KEPT LOW POPS FOR SATURDAY AND OVERALL THE DAY WILL BE MOSTLY DRY. THE LOW LEVEL JET WILL SHIFT EAST SATURDAY NIGHT AND WILL BE POINTING INTO THE STATE BY LATE SATURDAY NIGHT INTO SUNDAY. PROFILES WILL BE SATURATING DURING THIS PERIOD WITH PWATS NEAR 1.6 INCHES OR GREATER BY 12Z SUNDAY MORNING AND PUSHING 1.75 BY LATER IN THE DAY. THE SATURATED SOUNDINGS WILL LIMIT OVERALL INSTABILITY AND THE SEVERE WEATHER THREAT. THE POTENTIAL FOR HEAVY RAINFALL HOWEVER WILL BE THERE. WARM CLOUD DEPTHS OF 10-11 KFT ALONG WITH HIGH PWATS WILL LEAD TO EFFICIENT RAIN PRODUCING STORMS. IN ADDITION...STORM MOTIONS AND THE PERSISTENT MOISTURE ADVECTION AND FORCING THROUGH THE DAY WILL LEAD TO NUMEROUS ROUNDS OF THUNDERSTORMS WITH SOME AREAS RECEIVING AN ABUNDANCE OF RAIN. EXPECT LOCALLY HEAVY RAINFALL OCCUR...WITH THE POTENTIAL FOR IT TO BECOME MORE WIDESPREAD. WILL NEED TO MONITOR THIS POTENTIAL WITH UPCOMING FORECASTS AND WILL ADD TO THE HWO. THE GENERAL EVOLUTION OF THE SYSTEM BEYOND SUNDAY REMAINS UNCHANGED WITH THE UPPER LOW TO THE WEST LIFTING NORTHEAST AND BECOMING AN OPEN WAVE BY MONDAY WITH THE MAIN FRONTAL BOUNDARY STILL IN THE VICINITY. WHILE THE PWATS BACK OFF TO NEAR 1.2 INCHES...A BETTER POTENTIAL FOR SEVERE WEATHER WILL EXIST WITH HIGHER AND FATTER CAPES WHICH WILL BE MORE CONDUCIVE TO PARTICLE ACCELERATIONS AND STRONGER UPDRAFTS IN ADDITION TO BETTER LOW LEVEL AND DEEP LAYER SHEAR. TOO EARLY TO DETERMINE EXACT SEVERE THREATS BUT COULD BE CONDUCIVE TO A FEW SUPERCELLS. THE REMAINDER OF THE FORECAST WILL FEATURE THE TRANSITION TO A MORE ZONAL BUT STILL ACTIVE FLOW. THE EXTENDED IS LITTERED WITH THUNDERSTORM CHANCES WHICH WILL SOUND MORE WET THAT WHAT WILL OCCUR BUT THE POTENTIAL IS THERE FOR ANY GIVEN 12 HOUR PERIOD BUT MOST PERIODS WILL BE MORE DRY THAN WET. TEMPERATURES WILL RETURN TO MORE LATE MAY LIKE READINGS WITH HIGHS GENERALLY IN THE 70S AND 80S. && .AVIATION...21/18Z ISSUED AT 1242 PM CDT THU MAY 21 2015 WIDESPREAD VFR CONDITIONS ARE EXPECTED FOR THE DURATION OF THE FORECAST WITH UNRESTRICTED VISIBILITIES AND CEILINGS. GUSTY WNW WINDS ARE EXPECTED THIS AFTERNOON BECOMING LIGHT AND VARIABLE OVERNIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...COGIL LONG TERM...DONAVON AVIATION...COGIL  FXUS63 KDMX 222117 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 417 PM CDT FRI MAY 22 2015 .SHORT TERM /TONIGHT/... ISSUED AT 417 PM CDT FRI MAY 22 2015 SURFACE PRESSURE RIDGE WILL CONTINUE RETREATING EASTWARD AS THE BEGINNING OF AN ACTIVE WEATHER WEEKEND APPROACH THE CWA. SHORTWAVE HELPING TO FORCE THE AREA OF PCPN LIFTING NORTHWARD/NORTHEASTWARD ACROSS THE MID-MISSOURI RIVER VALLEY WILL WEAKEN TONIGHT. BEST DYNAMIC AND THERMODYNAMIC FORCING GOES TO THE WEST AND SOUTH OF THE CWA. THUS HAVE CONTINUED THE TREND OF A RELATIVELY DRY FORECAST AT LEAST TONIGHT. BEST CHANCES OF PCPN WILL BE ACROSS THE FAR SOUTHWESTERN AND WESTERN CWA THIS EVENING. SFC WINDS WILL TRANSITION FROM LIGHT AND VARIABLE TO SOUTHERLY LATER THIS EVENING AS THE PRESSURE RIDGE CONTINUES ITS RETREAT AND THE PRESSURE GRADIENT BEGINS TIGHTENING AS THE NEXT SYSTEM DRAWS CLOSER TO THE CWA. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 417 PM CDT FRI MAY 22 2015 CURRENT UPPER LEVEL SYSTEM MOVING INTO THE STATE THIS AFTERNOON WILL SHEAR OUT OVERNIGHT WITH NULL TO WEAK REMNANT FORCING REMAINING BY 12Z. OVERALL EXPECT SATURDAY TO REMAIN MOSTLY DRY THOUGH THE POTENTIAL FOR A FEW SHOWERS IS THERE IN THE MORNING MAINLY FAR WEST THEN AN INCREASING CHANCE OVER THE SOUTHWEST DURING THE AFTERNOON AS MOISTURE ADVECTION ENHANCES. THE MOISTURE ADVECTION MAXIMIZES SATURDAY NIGHT INTO SUNDAY AS THE LOW LEVEL JET REFOCUSES EAST INTO THE STATE AND GULF MOISTURE SURGES NORTHWARD INTO THE STATE. THE INCREASING MOISTURE WILL SATURATE PROFILES SATURDAY NIGHT WITH PWATS INCREASING ABOVE 1.5 INCHES BY 12Z. THE SATURATED PROFILES WILL LIMIT OVERALL INSTABILITY WITH MUCAPES GENERALLY LESS THAN 500 J/KG DURING THE PERIOD. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BECOME WIDESPREAD BY LATE SATURDAY EVENING AND ESPECIALLY AFTER MIDNIGHT AND CONTINUE INTO SUNDAY MORNING. POSSIBLE A BRIEF PERIOD DURING THE DAY SUNDAY WITH NOT AS WIDESPREAD ACTIVITY BEFORE CONVECTION BECOMES RENEWED BY THE AFTERNOON AND EVENING. HEAVY RAINFALL REMAINS POSSIBLE WITH HIGHLY EFFICIENT RAINFALL RATES DURING THE PERIOD CONSIDERING THE SATURATED PROFILES...HIGH PWATS AND GOOD WARM CLOUD DEPTHS. WHILE RAINFALL RATES ARE NOT EXPECTED TO BE EXTREME DUE TO LACK OF STRONG CONVECTION...THE NUMEROUS ROUNDS OF EFFICIENT RAIN PRODUCING SHOWERS AND STORMS WILL LIKELY LEAD TO AREAS WITH TOTAL RAINFALL IN EXCESS OF 3 INCHES. THIS WILL DIMINISH THE FLASH FLOOD THREAT THOUGH WILL NEED TO CONSIDER THE LACK OF MATURE CROPS WHICH WILL LEAD TO AN ACCELERATED RUN OFF OF ANY HEAVY PRECIPITATION THAT OCCURS. REFER TO THE HYDROLOGY SECTION FOR ADDITIONAL DETAILS REGARDING FLOODING POTENTIAL. PROFILES WILL DRY OUT SOME BY MONDAY MORNING AND SHOULD HAVE A PERIOD OF DRIER WEATHER MONDAY MORNING. A GOOD ELEVATED MIXED LAYER WILL DEVELOP IN RESPONSE THUS SHOULD HAVE SOME CAPPING THOUGH EARLY AFTERNOON. THE PRIMARY UPPER LEVEL SHORT WILL BE LIFTING OUT INTO THE AREA SOMETIME MONDAY. THE TIMING OF THE SYSTEM ARRIVING WITH MID LEVEL COOLING HELPING TO ERODE THE EML FOR THUNDERSTORM INITIATION. SHEAR PROFILES ARE BETTER SO SOME ORGANIZED STORMS ARE POSSIBLE. THEREFORE THROUGH THE WEEKEND...THE BEST SEVERE WEATHER THREAT IS ON MONDAY. AT THIS TIME WILL NOT GET INTO SPECIFIC DETAILS REGARDING THE SEVERE WEATHER THREAT WITH THE CONVECTION THROUGH SUNDAY NIGHT POSSIBLY HAVING AN IMPACT ON THE EVOLUTION INTO MONDAY. THE ACTIVE FLOW WILL CONTINUE THE THE EXTENDED WITH SEVERAL CHANCES FOR THUNDERSTORMS. AS MENTIONED IN PREVIOUS DISCUSSIONS...THE PERIOD WILL BE MORE DRY THAN WET BUT CHANCES ARE THERE REGARDLESS. HIGH TEMPERATURES WILL BE IN THE 70S AND 80S THROUGH THE EXTENDED. && .AVIATION...22/18Z ISSUED AT 1232 PM CDT FRI MAY 22 2015 VFR CONDITIONS WILL PREVAIL THROUGHOUT TAF PERIOD AS HIGH PRESSURE CONTINUES TO BE THE MAIN INFLUENCE AND PUSHES EASTWARD. CIGS AROUND 20KFT CURRENTLY MOVING IN OVER THE STATE AHEAD OF PRECIP IN KANSAS AND NEBRASKA...PRECIP NOT EXPECTED TO AFFECT TAF SITES. WINDS WILL TEND TO BE LIGHTER AND VARIABLE WITH SOUTHERLY WINDS PICKING UP TOWARDS THE END OF THE PERIOD TOMORROW. && .HYDROLOGY... ISSUED AT 417 PM CDT FRI MAY 22 2015 WET NEXT FEW DAYS IS EXPECTED TO AN INITIAL RISK FOR FLASH FLOODING SATURDAY NIGHT INTO SUNDAY NIGHT...AND THEN A SUBSEQUENT RISK OF AT LEAST ADDITIONAL RISES ON AREA RIVERS...AND POSSIBLY RIVER FLOODING...BEGINNING AS EARLY AS SUNDAY NIGHT AND CONTINUING INTO THE EARLY PARTS OF NEXT WEEK. THE MIDDLE AND LOWER PORTIONS OF THE DES MOINES AND RACCOON BASINS...AS WELL AS MISSOURI RIVER DRAINAGE BASINS IN THE SOUTHWEST CWA...ARE OF MOST CONCERN AT THIS TIME. SEE THE LONG TERM SECTION ABOVE FOR FURTHER DISCUSSION ON FLASH FLOODING. IN TERMS OF RIVER FLOODING...THE 12Z HYDRO MODEL 72 HR QPF ENSEMBLES ARE SHOWING A WIDE SPREAD BETWEEN THE EXPECTED AND 95 PERCENT MAX QPF TRACES...INDICATING RELATIVELY HIGH SENSITIVITY IN THE HYDROLOGIC MODEL TO QPF. FOR EXAMPLE...THE 72 EXPECTED QPF TRACES SLOW THE FALLS OF MOST STREAMS...WITH SOME SLIGHT TEMPORARY INCREASES...WHILE THE 72 HR 95 PERCENT MAX QPF TRACES SHOW SIGNIFICANT RISES...WITH MULTIPLE RIVER FORECAST POINTS RISING TO NEAR OR ABOVE FLOOD STAGE. IT SHOULD ALSO BE NOTED THAT THE 12Z QPF ENSEMBLES USED IN THE 12Z HYDRO MODEL APPEAR TO BE UNDERDONE...WITH TOTAL EXPECTED 72-HR QPF POSSIBLY FALLING CLOSER TO THE 95 PERCENT MAX QPF ENSEMBLE MEMBER THAN THE 50 PERCENT QPF ENSEMBLE MEMBER. GIVEN THE HYDROLOGIC MODEL SENSITIVITY TO THE QPF...AS WELL AS THE POSSIBILITY OF ENSEMBLE QPF BEING UNDERDONE...UNCERTAINTY IN THE RIVER RESPONSES IS HIGHER THAN AVERAGE FOR THIS PARTICULAR EVENT. THIS HIGHER THAN AVERAGE UNCERTAINTY WILL NECESSITATE CLOSE MONITORING OF QPF TRENDS...AND SUBSEQUENT IMPACTS ON THE HYDRO MODEL GOING FORWARD. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ZOGG LONG TERM...DONAVON AVIATION...CURTIS HYDROLOGY...ZOGG  FXUS63 KDMX 240825 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 325 AM CDT SUN MAY 24 2015 .SHORT TERM /TODAY/... ISSUED AT 325 AM CDT SUN MAY 24 2015 WELL DEFINED MCV MOVING INTO EAST CENTRAL KS AT 06Z WITH ATTENDANT RAIN SHIELD EXPANDING NORTHEAST TOWARD IOWA. MODERATE TO HVY RAINFALL ALREADY OCCURRING TO OUR SOUTH AT THIS TIME. OVER THE PAST 24 HOURS...H850 RIDGE AXIS OVER THE EAST COAST HAS MOVED LITTLE WITH STRONG SOUTHERLY FLOW SETTING UP AT H850...MOISTURE CHANNEL DIRECTED RIGHT AT EASTERN TX...NEARLY DUE NORTH TO EASTERN NEBRASKA/IOWA. CURRENTLY RAINFALL EFFICIENCY QUITE HIGH OVER EASTERN KS WHERE ONE HOUR RATES ARE APPROACHING TWO THIRDS OF AN INCH IN THE HEAVIEST SHOWERS. FOR TODAY...EXPECTING THE MCV TO MOVE NORTH WITH THE FIRST WAVE OF RAINFALL PROGRESSING THROUGH THE FORECAST AREA BY 18Z... WEAKENING SLIGHTLY AS IT MOVES NORTHEAST WITH TIME. HAVE RAISED QPF AMOUNTS THROUGH 12Z THIS MORNING...AND PUSHED AMOUNTS HIGHER OVER THE EAST HALF THROUGH 18Z WITH LESS EXPECTED WEST OF I35. BY LATE AFTERNOON THE SECOND WAVE...A DEEPENING SFC LOW OVER EASTERN KS AGAIN WILL LIFT NORTHEAST TOWARD IOWA. THIS WILL BRING YET ANOTHER PUSH OF MOISTURE TOMORROW NIGHT. PRECIPITABLE WATER TODAY ALREADY INCREASES TO 1.70 INCHES BY 12Z THROUGH INTERSTATE 80...AND ABOUT 1.5 INCHES FOR THE REMAINDER OF THE DAY OVER THE SOUTHEAST HALF OF THE FORECAST AREA. TODAY...EVEN WITH LACK OF MUCH INSTABILITY... SHOULD SEE RAINFALL TOTALS IN THE RANGE OF TWO THIRDS TO 1.5 INCHES BY AFTERNOON...WITH A FEW LOCATIONS NEARING TWO INCHES. THIS WILL SET THE STAGE FOR FLOODING POTENTIAL OVERNIGHT SUNDAY NIGHT. MORE INFORMATION IN THE HYDRO DISCUSSION BELOW. HIGHS TODAY WILL BE HELD IN CHECK WITH LOW CLOUDS AND RAIN EXPECTED MOST OF THE MORNING... ACROSS THE NORTHEAST THROUGH MID AFTERNOON AND SOME REDEVELOPMENT IN THE SOUTH BY LATE AFTERNOON. WITH A FEW HOURS BREAK IN THE RAINFALL...SOME LOCATIONS WILL LIKELY BREAK THE 70 DEGREE MARK BUT MANY AREAS WILL REMAIN IN THE UPPER 60S. SOUTH SOUTHEAST WINDS WILL CONTINUE AT 10 TO 15 MPH. .LONG TERM /TONIGHT THROUGH SATURDAY/... ISSUED AT 325 AM CDT SUN MAY 24 2015 LITTLE HAS CHANGED FOR THE INITIAL FORECAST PERIOD...WITH MAIN CONCERNS ON PRECIP CHANCES FOR THE REMAINDER OF THE HOLIDAY WEEKEND. LARGE UPPER TROUGH TO REMAIN IN THE WEST THROUGH MUCH OF THE PERIOD...WITH SHORTWAVE ENERGY EJECTING NORTHEASTWARD THROUGH THE REGION. FIRST STRONGER SHORTWAVE TROUGH TO LIFT THROUGH THE REGION TONIGHT...WITH THE ASSOCIATED SFC REFLECTION TRACKING FROM SE NE INTO SC MN TONIGHT INTO MONDAY MORNING. WITH A CONTINUED PUSH OF MOISTURE NORTHWARD FROM THE GULF AND WAA/THETA-E ADVECTION EXPECT WIDESPREAD PRECIPITATION ACROSS THE CWA TONIGHT. PWATS IN THE 1.5 INCH RANGE WITH DEEP WARM CLOUD DEPTHS...THEREFORE EXPECT EFFICIENT RAINFALL PRODUCTION. INSTABILITY WILL BE LIMITED...SO ONLY HAVE ISOLATED THUNDER AND THEREFORE THE FLASH FLOOD THREAT WILL BE DIMINISHED SOME BUT STILL POSSIBLE GIVEN DECENT RAIN EXPECTED TODAY AS WELL. AS THE UPPER LOW LIFTS NORTHWARD INTO MINNESOTA MONDAY...EXPECT A DRY PERIOD OR IF ANY LINGERING SHOWERS EXPECT WIDELY SCATTERED COVERAGE MAINLY BY LATE MONDAY MORNING INTO THE EARLY AFTERNOON HOURS. WAA TO CONTINUE WITH A WEAK BAROCLINIC ZONE PUSHING NORTHWARD INTO THE CWA BY LATE MONDAY AFTERNOON INTO MONDAY NIGHT. ANOTHER IMPULSE TO EJECT NORTHEASTWARD THROUGH THE AREA...MAY SET OFF SOME THUNDERSTORMS MONDAY NIGHT ACROSS THE SOUTHERN TWO- THIRDS OF THE CWA. AGAIN THIS PERIOD COULD BRING POTENTIAL FOR HEAVY RAINFALL ESPECIALLY GIVEN THE GREATER INSTABILITY PRESENT. CONTINUED CHANCES FOR THUNDERSTORMS INTO TUESDAY AND TUESDAY NIGHT AS A COLD FRONT SLOWLY SAGS SOUTHWARD ACROSS THE CWA. THIS SHOULD GIVE WAY TO A MOSTLY DRY WEDNESDAY WITH AN AREA OF SURFACE HIGH PRESSURE OVER THE REGION AND WEAK UPPER LEVEL SHORTWAVE RIDGING IN PLACE. SOUTHWEST FLOW PATTERN CONTINUES INTO THE END OF THE WEEK...WITH A STRONGER COLD FRONT EXPECTED TO DROP THROUGH THE STATE TOWARD NEXT WEEKEND. LONG RANGE MODELS THEN BUILD A STRONGER AREA OF HIGH PRESSURE INTO THE STATE FOR EARLY THE FOLLOWING WEEK. THEREFORE EXPECT AN ACTIVE WET PATTERN THROUGH MUCH OF THE UPCOMING WEEK...WITH A TREND TOWARD QUIETER WEATHER AFTER NEXT WEEKEND. TEMPERATURES TO BE NEAR AVERAGE...MAYBE SLIGHTLY COOLER THAN AVERAGE THROUGH THE UPCOMING WEEK. && .AVIATION...24/06Z ISSUED AT 1157 PM CDT SAT MAY 23 2015 VFR CONDITIONS WILL PERSIST OVERNIGHT WITH MVFR CEILINGS EVENTUALLY SPREADING NORTHWARD INTO THE STATE WITH SHOWERS. THE LOW CEILINGS AND SCATTERED SHOWERS WILL PERSIST INTO SUNDAY AND SUNDAY NIGHT WITH ANY RESTRICTIONS TO VISIBILITY COMING FROM FALLING RAIN. SURFACE WINDS WILL BE LIGHT TONIGHT AND INCREASE FROM THE SOUTH TO SOUTHEAST ON SUNDAY. && .HYDROLOGY... ISSUED AT 325 AM CDT SUN MAY 24 2015 MCV TRACKING OVER THE AREA THIS MORNING AND WILL BRING ALONG WITH IT MODERATE RAINFALL THROUGH THE DAYTIME HOURS. H850 FLOW AND PWATS ALONG WITH WARM CLOUD DEPTHS WILL PROMOTE EFFICIENT RAINFALL TODAY. TOTALS THROUGH 12Z SOUTH WILL APPROACH .50 TO .66 INCHES WHILE LESSER BUT SIMILAR AMOUNTS WILL FALL OVER THE NORTHEAST THROUGH THE AFTERNOON HOURS. ANOTHER SYSTEM ARRIVING BY EVENING WILL BRING ADDITIONAL QUARTER INCH AMOUNTS SOUTHWEST. TOTALS FOR THE DAY SHOULD RANGE FROM ABOUT 0.50 NORTHWEST TO FROM THE SOUTHWEST TO NORTHEAST. THE FIRST ROUND WILL HAVE LITTLE OVERALL IMPACT TO RIVERS THOUGH SUBSEQUENT RAINFALLS IN THE NEXT 24 TO 36 HOURS AFTER 00Z MAY CAUSE SOME HYDRO ISSUES ALONG MAINSTREAM RIVERS. AS THE FIRST SYSTEM DEPARTS THE NORTHEAST BY 20Z...THE SECOND SYSTEM WILL BEGIN AFFECTING SOUTHERN IOWA. ADDITIONAL CHANCES FOR HEAVY RAINFALL WILL COME MONDAY NIGHT INTO TUESDAY WITH THUNDERSTORMS EXPECTED ACROSS THE AREA. AT THIS TIME...NOT A LOT HAS CHANGED WITH THE MAJORITY OF THE RIVER OUTLOOKS EXPECTED TO STAY BELOW FLOOD STAGE. AGAIN...A FEW ENSEMBLES TO PUSH SOME OF THE RIVERS RISING ABOVE FLOOD STAGE WITH THE LOCATIONS CONTINUING TO BE ALONG THE DES MOINES AND RACCOON RIVER BASINS. NO HYDRO HEADLINES ARE EXPECTED...BUT THE SITUATION IS BEING CLOSELY MONITORED THROUGH THE HOLIDAY WEEKEND. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...BEERENDS AVIATION...COGIL HYDROLOGY...REV/BEERENDS  FXUS63 KDMX 242058 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 358 PM CDT SUN MAY 24 2015 .SHORT TERM /TONIGHT/... ISSUED AT 318 PM CDT SUN MAY 24 2015 A COUPLE ROUNDS OF MODERATE TO HEAVY RAINFALL ARE EXPECTED FOR THE CWA TONIGHT...WITH LITTLE IF ANY THUNDER EXPECTED EXCEPT EARLY IN THE PERIOD MAINLY ACROSS THE FAR SOUTHEASTERN CWA. THE 18Z WRF REFLECTIVITY SUMMARIZES FCST THOUGHTS RATHER WELL REGARDING RADAR TRENDS FOR THE SHORT TERM PERIOD OF THE FORECAST. THE FIRST ROUND WILL BE FROM LATE AFTERNOON INTO THIS EVENING...IN CONJUNCTION WITH THE MCV PRESENTLY LIFTING NORTHEAST THROUGH CENTRAL MISSOURI. THERE WILL BE A BRIEF PERIOD ACROSS THE FAR SOUTHEASTERN CWA...WHERE INSTABILITY WILL BE HIGHER UNTIL THE MCV PASSES LATER THIS EVE. ALTHOUGH WIDESPREAD SVR WX IS NOT EXPECTED...ANY STORMS THAT DO DEVELOP MAY HAVE TO BE MONITORED DUE TO THE COMBINATION OF ELEVATED INSTABILITY AS WELL AS SHEAR VALUES...AGAIN ACROSS THE FAR SOUTHEASTERN CWA. WOULD NOT BE SURPRISED TO SEE SOME ISOLATED HEAVY RAINERS FROM THE CONVECTION AS IT LIFTS NORTHEAST. THE SECOND ROUND OF MODERATE TO HEAVY RAINFALL WILL BE OVERNIGHT TONIGHT INTO MONDAY MORNING...IN CONJUNCTION WITH THE MCV PRESENTLY IN THE ARKLATEX REGION. GREATEST THREAT FOR HEAVY RAINFALL WILL BE ACROSS CENTRAL AND EASTERN PARTS OF THE CWA...ESPECIALLY IN CENTRAL AND SOUTHERN IOWA ROUGHLY CENTERED ON THE I-35 CORRIDOR GIVEN THE PCPN RESIDENCE TIME. PWAT VALUES ARE QUITE IMPRESSIVE...WITH VALUES AS HIGH AS AROUND 1.7 INCHES AND THUS EXCEEDING THE 90TH PERCENTILE AND APPROACHING RECORD HIGH VALUES FOR THIS TIME OF YEAR. WARM CLOUD DEPTHS WILL APPROACH OR EXCEED 12 KFT. ALTHOUGH DEEP-LAYER INSTABILITY WILL NOT BE HIGH...MUCAPES WILL BE SUFFICIENT ALONG WITH ANOMALOUS MOISTURE TO RESULT IN A HEAVY RAIN THREAT. EVEN THUNDER WILL NOT BE NEEDED FOR EFFICIENT RAINFALL PRODUCTION OVERNIGHT. AM NOT OVERLY CONCERNED ABOUT WIDESPREAD FLASH FLOOD THREAT HOWEVER...SO HAVE OPTED TO NOT ISSUE A FLASH FLOOD WATCH. THAT BEING SAID...SOME ISOLATED INSTANCES OF MINOR FLOODING IS POSSIBLE... ESPECIALLY IN URBAN AREAS OR AREAS WITH POOR DRAINAGE. ONLY MINOR TWEAKS TO FORECAST TEMPS TONIGHT...MAINLY LOWERING THEM A COUPLE DEGREES IN PLACES AS HIGHS TODAY DID NOT GO AS HIGH AS ANTICIPATED. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 318 PM CDT SUN MAY 24 2015 SURFACE LOW WILL CONTINUE TO LIFT NORTH THROUGH THE BEGINNING OF THE PERIOD...AND EXPECT ONGOING PRECIPITATION ACROSS MUCH OF THE AREA IN THE EARLY MORNING HOURS...ESPECIALLY THE NORTH. THIS WILL LIFT NORTH...WITH BOUNDARY LINGERING NEAR MN/IA BOARDER THROUGH THE MORNING HOURS. WEAK TROUGH WILL PUSH EAST THROUGH THE LATE MORNING INTO CENTRAL NEBRASKA. CONCERNS ABOUT PRECIPITATION REDEVELOPING NEAR EASTERN NEBRASKA IN THE AFTERNOON AND PUSHING EAST INTO IOWA LATE IN THE AFTERNOON. HIGH RES MODELS ARE TRENDING TOWARDS THIS SOLUTION. CONCERN WILL BE WITH SEVERE POTENTIAL WITH STORMS WHICH MAY DEVELOP...WITH MODELS INDICATING CAPE VALUES IN THE LATE AFTERNOON AND EARLY EVENING ACROSS CENTRAL IOWA NEAR OR ABOVE 2000 J/KG WITH SHEAR INCREASING ALONG WEAK BOUNDARY...SUFFICIENT TO ALLOW FOR STORMS WHICH DEVELOP TO PERSIST WITH POTENTIAL TO BECOME SEVERE...WITH HAIL AND WIND THE MAIN THREATS. SURFACE LOW WILL LIFT NORTHEAST ACROSS EASTERN IOWA THROUGH TUESDAY. THIS WILL ALLOW FOR PRECIPITATION CHANCES TO PERSIST ALONG BOUNDARY DRAPED ACROSS IOWA THROUGH TUESDAY. WITH SLOW MOVING LOW...CONCERN BECOMES FOR HEAVY RAIN POTENTIAL. CONDITIONS WILL REMAIN FAVORABLE TO ALLOW FOR RAINFALL RATES TO BE HEAVY AT TIMES...THOUGH MOISTURE BEGINS TO DIMINISH WITH PWAT RATES MUCH LOWER...CLOSER TO 1 INCH...AND WARM CLOUD DEPTHS NOT AS DEEP. HOWEVER...EFFICIENT RAINFALL WILL BE POSSIBLE AND CANNOT RULE OUT POTENTIAL LOCALIZED HEAVY RAIN. WILL NEED TO MONITOR FOR FLASH FLOOD AND FLOOD POTENTIAL GIVEN PREVIOUS DAYS RAINFALL ACROSS THE AREA. SYSTEM WILL FINALLY PUSH SOUTH OF THE AREA TUESDAY NIGHT...WITH A BREAK IN PRECIPITATION CHANCES WEDNESDAY BEFORE LARGE UPPER LEVEL LOW PUSHES EAST ACROSS NORTHERN CANADA WITH ASSOCIATED SYSTEM PUSHING INTO CENTRAL IOWA LATE THURSDAY BRINGING ANOTHER ROUND OF PRECIPITATION CHANCES THROUGH THE EXTENDED. MODELS HANG BOUNDARY UP IN CENTRAL/SOUTHERN IOWA THROUGH THE WEEKEND...WITH GFS THE MOST AGGRESSIVE DEVELOPING ANOTHER LOW ACROSS CENTRAL PLAINS STATES...AND KEEPING PERSISTING CHANCES FOR THUNDERSTORMS ACROSS IOWA. HAVE TRENDED TOWARDS ECMWF WITH PRECIPITATION CHANCES ENDING FROM NORTH TO SOUTH THROUGH THE WEEKEND. TEMPERATURES WILL BE GENERALLY STEADY THROUGH THE WEEK WITH HIGHS IN THE 70S AND 80S AND LOWS IN THE 50S AND 60S. HOWEVER...BEHIND BOUNDARY LATE IN THE PERIOD TEMPERATURES WILL AGAIN BE MUCH COOLER. && .AVIATION...24/18Z ISSUED AT 1244 PM CDT SUN MAY 24 2015 ANOTHER ROUND OF PCPN...MAINLY LIGHT...IS EXPECTED TO REACH IA BY MID-AFTN AND SPREAD NE. DO NOT EXPECT CIGS/VSBYS TO CHANGE MUCH FROM PRESENT VALUES WITH IT HOWEVER. HEAVIER PCPN IS EXPECTED OVERNIGHT AND WILL BRING LOWER CIGS/VSBYS...WITH A RETURN OF IFR/LIFR CONDITIONS TONIGHT/OVERNIGHT. STRONGER SOUTH WINDS MAY ACCOMPANY AREAS EAST OF THE LOW AS WELL. && .HYDROLOGY... ISSUED AT 318 PM CDT SUN MAY 24 2015 ALTHOUGH MODERATE TO HEAVY RAINFALL IS EXPECTED OVERNIGHT TONIGHT IN CONJUNCTION WITH THE TWO ROUNDS OF ACTIVITY...A WIDESPREAD FLASH FLOOD THREAT IS NOT ANTICIPATED...THUS FLASH FLOOD WATCH WAS NOT ISSUED. FORECAST RAINFALL AMOUNTS REMAIN BELOW FLASH FLOOD GUIDANCE VALUES. OF MORE CONCERN REGARDING FLASH FLOODING IS ITS POTENTIAL LATE MONDAY INTO MONDAY IN CONJUNCTION WITH THE ACTIVITY THEN. IN TERMS OF RIVER FLOODING...MINOR TO MODERATE WITHIN-BANK RISES ARE EXPECTED AT MULTIPLE LOCATIONS ESPECIALLY WITHIN THE MIDDLE TO LOWER DES MOINES RIVER BASIN...AS WELL AS THE LOWER RACCOON RIVER BASIN. IF RAINFALL OVER THE NEXT 36-48 HRS COMES IN HEAVIER THAN EXPECTED...THEN MINOR FLOODING COULD BE EXPECTED AT SOME LOCATIONS. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ZOGG LONG TERM...AWB AVIATION...ZOGG HYDROLOGY...ZOGG  FXUS63 KDMX 250820 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 320 AM CDT MON MAY 25 2015 .SHORT TERM /TODAY/... ISSUED AT 320 AM CDT MON MAY 25 2015 ANOTHER COMPLEX DAY AHEAD...THOUGH SYSTEM HAS NOT EVOLVED EXACTLY AS LAST NIGHTS MODELS SUGGESTED FOR 06-12Z MONDAY...UPPER LEVEL WAVE OVER NORTHEAST KS AND NORTHWEST MO BECOMING MORE ACTIVE AT 07Z. SHOWERS AND ISO THUNDER BEGINNING TO DEVELOP OVER THOSE AREAS HEADING INTO SOUTHERN IOWA NOW. HAVE UPDATED THE OVERNIGHT INTO MORNING POP GRIDS TO REFLECT THE INCOMING PRECIPITATION. FORTUNATELY PRECIPITABLE WATER VALUES HAVE DROPPED TO NEAR ONE INCH AND WARM CLOUD DEPTHS ARE SLIGHTLY UNDER 10KFT SO RAINFALL EFFICIENCY WILL NOT BE AS PROLIFIC AS SUNDAY MORNINGS SHOWERS AND MORE WELL DEFINED MCV THAT CROSSED THE AREA. SUBJECTIVE H850 00Z ANALYSIS CONTINUES TO SHOW SUBTROPICAL ANCHOR HIGH OFF THE SOUTHEAST US WITH BROAD AREA OF LOW PRESSURE OVER THE ROCKIES...LOW NEAR DENVER AT 00Z. THE MAIN MOISTURE CHANNEL HAS MOVED EAST OF IOWA NOW BUT THE LOW AND APPROACHING FRONT LATE THIS EVENING WILL STILL IMPACT THE REGION WITH MORE CHANCES FOR STORMS. AS THE UPPER LEVEL DISTURBANCE OVER KS TRACKS NORTHEAST...IT SHOULD EXIT EAST/NORTHEAST AREAS BETWEEN 15- 17Z. SOME BREAKS IN CLOUDS LIKELY SOUTHEAST THIRD...ALLOWING HIGHS TO BUILD INTO THE LOWER 80S THIS AFTERNOON. OVER THE NORTH LOWER TO MID 70S MORE LIKELY WITH THICKER CLOUD COVER. BETWEEN 20-00Z WILL BE LOOKING FOR MAIN H500 WAVE OVER THE ROCKIES TO EJECT NORTHEAST TOWARD IOWA. THIS WILL SET THE STAGE FOR INCREASING THUNDERSTORM DEVELOPMENT. BUFR SOUNDINGS SHOW 1200-1900 J/KG MLCAPE BY 21Z THIS AFTERNOON MOST AREAS. WIND FIELDS ALOFT NOT OVERLY IMPRESSIVE THIS AFTERNOON...BUT CERTAINLY ENOUGH TO ORGANIZE STORMS WITH THE POTENTIAL FOR SEVERE STORMS. CURRENTLY OUR AREA HAS BEEN UPDATED TO SLIGHT RISK FOR LATE AFTERNOON AND EARLY EVENING. MAIN THREATS APPEAR TO BE WIND AND HAIL AND A FEW TORNADOES. ACTIVITY LIKELY TO CONTINUE INTO THE EARLY EVENING. RAINFALL TODAY MAY STILL APPROACH .25 TO .75 INCHES WITH THE COMBINATION OF THIS MORNINGS PRECIPITATION AND THIS AFTERNOONS EXPECTED STORMS OVER THE WEST /NORTHWEST. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 320 AM CDT MON MAY 25 2015 ACTIVE PATTERN TO CONTINUE THROUGH MUCH OF THE PERIOD...WITH THE MAIN WESTERN US TROUGH TO LIFT NORTHEASTWARD THROUGH TUESDAY. THIS UPPER WAVE WILL APPROACH THE REGION TONIGHT AND MOVE THROUGH THE CWA TUESDAY BEFORE PUSHING INTO THE GREAT LAKES REGION TUESDAY NIGHT. SOUTHERLY FLOW AHEAD OF IT WILL CONTINUE TO PUSH MOISTURE NORTHWARD INTO THE AREA...WITH AN ELONGATED AREA OF LOW PRESSURE AND ASSOCIATED WARM FRONT STRETCHED NORTHEASTWARD ACROSS THE CWA TONIGHT INTO TUESDAY. AN UPPER VORT MAX CURRENTLY OVER CNTRL/NW TEXAS WILL LIFT NORTHWARD TOWARD THE REGION AS WELL...AND WITH ENERGY FROM THE MAIN UPPER TROUGH AND THIS SECONDARY SHORTWAVE TROUGH LIFTING THROUGH THE REGION LATE TONIGHT...EXPECT AN AREA OF THUNDERSTORMS TO DEVELOP ACROSS THE CWA MAINLY DURING THE EVENING/LATE NIGHT HOURS. DEEP LAYER SHEAR STRONGER IN THE EVENING THEN WEAKENS INTO THE OVERNIGHT HOURS...WITH INSTABILITY WANING THROUGH THE OVERNIGHT HOURS AS WELL. GIVEN THE AMOUNT OF SHEAR/INSTABILITY SOME SEVERE STORMS POSSIBLE WITH THE LATEST SPC OUTLOOK SHOWING A SLIGHT RISK ACROSS MUCH OF THE CWA FOR TONIGHT. LARGE HAIL AND DAMAGING WINDS WOULD BE THE MAIN THREATS...WITH AN ISOLATED TORNADO THREAT AS WELL HOWEVER IT LOOKS SLIGHTLY BETTER FURTHER SOUTH AND WEST OF THE CWA. THUNDERSTORM CHANCES CONTINUE INTO TUESDAY AS THE UPPER WAVE MOVES THROUGH THE CWA...AND THE SFC TROUGH AXIS TO PUSH EAST BY LATE TUESDAY/TUESDAY NIGHT. WEAK COLD FRONTAL BOUNDARY TO SAG SOUTH OF THE STATE FOR WEDNESDAY/WEDNESDAY NIGHT BEFORE LIFTING BACK NORTHWARD THURSDAY. HIGH PRESSURE TO BRIEFLY BUILD INTO THE STATE AS WELL WEDNESDAY SO EXPECT MAINLY DRY CONDITIONS WEDNESDAY/WEDNESDAY NIGHT. NAM TRIES TO HANG THE BOUNDARY ACROSS THE SOUTH...WITH SOME ADDITIONAL THUNDERSTORM DEVELOPMENT BUT THE MAJORITY OF THE MODELS PUSH IT SOUTH OF THE CWA. THUS HAVE GONE WITH THE CONSENSUS AND STUCK WITH DRY CONDITIONS FOR WEDNESDAY NIGHT. ANOTHER UPPER TROUGH TO BUILD INTO THE WESTERN US FOR THURSDAY INTO NEXT WEEKEND...WITH SOUTHWESTERLY FLOW SETTING UP AGAIN AND CHANCES FOR THUNDERSTORMS RETURN FOR LATE WEEK. A STRONGER COLD FRONT TO DROP THROUGH THE AREA NEXT WEEKEND WITH A LARGE AREA OF HIGH PRESSURE EXPECTED TO BUILD INTO THE AREA FOR SUNDAY INTO MONDAY. TEMPERATURES TO REMAIN NEAR AVERAGE FOR THE FIRST FEW DAYS OF THE PERIOD WITH A TURN TOWARD COOLER THAN AVERAGE TOWARD THE WEEKEND AND INTO EARLY NEXT WEEK. && .AVIATION...25/06Z ISSUED AT 1159 PM CDT SUN MAY 24 2015 WARM SECTOR HAS SPREAD ACROSS THE FORECAST AREA THIS EVENING AND WILL CONTINUE INTO THE DAY ON MONDAY. HAVE SEEN CEILINGS ACROSS MUCH OF THE AREA CLIMB ABOVE MVFR AND ANTICIPATE MUCH OF THE AREA TO BE VFR OVERNIGHT. SOME MVFR VISIBILITIES MAY OCCUR IN THE NORTHWEST NEAR KFOD WHERE LIGHT WINDS ALLOW FOR LIGHT FOG DEVELOPMENT. GENERALLY VFR CONDITIONS ON MONDAY WITH INCREASING SOUTHWEST SURFACE WINDS. SOME CONVECTION IS EXPECTED BY MONDAY EVENING WHICH WILL PRODUCE SCATTERED MVFR CONDITIONS IN AND AROUND THUNDERSTORMS. && .HYDROLOGY... ISSUED AT 320 AM CDT MON MAY 25 2015 RAIN EXPECTED ONCE AGAIN TODAY...BUT THREAT FOR ANY FLASH FLOODING REMAINS LOW. RAINFALL RATES EARLY TODAY NOT EXPECTED TO BE HIGH ENOUGH AND RAINFALL PERSISTENT ENOUGH. LATER TODAY...SCATTERED NATURE OF STORMS SHOULD NOT LEAD TO ANY WIDESPREAD COVERAGE UNTIL THE EVENING HOURS. MAIN CONCERNS ARE ADDITIVE EFFECTS OF YESTERDAYS THROUGH TUESDAYS RAINFALL...AND SUBSEQUENT EVENTS. SOME URBAN RUNOFF AND PONDING OF WATER MAY BE POSSIBLE WITH STRONGER STORMS. IN TERMS OF RIVER FLOODING...MINOR TO MODERATE WITHIN-BANK RISES ARE EXPECTED AT MULTIPLE LOCATIONS ESPECIALLY WITHIN THE MIDDLE TO LOWER DES MOINES RIVER BASIN...AS WELL AS THE LOWER RACCOON RIVER BASIN. IF RAINFALL OVER THE NEXT 24-36 HRS COMES IN HEAVIER THAN EXPECTED...THEN MINOR FLOODING COULD BE EXPECTED AT SOME LOCATIONS. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...BEERENDS AVIATION...COGIL HYDROLOGY...ZOGG/REV  FXUS63 KDMX 280811 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 311 AM CDT THU MAY 28 2015 .SHORT TERM /TODAY/... ISSUED AT 310 AM CDT THU MAY 28 2015 A SURFACE HIGH PRESSURE AREA DOMINATING THE REGION EARLY THIS MORNING WILL SLIDE OFF TO THE EAST TODAY...ALLOWING FOR A RETURN OF MODEST SOUTHEAST TO SOUTH FLOW ACROSS OUR FORECAST AREA. THIS SHOULD PROMOTE FAIRLY MILD TEMPERATURES ONCE AGAIN. HOWEVER...AT 500 MB THE RIDGE AXIS CURRENTLY OVERHEAD WILL ALSO SHIFT EASTWARD AS A BROAD SHORTWAVE TROUGH APPROACHES SLOWLY FROM THE SOUTHWEST. THIS FEATURE IS RESPONSIBLE FOR THE CLOUDS AND THUNDERSTORMS CURRENTLY AFFECTING EASTERN KANSAS...AND WILL SPREAD SHOWERS AND STORMS UP INTO OUR AREA LATER TODAY TEMPERING THE POTENTIAL FOR WARMING ESPECIALLY IN OUR SOUTHWEST AND WEST. THE TRICKY FORECAST QUESTION IS THE TIMING OF RAIN BEGINNING AS IT SLOWLY SPREADS FROM SOUTHWEST TO NORTHEAST. HOWEVER...GIVEN THE SUBSIDENCE ASSOCIATED WITH THE HIGH PRESSURE CURRENTLY OVER IOWA WHICH WILL BE SLOW TO DEPART...AS REFLECTED IN THE VERY LIMITED INSTABILITY FORECAST BY HIGH RES MODELS FOR TODAY...HAVE CONTINUED THE TREND OF SLOWING THE LEADING EDGE OF POPS WHICH WILL PRIMARILY BE CONFINED TO OUR SOUTHWESTERN COUNTIES UNTIL LATE IN THE DAY. AT ANY RATE...GIVEN THE AFOREMENTIONED RELATIVE LACK OF INSTABILITY ALONG WITH WEAK DEEP LAYER SHEAR...SEVERE WEATHER PROBABILITY WILL BE QUITE LOW AND NO SIGNIFICANT IMPACTS ARE EXPECTED. .LONG TERM /TONIGHT THROUGH WEDNESDAY/... ISSUED AT 310 AM CDT THU MAY 28 2015 PRIMARY CONCERN WILL BE PRECIP WINDOW FROM TONIGHT INTO EARLY SATURDAY. BROAD WEAK FORCING AHEAD OF CURRENT NV/ID SHORT WAVES HAS PRODUCED SCATTERED LOW END CONVECTION FROM NE INTO THE DAKOTAS OVERNIGHT. MUCH OF THE FORCING IS IN THE H85/H7 LAYER WITH AN EXTENDED PERIOD OF THETA-E ADVECTION...AND THIS SHOULD ENTER IA LATER TODAY AND CONTINUING THROUGH FRI...ESPECIALLY SE. THE BAROCLINIC ZONE IS NOT IMPRESSIVE SO IT MAY BE DRIVEN MORE BY PERSISTENT MOISTURE TRANSPORT THAN ANYTHING. SURFACE BASED POTENTIAL WILL ALSO COME INTO PLAY FRI AFTERNOON AND EVENING WITH FRONTAL PASSAGE. MLCAPES TYPICALLY VARY FROM 500-1500 J/KG AND APPEAR TO BE UNCAPPED. WIND PROFILES ARE NOT TOO IMPRESSIVE SO DEEP SHEAR SHOULD BE MARGINAL. THUS AGREE WITH SPC LOW END OUTLOOK AND DO NOT EXPECT MUCH SEVERE WEATHER. ALTHOUGH DO NOT EXPECT AMOUNTS TO BE EXTREME...LOCALLY HEAVY RAINS MAY BE MORE OF A CONCERN WITH NAEFS SPECIFIC HUMIDITIES...PWAT AND INTEGRATED WATER VAPOR TRANSPORT IN THE 90TH PLUS PERCENTILE. WITH WARM CLOUD DEPTHS 11KFT AND HIGHER...A PROLONGED PERIOD OF SW-NE MEAN WIND MAY RESULT IN SOME REPETITIVE BURSTS THU NIGHT INTO FRI. THE FRONT SHOULD EXIT THE FORECAST AREA SE FRI NIGHT...BUT HIGHER BASED WEAK FORCING MAY LINGER BEHIND THE FRONT AHEAD OF THE H7/H5 TROUGH INTO SAT MORNING. A COOLER AND ESPECIALLY DRIER AIRMASS WILL THEN FOLLOW FOR THE WEEKEND. THE PERIOD OF DRY WEATHER IS EXPECTED TO CONTINUE INTO EARLY NEXT WEEK WITH THE PASSAGE OF SHORT WAVE RIDGING. UPPER LEVEL FLOW AMPLITUDE WILL THEN INCREASE SLIGHTLY HEADING INTO MID WEEK WITH ANOTHER ITERATION OF A WRN CONUS TROUGH. ALTHOUGH ANY SURFACE FEATURE AFFECTS WILL BE BEYOND THE VALID PERIOD...WEAK MID LEVEL FORCING MAY BRING SOME SCATTERED WEAK CONVECTION AROUND WED. STRENGTHENING RETURN FLOW WELL AHEAD OF THIS SYSTEM SHOULD FINALLY RETURN TEMPS TO NORMAL AND JUST ABOVE BY THIS TIME AS WELL. && .AVIATION...28/06Z ISSUED AT 1149 PM CDT WED MAY 27 2015 CONDITIONS WILL BE VFR THROUGH PERIOD WITH WINDS REMAINING SOUTHERLY...THOUGH INCREASING BEYOND 12Z. WITH LIGHT WINDS FOR BEGINNING OF PERIOD MAY SEE LOCALIZED BR/FG BUT HAVE NOT INCLUDED MENTION IN SITES ATTM. WILL SEE GUSTS UP TO 25KTS AT SITES THROUGH 00Z. BOUNDARY WILL BEGIN TO BRING SHRA AND TSRA TO SITES LATE IN PERIOD...NEAR OR BEFORE 00Z IN THE WEST SPREADING EAST. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...LEE LONG TERM...SMALL AVIATION...AWB  FXUS63 KDMX 282023 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 323 PM CDT THU MAY 28 2015 .SHORT TERM /TONIGHT/... ISSUED AT 323 PM CDT THU MAY 28 2015 COMPLICATED FORECAST TONIGHT AS WE HAVE A FEW THINGS AFFECTING THE FORECAST. ADDING TO THE MIX...THE MODELS AND IN PARTICULAR THE HI- RES MODELS DO NOT SEEM TO HAVE A GREAT HANDLE ON THE MODE OF CONVECTION OR THE COVERAGE OF IT. REMNANTS OF THE MCC OVER MO FROM LAST NIGHT INITIALLY WERE DYING OUT AS THE SHOWERS/STORMS LIFTED TO THE NORTH AND RAN INTO THE SURFACE HIGH OVER IOWA. THE HIGH HOWEVER IS SHIFTING TO THE EAST AND RETURN FLOW/WEAK WARM ADVECTION HAS SHIFTED INTO SOUTHWEST IOWA. THIS ALLOWED FOR RE-GENERATION OF SHOWERS ACROSS SOUTHWEST IOWA. ALSO A SHORTWAVE LIFTING OUT OF KANSAS IS CURRENTLY PUSHING INTO SOUTHWEST IOWA AND AIDING IN THE RE-GENERATION OF SHOWERS. IT WILL LIFT ACROSS THE FORECAST AREA THIS EVENING INTO THE OVERNIGHT...REACHING NORTHERN/NORTHEAST IOWA BETWEEN 04Z AND 07Z. THUS FAR INSTABILITY IS WEAK AND THERE IS VERY LITTLE TO NO SHEAR SO WHAT WE HAVE OVER SOUTHERN/SOUTHWEST IOWA IS SHOWERS WITH A POTENTIAL FOR AN ISOLATED THUNDERSTORM THROUGH LATE AFTERNOON. THE SHORTWAVE SHOULD PROVIDE ENOUGH FORCING AND COUPLED WITH SOME THETA- E ADVECTION...THUNDERSTORMS SHOULD BECOME AT LEAST A LITTLE MORE PREVALENT THROUGH THE EVENING. HAVING SAID THAT THOUGH...WITH SUCH MEAGER INSTABILITY AND WEAK TO NON-EXISTENT SHEAR...THE COVERAGE OF THUNDERSTORMS IS REALLY IN QUESTION. WE MAY SEE MORE OF A SHOWERS WITH ISOLATED THUNDERSTORMS TYPE SCENARIO THROUGH THE EVENT THIS EVENING. GIVEN THE WEAK SHEAR OVER THE AREA EVEN IF WE DO GET A THUNDERSTORM...THE THREAT OF ANY STORM BEING SEVERE IS MINIMAL. HOWEVER WITH A DEEP WARM CLOUD DEPTH... LOCALLY HEAVY RAINFALL IS POSSIBLE FROM ANY STRONGER STORMS. AS FOR COVERAGE...THE HI-RES MODELS ARE HAVING A HORRIBLE TIME WITH HOW THE PRECIP WILL EVOLVE ACROSS THE CWA AND MOVE ACROSS. BASED ON CURRENT RADAR TRENDS...THE PRECIP SHIELD SHOULD CONTINUE TO EXPAND ACROSS SW IA AND LIFT TO THE NORTH NORTHEAST THROUGH THE EVENING WITH MOST OF THE PRECIP BEING DONE BY 06Z SO. THERE SHOULD ONLY BE ONE EVENT TONIGHT WITH THE SHORTWAVE PASSING BUT ALL OF THE HI-RES MODELS LINGER SOME SPOTTY SHOWERS/STORMS ACROSS THE CWA THROUGHOUT THE NIGHT LIKELY FROM LINGERING QG FORCING AND THETA-E ADVECTION AND WHILE THAT DOESN'T SEEM LIKELY...IT IS DIFFICULT TO PINPOINT WHERE LINGERING PRECIP MIGHT BE AND WHERE IT WILL BE ABSENT. I HIT THE POPS HIGHEST DURING PERIODS WHEN THE SHORTWAVE WILL LIFT ACROSS THEN DROP THE POPS SIGNIFICANTLY FOR THE REST OF THE PERIOD. THIS MAY BE OVERDONE BUT KEEPING HIGH CHANCE OR LIKELY POPS GOING FOR A 12 HOUR PERIOD WOULD ALSO BE OVERDONE. LATER SHIFTS CAN ADJUST AS THIS EVENT EVOLVES ACROSS CENTRAL IOWA. THE 18Z NAM ACTUALLY HAS FINALLY PICKED UP ON THIS THOUGH IT IS CLOSE TO PUBLISH TIME. THE FORECAST IS AT LEAST TRENDED IN THAT DIRECTION. POPS SHOULD AGAIN PICK UP TOWARDS/AFTER 12Z AS ANOTHER SHORT WAVE APPROACHES CENTRAL IOWA. ALSO THERE MAY BE SOME PATCHY LIGHT FOG DEVELOPING IN AREAS THAT HAVE A LITTLE BETTER RAINFALL FROM THE EVENING BUT THIS SHOULD NOT HAVE AN IMPACT TO CENTRAL IOWA COMMUTERS. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 323 PM CDT THU MAY 28 2015 PATTERN CONTINUES TO BE ACTIVE THROUGH FRIDAY NIGHT...WITH THE MAIN UPPER LEVEL SYSTEM APPROACHING THE REGION FRIDAY. THIS WILL BRING MORE SHOWERS/THUNDERSTORMS BEFORE COOLER HIGH PRESSURE BUILDS IN FOR THE WEEKEND. CURRENT WATER VAPOR IMAGERY SHOWS MULTIPLE WAVES OVER THE SOUTHERN PLAINS. ALONG WITH THE MEAN TROUGH ADVANCING SOUTHEAST...A SHORT WAVE CURRENTLY OVER NORTHERN NEW MEXICO WILL DRIFT NORTHEAST WITH TIME AND ARRIVE OVER SOUTHERN IOWA BY 21-00Z FRIDAY. THE COMBINATION OF THE APPROACHING COOL FRONT AND SHORTWAVE FRIDAY WILL INCREASE THE CHANCES FOR STORMS ESPECIALLY IN THE AFTERNOON/EVENING HOURS. OVERNIGHT TEMPS WILL REMAIN MILD...WITH HIGHS FRIDAY COOLER THAN TODAY...WITH CLOUDS AND SHOWERS MORE LIKELY. WIDESPREAD SEVERE CHANCES AGAIN APPEAR LESSENED FRIDAY... AS MODELS SHOW BEST BULK SHEAR ARRIVING BEHIND THE BOUNDARY FRIDAY EVENING. MEANWHILE...MUCAPE SHOULD INCREASE TO 800 TO 1600 J/KG BETWEEN 18 AND 00Z SATURDAY. WITH THE LACK OF ANY CAP...LIKELY THAT GRADUAL RELEASE OF INSTABILITY WILL BECOME MORE COMMON IN THE AFTERNOON HOURS AS THE MORNINGS CONVECTIVE SYSTEM DIMINISHES IN INTENSITY. BIGGEST THREATS LATER IN THE DAY SHOULD BE FROM WIND AND HAIL AS FORECAST UPPER LEVEL WIND FIELDS REMAIN MARGINAL AND SHOULD REDUCE STORM ORGANIZATION. WITH THE AIRMASS IN PLACE NOW...PRECIPITABLE WATER VALUES WILL CONTINUE TO INCREASE AS MASS CONVERGENCE INCREASES THROUGH FRIDAY AFTERNOON AHEAD OF THE BOUNDARY. PWAT VALUES APPROACH 1.5 TO 1.75 FROM I35 EAST SOUTHEAST DURING THE AFTERNOON HOURS AND EARLY EVENING. CONCURRENT WARM CLOUD DEPTHS WILL TOP OUT AT 10 TO 12KFT FOR MOST OF THE SOUTHEAST TWO THIRDS OF THE FORECAST AREA. DESPITE THE REALITY OF EFFICIENT RAINFALL...MOST OF THE GRIDDED FLASH FLOOD GUIDANCE SUGGESTS 1 AND 3 HOUR VALUES NEAR 2 INCHES... AND 6 HOUR NEAR 2.5 INCHES. THE OVERALL THREAT FOR FLASH FLOODING REMAINS LOW...HOWEVER BUFR SOUNDINGS INDICATE THAT THERE WILL BE A 2 TO 3 HOUR PERIOD OF SLOW MOVING STORMS POSSIBLE OVER THE AREA DURING THE DAY THROUGH EVENING. OVER THE NORTHWEST BETWEEN 10 AM AND NOON...THE HIGHWAY 20 CORRIDOR IN THE EARLY AFTERNOON...THE I80 CORRIDOR IN THE EARLY EVENING. THOUGH THERE IS SOME UNCERTAINTY ABOUT OVERALL COVERAGE... THERE IS A CHANCE FOR SOME URBAN RUN OFF ISSUES IF A QUICK 1 TO 2 INCHES OF RAINFALL FALLS IN SOME OF THE HEAVIER STORMS. THE CHANCES FOR ADDITIONAL LOCALLY HEAVY RAINFALL SHOULD SHIFT TO SOUTHEAST IOWA BETWEEN 00 AND 06Z AS THE BOUNDARY PROGRESSES SOUTHEAST AND THE DIURNAL INCREASE IN H850 WINDS ARRIVES OVER THAT AREA BETWEEN 03-06Z. ONCE THE STORMS PUSH SOUTHEAST RAINFALL SHOULD DIMINISH INTO 12Z SATURDAY MORNING WITH COOLER AND LESS HUMID CONDITIONS FOR THE BALANCE OF THE DAY SATURDAY. OVER THE WEEKEND H850 TEMPS WILL COOL TO 6 TO 8C OVER THE REGION...THIS WILL CAP HIGHS IN THE UPPER 60S TO MID 70S WITH COMFORTABLE HUMIDITY. IN THE LONG RANGE THE MEAN H500 PATTERN REMAINS ACTIVE WITH A RELATIVELY PERSISTENT SUBTROPICAL RIDGE OVER THE SOUTHEAST US AND A RATHER COOL POLAR JET ACROSS THE PACIFIC. THE COMBINATION OF THESE TWO FEATURES IS LIKELY TO PROMOTE ADDITIONAL SHORTWAVES TO PEEL OFF THE MAIN FLOW AND DEVELOP INTO THE ROCKIES/PLAINS WHILE H850 FLOW REMAINS DIRECTED AT THE PLAINS STATES THROUGH THE EXTENDED PERIOD. THE NEXT WAVE TO AFFECT THE AREA SHOULD ARRIVE AROUND WEDNESDAY NIGHT OF NEXT WEEK WITH CHANCES FOR STORMS LINGERING INTO THE END OF THE EXTENDED. HIGH TEMPERATURES THROUGH THE PERIOD WILL REMAIN WARM WITH MID 70S TO MID 80S MOST LIKELY AND LOWS IN THE 60S. && .AVIATION...28/18Z ISSUED AT 104 PM CDT THU MAY 28 2015 COMPLEX FORECAST AS THERE WILL BE SEVERAL ROUNDS OF SHOWERS/STORMS AFFECTING TAF LOCATIONS. REMNANT SHOWERS HAVE LIFTED OUT OF MO AND ADDITIONAL DEVELOPMENT WILL BE AIDED BY A SHORTWAVE LIFTING OUT OF THE SW MOVING ACROSS THE FORECAST AREA. AS THE SHORTWAVE MOVES ACROSS IT SHOULD PROVIDE ENOUGH FORCING FOR THUNDERSTORMS TO DEVELOP. THERE WILL THEN BE A BREAK LATE TONIGHT/FRIDAY MORNING BEFORE THE COLD FRONT MOVES THROUGH AND ADDITIONAL STORMS FORM. A S TO SE SFC FLOW WILL BE COMMON THROUGH THE FCST PD AT 15-25KTS AND DIMINISH AFTER SUNSET. LOCAL MVFR CONDITIONS WILL BE POSSIBLE IN SHOWERS AND POSSIBLY SOME FOG LATE TONIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...FAB LONG TERM...REV AVIATION...FAB  FXUS63 KDMX 010914 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 414 AM CDT MON JUN 1 2015 .SHORT TERM /TODAY/... ISSUED AT 414 AM CDT MON JUN 1 2015 MID LEVEL RIDGING WILL BUILD OVERHEAD TODAY FROM THE SOUTHWEST...EVEN AS A SURFACE RIDGE REMAINS ENTRENCHED TO OUR NORTHEAST. THIS WILL RESULT IN ANOTHER DRY DAY WITH A FEW MID/HIGH CLOUDS BUT OTHERWISE SUNNY SKIES. WINDS WILL TURN TO MORE OF A SOUTHEAST DIRECTION THAN YESTERDAY AND GIVEN THE SLIGHTLY WARMER MORNING LOWS AND HIGHER TEMPERATURES ALOFT...ALONG WITH ANOTHER DAY OF AIRMASS MODIFICATION...EXPECT THAT SURFACE TEMPERATURES WILL EXCEED YESTERDAY BY TWO OR THREE DEGREES AND HAVE ADJUSTED THE FORECAST APPROPRIATELY. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 414 AM CDT MON JUN 1 2015 ONE MORE DRY DAY THROUGH TUESDAY AS HIGH PRESSURE REMAINS OVER THE GREAT LAKES. THE AREA OF HIGH PRESSURE WILL BEGIN SHIFTING EAST ALREADY ON TUESDAY THOUGH AND WILL BE CENTERED OVER THE NEW ENGLAND REGION ON WEDNESDAY. THIS WILL RESULT IN INCREASING SOUTHERLY FLOW AND COMBINED WITH THE LOW LEVEL JET SHIFTING EAST...WILL BRING A STRONG PUSH OF MOISTURE ADVECTION INTO THE WESTERN PORTION OF THE STATE TUESDAY NIGHT. THE STABLE CONDITIONS FROM THE PAST FEW DAYS WILL END WITH INSTABILITY DEVELOPING AS THE MOISTURE ARRIVES. THE UPPER LEVEL FLOW ON WEDNESDAY WILL BE CHARACTERIZED BY A CLOSED LOW OVER THE SOUTHERN APPALACHIANS WITH BROAD WEST TO SOUTHWEST FLOW MOVING INTO IOWA. THIS FLOW WILL HAVE NUMEROUS SHORTWAVES EMBEDDED AND COMBINED WITH THE CONVECTIVE INSTABILITY...WILL LEAD TO THE POTENTIAL FOR SEVERAL ROUNDS OF THUNDERSTORMS...ESPECIALLY OVER THE NORTHWEST HALF OF THE STATE LATE TUESDAY NIGHT THROUGH FRIDAY. DEEP LAYER SHEAR PROFILES WILL BE GENERALLY WEAK DURING THIS PERIOD WITH MULTICELLS THE PRIMARY STORM MODE. INSTABILITY WILL BE ENOUGH WITH SFC BASED CAPES IN EXCESS OF 2000 J/KG DURING THE PEAK HEATING HOURS FOR STRONG UPDRAFTS FOR LARGE HAIL DEVELOPMENT AND CERTAINLY THE POTENTIAL FOR DAMAGING WINDS WITH COLD POOL DEVELOPMENT. ANOTHER THREAT WILL BECOME AREAS OF HEAVY RAINFALL AS PWATS INCREASE TO NEAR 1.75 INCHES ALONG WITH GOOD WARM CLOUD DEPTHS AND SLOW STORM MOVEMENTS. UPPER LEVEL RIDGING WILL MOVE INTO THE MIDWEST BY FRIDAY NIGHT INTO SATURDAY ALONG WITH THE INFLUENCE OF CANADIAN HIGH PRESSURE MOVING ACROSS THE WESTERN GREAT LAKES...WILL BRING DRIER AIR TO THE STATE. THUNDERSTORM CHANCES WILL INCREASE AGAIN BY SUNDAY AS THE HIGH PRESSURE SHIFTS EAST AND RETURN FLOW BECOMES ESTABLISHED ONCE AGAIN. HIGH TEMPERATURES IN THE 70S AND 80S WILL BE COMMON THROUGH THE PERIOD. && .AVIATION...01/06Z ISSUED AT 1148 PM CDT SUN MAY 31 2015 VFR CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD WITH HIGH PRESSURE DOMINATING THE WEATHER PATTERN INTO MONDAY NIGHT. SOME WIND SHIFT TO THE SOUTHEAST AS WEAK MIXING DEVELOPS MONDAY AFTERNOON...BUT WINDS REMAIN BELOW 12 KNOTS. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...LEE LONG TERM...DONAVON AVIATION...PODRAZIK  FXUS63 KDMX 020856 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 356 AM CDT TUE JUN 2 2015 .SHORT TERM /TODAY/... ISSUED AT 322 AM CDT TUE JUN 2 2015 THE PRIMARY FORECAST CHALLENGE TODAY WILL BE CLOUD TRENDS WITH STRATUS LIFTING NORTH/NORTHWEST FROM MISSOURI AND ILLINOIS AND HIGH CIRRUS BLOW OFF FROM STORMS ACROSS THE DAKOTAS AND NEBRASKA. THE AREA OF STRATUS IS ASSOCIATED WITH A RIBBON OF MOISTURE ADVECTION LIFTING OUT OF THE OHIO VALLEY. THIS MOISTURE ADVECTION WILL BE FOCUSED OVER CENTRAL IOWA THOUGH MUCH OF THE DAY. SOUNDINGS SHOW THAT THIS MOIST LAYER IS QUITE SHALLOW THEREFORE AFTER CLOUDS EXPAND INTO CENTRAL AND SOUTHERN IOWA THIS MORNING...THE STRATUS SHOULD BE SCATTERING BY THIS AFTERNOON. THE HIGH LEVEL CLOUDS FROM THE WEST SHOULD EVENTUALLY DIMINISH AS WELL AS OVERNIGHT CONVECTION TO THE WEST WEAKENS. THE LARGE AREA OF HIGH PRESSURE THAT IS RIDGED THROUGH THE CENTRAL GREAT LAKES WILL CONTINUE A SLOW SHIFT TO THE EAST TODAY. THIS IS ALLOWING FOR THE SHALLOW MOISTURE RETURN DURING THE DAY. PRECIPITATION CHANCES WILL BE NIL WITH A CAP IN PLACE AROUND 850 MB. HIGH TEMPERATURES ARE IN ANTICIPATION OF SOME SUN BY THIS AFTERNOON WITH HIGHS IN THE LOW TO MID 70S. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 322 AM CDT TUE JUN 2 2015 ACTIVE WEATHER PATTERN SETTING UP FOR EXTENDED WITH MULTIPLE CHANCES FOR THUNDERSTORMS EXPECTED THROUGH THE END OF THE WEEK...WITH HEAVY RAIN POSSIBLE AT TIMES. UPPER LEVEL LOW ACROSS CANADA WITH ASSOCIATED BOUNDARY AND SURFACE LOW CURRENTLY LOCATED IN WESTERN DAKOTAS WILL PUSH EAST FOR THE BEGINNING OF PERIOD...BEGINNING TO INFLUENCE IOWA BY LATE TONIGHT. TRACK OF SURFACE LOW IS SLIGHTLY MORE EASTERLY...HELPING TO DELAY ONSET OF PRECIPITATION IN THE NORTHWEST...AND HAVE TRENDED SLOWER FOR ONSET OF PRECIPITATION. PRECIPITATION CHANCES WILL PERSIST THROUGH THE DAY WEDNESDAY...THOUGH MODELS INDICATING HEAVIEST RAINFALL MAY BE FURTHER NORTH INTO SOUTHERN MN WITH ONGOING MCS PUSHING EAST INTO MN...THOUGH ENOUGH FORCING AND MOISTURE FURTHER NORTH TO WARRANT PRECIPITATION CHANCES ACROSS IOWA ALONG BOUNDARY. WITH AFTERNOON CONVECTION WILL SEE A CHANCE FOR SEVERE THUNDERSTORMS WEDNESDAY...WITH CAPE VALUES GENERALLY 1000-2000 J/KG THROUGH THE LATE AFTERNOON. MODELS INDICATE SLIGHT CAP WHICH ERODES BY LATE AFTERNOON. SHEAR WILL BE SUFFICIENT TO ALLOW FOR ANY STORMS WHICH DO FORM TO PERSIST...THOUGH BULK SHEAR VALUES OF 20-30 KTS WILL HELP TO KEEP SEVERE THREAT LIMITED...WITH HAIL AND HIGH WINDS THE MAIN THREATS. IN ADDITION...PWAT VALUES WILL BE NEAR OR ABOVE 1.5 INCHES...HIGH FOR JUNE...AND WILL ALLOW FOR HEAVY RAIN POTENTIAL WITHIN THUNDERSTORMS...ESPECIALLY IN THE NORTH. SYSTEM WILL PUSH SLOWLY EAST WEDNESDAY NIGHT...THOUGH STALLED SURFACE LOW IN CENTRAL KS WILL KEEP PERSISTENT CHANCES FOR PRECIPITATION ACROSS IOWA AS RIDGE BUILDS INTO UPPER MIDWEST. MAY SEE ANOTHER MCS DEVELOP WHICH PUSHES EAST INTO IOWA LATE IN THE OVERNIGHT WEDNESDAY AND THROUGH THE DAY THURSDAY. HOWEVER...MODELS ARE NOT IN GOOD AGREEMENT WITH PLACEMENT OF SYSTEM...WITH GFS FURTHER NORTH THAN ECMWF. TIMING AND LOCATION OF PRECIPITATION WILL BE HEAVILY DEPENDENT ON TRACK OF OVERNIGHT MCS ACTIVITY THROUGHOUT THE WEEK. THEREFORE...DO NOT HAVE HIGH CONFIDENCE IN LOCATION OF BEST RAINFALL POTENTIAL ATTM...THOUGH HAVE TRENDED TOWARDS THE GENERAL MODEL CONSENSUS OF FURTHER SOUTHWEST FOR THURSDAY AS LLJ PUSHES INTO SOUTHERN NE WEDNESDAY NIGHT. ONCE AGAIN...AFTERNOON THUNDERSTORMS WILL BE POSSIBLE THURSDAY WITH BOUNDARY EXPECTED TO REMAIN ACROSS CENTRAL IOWA. SMILIER TO WEDNESDAY...CAPE VALUES WILL BE BETWEEN 1000-2000 J/KG OR HIGHER...THOUGH SHEAR WILL BE STRONGER WITH BULK SHEAR VALUES NEAR OR ABOVE 30KTS...WITH BETTER LOW LEVEL SHEAR....ESPECIALLY IN THE SOUTHWEST...THOUGH BETTER SET UP TO THE WEST OF IOWA IN NE...WHICH WILL PUSH EASTWARD OVERNIGHT. THURSDAY NIGHT WILL SEE THE BEST CHANCES FOR HEAVY RAINFALL WITH STRONG MOISTURE TRANSPORT AND DEEP WARM CLOUD DEPTHS. IN ADDITION...PWAT VALUES WILL BE HIGH...NEAR 1.6 INCHES. SYSTEM WILL PERSIST INTO FRIDAY BEFORE FINALLY PUSHING SOUTH...HOWEVER GFS LINGERS SYSTEM LONGER THAN ECMWF...AND HAVE KEPT PRECIPITATION CHANCES INTO FRIDAY NIGHT THOUGH MAY BE TOO LONG. WILL SEE A BRIEF BREAK IN PRECIPITATION CHANCES FOR SATURDAY WITH HIGH PRESSURE BUILDING INTO TEXAS BEFORE ANOTHER TROUGH DIGS ACROSS UPPER PLAINS FOR LATE SATURDAY AND SUNDAY. TEMPERATURES WILL REMAIN FAIRLY STEADY THROUGH PERIOD WITH HIGHS IN THE 70S AND 80S AND LOWS IN THE 50S AND 60S...THOUGH MAY BE LOWER WITH OVERNIGHT PRECIPITATION. IN ADDITION...IF CLOUDS CLEAR DURING THE DAY...MAY BE TOO COOL ON HIGHS. && .AVIATION...02/06Z ISSUED AT 1147 PM CDT MON JUN 1 2015 MOISTURE WILL CONTINUE TO MOVE NORTHWARD INTO THE STATE OVERNIGHT WITH AREAS OF LOWER STATUS MOVING NORTH/DEVELOPING TOWARD DAYBREAK...ESPECIALLY IN THE SOUTH AND WEST. HAVE INCLUDED THIS IN THE KOTM AND KDSM TAFS WHERE MVFR CONDITIONS ARE EXPECTED TOWARD DAYBREAK. INCREASED HEATING AND MIXING ON TUESDAY WILL ALLOW CLOUDS BASES TO RISE AND COVERAGE TO DECREASE WITH VFR CONDITIONS TO RETURN IN ALL AREAS BY LATE MORNING. SURFACE WINDS WILL INCREASE FROM THE SOUTHEAST IN CENTRAL IOWA BECOMING GUSTY BY AFTERNOON. THE VFR CONDITIONS WILL PERSIST INTO TUESDAY EVENING AS WELL. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DONAVON LONG TERM...AWB AVIATION...COGIL  FXUS63 KDMX 022024 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 324 PM CDT TUE JUN 2 2015 .SHORT TERM /TONIGHT/... ISSUED AT 323 PM CDT TUE JUN 2 2015 STUBBORN STRATUS/STRATOCU DECK OVER SOUTH CENTRAL/SOUTHEAST IOWA SHOULD CONTINUE TO ERODE THROUGH THE EVENING HOURS. SOUTHWEST TO NORTHEAST ORIENTED UPPER LEVEL RIDGE WILL FLATTEN DURING THE COURSE OF THE EVENING AND OVERNIGHT AS MULTIPLE TRANSIENT SHORTWAVES EJECT NORTHEASTWARD FROM A NORTHWEST PACIFIC COAST LOW. LOW-LEVEL SOUTHERLY FLOW WILL VEER TO THE SOUTHWEST OVERNIGHT...TRANSPORTING A 925-700MB THERMAL RIDGE/MOISTURE PLUME CURRENTLY OVER NEBRASKA INTO IOWA BY WEDNESDAY MORNING. EVOLUTION OF CONVECTION DURING THE OVERNIGHT HOURS IS A BIT UNCERTAIN. MOST HIGH- RES CAMS TAKE AN MCS OUT OF THE WESTERN DAKOTAS AND WESTERN NEBRASKA THIS EVENING...THOUGH VARIOUS SOLUTIONS TAKE THE TRACK ANYWHERE FROM NORTHERN SOUTH DAKOTA TO NORTHERN NEBRASKA. ADDITIONAL SOLUTIONS LIKE THE 18Z HRRR DEVELOP NEW CONVECTION IN WESTERN IOWA AROUND 09Z. THIS SOLUTION IS CERTAINLY PLAUSIBLE GIVEN THE MUCAPE VALUES OF AROUND 1500-1800 J/KG ROOTED AT THE TOP OF THE 850MB WARM NOSE/MOISTURE PLUME ALONG WITH A 30-40 KT LOW LEVEL JET. HAVE MAINTAINED A BROAD POP GRID GRADIENT GIVEN THESE UNCERTAINTIES THAT INCREASES FROM WEST TO EAST AFTER 06Z. SEVERE THREAT APPEARS LOW GIVEN THE LACK OF VERTICAL WIND SHEAR. HEAVY RAIN AND ISOLATED HAIL APPEAR TO BE THE MAIN THREATS. FORECAST PWAT VALUES OF AROUND 1.5 INCHES RANK IN THE 99TH PERCENTILE BASED ON OAX SOUNDING CLIMATOLOGY. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 323 PM CDT TUE JUN 2 2015 COMPLICATED FORECAST THE NEXT FEW DAYS. TRENDS INCREASING FOR SEVERAL PERIODS OF THUNDERSTORMS WITH CONSIDERATIONS NEEDED FOR BOTH MESO SCALE AND SYNOPTIC SCALE EVOLUTION OF SYSTEMS. THIS WILL LIMIT CONFIDENCE OF DETAILS...BUT SHOULD STILL ALLOW FOR MAIN FEATURES TO BE FORECAST WITH SOME CONFIDENCE. SUBJECTIVE H850 ANALYSIS SHOWS RIDGE EXITING TO THE EAST WHILE THE MOISTURE CHANNEL BEGINS TO EDGE EAST WITH TIME. BY 12Z WEDNESDAY MODELS IN GENERAL AGREEMENT WITH DECAYING MCS OVER EASTERN NEBRASKA/WESTERN IOWA MOVING EAST DURING THE MORNING HOURS. WITH THE HIGH CONTINUING OVER THE EASTERN GREAT LAKES...LIKELY THAT THE EASTERN/SOUTHEAST COUNTIES WILL HAVE A MORE LIMITED THUNDER CHANCE THROUGH EARLY WED AFTERNOON. DESPITE SOME CLOUD COVER FROM OVERNIGHT THUNDERSTORMS...BREAKS IN CLOUDS WITH INCREASING INSTABILITY SHOULD RETURN BY MID AFTERNOON WEDNESDAY. THE COMBINATION OF A WEAK H700 WAVE AND UNSTABLE CONDITIONS WILL PROMOTE SHOWERS AND THUNDERSTORMS OVER THE AREA DURING THE AFTERNOON WITH THE FOCUS SHIFTING FROM CENTRAL/NORTHERN SECTIONS TO THE SOUTH BY LATE AFTERNOON CLOSER TO ANOTHER SURFACE WARM FRONT. FROM WEDNESDAY THROUGH WEDNESDAY NIGHT...SEVERE CHANCES REMAIN LOW WITH THE BETTER CHANCES FOR ANY SEVERE LATE WED AFTERNOON INTO THE EVENING HOURS AND PERHAPS AGAIN THURSDAY AFTERNOON. HOWEVER...WILL NEED TO MONITOR LOCALLY HEAVY RAINFALL POTENTIAL THROUGH THIS PERIOD. CONFIDENCE BEYOND 36 HOURS BEGINS TO DIMINISH...AS EVOLUTION OF MESOSCALE CONVECTIVE SYSTEMS MAY ALTER THE SYNOPTIC EVOLUTION OF THE MAIN TROUGH AND ASSOCIATED BOUNDARIES OVER THE CENTRAL PLAINS. BY WEDNESDAY NIGHT...H850 LOW LEVEL JET SHOULD REFIRE CONVECTION OVER NORTHERN MISSOURI OR SOUTHERN IOWA. MESO NMM MODEL SHOWS SOUTHWARD DRIFT OF THE BOUNDARY AS WELL AS THE EURO KEEPING MOST OF THE CONVECTION SOUTH OF THE REGION. THE GFS AND NAM HAVE A MORE NORTHERLY TREND FOR NOW. THROUGH FRIDAY THE EURO CONTINUES THE TREND FOR MOST OF THE HEAVIER RAINFALL TO REMAIN JUST SOUTH OF THE IOWA MISSOURI BORDER...WHILE THE GFS/NAM AND TO A LESSER EXTENT THE GEM CONTINUE TO FOCUS THE AXIS OF BEST LIFT/THUNDER OVER CENTRAL TO SOUTHERN IOWA. THIS WILL DETERMINE THE AREA OF MOST RAINFALL AND POTENTIAL FOR ANY HYDRO ISSUES. HIGH MOISTURE RETURN FLOW AT H850 IS HEADING TOWARD THE FORECAST AREA...GFS PRECIPITABLE WATER VALUES INCREASING TO 1.5 TO 1.75 INCHES FROM 12Z WED TO 12Z FRIDAY. GFS WARM CLOUD DEPTHS ALSO ARE ON THE RISE...IN A RANGE OF 11KFT TO NEAR 13KFT SOUTH THURSDAY NIGHT. THOUGH THE GFS MAY NOT BE THE PREFERRED SOLUTION FOR ITS MORE NORTHERLY PLACEMENT OF STORM FEATURES...WILL NEED TO MONITOR EFFICIENT RAINFALL PROCESSES IN ANY STORMS THAT DEVELOP OVER THE NEXT 72 HOURS. CURRENTLY THE GFS WITH ITS MORE NORTHERLY PLACEMENT OVER IOWA IS SHOWING 4.25 TO 4.75 INCHES OF QPF OVER THE I80 CORRIDOR THROUGH FRIDAY MORNING WHILE THE EURO HAS ONLY 0.5 TO 1.25 INCHES WITH THE HEAVIER VALUES SOUTH OF US34. THE EURO HAS ITS AXIS OF HEAVY RAIN IS FROM NORTHERN KS THROUGH NORTHERN MO. DESPITE THE LACK OF CONSENSUS...IT IS LIKELY THAT HEAVY DOWNPOURS AND PERHAPS LOCALLY HEAVY RAINFALL WILL ACCOMPANY SOME OF THE STORMS. FOR NOW HYDRO SITUATION CAN TAKE A ROUND OF HEAVY RAINFALL AS GUIDANCE REMAINS AT 2 TO 3 INCHES FOR A 3 HR PERIOD ACROSS THE SOUTH. IF RAINFALL RATES APPROACH 2 INCHES PER HOUR AT ANY TIME...MAY HAVE SOME CONCERNS WITH LOCAL URBAN RUNOFF EFFECTS OR WITH ANY SUBSEQUENT EPISODES OF HEAVY RAINFALL THAT MIGHT OCCUR MAY NEED TO CONSIDER HEADLINES. GIVEN TODAYS UNCERTAINTY OF EVOLUTION OF MESO/SYNOPTIC FEATURE INTERACTIONS WILL NOT ISSUE ANY HEADLINES FOR NOW. TEMPERATURES THROUGH THE PERIOD WILL REMAIN MILD...75 TO 85 RANGE...WITH DEW POINTS AND HUMIDITY RATHER HIGH THE NEXT FEW DAYS IN THE MID TO UPPER 60S. SOME BREAKS IN THE RAINY PATTERN WILL OCCUR MAINLY FOR LATER ON SUNDAY INTO MONDAY. && .AVIATION...02/18Z ISSUED AT 1233 PM CDT TUE JUN 2 2015 MVFR STRATUS OVER SOUTHERN IOWA WILL CONTINUE TO LIFT AND ERODE THROUGH THE COURSE OF THE AFTERNOON. SOUTH TO SOUTHEASTERLY WINDS OF 10 TO 15 KTS WILL PERSIST THROUGH THE AFTERNOON WITH A FEW HIGHER GUSTS POSSIBLE. SHOWERS AND THUNDERSTORMS MOVE INTO WESTERN IOWA TOWARDS SUNRISE ON WEDNESDAY AND SPREAD EAST THROUGH THE MORNING...WEAKENING AS THEY MOVE INTO CENTRAL AND EASTERN IOWA. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SKOW LONG TERM...REV AVIATION...SKOW  FXUS63 KDMX 030902 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 402 AM CDT WED JUN 3 2015 .SHORT TERM /TODAY/... ISSUED AT 324 AM CDT WED JUN 3 2015 STRONG THETA-E ADVECTION ONGOING ACROSS WESTERN IOWA EARLY THIS MORNING WITH MUCAPES INCREASING TO 1000-2000 J/KG. THE 40+ KT LOW LEVEL JET FOCUSED ACROSS KANSAS AND NEBRASKA WILL SHIFT EAST INTO WESTERN IOWA OVER THE NEXT SEVERAL HOURS. THIS SHOULD BRING AN INCREASE IN THUNDERSTORM DEVELOPMENT OVER THE WEST THROUGH 12Z. THE LOW LEVEL JET AND MOISTURE TRANSPORT IS EXPECTED TO WEAKEN RAPIDLY AFTER 12Z THEREFORE ANY ACTIVITY SHOULD WEAKEN AS WELL. THE EXCEPTION MAY BE THE FAR SOUTHWEST WHERE GREATER INSTABILITY WILL REMAIN. OVERALL...SHOULD HAVE A MOSTLY QUIET PERIOD LATE MORNING INTO THE EARLY AFTERNOON. A COUPLE AREAS TO WATCH BY MID TO LATE AFTERNOON FOR REDEVELOPMENT. ONE IS THE SFC WARM FRONT THAT WILL BE ACROSS FAR SOUTHERN NEBRASKA AND NEAR THE IA/MO BORDER. THE FOCUS ALONG THIS BOUNDARY SHOULD INITIALLY BE TO THE WEST OVER SOUTH CENTRAL NEBRASKA. THE OTHER AREA IS THE BOUNDARY DROPPING SOUTHEAST THROUGH SOUTH DAKOTA AND MINNESOTA. THIS MAY LEAD TO REDEVELOPMENT OVER NORTH CENTRAL IOWA LATE IN THE PERIOD. THE LAYER PARCEL STATIC STABILITY BY THE AFTERNOON IS QUITE LOW SO IT WILL NOT TAKE MUCH FORCING TO DISPLACE PARCELS FOR CONVECTION TO TRIGGER. PWAT VALUES WILL INCREASE TO NEAR 1.5 INCHES TODAY ALONG WITH RELATIVELY SLOW STORM MOTIONS MAY LEAD TO A FEW LOCATIONS TO TOP 1 INCH OF RAIN. DEEP LAYER SHEAR OF 25 TO 30 KTS COULD LEAD TO STORMS TO BECOME ORGANIZED FOR SHORT PERIODS OF TIME LEADING TO A LARGE HAIL THREAT ALONG WITH POTENTIAL FOR 60 MPH WINDS AS DCAPE VALUES INCREASE ABOVE 1000 J/KG. HIGH TEMPERATURES TODAY WILL BE CONTINGENT ON CLOUD COVER. WITH SOME SUN...HIGHS IN THE MID TO UPPER 70S IS EXPECTED. .LONG TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 324 AM CDT WED JUN 3 2015 ACTIVE WEATHER PATTERN EXPECTED FOR BEGINNING OF PERIOD WITH THUNDERSTORM CHANCES THROUGHOUT THE END OF THE WEEK AS SURFACE LOW PRESSURE SYSTEM SLOWLY PUSHES EASTWARD UNDER WEAK UPPER LEVEL RIDGE ACROSS UPPER MIDWEST. EXPECT PRECIPITATION TO BE ONGOING FOR BEGINNING OF PERIOD WITH BOUNDARY DROPPING SLOWLY ACROSS IOWA. MODELS ARE VERY SLOW WITH PROGRESSION OF THIS BOUNDARY...GENERALLY STALLING IT ACROSS CENTRAL IOWA WITH CONTINUING CHANCES FOR THUNDERSTORMS ALONG IT OVERNIGHT...ESPECIALLY AS LLJ BEGINS TO INCREASE AND PUSH INTO SOUTHWESTERN IOWA. MODELS REMAINING CONSISTENT IN INITIATING ANOTHER MCS OVERNIGHT...AND MAIN CONCERN WILL BE PLACEMENT OF THIS SYSTEM. MODELS HAVE BEGUN TO PULL FURTHER SOUTH WITH THIS...AND GIVEN SOUTHERN DIVE TO CURRENTLY ONGOING MCS ACROSS NE...AGREE WITH THIS SOUTHERN TREND. ECMWF WAS FIRST TO PULL FURTHER SOUTH TO NEAR NE/KS BOARDER AND NAM HAS FOLLOWED SUIT...WITH GFS AND GEM MUCH FURTHER NORTH. HAVE THEREFORE TRENDED TOWARDS ECMWF FOR MUCH OF FORECAST THROUGH END OF THE WEEK. INITIATION IS ONCE AGAIN ACROSS CENTRAL NE/KS AND HAVE THEREFORE CUT BACK ON POPS UNTIL LATER IN OVERNIGHT TONIGHT. AS SYSTEM PUSHES EAST INTO IOWA THURSDAY...WILL SEE CONTINUED CHANCES FOR THUNDERSTORMS...THOUGH EXPECT TO SEE DISSIPATION IN THE LATE MORNING HOURS BEFORE DEVELOPMENT AGAIN NEAR STALLED BOUNDARY ACROSS CENTRAL IOWA IN THE AFTERNOON AND HAVE TRENDED FORECAST THIS WAY. AFTERNOON STORMS WILL HAVE POTENTIAL TO BE SEVERE THURSDAY...WITH CAPE VALUES BY LATE AFTERNOON NEAR 1000-1500 J/KG WITH HIGHER VALUES ACROSS THE SOUTH. SHEAR VALUES WILL BE SUFFICIENT TO ALLOW FOR STORMS WHICH DEVELOP TO PERSIST...WITH BEST CHANCES FOR SEVERE STORMS IN THE FAR SOUTHWESTERN PORTIONS OF IOWA. HOWEVER...WEAK CAP NOTED WHICH WILL HELP TO LIMIT SEVERE POTENTIAL. MOST FORECAST UNCERTAINTY WILL BE THURSDAY NIGHT WITH MCS POTENTIAL ONCE AGAIN. CONCERN WILL BE WHERE MCS SETS UP...WHICH WILL BE HEAVILY DEPENDENT ON PRECEDING SYSTEMS. HOWEVER...WITH FAVORED SOUTHERN TREND TO MODELS HAVE BEGUN TO SHIFT CHANCES FURTHER SOUTH. ECMWF INDICATES THAT SYSTEM MAY BE SOUTH OF IOWA INTO KS/MO AND MAY STILL BE TOO AGGRESSIVE WITH POPS THURSDAY NIGHT. WITH SYSTEM...WILL SEE LINGERING PRECIPITATION CHANCES INTO FRIDAY BEFORE LOW FINALLY PUSHES EAST OF AREA. CONCERN FOR HEAVY RAIN WILL PERSIST WITH PRECIPITATION CHANCES THROUGH THE END OF THE WEEK. PWAT VALUES REMAIN HIGH...GENERALLY AROUND 1.6 INCHES WITH STRONG MOISTURE TRANSPORT INTO IOWA AS WELL. WARM CLOUD DEPTHS WILL BE HIGH THROUGH THE OVERNIGHT WEDNESDAY NIGH AND AGAIN THURSDAY NIGHT. MAIN CONCERN WILL BE WITH PRECIPITATION THURSDAY NIGHT AS PWAT VALUES INCREASE TO NEAR 1.8 INCHES AND SOUNDINGS INDICATE GOOD SATURATION THROUGH COLUMN. HOWEVER...AGAIN LOWER CONFIDENCE IN HEAVY RAIN THURSDAY NIGHT DEPENDING ON PLACEMENT OF SYSTEM WHICH MAY BE SOUTH OF IOWA. SATURDAY WILL SEE A BRIEF BREAK IN PRECIPITATION CHANCES. FLOW ACROSS IOWA WILL BE MOSTLY ZONAL THROUGH THE PERIOD WITH LARGE UPPER LEVEL LOW DIGGING INTO SOUTHERN CA COAST FRIDAY AND PUSHING EAST HELPING TO BREAK DOWN RIDGE SOMEWHAT. HOWEVER...A DEEPENING UPPER LEVEL LOW DROPS SOUTH THROUGH CANADA FOR LATE IN THE PERIOD. THIS WILL RESULT IN CONTINUED ACTIVE WEATHER LATE SATURDAY AND SUNDAY BEFORE CANADIAN LOW PUSHES BOUNDARY SOUTH OF IOWA. TEMPERATURES WILL BE FAIRLY STEADY THROUGH PERIOD WITH HIGHS IN THE 70S AND 80S AND LOWS IN THE 50S AND 60S. HOWEVER...TEMPERATURES WILL BE HEAVILY DEPENDENT ON CONVECTIVE TRENDS...AND MAY BE TOO COOL ON HIGHS IF SKIES CLEAR AND MAY BE TOO WARM ON LOWS WITH ONGOING PRECIPITATION POSSIBLE. && .AVIATION...03/06Z ISSUED AT 1159 PM CDT TUE JUN 2 2015 LOW VFR CIGS DEVELOPING ACROSS WESTERN IOWA TO SPREAD ACROSS ENTIRE CWA OVERNIGHT. THUNDERSTORM DEVELOPMENT EXPECTED TOWARD SUNRISE...STILL GREATER CERTAINTY OF THIS ACTIVITY IMPACTING THE NORTHERN AND WESTERN TAF SITES. OTHERWISE MAINLY VFR CONDITIONS WITH SOUTHEASTERLY TO SOUTHERLY WINDS EXPECTED. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DONAVON LONG TERM...AWB AVIATION...BEERENDS  FXUS63 KDMX 032023 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 323 PM CDT WED JUN 3 2015 .SHORT TERM /TONIGHT/... ISSUED AT 322 PM CDT WED JUN 3 2015 TONIGHT...MAIN FORECAST CONCERN DEALT WITH PRECIP/SEVERE WEATHER CHANCES TONIGHT INTO THURSDAY MORNING OR LACK THEREOF AS MODELS CONTINUE TO TREND DRIER TONIGHT. FORECAST AREA CURRENTLY WITHIN SPLIT FLOW OF UPPER LEVEL VORT MAXES WITH THE 500MB SHORTWAVE EXITING THE AREA BY 00Z THURSDAY OR EVEN SOONER. CURRENTLY...WEAK COLD FRONT DRAPED ACROSS WEST-CENTRAL TO NORTH- CENTRAL IOWA AND THERE IS WEAK SUBSIDENCE IS IN PLACE. EVEN WITH SOME DESTABILIZATION OCCURRING OVER PORTIONS OF WESTERN IOWA...THE FRONTOGENETICAL FORCING IS VERY WEAK AND MOISTURE CONVERGENCE REMAINS UNIMPRESSIVE. MIGHT SEE SOMETHING DEVELOP ALONG THE FRONT THROUGH THE EVENING ACROSS NORTHERN IOWA CLOSER TO THE LOW...AND KEPT SMALL POPS GOING IN THIS AREA. LOW CONFIDENCE WITH SEVERE POTENTIAL DUE TO LACK OF SIGNIFICANT INSTABILITY AND SHEAR PRESENT THROUGH THE EVENING. OTHERWISE...THERE IS REALLY NOTHING FOR STORMS TO FOCUS ON REDEVELOPMENT UNTIL AFTER 06Z. THE 03.12Z MODELS RUNS HAVE COME INTO DECENT AGREEMENT WITH MUCH OF IOWA REMAINING DRY THROUGH THURSDAY MORNING. THE NEXT SHORTWAVE LOOKS TO EJECT OUT OF THE CENTRAL ROCKIES AND RIDE THE 500MB RIDGE TRACKING GENERALLY ALONG THE NE/KS BORDER INTO NORTHWESTERN MO OVERNIGHT TONIGHT. CUT BACK CONSIDERABLY ON POPS TONIGHT INTO THURSDAY MORNING AND EVEN WENT COMPLETELY DRY ACROSS THE NORTH PAST 06Z. THE LATEST HIRES MODELS...HRRR/HOPWRF/ARW- NMMWRF KEEP THE BULK OF THE CONVECTION IN WESTERN IOWA UNTIL 06Z. KEPT LIKELY TO CATEGORICAL POPS GOING ACROSS THE FAR SOUTHWEST AS HIGHER CONFIDENCE SOME OF THIS CONVECTION WILL SNEAK INTO THIS AREA B/T 06-12Z THURSDAY. THE MAIN THREAT LOOKS TO BE HEAVY RAIN AND POTENTIALLY SOME LOCALIZED FLASH FLOODING. SOME ISOLATED AREAS IN SOUTHERN IOWA...PER RADAR ESTIMATES...RECEIVED 1-2 INCHES FROM THIS MORNINGS CONVECTION. PRECIPITABLE WATER VALUES REMAIN IN THE 1.5-2 INCH RANGE WITH GOOD MOISTURE TRANSPORT INTO SOUTHWEST IOWA. WARM LAYER CLOUD DEPTHS OVER 12000 FEET...SO IF STORMS DO DEVELOP OVERNIGHT...SOME EFFICIENT RAIN PRODUCERS ARE LIKELY IN THE FAR SOUTHWEST. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 322 PM CDT WED JUN 3 2015 SIMILAR CHALLENGES TO YESTERDAY IN EXTENDED...WITH MESOSCALE SYSTEMS PROVIDING MOST OF THE UNCERTAINTY IN THE SYNOPTIC SCALE PATTERN EVOLUTION THROUGH FRIDAY NIGHT. OVERALL...MESOSCALE GUIDANCE DID WELL YESTERDAY...ALONG WITH PREFERENCE FOR EURO MODEL OVER NAM/GFS WHICH FORECAST A MORE NORTHERLY EXTENT OF MCS DEVELOPMENT LAST NIGHT AND TODAY. BY 12Z THURSDAY EXPECTING ANY LEFTOVER CONVECTION TO MOVE ACROSS WESTERN/SOUTHERN SECTIONS WITH LESSER CHANCES OVER THE NORTH. NMM/EURO/4 KM WRF ALL SUGGEST THAT BULK OF ACTIVITY WILL BE SOUTH OF THE AREA THROUGH THE DAY. WOULD LEAN TOWARD COMPLETELY RAINFREE...BUT SOME UNCERTAINTY STILL EXISTS SO WILL LEAVE SOME CHANCE POP OVER THE WEST/SOUTH FOR THE MORNING HOURS INCREASING SLIGHTLY IN THE AFTERNOON FOR ALL LOCATIONS. THURSDAY NIGHT MAY FINALLY BRING THE FRONT AND BEST FOCUS FOR HEAVIER CONVECTION FARTHER NORTH. LIKE TODAY...THERE IS A CHANCE FOR A FEW STRONGER THUNDERSTORMS LATER THURSDAY AFTERNOON/EVENING. HIGHS THURSDAY WILL ONCE AGAIN BE DEPENDENT ON CLOUD COVER...BUT LIKELY WE MAY BE A FEW DEGREES WARMER THAN TODAY. THURSDAY NIGHT THE SFC BOUNDARY WILL LIFT FARTHER NORTH...STILL MODULATED BY THE MESO SCALE CONVECTIVE SYSTEMS...WITH THE POTENTIAL FOR A ROUND OF MODERATE TO LOCALLY HEAVY RAINFALL ACROSS THE SOUTH. THE EXACT DETAILS DEPEND ON TONIGHTS/TOMORROWS CONVECTIVE TRENDS. FOR NOW...HAVE INCREASED POP OVER THE SOUTH. PRECIPITABLE WATER....WARM CLOUD DEPTHS REMAIN HIGH SO EFFICIENT RAINFALL PROCESSES WILL ONCE AGAIN NEED TO BE MONITORED THROUGH FRIDAY NIGHT. EARLIER THIS MORNING...NORTHERN MISSOURI SAW A FEW AREAS RECEIVE 2 TO 4 INCH TOTALS IN A SHORT AMOUNT OF TIME. THE PERSISTENT TROUGH CAUSING THE STORMS OVER THE PLAINS WILL REMAIN IN THE REGION THROUGH SUNDAY...HOWEVER THURSDAY NIGHTS CONVECTION AND A HIGH OVER THE GREAT LAKES WILL PUSH THE BOUNDARY SOUTH LONG ENOUGH TO BRING A BREAK TO THE RAIN THREAT FOR LATE FRIDAY EVENING THROUGH SATURDAY MORNING. AS ANOTHER SERIES OF WAVES APPROACHES FROM THE SOUTHWEST...ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED FOR SATURDAY NIGHT INTO SUNDAY. WITH THE EASTWARD PROGRESSION OF A STRONGER H500 NORTHERN STREAM WAVE OVER SOUTHERN CANADA SUNDAY...A RIDGE OF HIGH PRESSURE WILL SETTLE INTO THE AREA WITH LESS RAIN CHANCES MONDAY THROUGH WEDNESDAY AS THE STRONGER NORTHERN STREAM SHORT DISPLACES THE TROUGH OVER THE CENTRAL PLAINS. THERE WILL BE A CHANCE OF THUNDERSTORMS OVER THE SOUTH. TEMPERATURES THROUGH THE PERIOD LOOK NEAR TO SLIGHTLY ABOVE NORMAL. HIGHS ARE EXPECTED IN THE MID 70S TO MID 80S WITH LOWS IN THE LOWER 60S TO UPPER 60S WITH SOME WARMING AT DAYS 6 AND 7. && .AVIATION...03/18Z ISSUED AT 1228 PM CDT WED JUN 3 2015 MAIN CONCERN DEALT WITH MVFR CIGS...OR LACK THEREOF THIS AFTERNOON AND TONIGHT. IOWA IS SPLIT BEING TWO PIECES OF ENERGY AND MAINLY LEAVING CLOUD COVER OVER THE STATE. EXPECTING SOME MVFR CIGS ACROSS NORTHERN IOWA THROUGH THE AFTERNOON AT FOD/MCW. MAY AFFECT ALO FOR A SHORT STINT BUT LOW CONFIDENCE IN LONG DURATION OF THESE MVFR CIGS AND LEFT MENTION OUT ATTM. DSM LOOKS TO IMPROVE TO VFR CIGS PAST 18Z AND LEFT OUT ANY MVFR CIGS THROUGH THE AFTERNOON. STILL EXPECTING THE POTENTIAL FOR OVERNIGHT INTO THURSDAY MORNING CONVECTION TO DEVELOP...BUT WITH LOW CONFIDENCE IN TIMING AND LOCATION...LEFT OUT MENTION OF ANY MVFR VIS/CIGS ATTM. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...PODRAZIK  FXUS63 KDMX 040841 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 341 AM CDT THU JUN 4 2015 .SHORT TERM /TODAY/... ISSUED AT 314 AM CDT THU JUN 4 2015 CURRENT CONVECTION IS ENTERING FAR SOUTHWEST IOWA AND ADVANCING TOWARD THE EXTREME SOUTHWEST CORNER OF THE FORECAST AREA. THIS CONVECTION IS SUPPORTED BY STRONG LOW LEVEL JET ACROSS THE PLAINS WITH DEEP MOISTURE CONVERGENCE OCCURRING JUST SOUTHWEST OF IOWA. THE 850MB RIDGE SHOULD ACT AS SOMEWHAT OF AN EASTERN EDGE TO THE EXTENT OF THE CONVECTION THIS MORNING AND THEREFORE DONT EXPECT MUCH IMPACT BEYOND THE FAR SOUTHWEST THROUGH THE MORNING HOURS. BY THE AFTERNOON...SOME THREAT OF CONVECTION WILL EXTEND FARTHER EAST...HOWEVER THE STRONGER SYNOPTIC FORCING REALLY DOESNT ARRIVE UNTIL LATER AND THERE IS SOME QUESTION IF THE MORE ROBUST CONVECTION WILL WAIT UNTIL LATER THIS EVENING INTO TONIGHT WHEN THE LOW LEVEL JET INTENSIFIES. HAVE GENERALLY CONTINUED THE THREAT OF POPS ACROSS THE MUCH OF THE FORECAST AREA BY LATE AFTERNOON...ALTHOUGH BEST THREAT WILL CONTINUE TO BE IN THE WEST. TEMPERATURES WILL BE PROBLEMATIC TODAY GIVEN THE PRECIPITATION THREAT AND ASSOCIATED CLOUDINESS. HAVE CUT BACK ON HIGHS IN THE FAR SOUTH/SOUTHWEST WHERE CLOUDS MAY LINGER FOR MUCH OF THE DAY. WILL LIKELY SEE THE WARMEST TEMPERATURES IN THE NORTH AND EAST WHERE THE BEST CHANCES OF SUNSHINE WILL BE...MUCH LIKE THE TEMPERATURES DISTRIBUTION SEEN ON WEDNESDAY. .LONG TERM /TONIGHT THROUGH WEDNESDAY/... ISSUED AT 314 AM CDT THU JUN 4 2015 FORECAST CONCERNS WILL REMAIN WITH PRECIPITATION CHANCES THROUGH THE EXTENDED. ANOTHER MCS IS EXPECTED TO DEVELOP TONIGHT...AND TIMING AND PLACEMENT OF THIS SYSTEM IS MAIN CONCERN FOR TONIGHT. MODELS HAVE A GOOD HANDLE ON CURRENT ONGOING CONVECTION NEAR NE/KS BOARDER...AND ATTEMPT TO BRING THIS BOUNDARY FURTHER NORTH DURING THE DAY THURSDAY...WITH DEVELOPMENT ALONG IT AGAIN IN THE OVERNIGHT HOURS...ESPECIALLY WITH LLJ INCREASING THROUGH THE EVENING HOURS. EXPECT DEVELOPMENT TO BE AGAIN ALONG THE NOSE OF THE JET INTO SOUTH CENTRAL NE...THOUGH COULD BE FURTHER EAST THAT TONIGHT. EXPECT SYSTEM TO PUSH INTO SOUTHEASTERN IOWA...BEFORE DROPPING SOUTHEAST. MODELS HAVE A MORE EASTERLY PUSH TO THIS SYSTEM...AND HAVE THEREFORE KEPT PRECIPITATION CHANCES HIGHEST GENERALLY ALONG AND SOUTH OF INTERSTATE 80 THROUGH THE OVERNIGHT. HOWEVER...DO NOT HAVE HIGH CONFIDENCE IN NORTHERN EXTENT OF PRECIPITATION...AND MAY SEE SYSTEM FURTHER SOUTH INTO KS/MO DEPENDING ON PLACEMENT OF BOUNDARY THROUGH THE DAY TODAY. CONCERN WILL BECOME WITH HEAVY RAINFALL AMOUNTS WITH THIS OVERNIGHT SYSTEM. MOISTURE TRANSPORT IS STRONG INTO SOUTHERN IOWA WITH PWAT VALUES NEAR OR ABOVE 1.7 INCHES WHICH IS HIGH FOR JUNE. IN ADDITION...SOUNDINGS INDICATE GOOD SATURATION WITH DEEP WARM CLOUD DEPTHS. THEREFORE...EXPECT HEAVY RAINFALL WHERE THIS SYSTEM SETS UP. RIDGE WILL PERSIST ACROSS IOWA FOR FRIDAY...THOUGH SYSTEM WILL FINALLY PUSH EAST WITH A BREAK IN PRECIPITATION CHANCES...THOUGH THIS WILL BE SHORT LIVED WITH LARGE UPPER LEVEL LOW ACROSS SOUTHERN CA CONTINUING TO ALLOW FOR SHORT WAVES TO PUSH ACROSS IOWA. IN ADDITION...UPPER LEVEL LOW WILL PUSH EAST ACROSS CANADA...HELPING TO BEGIN TO BREAK DOWN RIDGE FOR LATE IN THE WEEKEND. SATURDAY WILL SEE SURFACE LOW PUSH EAST ACROSS DAKOTAS HELPING TO BREAK RIDGE DOWN TO MORE ZONAL FLOW WITH BOUNDARY PUSHING ACROSS IOWA. ACROSS THE WEST WILL SEE SOME THREAT FOR SEVERE WEATHER SATURDAY WITH CAPE VALUES GENERALLY AROUND 1500 J/KG OR HIGHER AND STRONG SHEAR VALUES. HOWEVER...CURRENTLY BEST THREAT LOOKS TO BE FURTHER WEST INTO NEBRASKA...AND HAVE SLOWED ONSET OF PRECIPITATION SOME WHICH MATCHES THIS THINKING. BOUNDARY WILL PUSH SOUTH THROUGH SUNDAY WITH BEST PRECIPITATION CHANCES SATURDAY NIGHT. COULD AGAIN SEE POTENTIAL FOR HEAVY RAINFALL SATURDAY NIGHT AS PWAT VALUES AGAIN NEAR 1.8 INCHES AND STRONG MOISTURE TRANSPORT INTO IOWA. BEHIND SYSTEM FOR EARLY IN THE WEEK WILL FINALLY SEE A BREAK IN PRECIPITATION CHANCES AS HIGH PUSHES SOUTH...AND DRY PATTERN HOLDING PRIMARILY THROUGH THE END OF THE PERIOD. TEMPERATURES WILL BE FAIRLY STEADY THROUGH THE PERIOD...WITH COOLEST DAY COMING SATURDAY BEHIND BOUNDARY. HOWEVER...OVERALL HIGHS WILL BE IN THE 80S AND 70S...THOUGH MAY BE TOO COOL FOR BEGINNING OF PERIOD WITH CLOUDS EXPECTED TO PERSIST. OVERNIGHT LOWS WILL GENERALLY BE 60S AND 70S...THOUGH AGAIN MAY BE TOO WARM WITH CONVECTION INFLUENCING TEMPERATURES. && .AVIATION...04/06Z ISSUED AT 1146 PM CDT WED JUN 3 2015 VFR CONDITIONS EXPECTED THROUGHOUT THE TAF PERIOD. SOME THUNDERSTORMS DEVELOPING OFF TO THE SOUTHWEST MAY PUSH NEAR WESTERN/SOUTHERN TAF SITES TOWARD 12Z. FOR NOW UNCERTAINTY TOO HIGH SO HAVE LEFT ANY MENTIONS OUT OF THE TERMINALS. WINDS TO BE LIGHTER AND VARIABLE THROUGH THE PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...COGIL LONG TERM...AWB AVIATION...BEERENDS  FXUS63 KDMX 042023 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 323 PM CDT THU JUN 4 2015 .SHORT TERM /TONIGHT/... ISSUED AT 323 PM CDT THU JUN 4 2015 PRIMARY FORECAST CHALLENGE IS COMPLEX CONVECTIVE/PRECIP FORECAST FOR TONIGHT. A SHARP SYNOPTIC FRONTAL BOUNDARY IS DRAPED NEAR THE CENTRAL NEBRASKA/KANSAS BORDER AND DOWN INTO WESTERN MISSOURI...WHILE NORTH OF THIS THERE ARE SEVERAL WEAKER AND MORE AMBIGUOUS BOUNDARIES BOTH AT THE SURFACE AND ALOFT...GENERALLY STRETCHING FROM SOUTH CENTRAL NEBRASKA OVER INTO IOWA. MEANWHILE A 500 MB WAVE IS APPROACHING FROM THE WEST AND NORTHWEST AND WILL MOVE OVERHEAD LATER TONIGHT. CURRENTLY ELEVATED THUNDERSTORMS ARE DEVELOPING ACROSS SOUTHERN AND SOUTHEASTERN NEBRASKA AS 850 MB WARM AIR ADVECTION NOSES UP INTO THE REGION OF THE AFOREMENTIONED BOUNDARIES. THESE STORMS SHOULD NOT AFFECT OUR AREA LATE THIS AFTERNOON AND EVENING...UNLESS THEY JUST CLIP OUR SOUTHWEST CORNER. MEANWHILE...THUNDERSTORMS SHOULD DEVELOP RAPIDLY ALONG THE STRONGER SYNOPTIC BOUNDARY NEAR THE KANSAS/NEBRASKA BORDER THIS EVENING AND MOVE EASTWARD...PROBABLY CONGEALING INTO AN MCS THAT WILL LIKELY AFFECT OUR SOUTHERN AREAS AFTER DARK. IN ADDITION...SOME OF THE HIGH RESOLUTION MODELS ARE DEVELOPING ELEVATED STORMS ACROSS NORTHEASTERN NEBRASKA AND SOUTHEASTERN SOUTH DAKOTA AROUND SUNSET IN CONJUNCTION WITH THE APPROACHING 500 MB TROUGH AND MOVING SAID STORMS ACROSS OUR NORTHERN AND CENTRAL COUNTIES BETWEEN ABOUT 02Z AND 07Z. IN LIGHT OF THE MULTIPLE AREAS OF POTENTIAL RAINFALL HAVE MAINTAINED CHANCE POPS NORTH TO LIKELY POPS SOUTH...BUT OVERALL CONFIDENCE IN DETAILS OF CONVECTIVE EVOLUTION IS RELATIVELY LOW. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 323 PM CDT THU JUN 4 2015 WITH THE PATTERN PERSISTING INTO SATURDAY NIGHT...FEW MAJOR CHANGES ANTICIPATED TO PREVIOUS FEW DAYS THINKING. 12Z SUBJECTIVE H850 ANALYSIS THIS AM SHOWS THE SETUP THAT LED TO HEAVY RAINFALL SOUTH OF THE AREA LAST NIGHT...ALONG WITH THE UPSTREAM WAVE OVER WYOMING WHICH WILL RIDE OVER THE RIDGE BY FRIDAY MORNING. WITH FORECAST...WILL TODAY FAVOR A BLEND OF MESOSCALE AND SYNOPTIC MODELS IN THE SHORT TERM WITH SOLUTIONS CLOSER TODAY THAN PAST FEW DAYS. NMM-WRF SHOWS COMPLEX OF STORMS NOW DEVELOPING OVER NEBRASKA IN BETTER WARM AIR ADVECTION ZONE ALONG THE H850 BOUNDARY WILL BE NEARLY OUT OF THE AREA BETWEEN 12-18Z FRIDAY. ALSO OF NOTE IS THE H700/H500 SHORTWAVE OVER THE DAKOTAS WHICH SHOULD ASSIST THE DEVELOPMENT WITH ONLY LINGERING THUNDERSTORMS OVER THE FORECAST AREA FROM 12-18Z FRIDAY. HAVE CUT BACK ON POP WITH THE NEWER GUIDANCE FOR FRIDAY MORNING...LEAVING MOST OF AFTERNOON DRY NORTH WITH SLIGHT/CHANCE ACROSS CENTRAL SOUTH AS SOME REDEVELOPMENT MAY OCCUR OVER CENTRAL OR SOUTHERN IOWA BY EARLY TO MID AFTERNOON IN WEAK SFC CONVERGENCE ZONE AND UNSTABLE AIRMASS. CURRENT THOUGHT IS THAT THE GFS/NAM ARE TOO QUICK TO BRING NEXT UPSTREAM WAVE INTO THE AREA OVERNIGHT FRIDAY NIGHT SO HAVE CUT BACK ON POP UNTIL SATURDAY. WITH APPROACHING WAVE...SOME TIMING ISSUES BETWEEN GFS/NAM AND EURO. BULK OF FORCING APPEARS TO ARRIVE LATE AFTERNOON AND NIGHT AND HAVE TRENDED POP COVERAGE/QPF DURING THESE PERIODS. THE SAT SYSTEM HAS A MORE ORGANIZED UPPER LEVEL WIND FIELD...THUS SEVERE CHANCES WILL TEND TO BE BETTER FOCUSED OVER THE AREA IN THE EVENING AND OVERNIGHT AS POTENTIAL FOR MCS DEVELOPS AND OUTFLOWS ACROSS THE AREA TOWARD 12Z SUNDAY. ONCE AGAIN PRECIPITABLE WATER VALUES OVER 1.75 INCHES AND WARM CLOUD DEPTHS ABOVE 12KFT...WILL PROMOTE EFFICIENT RAINFALL WITH ANY STORMS. WITH CONTINUED LACK OF WIDESPREAD HEAVY RAINFALL THROUGH TODAY...WE MAY SEE ONLY URBAN HYDRO ISSUES SUCH AS PONDING OF WATER BUT PROBABLY NOT IN NEED OF HEADLINES...UNLESS FOCUS OF MCS SATURDAY NIGHT IS FARTHER SOUTH OVER THE SAME AREAS THAT RECEIVE RAIN TONIGHT/EARLY FRIDAY. AS WAVE DEPARTS SUNDAY...COMFORTABLE CONDITIONS EXPECTED WITH SEASONAL TEMPS SUNDAY THROUGH MONDAY. AFTER SUNDAY...GENERALLY DRY AND QUIETER WX EXPECTED THROUGH WED OF NEXT WEEK. HEIGHT FIELDS/H850 TEMPERATURES BEGIN TO BUILD TO NEAR 20C BY 06Z WED. THIS WILL ALLOW DAYTIME HIGHS TO PUSH THE MID TO UPPER 80S BY TUESDAY OR WEDNESDAY. HAVE RAISED CENTRAL IA HIGHS TO MID 80S...MAY NEED TO BOOST TEMPS OVER THE NEXT COUPLE OF DAYS IF TRENDS HOLD. OTHERWISE ...TOWARD THE END OF THE SEVEN DAY ANOTHER WELL DEFINED SYSTEM WILL APPROACH BRINGING ROUND OF THUNDERSTORMS TO THE REGION BY LATE THURSDAY. MEANWHILE...TEMPERATURES WILL REMAIN IN THE 70S TO LOWER 80S WITH LOWS GENERALLY IN THE 60S. && .AVIATION...04/18Z ISSUED AT 1227 PM CDT THU JUN 4 2015 MAINLY LIGHT AND VARIABLE WINDS ARE FORECAST THROUGH THE TAF PERIOD AS A DECAYED FRONTAL ZONE REMAINS STALLED ACROSS THE AREA. A WEAK DISTURBANCE MOVING OVERHEAD TONIGHT WILL TRIGGER SHRA AND TSRA DEVELOPMENT OVERNIGHT...BUT CONFIDENCE IN TIMING AND PLACEMENT IS RELATIVELY LOW SO HAVE MAINTAINED JUST VCTS/VCSH IN THE 18Z TAFS. THESE DETAILS SHOULD BE REFINED AS THE SYSTEM APPROACHES THIS EVENING AND TONIGHT. EXPECT RESTRICTED CONDITIONS WITHIN ANY SHRA/TSRA...AND ALSO IN MORE WIDESPREAD STRATUS/BR DEVELOPING LATE TONIGHT INTO EARLY FRI MORNING AS IT DID THIS MORNING. VFR CONDITIONS SHOULD ONCE AGAIN PREVAIL FROM LATE FRI MORNING THROUGH THE AFTERNOON. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...LEE LONG TERM...REV AVIATION...LEE  FXUS63 KDMX 062031 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 331 PM CDT SAT JUN 6 2015 .SHORT TERM /TONIGHT/... ISSUED AT 330 PM CDT SAT JUN 6 2015 CONVECTIVE TRENDS OVERNIGHT ARE THE PRIMARY FORECAST CHALLENGE. CENTRAL IOWA HAS BEEN CLOUDY MUCH OF THE DAY WITH DEBRIS FROM A DECAYING MCS AND A FEW SHOWERS AND STORMS AS A SECOND WAVE OF THETA-E ADVECTION MOVES INTO THE NORTHWEST PORTION OF THE STATE. INSTABILITY IS INCREASING THROUGH MUCH OF THE MID MISSOURI VALLEY WHERE SOLAR HEATING IS ONGOING WITH TEMPERATURES RISING INTO THE 80S AND DEWPOINTS IN THE MID TO UPPER 60S. THE INITIAL CONVECTION SHOULD CONTINUE TO MOVE SLOWLY ACROSS NORTHWEST IOWA AND WILL HAVE AN ATTENDANT LARGE HAIL THREAT WITH HAIL TO THE SIZE OF QUARTERS POSSIBLE. THE OTHER DIURNAL THUNDERSTORM DEVELOPMENT IS EXPECTED TO OCCUR WEST OF THE AREA NEAR THE REGION OF BETTER INSTABILITY. THIS ACTIVITY WILL EVENTUALLY PROPAGATE EAST AS THE LOW LEVEL JET VEERS INTO THE STATE AND SHORT WAVE ENERGY LIFTS INTO THE REGION. THE INITIAL ACTIVITY TO THE WEST SHOULD BECOME MORE LINEAR AS IT SHIFTS EAST INTO THE AREA AND VERY WELL COULD TRANSITION TO A QLCS EVENT. LOW LEVEL EFFECTIVE SRH VALUES INCREASE TO GREATER THAN 300 M2/S2 IN ADDITION TO THE 0-3 KM SHEAR VECTOR NEAR 50 KNOTS WILL BE FAVORABLE FOR MESOVORTEX DEVELOPMENT WITH A FOCUSED AREA FOR ENHANCED WINDS OR POTENTIAL FOR A FEW SPIN UP TORNADOES. THIS POTENTIAL COULD MOVE EAST OF INTERSTATE 35 AFTER 06Z. STORMS SHOULD BE LOSING THEIR HAIL THREAT DURING THIS TIME AS PWATS INCREASE TO NEAR 1.75 INCHES AND PROFILES SATURATE. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 330 PM CDT SAT JUN 6 2015 THE UPCOMING WEEK WILL BE BRACKETED BY THE THREAT FOR STRONG TO SEVERE THUNDERSTORMS...WITH SOME OF THE WARMEST TEMPS SO FAR THIS SEASON POSSIBLE ON MONDAY AND TUESDAY. THE NEAR SURFACE MESOSCALE AND SYNOPTIC SETUP FOR SUNDAY WILL LEAN HEAVILY ON THE TRACK OF TONIGHT'S MCS ACROSS THE CWA. SHOULD THE MCS TAKE A SOUTHERLY COURSE AS SHOWN BY THE EC/GFS...THE RESULTANT OUTFLOW BOUNDARY WILL ALSO PUSH THE THREAT FOR SEVERE WEATHER INTO FAR SOUTHERN IOWA AND MISSOURI. HOWEVER...A MORE NORTHERLY SOLUTION AS HINTED AT BY THE NAM MAY RESULT IN THE SURFACE BOUNDARY ONLY REACHING THE DES MOINES AREA BY 18Z SUNDAY. IN EITHER CASE...THE ENVIRONMENT AHEAD OF THE FRONT WILL BE SUPPORTIVE OF ROBUST CONVECTION WITH 1500-2000 J/KG OF SBCAPE AND 30-40 KTS OF DEEP LAYER SHEAR. HAIL AND DAMAGING WINDS WOULD BE THE BIGGEST THREAT WITH UNFAVORABLY HIGH LCL HEIGHTS AND LOW NEAR- SURFACE HELICITY VALUES. HAVE CONTINUED A BLENDED APPROACH TO THE TIMING AND LOCATION OF CONVECTION TOMORROW GIVEN THE VARIABILITY IN BOUNDARY LOCATION...WHICH LINES UP WELL WITH THE SPC DAY 2 CONVECTIVE OUTLOOK MARGINAL AND SLIGHT RISK PLACEMENTS. THIS BOUNDARY SHOULD EXIT THE CWA BY 06Z MONDAY MORNING. MONDAY AND ESPECIALLY TUESDAY WILL FEATURE WARMING TEMPERATURES AS A THERMAL RIDGE OVER THE HIGH PLAINS SHIFTS EASTWARD ON NORTHWEST TO WESTERLY FLOW. 850 MB TEMPERATURES WILL RISE FROM +16 C AT 00Z MONDAY TO +22 C BY 06Z WEDNESDAY. DRIER AIR AND RESULTANT STEEP LOW LEVEL LAPSE RATES WILL ALSO PROMOTE DEEP MIXING AND WARMER TEMPERATURES. RAISED HIGHS BY SEVERAL DEGREES ON TUESDAY BUT STILL REMAIN BELOW THE MEX/EC GUIDANCE...WHICH TOP 90 DEGREES FOR DES MOINES. A WEAK COLD FRONT WILL SLIDE SOUTHWARD ACROSS CENTRAL IOWA ON WEDNESDAY AND THEN BECOME STATIONARY ACROSS THE AREA UNDER WEAK UPPER LEVEL SPLIT FLOW. THE BOUNDARY WILL LIFT NORTHWARD AS A WARM FRONT ON THURSDAY OUT AHEAD OF A DEEPENING SURFACE CYCLONE EJECTING FROM THE FRONT RANGE. MEDIUM RANGE SOLUTIONS DIVERGE ON THE TRACK OF THIS LOW...BUT IN EITHER CASE PARTS OF IOWA LOOKS TO BE UNDER THE GUN FOR STRONG TO SEVERE THUNDERSTORMS THURSDAY EVENING AND AGAIN FRIDAY. && .AVIATION...06/18Z ISSUED AT 1249 PM CDT SAT JUN 6 2015 CONVECTIVE TRENDS THE PRIMARY AVIATION CONCERN THROUGH THE PERIOD. AN AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS MAY REACH KDSM THIS AFTERNOON. OTHER DEVELOPMENT MAY REACH KFOD BY THE AFTERNOON HOWEVER MORE WIDESPREAD THUNDERSTORMS ARE EXPECTED TO MOVE THROUGH OVERNIGHT. IFR TO MVFR CIGS ARE LIKELY TO ACCOMPANY ANY STORMS IN ADDITION TO STRONG GUSTY WINDS. SOUTHERLY WINDS TODAY WILL BECOME SOUTHWEST LATE TONIGHT THEN SWITCH TO NORTHWEST SUNDAY MORNING. && .HYDROLOGY... ISSUED AT 330 PM CDT SAT JUN 6 2015 AS PWATS INCREASE TO 1.75 INCHES...THE THREAT FOR HEAVY RAINFALL WILL INCREASE. IN ADDITION TO THE POTENTIAL FOR EXTREMELY HEAVY RAINFALL RATES DUE TO THE DEEP WARM CLOUD DEPTHS... HIGH PWATS AND INITIAL SLOWER STORM MOTIONS...BACK BUILDING OF STORMS MAY OCCUR BEHIND THE LINEAR LINE. AS MENTIONED BY NESDIS...THE LOW LEVEL JET WILL BECOME JUXTAPOSED FAVORABLY WITH THE INSTABILITY AXIS WILL AID FOR MAX INSTABILITY TRANSPORT INTO THE UPWIND PORTIONS OF THE DEVELOPING DIFFLUENT THICKNESSES. WITH THIS POTENTIAL...WILL BE ISSUING A FLASH FLOOD WATCH FOR TONIGHT FOR MOST LOCATIONS NORTH OF INTERSTATE 80 AND WEST OF INTERSTATE 35 EXCEPT FOR THE MN BORDER LOCATIONS. RAINFALL OF 2 TO 4 INCHES IS POSSIBLE IN SOME LOCATIONS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 8 PM CDT THIS EVENING THROUGH LATE TONIGHT FOR AUDUBON-BOONE-CALHOUN-CARROLL-CRAWFORD-DALLAS-GREENE- GUTHRIE-HAMILTON-HUMBOLDT-PALO ALTO-POCAHONTAS-POLK-SAC-STORY- WEBSTER-WRIGHT. && $$ SHORT TERM...DONAVON LONG TERM...SKOW AVIATION...DONAVON HYDROLOGY...DONAVON  FXUS63 KDMX 080848 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 348 AM CDT MON JUN 8 2015 .SHORT TERM /TODAY/... ISSUED AT 347 AM CDT MON JUN 8 2015 UPPER TROF IS EXPECTED TO SLIDE ACROSS IOWA TODAY AND WILL PROVIDE THE IMPACTS FOR TODAY. AS THE TROF PROGRESSES SOUTHEAST THIS MORNING...MID LEVEL LAPSE RATES WILL STEEPEN WITH INSTABILITY DEVELOPING ACROSS THE EASTERN THIRD OR SO OF THE CWA. ALONG WITH SOME WEAK FORCING ASSOCIATED WITH THE SYSTEM...A FEW STORMS WILL BE POSSIBLE IN THE FAR EASTERN FORECAST AREA BY MIDDAY THEN QUICKLY EXITING TO THE EAST AS THE SYSTEM TRANSLATES INTO ILLINOIS. A FEW STORMS COULD PRODUCE SOME GUSTY WINDS GIVEN THE INVERTED V PROFILE IN THE SOUNDINGS. FARTHER WEST...SUBSIDENCE WILL INCREASE MUCH EARLIER WITH DRY CONDITIONS TODAY AND BREEZY NORTHWEST WINDS. THE THERMAL TROF WILL CROSS THE STATE THIS MORNING WITH WARM ADVECTION BY AFTERNOON...ESPECIALLY THE WEST. GIVEN THE SUNSHINE AND DEEP MIXING TEMPERATURES SHOULD REMAIN QUITE WARM TODAY...ESPECIALLY WITH THE INCREASING WARM ADVECTION BY THIS AFTERNOON IN THE WEST. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 347 AM CDT MON JUN 8 2015 IT WILL BE RELATIVELY QUIET THROUGH TUESDAY WITH WARMING TEMPERATURES THROUGH THAT TIME. TUESDAY WILL SEE THE WARMEST TEMPS WITH HIGHS MOST LOCATIONS IN THE LOWER 90S. TUESDAY INTO TUESDAY NIGHT A SHORTWAVE DROPS DOWN OUT OF THE NORTHERN PLAINS AS A COINCIDENT WITH THIS WILL BE A SURFACE COLD FRONT WORKING DOWN ACROSS NORTHERN INTO CENTRAL IOWA. WE WILL BE MODESTLY UNSTABLE TUESDAY AND TUESDAY NIGHT AND THERE ARE INDICATIONS THAT THERE WILL BE SOME DECENT FORCING IN THE 850-700MB LAYER HOWEVER MOISTURE IS LACKING SO AT LEAST AT THIS POINT I AM GOING DRY FOR TUESDAY. I ALSO TOOK A LOOK AT SHEAR AND THE BEST INSTABILITY/FORCING AND SHEAR REMAINS ACROSS CENTRAL MN INTO WI. THERE IS A PERIOD LATE TUESDAY NIGHT INTO WEDNESDAY MORNING WHERE THE FAR NORTHEAST PORTION OF THE FORECAST AREA GETS BRUSHED BY THE BETTER FORCING AND SHEAR SO I DID PUT SOME SLIGHT CHANCE POPS THAT AREA TO ACCOUNT FOR THE POTENTIAL FOR THUNDERSTORMS IN THAT AREA...HOWEVER WE STILL LACK GOOD MOISTURE SO I FELT IT DID NOT WARRANT MORE THAN A SLIGHT CHANCE FOR THE AREA. THINGS BEGIN TO GET INTERESTING WEDNESDAY AND ESPECIALLY LATE WEEK IN TO THE WEEKEND. THE FRONT STALLS ACROSS THE STATE ON WEDNESDAY BUT BETTER FORCING DOESN'T ARRIVE UNTIL A SHORTWAVE APPROACHES LATER WEDNESDAY NIGHT AND THURSDAY. A SURFACE LOW DEVELOPS OVER THE CENTRAL PLAINS WEDNESDAY NIGHT AND THURSDAY AND THAT STALLED BOUNDARY THEN BEGINS TO LIFT NORTH AS A WARM FRONT. IN ADDITION...SOUNDINGS WERE SHOWING WARM CLOUD DEPTHS ON THE ORDER OF 12K FT AND PWATS AROUND 2 INCHES. STORMS SHOULD DEVELOP ALONG THAT BOUNDARY THURSDAY AND THURSDAY NIGHT WITH A POTENTIAL FOR HEAVY RAINFALL. RATHER IMPRESSIVE FORCING IS IN PLACE THURSDAY AND THURSDAY EVENING AS WELL AND WITH INCREASING SHEAR OCCURRING THROUGH THE DAY INTO THURSDAY NIGHT...SEVERE STORMS ALSO APPEAR PROBABLE. MODELS DIVERGE SOME FOR FRIDAY BUT THERE APPEARS TO BE SOME AGREEMENT WITH RIDGING TAKING PLACE ACROSS THE UPPER MIDWEST FRIDAY THOUGH THE LOCATION OF THE BOUNDARY IS STILL IN QUESTION AND WHILE MY CONFIDENCE IS LOWER FOR FRIDAY...WITHOUT MORE CERTAINTY THAT THE FRONT WILL LIE FURTHER SOUTH...I HAD TO PUT CHANCE POPS IN FOR THE PERIOD. FOR THE WEEKEND...THE UPPER RIDGE GETS PUSHED TO THE EAST AS A CANADIAN LOW TREKS EAST AND A SHORTWAVE GETS EJECTED FROM THAT AND RIDES ACROSS THE NORTHERN PLAINS. AT THE SURFACE...FEATURES ARE A BIT MORE IN QUESTION BUT A FRONTAL BOUNDARY IS PROGGED TO LIFT ACROSS THE STATE SATURDAY INTO SATURDAY NIGHT. WITH A BOUNDARY IN PLACE...INCREASING INSTABILITY AND SUFFICIENT SHEAR ALONG THE BOUNDARY...I DID PUT CHANCE POPS IN THE FORECAST FOR THE WEEKEND. I DON'T THINK THE WHOLE DAY WILL BE A WASH OUT BUT CERTAINLY LATE AFTERNOON INTO THE NIGHT WILL NEED TO BE WATCHED. TEMPS A LITTLE COOLER FOR LATE WEEK INTO THE WEEKEND BUT STILL AT OR NEAR SEASONAL NORMALS. && .AVIATION...08/06Z ISSUED AT 1209 AM CDT MON JUN 8 2015 VFR CONDITIONS ARE ANTICIPATED THROUGH THE PERIOD...MAINLY WITH ONLY SCT CLOUDS AND INFREQUENT CIGS. THERE IS SOME POTENTIAL FOR MVFR PLUS RADIATION FOG SE NEAR KOTM WHERE HEAVY RAINS FELL TODAY...BUT CONFIDENCE IS NOT GREAT ENOUGH TO INCLUDE RIGHT NOW WITH MINOR DRYING NW WINDS AND A FEW PERIODS OF CIGS. WINDS WILL BECOME MORE NWLY MON WITH TYPICAL MINOR DIURNAL GUSTS. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...COGIL LONG TERM...FAB AVIATION...SMALL  FXUS63 KDMX 082041 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 341 PM CDT MON JUN 8 2015 .SHORT TERM /TONIGHT/... ISSUED AT 340 PM CDT MON JUN 8 2015 A WEAK BOUNDARY IS MOVING THROUGH SOUTHERN IOWA THIS AFTERNOON AND MAINLY ADVECTING DRIER AIR INTO THE AREA. DEWPOINTS IN ADVANCE OF THE BOUNDARY HAVE BEEN IN THE MID TO UPPER 60S WHILE POST FRONTAL DEWPOINTS HAVE MIXED OUT INTO THE 50S. A FEW THUNDERSTORMS DEVELOPED AHEAD OVER THE BOUNDARY OVER FAR SOUTHEAST IOWA AND HAVE SINCE MOVED OUT OF THE STATE. ANOTHER CONVERGENT ZONE REMAINS OVER EAST CENTRAL TO CENTRAL IOWA FROM NEAR AMES AND EAST ALONG HWY 30. SOME AGITATED CUMULUS HAS DEVELOPED IN THIS REGION WITH VERY WEAK RADAR RETURNS SHOWING UP FROM NEAR TAMA AND EAST. ANY MOISTURE CONVERGENCE HAS DROPPED SOUTH OF THE AREA AND OVERALL FORCING IS QUITE LOW. THEREFORE...HAVE REMOVED MOST POPS THAT WERE IN FOR THE EASTERN AREAS. A SURGE OF THETA-E ADVECTION MOVES ACROSS NORTH CENTRAL IOWA OVERNIGHT WITH MUCH OF THE FORCING OCCURRING AT 750 MB OR ABOVE. A FEW HIGHER RES SOLUTIONS TRYING TO BRING LIGHT PRECIPITATION TO THAT REGION. DESPITE SOME MOISTURE ADVECTION...PROFILES REMAIN RELATIVELY DRY. THE PRIMARY IMPACT WILL BE PASSING MID LEVEL CLOUDS. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO MID 60S AND WINDS WILL DIMINISH TO LESS THAN 10 MPH AND BECOME MORE WEST TO SOUTHWEST. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 340 PM CDT MON JUN 8 2015 SOME OF THE WARMEST TEMPERATURES FOR THE SEASON THUS FAR ARE STILL ON TRACK FOR TUESDAY UNDER STRONG WAA AS 850 MB TEMPS RISE FROM +16 TO +23 C BETWEEN 12Z TUE AND 12Z WED. CURRENT TEMPERATURE FORECAST FOR TOMORROW LOOKS TO BE ON TRACK AND HAVE MADE MINIMAL CHANGES. A SURFACE BOUNDARY SLIDES SOUTHEASTWARD ACROSS IOWA LATE TUESDAY INTO WEDNESDAY. DESPITE DECENT FG FORCING FROM 925 TO 850 MB AS THE FRONT ENTERS NORTHERN IOWA (THAT WEAKENS THE FURTHER SOUTH IT TRAVELS)...MOISTURE REMAINS VERY LIMITED IN THE LOW LEVELS. NAM/GFS DIFFER ON MID LEVEL LAPSE RATES AND THE RESULTANT AMOUNT OF ELEVATED INSTABILITY ABOVE THIS FORCING...WITH MAXIMUM MUCAPES OF 500-700 J/KG. STILL KEPT SOME TOKEN POPS IN THE NORTHEAST CWA BUT WOULD NOT BE SURPRISED WITH A DRY FROPA. ATTENTION THEN TURNS TO AN ACTIVE END OF THE WEEK AS TROPICAL MOISTURE FROM EX-HURRICANE BLANCA WORKS NORTHEASTWARD FROM THE BAJA CALIFORNIA PENINSULA ACROSS THE ROCKIES AND INTO THE MIDWEST ON THURSDAY. LOW LEVEL MOISTURE TRANSPORT OFF THE GULF OF MEXICO WILL ALSO INCREASE DURING THIS TIME OUT AHEAD OF A SURFACE CYCLONE DEVELOPING ALONG THE FRONT RANGE. THE AFOREMENTIONED COLD FRONT SLIDING SOUTH THROUGH IOWA ON WEDNESDAY WILL STALL ALONG THE IOWA/MISSOURI BORDER LATE WEDNESDAY AND LIFT BACK NORTH AS A WARM FRONT AS THE RETURN MOISTURE ARRIVES FROM THE SOUTH. THIS INCREASING THETA-E ADVECTION WILL FUEL INCREASING CHANCES FOR THUNDERSTORMS THROUGHOUT THE DAY ON THURSDAY. THE BEST CHANCE FOR WIDESPREAD HEAVY RAINFALL WILL ARRIVE THURSDAY AFTERNOON AND OVERNIGHT INTO FRIDAY. MIXING RATIOS IN THE 700 TO 500 MB REGION MAX OUT AT 6.0 G/KG WITH SURFACE MIXING RATIOS OF OVER 12 G/KG. PWAT VALUES MAX OUT AT OVER TWO INCHES ACROSS IOWA DURING THIS TIME WITH WARM CLOUD DEPTHS OF OVER 13,000 FT. HOWEVER...MEDIUM RANGE GUIDANCE REMAINS INCONSISTENT IN THE PLACEMENT OF THE FRONT RANGE LOW AND ATTENDANT WARM FRONT AS IT MOVES EASTWARD...WHICH WILL HAVE A DIRECT EFFECT ON THE PLACEMENT OF HEAVY RAIN AND POSSIBLY ANY SEVERE WEATHER POTENTIAL FOR THE CWA. THE 12Z EC REMAINS THE STRONGER AND MORE PROGRESSIVE SOLUTION THAT TAKES THE RAIN INTO NORTHERN IOWA...WHILE THE WEAKER AND SLOWER GFS TAKES THE LOW AND HEAVY RAIN INTO SOUTHERN IOWA. AS THIS SYSTEM DEPARTS ON FRIDAY IT WILL ONCE AGAIN LEAVE A STATIONARY BOUNDARY IN ITS WAKE...WHICH WILL BE THE FOCUS FOR OCCASIONAL SHOWERS AND THUNDERSTORMS THROUGH THE WEEKEND. GIVEN THE WEAK UPPER LEVEL FLOW...THE TIMING AND LOCATIONS OF THESE FEATURES ARE A BIT UNCERTAIN THIS FAR OUT. && .AVIATION...08/18Z ISSUED AT 1255 PM CDT MON JUN 8 2015 VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD. A FEW THUNDERSTORMS ARE POSSIBLE OVER EASTERN IOWA THIS AFTERNOON BUT SHOULD REMAIN EAST OF SITES. BREEZY NORTHWEST WINDS THIS AFTERNOON WILL DIMINISH THIS EVENING THEN BECOME BREEZY FROM THE SOUTHWEST LATE TUESDAY MORNING. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DONAVON LONG TERM...SKOW AVIATION...DONAVON  FXUS63 KDMX 090840 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 340 AM CDT TUE JUN 9 2015 .SHORT TERM /TODAY/... ISSUED AT 340 AM CDT TUE JUN 9 2015 THE MAIN FORECAST CONCERN TODAY WILL BE TEMPERATURES. 850 TEMPS WARM QUITE A BIT TODAY WITH +22 EVEN AS FAR NORTH AS MASON CITY BY 21Z. I NUDGED TEMPS UP BIT MOST LOCATIONS...ESPECIALLY NORTH WHERE WE WERE COOLER TO BEGIN WITH. LOOK FOR HIGHS TODAY TO BE MOSTLY IN THE LOWER 90S ACROSS ALL BUT THE FAR SOUTHEASTERN PORTION OF THE FORECAST AREA AND WE ARE STILL LOOKING AT UPPER 80S THERE SO A VERY WARM DAY IS ON TAP. MODELS ARE A LITTLE SLOWER ON A SHORTWAVE PUSHING ACROSS THE NORTHERN PLAINS INTO WISCONSIN AND ARE NOW PUSHING THIS THROUGH TONIGHT. THE ATTENDANT SURFACE LOW AND COLD FRONT ARE LIKEWISE SLOWER AS WELL. SOUNDINGS ARE QUITE DRY AND DESPITE DECENT INSTABILITY AND STEEP LAPSE RATES THERE IS NO FORCING AND NO BOUNDARY TO FOCUS ANYTHING ON AND THE BETTER SHEAR IS TIED TO THE LOW AND SURFACE BOUNDARY SO I DO NOT HAVE PRECIP IN THE GRIDS FOR TODAY. I DO HOWEVER HAVE SOME TOKEN SLIGHTS IN AT 00Z TO BLEND WITH NEIGHBORS AS WE HEAD INTO EVENING AND THE FRONT NEARS. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 340 AM CDT TUE JUN 9 2015 FAIRLY QUIET INITIALLY WITH A WEAK COLD FRONT DROPPING THROUGH THE STATE TONIGHT. COULD SEE A FEW ISOLATE POP UP STORMS ALONG THE FRONT BY LATE EVENING INTO THE EARLY MORNING HOURS ACROSS THE NORTHERN CWA...BUT OVERALL MOISTURE IS LIMITED SO ACTIVITY NOT EXPECTED TO BE WIDESPREAD. FRONTAL BOUNDARY TO STALL OUT ACROSS THE SOUTHERN CWA...AND LIFT BACK NORTH AS A WARM FRONT LATE WEDNESDAY NIGHT INTO THURSDAY. COULD AGAIN SEE SOME CONVECTIVE ACTIVITY WED NIGHT INTO THURSDAY AS MOISTURE RETURNS TO THE STATE IN ADVANCE OF A DEVELOPING AREA OF LOW PRESSURE ACROSS THE CENTRAL PLAINS. THE GULF WILL OPEN UP INTO THURSDAY/FRIDAY...WITH MOISTURE TRANSPORT DIRECTED INTO CENTRAL IOWA TOWARD THURSDAY NIGHT/FRIDAY. A FEW IMPULSES OF ENERGY WILL MOVE THROUGH THE REGION WITH CONVECTION EXPECT THURSDAY INTO FRIDAY. SEVERE CHANCES INCREASE LATE THURSDAY INTO FRIDAY AS WELL...WITH DEEP LAYER SHEAR INCREASING ACROSS THE STATE. ADDITIONALLY HEAVY RAINFALL A THREAT AS WELL...WITH PWATS PUSHING 1.5 TO 2 INCHES ACROSS THE CWA. THESE VALUES ARE IN THE UPPER PERCENTILES TO NEAR MAXIMUM VALUES FOR JUNE...IN ADDITION FREEZING LEVELS INCREASE TO AROUND 12-13KFT. DEEP WARM CLOUD DEPTHS WILL ALLOW FOR EFFICIENT RAIN PRODUCTION AND STORM MOTIONS MAY TREND TOWARD THE SLOWER SIDE. WILL HAVE TO MONITOR IN THE COMING SHIFTS...BUT CONTINUED WITH THE HEAVY RAINFALL MENTION IN THE GRIDS. A WIDESPREAD HALF INCH TO INCH LOOKS POSSIBLE THURSDAY INTO FRIDAY...WITH PORTIONS OF NORTHERN IOWA EXPECTED TO SEE UPWARDS OF 2 INCHES OF RAINFALL WITH LOCALLY HIGHER AMOUNTS STILL POSSIBLE. ADDITIONAL THUNDERSTORM ACTIVITY CONTINUES FOR THE WEEKEND AS ENERGY CONTINUES TO LIFT THROUGH THE REGION IN SOUTHWEST TO WESTERLY FLOW ALOFT...WITH A MORE ZONAL FLOW PATTERN SETTING UP BY EARLY NEXT WEEK. ANOTHER WARM DAY EXPECTED FOR WEDNESDAY...THEN MORE SEASONAL TEMPERATURES OR JUST COOLER THAN NORMAL EXPECTED FOR THE REMAINDER OF THE PERIOD. && .AVIATION...09/06Z ISSUED AT 1131 PM CDT MON JUN 8 2015 ANOTHER FORECAST WITH VFR CONDITIONS THROUGH THE ENTIRE TAF PERIOD. WINDS BEGIN TO MIX LATE IN THE MORNING TUESDAY AND DECOUPLE AROUND 00Z WEDNESDAY. HIGHEST GUSTS LOOK TO BE RANGE IN THE 20-25 KNOT RANGE BY THE AFTERNOON TUESDAY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...FAB LONG TERM...BEERENDS AVIATION...PODRAZIK  FXUS63 KDMX 092015 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 315 PM CDT TUE JUN 9 2015 .SHORT TERM /TONIGHT/... ISSUED AT 314 PM CDT TUE JUN 9 2015 TEMPERATURES WARMED INTO THE LOW TO MID 90S ACROSS CENTRAL IOWA THIS AFTERNOON. DEEP MIXING ALONG WITH DRIER AIR ALOFT HAS HELPED LOWER DEWPOINTS INTO THE MID 50S AT MANY LOCATIONS. A FEW VERY HIGH BASED THUNDERSTORMS MAY MOVE INTO NORTH CENTRAL IOWA THIS EVENING. MOISTURE ASSOCIATED WITH THE SYSTEM AREA QUITE LIMITED AND WILL LIMIT OVERALL COVERAGE AND ANY ACTIVITY WILL DIMINISH AS IT SHIFT FARTHER SOUTH INTO AN EVEN MORE MOISTURE STARVED AIRMASS. A FRONTAL BOUNDARY WILL ENTER THE STATE AFTER 06Z AND BE ENTERING THE CENTRAL PORTION OF THE STATE AROUND 12Z WEDNESDAY. LITTLE TO NO PRECIPITATION IS EXPECTED AFTER 06Z. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 314 PM CDT TUE JUN 9 2015 A SEASONALLY ACTIVE WEATHER PATTERN IS SETTING UP FOR MUCH OF THE LONG TERM FORECAST PERIOD. DURING THE DAY WEDNESDAY A WEAKENING COOL FRONT WILL SAG SOUTHWARD ACROSS IOWA...LIKELY STALLING IN FAR SOUTHERN IOWA BY LATE AFTERNOON. THIS WILL MAKE FOR ANOTHER HOT AND HUMID DAY ALONG AND AHEAD OF THE BOUNDARY...ESPECIALLY FROM ABOUT THE I-80 CORRIDOR SOUTHWARD. FORECAST SOUNDINGS INDICATE THAT BY LATE AFTERNOON OR EARLY EVENING CONVECTIVE TEMPERATURES WILL BE REACHED IN SOUTHERN IOWA...WHICH SHOULD BE SUFFICIENT TO GENERATE ISOLATED TO SCATTERED THUNDERSTORMS ALONG AND NEAR THE FRONTOLYZING BOUNDARY. INSTABILITY IN THIS AREA MAY BE FAIRLY ROBUST...HOWEVER DEEP LAYER SHEAR IS EXPECTED TO BE PRETTY WEEK AND WITH VIRTUALLY NO LOW LEVEL FLOW/CONVERGENCE. THESE STORMS WILL THUS POSE AN ISOLATED/MARGINAL RISK FOR SEVERE WEATHER MAINLY IN THE FORM OF HAIL/WINDS...AS OUTLINED BY THE SPC DAY 2 OUTLOOK. THE LATE WEDNESDAY STORMS SHOULD GRADUALLY WEAKEN AFTER SUNSET...BUT THEN A MUCH LARGER AND POTENTIALLY MORE HAZARDOUS STORM SYSTEM WILL BEAR DOWN ON THE AREA FOR THURSDAY INTO FRIDAY. AT 500 MB...A NORTHERN STREAM SHORTWAVE MOVING ACROSS THE NORTHERN ROCKIES ON WEDNESDAY WILL BEGIN TO DIG OUT A RELATIVELY WEAK CUTOFF LOW OVER CALIFORNIA. BY WEDNESDAY NIGHT THE NORTHERN WAVE WILL MATURE AS IT MOVES OVER SOUTH DAKOTA/NEBRASKA AND GENERATES A SURFACE CYCLONE IN THE LEE OF THE ROCKIES SOMEWHERE AROUND THE COLORADO/NEBRASKA BORDER. THIS WILL CAUSE THE FORMERLY DISCUSSED FRONTAL BOUNDARY ACROSS SOUTHERN IOWA TO MOVE BACK NORTHWARD AS A WARM FRONT. THE BROAD ASCENT AHEAD OF THE APPROACHING TROUGH/LOW WILL WORK WITH THE UNSTABLE AIR WITHIN THE RESULTING WARM SECTOR...EVEN DURING THE OVERNIGHT HOURS INTO THURSDAY MORNING...TO GENERATE WIDESPREAD SHOWERS AND THUNDERSTORMS TO OUR WEST. AS THE 500 MB WAVE THEN SLOWLY TRACKS ACROSS IOWA LATE THURSDAY AND THURSDAY NIGHT THIS CONVECTION WILL LIKEWISE MOVE ACROSS THE STATE...WITH SEVERAL ROUNDS OF THUNDERSTORMS LIKELY ADVECTING ACROSS AND/OR GENERATING OVERHEAD AS SUBTLE IMPULSES ALOFT MOVE OVER THE RAPIDLY DESTABILIZING LOW LEVEL AIRMASS AND WARM FRONT ESPECIALLY FROM THURSDAY AFTERNOON INTO THURSDAY NIGHT. THIS IS OVERALL A GOOD SETUP FOR SEVERE WEATHER...PRIMARILY IN THE FORM OF HAIL/WIND...HOWEVER A PRIMARY LIMITING FACTOR WILL BE THE DEGREE TO WHICH EARLY THURSDAY CONVECTION/CLOUD DEBRIS LIMITS DESTABILIZATION LATER IN THE DAY. ASIDE FROM THE SEVERE WEATHER THREAT...THERE REMAINS SIGNIFICANT CONCERN FOR HEAVY RAINFALL AND RESULTING FLOODING/FLASH FLOODING EFFECTS ACROSS MUCH OF THE AREA. THE SLOW PROGRESSION OF THE 500 MB SYSTEM WILL RESULT IN A PROLONGED PERIOD OF BROAD FORCING AND THUNDERSTORM DEVELOPMENT...ESPECIALLY NORTH OF THE EFFECTIVE WARM FRONT ACROSS OUR NORTHERN AND NORTHWESTERN COUNTIES...AND FORECAST SOUNDINGS CONSISTENTLY SHOW DEEP WARM CLOUD DEPTHS AND PWATS APPROACHING TWO INCHES. THIS COMBINATION OF FACTORS WILL LIKELY RESULT IN A SWATH OF HEAVY RAIN ACROSS PARTS OF NORTHERN AND NORTHWESTERN IOWA AND SOUTHERN MINNESOTA AND WISCONSIN. HOWEVER...THE POTENTIAL SCOPE AND MAGNITUDE OF ANY FLOODING/FLASH FLOODING WILL BE MITIGATED BY THE RELATIVELY DRY ANTECEDENT CONDITIONS IN PLACE...IN TERMS OF SOIL CONDITION AND RIVER STAGES...AND THE FACT THAT THE HEAVY RAIN SWATH WILL BE ORIENTED MORE OR LESS PERPENDICULAR TO MOST OF OUR RIVER BASINS. THUS NO HEADLINES HAVE BEEN ISSUED AT THIS TIME...ALTHOUGH THEY MAY BE CONSIDERED IN THE NEXT COUPLE OF DAYS. AS THE NORTHERN STREAM 500 MB SHORTWAVE DEPARTS RAPIDLY ON FRIDAY THINGS SHOULD CLEAR OUT ACROSS OUR FORECAST AREA...EXCEPT THAT THE FORMER WARM FRONT NOW MOVING BACK SLOWLY SOUTHWARD WILL ONCE AGAIN STALL SOMEWHERE ACROSS CENTRAL IOWA. THIS SHOULD PROVIDE A BRIEF RESPITE LATE FRIDAY AND FRIDAY NIGHT...HOWEVER THE ENTIRE SCENARIO WILL REPEAT ITSELF TO SOME EXTENT WHEN THE AFOREMENTIONED SOUTHWEST U.S. 500 MB CUTOFF LOW/TROUGH MOVES OVERHEAD THIS WEEKEND. THIS SHOULD ONCE AGAIN PUSH THE BOUNDARY BACK NORTHWARD AND GENERATE WIDESPREAD SHOWERS AND THUNDERSTORMS...MAINLY AROUND SATURDAY NIGHT...THEN ONCE AGAIN SAG THE FRONT BACK SOUTHWARD AND STALL IT SOMEWHERE AROUND THE IOWA/MINNESOTA BORDER. LOOKING INTO NEXT WEEK THE 500 MB FLOW IS ROUGHLY ZONAL...WHICH WILL PROBABLY ALLOW ANY SHORTWAVE IMPULSES MOVING THROUGH IT TO ACTIVATE THE WOBBLING BOUNDARY ON ONE OR MORE OCCASIONS AND RESULT IN A PROLONGED PERIOD OF THUNDERSTORM CHANCES AND INTERMITTENT RAINFALL. DEPENDING ON THE MAGNITUDE OF RAINFALL REALIZED THIS THURSDAY AND THURSDAY NIGHT...SUCH A SCENARIO COULD RESULT IN THE FIRST SUSTAINED PERIOD OF FLOOD THREAT THAT WE HAVE SEEN SINCE LAST SEPTEMBER. && .AVIATION...09/18Z ISSUED AT 1228 PM CDT TUE JUN 9 2015 VFR CONDITIONS AND BREEZY SOUTHWEST WINDS CAN BE EXPECTED THROUGH THE AFTERNOON TODAY. THE WIND WILL DIMINISH BY EARLY EVENING. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE NEAR KFOD AND KMCW IN THE EVENING. A BOUNDARY WILL MOVE SOUTH THROUGH THE AREA LATE TONIGHT INT0 WEDNESDAY MORNING AND WILL SWITCH THE WINDS TO NORTHERLY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...DONAVON LONG TERM...LEE AVIATION...DONAVON  FXUS63 KDMX 100851 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 351 AM CDT WED JUN 10 2015 .SHORT TERM /TODAY/... ISSUED AT 351 AM CDT WED JUN 10 2015 A COLD FRONT WILL CONTINUE TO SINK SOUTH ACROSS CENTRAL IOWA TODAY SETTLING MOST LIKELY ACROSS FAR SOUTHERN IOWA BY THIS AFTERNOON. SOME FORCING IN THE VICINITY OF THE FRONT IS HELPING TO KEEP SOME ISOLATED THUNDERSTORMS GOING IN FAR NORTHWEST IOWA EARLY THIS MORNING BUT THE FORCING IS EXPECTED TO WEAKEN BY DAYBREAK AS A VERY SUBTLE WAVE SHIFTS SOUTHEAST AND THE SURFACE LOW THAT THE FRONTAL BOUNDARY IS TIED TO CONTINUES TO MOVE INTO THE GREAT LAKES REGION. OTHER THAN A WIND SHIFT AND SOME CLOUDS...THERE WILL BE LITTLE SENSIBLE WEATHER ASSOCIATED WITH THE FRONTAL PASSAGE THIS MORNING INTO THE AFTERNOON. HOWEVER...DURING PEAK HEATING HOURS OF THE AFTERNOON THE STALLED FRONTAL BOUNDARY WILL SERVE AS A FOCUS FOR THUNDERSTORM DEVELOPMENT AS VERY STRONG INSTABILITY DEVELOPS ALONG AND AHEAD OF THE FRONTAL BOUNDARY WHERE DEWPOINTS WILL REMAIN IN THE MID 60S. MODELS ARE SUGGESTING MUCAPES ON THE ORDER OF 3000+ J/KG. IN ADDITION... FORCING WILL INCREASE AGAIN LATER TODAY AS A SURFACE LOW DEVELOPS OVER THE PLAINS AND MOVES EAST...EVENTUALLY INTERACTING WITH THE FRONTAL BOUNDARY. THE ONE THING THIS SCENARIO HAS GOING AGAINST IT SOMEWHAT IS WEAK SHEAR IN THE VICINITY OF THE FRONTAL BOUNDARY. HAVING SAID THAT THE FRONTAL BOUNDARY AND THE AMOUNT OF INSTABILITY DURING PEAK HEATING SHOULD BE ENOUGH TO GET THUNDERSTORMS WITH ROBUST UPDRAFTS GOING BUT THE LACK OF SHEAR WILL NOT ALLOW STORMS TO BE SUSTAINED...AT LEAST BE STRONG FOR VERY LONG. THUS THERE WILL BE A RISK FOR SOME LARGE HAIL AS THE UPDRAFTS GO UP THEN DAMAGING WIND AS THE STORMS WEAKEN OR COLLAPSE. SHORT TERM MODELS...INCLUDING HI-RES MODELS...DO NOT SEEM TO PICK UP ON THE THUNDERSTORM DEVELOPMENT POTENTIAL DURING THE LATE AFTERNOON AS NONE OF THEM DEVELOP MUCH OR ANY QPF ACROSS THE AREA. WE HAD SLIGHT CHANCE POPS GOING IN THE GRIDS ALREADY SO THIS WAS LEFT THOUGH REFINED SOME TO MAINLY THE SOUTHERN TIER OR TWO AND I DID INCREASE THEM TO CHANCE POPS BETWEEN 23Z AND 00Z. .LONG TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 351 AM CDT WED JUN 10 2015 WEAK FRONTAL BOUNDARY TO BE IN PLACE ACROSS THE SOUTHERN CWA THIS EVENING TO LIFT NORTHEASTWARD AS A WARM FRONT LATE TONIGHT. LARGE AMOUNT OF INSTABILITY PRESENT...WITH MARGINAL SHEAR WITH ANY ACTIVITY THAT DEVELOPS ALONG THE BOUNDARY. MOISTURE TRANSPORT TO INCREASE INTO THE AREA TOWARD LATER EVENING...WITH SHEAR INCREASING A BIT SO SOME SEVERE ACTIVITY POSSIBLE. STRONGER UPPER LEVEL WAVE TO LIFT OUT OF THE GREAT BASIN REGION THROUGH THE STATE THURSDAY AND MERGE WITH A NORTHERN STREAM WAVE FRIDAY. THIS WILL ALLOW FOR A LONGER DURATION PRECIPITATION EVENT THURSDAY INTO FRIDAY...WITH AN AXIS OF LOW PRESSURE EXPECTED TO STRETCH FROM WESTERN IOWA INTO CENTRAL/WESTERN KS BY LATE THURSDAY. WARM FRONT TO BE SITUATED ACROSS NORTHERN IOWA...WITH A TREMENDOUS AMOUNT OF MOISTURE ADVECTING INTO THE STATE. EXPECT THUNDERSTORMS TO DEVELOP ALONG AND NORTH OF THE WARM FRONT AS IT LIFTS THROUGH CENTRAL/NORTHERN IOWA THURSDAY. ADDITIONAL ACTIVITY EXPECTED TO DEVELOP ALONG THE SFC TROUGH AXIS ACROSS WRN IA BY LATE THURSDAY. DEF ZONE PRECIP EXPECTED TO THE NORTHWEST OF THE SURFACE LOW ACROSS THE NORTHERN/NORTHWESTERN CWA THURSDAY NIGHT...WITH THE SYSTEM PUSHING EAST INTO FRIDAY. PWAT VALUES STILL EXPECTED TO PUSH TOWARDS THE MAXIMUM VALUES FOR THIS TIME OF YEAR AROUND 2+ INCHES...WITH DEEP WARM CLOUD DEPTHS OF AROUND 14 KFT. THEREFORE STILL A LIKELY HEAVY RAIN SCENARIO SETTING UP...WITH CHANCES FOR SEVERE STORMS AS WELL. FLASH FLOOD GUIDANCE VALUES REMAIN HIGH GIVEN THE DRIER CONDITIONS THAT HAVE BEEN IN PLACE...BUT COULD STILL SEE SOME POTENTIAL FOR FLASH FLOODING WITH THIS SYSTEM AND RIVER FLOODING A POSSIBILITY TOO GIVEN THE WIDESPREAD LARGER AMOUNTS OF RAIN EXPECTED. HOWEVER CONFIDENCE ON THE POSSIBILITY OF WIDESPREAD FLASH FLOODING NOT GREAT GIVEN THE HIGH GUIDANCE VALUES...THE HIGHER PRECIPITATION TO BE SPREAD OUT OVER A LONGER TIME...AND FALLING IN AN AREA OF THE CWA THAT IS LESS RESPONSIVE/FLASHY. POSSIBILITY OF SOME RISES ON AREA RIVERS...SO WILL HAVE TO MONITOR FOR POSSIBLY FLOOD WATCH BUT AGAIN THREAT DIMINISHED SOME WITH THE ORIENTATION OF THE AXIS OF HEAVY RAINFALL NOT LINING UP WITH THE RIVER BASINS. AS SYSTEM PULLS EAST OF THE AREA FRIDAY...STILL HAVE THE UPPER LOW OVERHEAD AND MAY SEE SOME LINGERING ACTIVITY. OTHERWISE MAINLY DRY CONDITIONS FOR LATE FRIDAY INTO FRIDAY NIGHT. FRONTAL BOUNDARY COULD GET HUNG UP ACROSS THE SOUTH AND LIFT BACK NORTH SATURDAY WITH ANOTHER WAVE LIFTING OUT OF THE DESERT SOUTHWEST. SOUTHWEST FLOW ALOFT WILL TRANSITION INTO A MORE ZONAL FLOW PATTERN INTO EARLY NEXT WEEK. OVERALL CONTINUE TO SEE WEAK IMPULSES LIFT INTO THE REGION...RESULTING IN CONTINUED CHANCES FOR THUNDERSTORMS ACROSS MUCH OF THE CWA FOR THE WEEKEND INTO EARLY NEXT WEEK. TEMPS TO COOL A BIT FRIDAY INTO SATURDAY BEHIND THE COOL FRONT...THEN MODERATE AND WARM AGAIN INTO EARLY NEXT WEEK. && .AVIATION...10/06Z ISSUED AT 1133 PM CDT TUE JUN 9 2015 CONDITIONS WILL REMAIN VFR THROUGH PERIOD. WINDS WILL BECOME NORTHERLY NEAR 12Z AT SITES...BECOMING MORE NORTHEASTERLY IN THE AFTERNOON AND EASTERLY NEAR 00Z AT SITES. WINDS MAY GUST IN THE AFTERNOON. LATE IN PERIOD COULD SEE VCTS OR TSRA AT SOUTHERN SITES...KOTM/KDSM...THOUGH HAVE NOT INCLUDED MENTION ATTM DUE TO UNCERTAINTIES IN TIMING AND LOCATION OF TS. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...FAB LONG TERM...BEERENDS AVIATION...AWB  FXUS63 KDMX 102032 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 332 PM CDT WED JUN 10 2015 .SHORT TERM /TONIGHT/... ISSUED AT 332 PM CDT WED JUN 10 2015 A DECAYING SURFACE FRONT HAS SAGGED SOUTHWARD ACROSS THE AREA TODAY...AND IS NOW STALLED ROUGHLY ALONG AND SOUTH OF HIGHWAY 34. ALONG AND SOUTH OF THIS BOUNDARY STRONG INSTABILITY HAS DEVELOPED BENEATH A MID LEVEL CAP...AND AS SURFACE TEMPERATURES CONTINUE TO RISE THIS AFTERNOON THUNDERSTORMS SHOULD EVENTUALLY DEVELOP BY THIS EVENING. MEANWHILE A LARGE STORM SYSTEM IS WORKING ITS WAY FROM THE ROCKIES INTO THE WESTERN HIGH PLAINS...AND WILL APPROACH IOWA FROM THE WEST TONIGHT. THIS WILL PULL THE AFOREMENTIONED FRONTAL BOUNDARY BACK NORTHWARD OVERNIGHT ALONG WITH ANY SCATTERED THUNDERSTORMS THAT DEVELOP ALONG IT. FINALLY...THE LARGE SWATH OF SHOWERS AND STORMS ON THE LEADING FLANK OF THE STORM SYSTEM APPROACHING FROM THE HIGH PLAINS WILL REACH OUR WESTERN AND NORTHWESTERN COUNTIES RIGHT AROUND SUNRISE TOMORROW MORNING...MORE OF WHICH IS DISCUSSED IN THE LONG TERM SECTION BELOW. REGARDING SEVERE WEATHER THREATS THROUGH TONIGHT...DESPITE A LACK OF DEEP LAYER SHEAR THE STRONG INSTABILITY AND PRESENCE OF A FRONTAL BOUNDARY ACROSS SOUTHERN IOWA LATE THIS AFTERNOON AND EVENING DICTATES SOME THREAT OF SEVERE WEATHER WITH LARGE HAIL...DAMAGING WINDS...AND POSSIBLY EVEN A TORNADO OR TWO. THIS IS WELL HANDLED IN THE SHORT TERM SPC PRODUCTS. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 332 PM CDT WED JUN 10 2015 VERY ACTIVE PATTERN IN STORE FOR IOWA INTO NEXT WEEK. INITIAL CONCERN WILL BE CONVECTION WITH THE POTENTIAL FOR HEAVY RAIN. SHORT WAVES CROSSING THE CENTRAL AND NRN ROCKIES WILL DEVELOP AN MCS INTO THE MO RIVER VALLEY OVERNIGHT...CROSSING THE RIVER INTO PORTIONS OF IA BY MORNING. THE SYSTEM WILL PRODUCE UNSEASONABLY STRONG SYNOPTIC SCALE FORCING STARTING WITH WRN GREAT LAKES RIGHT ENTRANCE REGION DIVERGENCE ACROSS THE UPPER MS VALLEY AND DECENT DPVA FARTHER SOUTH. THIS WILL BE COINCIDENT WITH STRONG...COMPACT H85/H7 THETA-E ADVECTION AND FRONTOGENETICAL FORCING. THIS WILL BE COUPLED WITH A VERY FAVORABLE AIRMASS FOR EFFICIENT RAINFALL. 00Z NAEFS PWATS AND INTEGRATED WATER VAPOR TRANSPORT ARE BOTH TOWARD CLIMATOLOGICALLY EXTREME LEVELS INTO THE NOTED BAROCLINIC ZONE AND WARM FRONT. MOISTURE TRANSPORT INTO THE FRONT WILL BE QUITE STRONG WITH 305K ISENT SURFACE SHOWING 40+ KTS OF INFLOW AND EXTREME MOISTURE/TRANSPORT CONVERGENCE WITH DETERMINISTIC PWATS PUSHING 2 INCHES AND WARM CLOUD DEPTHS OVER 4KM. THIS FAIRLY UNIQUE COUPLING OF SYNOPTIC SCALE FORCING AND FAVORABLE AIRMASS WILL PRODUCE AN ENVIRONMENT EXTREMELY FAVORABLE FOR EFFICIENT HEAVY RAINS. THE BIG QUESTION WILL BE LATITUDINAL EXTEND DEPENDING ON HOW MESOSCALE OUTFLOW BOUNDARIES PLAY OUT OVERNIGHT. CONFIDENCE IS NOT HIGH...BUT MOST LIKELY SCENARIO AT THIS POINT PLACES HEAVY RAINFALL AXIS SOMEWHERE ALONG THE IA/MN BORDER WHERE WIDESPREAD TWO TO THREE INCH AMOUNTS ARE POSSIBLE WITH LOCALLY HIGHER AMOUNTS. THUS A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THESE AREAS. THE LACK OF TOPOGRAPHY...SLOWLY MATURING CROPS...AND PREVIOUS TABLE SETTING HEAVY RAINS ARE SOMEWHAT OF A DETERRENT...BUT THE NOTED BLEND OF FORCING AND ENVIRONMENT MAY OVERCOME THESE QUESTIONS. THERE COULD ALSO VERY WELL BE A SEVERE WEATHER THREAT FARTHER SOUTH ALONG AND AHEAD OF THE LOW/TRIPLE POINT. NAM/GFS MLCAPES ARE UNCAPPED WITH A NOTED LOBE OF EXTREME 0-1KM SHEAR AND SRH JUST AHEAD LEADING TO AN ELEVATED TORNADO THREAT...ESPECIALLY FARTHER NORTH TOWARD THE RAIN AND POTENTIALLY LOWER LCLS. FEEL THE LOCALIZED POTENTIAL IS HIGHER THAN WHAT IS CURRENTLY DEPICTED BY THE SPC DAY 2 OUTLOOK. THE FORCING SHOULD BE ALL BUT GONE INTO FRIDAY WITH A BRIEF LULL BEFORE THE WEATHER TURNS ACTIVE ONCE AGAIN. REMNANTS OF CURRENT SWRN US TROUGH WILL LIFT ACROSS THE PLAINS WITH FORCING REACHING THE PLAINS LATE SAT INTO SAT NIGHT. THIS WILL ANOTHER BOUNDARY INTO IOWA WITH ADDITIONAL TRIGGERS FOR CONVECTION WITH SEVERE WEATHER HEAVY RAINS AGAIN POSSIBLE. THE BOUNDARY ASSOCIATED WITH THIS SYSTEM DRIFTS BACK AND FORTH WITH WEAK FLOW INTO THE EXTENDED PERIOD. DETAILS WILL BE VERY HARD TO COME BY DUE TO UNPREDICTABLE CONVECTION AND OUTFLOW...BUT THIS RESULTS IN AN EXTENDED PERIOD OF CHANCES POPS FOR SEVERE DAYS. NOTHING ORGANIZED TO NOTE THIS FAR OUT...BUT THE POTENTIAL FOR HEAVY RAINS AND FLOODING DO NOT LOOK TO IMPROVE APPRECIABLY THROUGH THE VALID PERIOD. && .AVIATION...10/18Z ISSUED AT 1240 PM CDT WED JUN 10 2015 VFR CONDITIONS ARE FORECAST THROUGH THIS AFTERNOON. ISOLD-SCT TS WILL DEVELOP IN SOUTHERN IA TOWARD THIS EVENING...THEN MOVE NORTHWARD OVERNIGHT AND MERGE WITH A LARGER AREA OF SHRA/TSRA APPROACHING FROM THE WEST. THIS MAY RESULT IN SOME TSTORM EFFECTS AT OTM/DSM LATER THIS EVENING...THEN FURTHER NORTH BY THURS MORNING. HAVE INCLUDED ONLY VCTS AT THE SOUTHERN TERMINALS DUE TO SCT NATURE OF TS INITIALLY...BUT PREVAILING TSRA AT FOD/MCW TOMORROW AS IT SHOULD BE WIDESPREAD. ONLY ADVERTISED MVFR CONDITIONS AT THOSE NORTHERN TERMINALS...BUT IFR OR LOWER IS CERTAINLY POSSIBLE RIGHT TOWARD THE END OF THE 18Z TAF PERIOD. && .HYDROLOGY... ISSUED AT 1240 PM CDT WED JUN 10 2015 WIDESPREAD MODERATE TO HEAVY RAINFALL IS STILL ON TRACK THU INTO THU EVE WITH NRN IA LIKELY TO SEE THE HIGHER END AMOUNTS. QPF REMAINS ON THE ORDER OF SEVERAL INCHES IN THESE AREAS THROUGH 12Z FRI AND RFC DETERMINISTIC CONTINGENCY FORECASTS SUGGEST THAN MANY MAIN STEM RIVERS MAY REACH MINOR FLOOD STAGE IF THIS QPF MATERIALIZES...WITH A FEW SPOTS JUST INTO MODERATE FLOODING AS WELL. AREAS PRIMARILY IMPACTED AT THIS TIME WOULD SEEM TO INCLUDE THE CEDAR BASIN...RACCOON BASIN AND DES MOINES RIVER BASIN ABOVE SAYLORVILLE. CURRENT RIVER FORECASTS ONLY DEPICT QPF THROUGH 12Z THU HOWEVER...SO THIS IS NOT DEPICTED IN THE OFFICIAL FORECASTS JUST YET. SIGNIFICANT CHANGES MAY OCCUR WITH THE 11.00Z AND 11.12Z RUNS HOWEVER...LOOKING AHEAD TO THIS EVENING AND THU MORNING. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY NIGHT FOR CERRO GORDO-EMMET-HANCOCK-KOSSUTH-PALO ALTO-WINNEBAGO- WORTH. && $$ SHORT TERM...LEE LONG TERM...SMALL AVIATION...LEE HYDROLOGY...SMALL  FXUS63 KDMX 110927 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 427 AM CDT THU JUN 11 2015 .SHORT TERM /TODAY/... ISSUED AT 427 AM CDT THU JUN 11 2015 SEVERAL CONCERNS TODAY DEALT WITH THE HEAVY RAIN AND SEVERE WEATHER POTENTIAL. MODELS ARE IN FAIR AGREEMENT WITH THE OVERALL SYNOPTIC SETUP TODAY BUT DIFFER QUITE A BIT WRT MESOSCALE SET UP AND THUS LEANED TOWARD A BLEND OF THE HIRES MODELS...HRRR/HOPWRF/ARW-NMM WRF/NSSL 4.0KM WRF FOR TIMING OF POPS TODAY AS THEY SEEM TO HAVE A GOOD GRASP ON CURRENT RADAR TRENDS. HEAVY RAIN POTENTIAL...CURRENT MCS MOVING ACROSS CENTRAL IOWA LOOKS TO PERSIST THROUGH AT LEAST 15Z WITH BACKBUILDING DOWN INTO NORTHEAST KANSAS AND THIS SHOULD CONTINUE TO PUSH INTO IOWA THROUGH THE MORNING HOURS. THE RAIN IS LIKELY TO CONTINUE OVER NORTHERN SECTIONS OF THE FORECAST AREA THROUGH THIS AFTERNOON WITH THE SURFACE BOUNDARY PUSHING NORTH BEFORE STALLING B/T HWY 30 TO HWY 20 CORRIDORS. VERY GOOD MOISTURE TRANSPORT AND MOISTURE CONVERGENCE...DEEP WARM LAYER CLOUD DEPTHS RISING OVER 12000 FEET AND PRECIPITABLE WATER VALUES IN THE 1.5-2.0 INCH RANGE IN NORTHERN IOWA. THE WARM LAYER CLOUD DEPTHS SLIGHTLY HIGHER FURTHER SOUTH IN THE WARM SECTOR BUT SHOULD BE A BREAK IN THE RAIN LATE THIS MORNING BEFORE THE COLD FRONT SWEEPS ACROSS THE STATE B/T 19-23Z TODAY. REGARDLESS...EXPECTING RAINFALL RATES TO EXCEED 2 INCHES PER HOUR AT TIMES EVEN WITH THE CURRENT LOWER MUCAPE VALUES OVER WESTERN IOWA IN THE 1000-2000 J/KG RANGE. THUS WITH THE EFFICIENT RAIN PRODUCERS TODAY...HAVE EXPANDED THE FLASH FLOOD WATCH FOR MUCH OF THE FORECAST AREA EXCEPT THE SOUTHEAST. SEVERE WEATHER POTENTIAL...VERY STRONG SHORTWAVE OVER KS/NE WITH SURFACE BOUNDARY DRAPED ROUGHLY ALONG THE INTERSTATE 80 CORRIDOR IN IOWA. EXPECTING THIS BOUNDARY TO SURGE NORTHWARD TO AFOREMENTIONED LOCATION AS THE SURFACE LOW TRACKS NORTHEAST INTO WESTERN IOWA BY THE EARLY AFTERNOON. INITIATION ALONG THE COLD FRONT VARIES FROM 19Z TO 22Z IN SOUTHWEST IOWA BUT WILL QUICKLY MOVE INTO THE FORECAST AREA...IF THEY STORMS DID NOT INITIATE IN THE FORECAST AREA...BY 20Z. THE TORNADO POTENTIAL HAS INCREASED SINCE PREVIOUSLY FORECAST...AND MAY POTENTIALLY INCREASE EVEN FURTHER IF CLEARING OCCURS A BIT SOONER TO ALLOW FOR EVEN BETTER DESTABILIZATION. THE DEEP LAYER SHEAR (0-6KM) IS AS HIGH AS 40 KNOTS IN SOUTHERN IOWA WITH 0-1KM AND 0-3KM SHEAR 15-20 KNOTS AND 25-30 KNOTS RANGE RESPECTIVELY. ALMOST A CLASSIC SICKLE SHAPED HODOGRAPH IN SOUTHWEST IOWA BY THIS AFTERNOON INTO THE EARLY EVENING. INSTABILITY DOES IMPROVE ONCE THIS CURRENT CONVECTION MOVES OFF TO THE NORTHEAST AND CONFIDENCE IS GROWING FOR AT LEAST A FEW SUPERCELLS BEFORE TRANSITIONING TO MORE OF A QLCS LATE IN THE PERIOD. .LONG TERM /TONIGHT THROUGH WEDNESDAY/... ISSUED AT 427 AM CDT THU JUN 11 2015 MAIN FOCUS CONTINUES TO BE ON THUNDERSTORM CHANCES TONIGHT WITH BOTH SEVERE WEATHER AND HEAVY RAINFALL THE MAIN HAZARDS. SFC LOW EXPECTED TO BE IN THE VICINITY OF CENTRAL IOWA BY 00Z FRIDAY...WITH HIGH VARIABILITY IN MODEL PLACEMENT AND PROGRESSION OF THE SFC LOW ACROSS IOWA. NAM/CANADIAN THE SLOWEST WITH THE EC/GFS A BIT FASTER. WARM FRONT TO LIFT ACROSS NORTHERN IOWA...WITH ATTENDANT COLD FRONT TRAILING ACROSS SW IA/SE NE AT THE BEGINNING OF THE PERIOD. STORMS EXPECTED TO BE ONGOING DEVELOPING IN VICINITY OF THE SFC TROUGH AXIS THROUGH THE LATE AFTERNOON HOURS AND MARCH EASTWARD THROUGH THE EVENING/LATE NIGHT HOURS. ADDITIONAL ACTIVITY EXPECTED ALONG THE WARM FRONT FURTHER NORTH INTO NORTH CENTRAL AND NORTHEASTERN IOWA. PARAMETERS REMAIN SIMILAR AS IT HAS BEEN IN PREVIOUS DAYS WITH STRONG SHEAR...GOOD INSTABILITY AND ABUNDANT MOISTURE. PWATS NEAR MAX VALUES FOR THIS TIME OF YEAR...WITH THE ORIGINS OF THE AIRMASS TROPICAL IN NATURE FROM THE REMNANTS OF HURRICANE BLANCA. GREATEST THREAT FOR SEVERE ACTIVITY IS EXPECTED WITH THE LINE OF STORMS TO MOVE THROUGH CENTRAL/SOUTHERN IOWA DURING THE EVENING HOURS. ADDITIONALLY THE HIGH PWATS AND DEEP WARM CLOUD DEPTHS WILL PROVIDE THE THREAT FOR FLASH FLOODING SO THE A FLASH FLOOD WATCH WILL BE CONTINUED INTO THE EVENING HOURS WEST AND INTO THE LATE NIGHT HOURS NORTHEAST. CONVECTIVE ACTIVITY EXPECTED TO WEAKEN AS IT PUSHES EAST LATER THIS EVENING INTO THE OVERNIGHT HOURS...SO WILL REFRAIN FROM ISSUING A FLASH FLOOD WATCH FOR THE SOUTHEASTERN THIRD OF THE CWA. SOME HEAVY RAINFALL IS STILL POSSIBLE...BUT THE MORE INTENSE RAINFALL RATES WITH THE STRONGER THUNDERSTORMS EXPECTED TO REMAIN FURTHER WEST/NORTHWEST. RAINFALL RATES OF 1 TO 2 INCHES PER HOUR WERE COMMON WITH THE ACTIVITY THAT ALREADY OCCURRED WEDNESDAY EVENING...WITH INCREASED MOISTURE EXPECTED FOR THURSDAY EVENING. ACTIVITY DOES LOOK PROGRESSIVE ENOUGH THAT TRAINING OF CELLS NOT AS MUCH OF A CONCERN AS THE INTENSE RAINFALL RATES. AS THE SYSTEM QUICKLY SHOVES EAST...PRECIPITATION CHANCES WILL WANE INTO FRIDAY MORNING...WITH DRY CONDITIONS SETTING UP FOR MUCH OF FRIDAY AFTERNOON AND THE EVENING. THE EXCEPTION WITH BE IN THE FAR SOUTH WHERE THE FRONTAL BOUNDARY MAY STALL AND SOME ADDITIONAL REDEVELOPMENT WILL BE POSSIBLE FRIDAY NIGHT. FRONTAL BOUNDARY TO THEN LIFT NORTHWARD SATURDAY AS ANOTHER UPPER LEVEL WAVE LIFTS OUT OF THE CENTRAL PLAINS. PRECIPITATION CHANCES EXPECTED TO SPREAD NORTHWARD THROUGH THE DAY SATURDAY WITH ACTIVITY CONTINUING INTO THE OVERNIGHT HOURS. THE ACTIVE PATTERN CONTINUES INTO THE REMAINDER OF THE WEEKEND AND EARLY NEXT WEEK WITH MORE ZONAL FLOW ALOFT AND WEAK IMPULSES PUSHING THROUGH THE AREA WITH A FRONTAL BOUNDARY TO PUSH SOUTH THROUGH THE AREA SUNDAY INTO MONDAY. BY EARLY NEXT WEEK INTO THE MIDDLE OF NEXT WEEK...EXTENDED RANGE MODELS TRY TO STALL OUT A BOUNDARY ACROSS THE CENTRAL US...ORIENTED FROM WEST TO EAST. MAJORITY OF THE MODELS HINT THAT IT MAY STALL OUT SOUTH OF IOWA...WITH ADDITIONAL UPPER LEVEL ENERGY PUSHING TO THE NORTH OF IOWA. THESE TRENDS WOULD HINT AT A DRIER FORECAST FOR NEXT WEEK WITH THE STATE BETWEEN TWO MORE ACTIVE REGIONS. HOWEVER THE UNCERTAINTY IS HIGH AND COULD HAVE SOME OF THIS ACTIVITY BLEED INTO THE CWA. THEREFORE WILL STICK CLOSE TO GUIDANCE GRIDS KEEPING LOWER CHANCE POPS ACROSS MUCH OF THE AREA THROUGHOUT THE REMAINDER OF THE FORECAST PERIOD. AS FOR TEMPS...COOLER CONDITIONS EXPECTED FOR FRIDAY BEHIND THE COOL FRONT PUSHING THROUGH WITH A GRADUAL WARM-UP FOR THE WEEKEND WITH TEMPS REMAINING MOSTLY IN THE 70S. A RETURN TO THE LOWER 80S IS EXPECTED FOR SUNDAY THROUGH THE END OF THE FORECAST PERIOD WITH WARMER TEMPS POSSIBLE NEXT WEEK IF THE DRIER FORECAST ENDS UP PANNING OUT. && .AVIATION...11/06Z ISSUED AT 1153 PM CDT WED JUN 10 2015 APPROACHING LOW PRESSURE SYSTEM WILL BRING WIDESPREAD TSRA TO SITES BEGINNING IN THE WEST BY 12Z...SPREADING EASTWARD THROUGH MUCH OF PERIOD. TSRA MAY BRING MVFR OR LOWER CONDITIONS AT TIMES...ESPECIALLY WITH HEAVY RAIN AND REDUCED VISIBILITIES. WINDS WILL SHIFT TO THE EAST...BECOMING NORTHERLY BEHIND SYSTEM NEAR 00Z. WINDS MAY BE GUSTY IN THE AFTERNOON...UP TO 20KTS. && .HYDROLOGY... ISSUED AT 427 PM CDT THU JUN 11 2015 WIDESPREAD MODERATE TO HEAVY RAINFALL IS STILL ON TRACK FOR TODAY. QPF REMAINS ON THE ORDER OF SEVERAL INCHES THROUGH 12Z FRI AND RFC DETERMINISTIC CONTINGENCY FORECASTS SUGGEST THAN MANY MAIN STEM RIVERS MAY REACH MINOR FLOOD STAGE IF THIS QPF MATERIALIZES...WITH A FEW SPOTS JUST INTO MODERATE FLOODING AS WELL. AREAS PRIMARILY IMPACTED AT THIS TIME WOULD SEEM TO INCLUDE THE CEDAR BASIN...RACCOON BASIN AND DES MOINES RIVER BASIN. CURRENT RIVER FORECASTS ONLY DEPICT QPF THROUGH 12Z THU HOWEVER...SO THIS IS NOT DEPICTED IN THE OFFICIAL FORECASTS JUST YET. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 10 AM CDT THIS MORNING THROUGH LATE TONIGHT FOR BLACK HAWK-BREMER-BUTLER-CLARKE-FRANKLIN-GRUNDY- HARDIN-JASPER-MARSHALL-POLK-STORY-WARREN. FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR ADAIR-ADAMS-AUDUBON- BOONE-CALHOUN-CARROLL-CASS-CRAWFORD-DALLAS-GREENE-GUTHRIE- HAMILTON-HUMBOLDT-MADISON-POCAHONTAS-RINGGOLD-SAC-TAYLOR-UNION- WEBSTER-WRIGHT. FLASH FLOOD WATCH FROM 7 AM CDT THIS MORNING THROUGH LATE TONIGHT FOR CERRO GORDO-EMMET-HANCOCK-KOSSUTH-PALO ALTO- WINNEBAGO-WORTH. && $$ SHORT TERM...PODRAZIK LONG TERM...BEERENDS AVIATION...AWB HYDROLOGY...SMALL  FXUS63 KDMX 130840 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 340 AM CDT SAT JUN 13 2015 .SHORT TERM /TODAY/... ISSUED AT 340 AM CDT SAT JUN 13 2015 FORECAST CONCERN WAS FOCUSED ON CONTINUATION OF DRIZZLE/FOG THIS MORNING AND ADDITIONAL RAIN/TS CHANCES TOWARDS MIDDAY INTO THE AFTERNOON OVER THE SOUTHERN HALF OF THE FORECAST AREA. THE LATEST HRRR (13.07Z) SEEMS TO HAVE A DECENT HANDLE ON CURRENT RADAR TRENDS WRT TO WEAK CONVECTION IN EASTERN KANSAS/WESTERN MISSOURI AND LEANED TOWARD IT FOR POP/WX TRENDS THIS MORNING. OTHERWISE...THE NAM12/RUC THIS AFTERNOON. HAVE KEPT DRIZZLE MENTIONED ACROSS THE NORTH AS FORECAST SOUNDINGS ACROSS FINALLY LOSE THEIR LOW LEVEL MOISTURE TO SUPPORT DRIZZLE BY AROUND 14-15Z. STILL POTENTIAL FOR LIGHT SHOWER ACTIVITY WITH ADDITIONAL WEAK AND SUBTLE RIBBONS OF THETA-E ADVECTION MOVING THROUGH THIS AREA THROUGH MIDDAY AS A VERY WEAK SURFACE LOW IN EASTERN IOWA CONTINUES TO TRACK EAST-NORTHEAST. THE 500MB SHORTWAVE AND ASSOCIATED VORTICITY LOOKS TO LAG BEHIND THIS SURFACE LOW AS IT RIDES THE UPPER LEVEL RIDGE THAT IS DOMINATING THE SOUTHEAST PORTION OF THE COUNTRY. THE SOUTH-CENTRAL TO SOUTHEAST SECTIONS OF THE FORECAST ARE ON THE OUTER EDGES OF THE RING OF FIRE FROM THIS UPPER RIDGE. THUS THERE IS PLENTY OF MOISTURE TRANSPORT INTO THIS AREA ALONG WITH WEAK AND BROAD FORCING FOR ASCENT ALONG THE 305-320K ISENTROPIC SURFACES. THIS SHOULD BE ENOUGH TO KEEP HIGH CHANCE TO LIKELY POPS GOING BY THIS AFTERNOON OVER THE SOUTHEAST. CERTAINLY POCKETS OF HEAVY RAIN POSSIBLE WITH THE WARM LAYER CLOUD DEPTHS INCREASING TO 11500-13000 FEET BY LATE THIS AFTERNOON AND PRECIPITABLE WATER VALUES IN THE 1.5 INCH OR SLIGHTLY HIGHER RANGE. PARTIAL TRAINING POSSIBLE AS STORM MOVEMENTS LOOK TO BE FROM THE SOUTHWEST TO NORTHEAST ACROSS THE SOUTH THIS AFTERNOON...BUT LOW CONFIDENCE WITH A CONTINUOUS STREAM OF STORM ACTIVITY. THOUGH NOT A GREAT CHANCE...CANNOT RULE OUT SOME LOCALIZED POTENTIAL FOR FLASH FLOODING IN THE SOUTHEAST LATE THIS AFTERNOON. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 340 AM CDT SAT JUN 13 2015 ACTIVE PATTERN TO CONTINUE WITH PLENTY OF SHORTWAVE ENERGY TRACKING ACROSS THE CENTRAL PLAINS NEXT SEVEN DAYS. AS HAS BEEN THE CASE FOR A WHILE...TIMING AND PLACEMENT OF VARIOUS SYSTEMS CONTINUES TO BE A CHALLENGE...WITH OVERALL MODEL FORECASTS NOT ADEQUATELY RESOLVING TRENDS BEYOND ABOUT 36 TO 48 HOURS. THUS...CONFIDENCE NOT SO FAR OUT IN TIME REMAINS LOW THIS FORECAST. SYSTEM TONIGHT WILL MAINLY AFFECT CENTRAL/SOUTHEAST SECTIONS AS UPPER LEVEL WAVE PULLS MOISTURE ACROSS THE STALLED SFC BOUNDARY JUST TO THE SOUTH OF THE STATE. MODELS CONTINUE TO FOCUS THE FORCING AND QPF ACROSS THIS AREA...WITH SOME HINT AT A FEW AREAS POSSIBLY RECEIVING LOCALLY HEAVY RAINFALL. GFS MOST ADAMANT ABOUT POSSIBILITY...WITH PWATS NEARING 2 INCHES AND WARM CLOUD DEPTHS SUPPORTING EFFICIENT RAINFALL. ARW AND NMM WRF ALSO POINT TO SOME POTENTIAL...BUT AT THIS TIME NOT CONFIDENT THAT STORMS WILL BE WIDESPREAD ENOUGH TO WARRANT HEADLINES FOR POTENTIAL FLASH FLOODING. CURRENT GRIDDED FFW GUIDANCE SUGGESTS 1.75/2.2/2.8 FOR 1/3/6 HOUR TOTALS OVER THE SOUTHEAST. VERY POSSIBLE THAT A FEW LOCATIONS MAY RECEIVE 1 TO 2 INCHES OF RAIN OVERNIGHT TONIGHT IN THE SOUTH/SOUTHEAST. COVERAGE MAY BE SCATTERED...HOWEVER. EARLY THIS EVENING A FEW STORMS SOUTHEAST MAY ALSO BE STRONG TO NEAR SEVERE. AS THE WAVE MOVES EAST/NORTHEAST OF THE AREA BY 18Z SUNDAY THE AREA SHOULD REALIZED A DECREASE IN POP THROUGH THE DAY...THOUGH CLOUDS WILL LIKELY REMAIN OVER THE SOUTH. A NORTHERN STREAM SHORTWAVE AND ASSOCIATED COOL FRONT WILL DRIFT SOUTHEAST INTO MONDAY WHILE ANOTHER SOUTHERN PLAINS WAVE MOVES EAST NORTHEAST OVER MISSOURI AND SOUTHERN IOWA...KEEPING THUNDER CHANCES ACTIVE THROUGH MONDAY AFTERNOON. THERE SHOULD BE A BREAK IN THE RAINFALL MONDAY EVENING THROUGH TUESDAY OVER MOST OF THE AREA PRIOR TO ANOTHER NORTHERN STREAM SHORT WAVE MOVING EAST ACROSS THE REGION. HAVE INCREASE POP ONCE AGAIN FOR THE LATTER PORTION OF NEXT WEEK...WITH THE REALIZATION THAT COVERAGE AND PROBABILITY WILL LIKELY NEED ATTENTION WITH TIME DUE TO THE LOWERED CONFIDENCE IN THE FORECAST. THERE IS SOME HINT THAT HEIGHTS AND H850 TEMPS WILL BE ON THE RISE BY WED/THURS PRIOR TO A STRONGER COLD FRONT APPROACHING BY NEXT THURSDAY NIGHT/FRIDAY. WITH UPPER LEVEL WINDS INCREASING DRAMATICALLY NEAR WEEKS END...POTENTIAL FOR A MORE PRONOUNCED AND STRONGER CONVECTIVE EVENT WITH LOCALLY HEAVY RAINFALL ONCE AGAIN EITHER THURSDAY OR FRIDAY. TEMPS WILL REMAIN WARM WITH HUMIDITY ON THE RISE...MAINLY 70S TO LOWER 80S UNTIL MID TO LATE WEEK WHEN TEMPERATURES RISE INTO THE MID 80S. LOWS WILL HOLD IN THE 60S MAINLY WITH SOME 50S POSSIBLE TUESDAY MORNING. && .AVIATION...13/06Z ISSUED AT 1158 PM CDT FRI JUN 12 2015 LOW MVFR AND IFR CEILINGS AND VISIBILITIES WILL PERSIST THROUGH MUCH OF PERIOD. WITH AMPLE LOW LEVEL MOISTURE AND -DZ ACROSS STATE...COULD SEE CONDITIONS DROP TO LIFR AT TIMES. CONDITIONS WILL IMPROVE TO MVFR NEAR 18Z...FINALLY LIFTING TO VFR VERY LATE IN PERIOD. MAY SEE ADDITIONAL SHRA/TSRA AT SOUTHERN SITES...KOTM/KDSM LATE IN PERIOD AS WELL. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...AWB  FXUS63 KDMX 140832 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 332 AM CDT SUN JUN 14 2015 .SHORT TERM /TODAY/... ISSUED AT 332 AM CDT SUN JUN 14 2015 MAIN FOCUS FOR THE FORECAST TODAY WAS PRECIP CHANCES...OR LACK THEREOF AND TEMPERATURES. TRENDED TOWARD A DRIER FORECAST FOR TODAY...ESPECIALLY OVER WESTERN TO NORTHERN SECTIONS OF THE FORECAST AREA. MODELS ARE IN FAIR AGREEMENT WITH THE DRIER FORECAST FOR TODAY AND UTILIZED A BLEND OF THE NAM/ECMWF. A WEAK SURFACE HIGH PRESSURE IN PLACE OVER IOWA IS SLOW TO SLIDE EAST-NORTHEAST TODAY AND SHOULD KEEP THE PRECIP ACTIVITY...IF ANY DEVELOPS...CONFINED TO THE SOUTH TO SOUTHEAST. NAM SHOWS A FEW RIPPLES OF THETA-E ADVECTION AND WEAK ISENTROPIC LIFT THROUGHOUT THE DAY TODAY OVER SOUTHERN IOWA. 14.06Z HRRR AND 14.03Z HOPWRF SHOW ISOLATED POP-UP TS/SHOWERS BUT WEAK SHEAR AND MINIMAL INSTABILITY WILL KEEP ANYTHING FROM BEING LONG-LIVED. STILL...THE AIRMASS HAS NOT CHANGED MUCH FROM PREVIOUS COUPLE OF DAYS WRT TO LOCALLY HEAVY RAIN POTENTIAL. PRECIPITABLE WATER VALUES RANGE IN THE 1.5-2.0 INCH RANGE AND WARM LAYER CLOUD DEPTHS RANGE FROM 3800-4000 METERS IN SOUTHERN IOWA. HENCE...IF ANYTHING DOES DEVELOP IT SHOULD HAVE SOME DECENT RAINFALL RATES FOR SHORT STINT BUT NOT CONCERNED WITH FLASH FLOODING DUE TO THE SHORT-LIVED NATURE OF STORMS AND LACK OF WIDESPREAD CONVECTION TODAY. FOR TEMPERATURES...SINCE WENT DRY ACROSS THE WEST TO NORTH AND LOWERED POPS IN THE SOUTHEAST...LEANED TOWARD RAISING MAX TEMPS A COUPLE OF DEGREES. MOS GUIDANCE HAS CAUGHT ONTO THIS TREND AND LEANED CLOSER THE METMOS FOR MUCH OF THE FORECAST AREA. SOUTHERN IOWA LOOKS TO REMAIN THE COOLEST WITH THE MORE ABUNDANT CLOUD COVER AND PRECIP CHANCES. .LONG TERM /TONIGHT THROUGH SATURDAY/... ISSUED AT 332 AM CDT SUN JUN 14 2015 IN THE EXTENDED...PATTERN TO EVOLVE VERY SLOWLY THIS WEEK...WITH SOME WARMING TOWARD THE END OF THE WEEK BEFORE MUCH COOLER AIR BUILDS SOUTH INTO THE REGION. LOW CONFIDENCE FORECAST AGAIN TONIGHT...MODELS OF LITTLE ASSISTANCE LAST NIGHT THOUGH RAIN DID FALL JUST TO THE EAST OF THE REGION ON SATURDAY. SFC ANALYSIS THIS EVENING SHOWS THAT THE BOUNDARY OVER THE REGION YESTERDAY LIFTED NORTHEAST AND BASICALLY WEAKENED. WHAT WAVE DID EXIST ALOFT ALSO LIFTED MORE NORTHEAST THAN NORTH RESULTING IN THE H850 MOISTURE CHANNEL FOCUSED JUST TO THE EAST OF THE AREA...KEEPING THE ISENTROPIC LIFT AND MORE PERSISTENT RAINFALL IN EASTERN IOWA TO WISCONSIN. NEXT CHALLENGE IS THE UPSTREAM WAVE PROGGED TO AFFECT THE AREA TONIGHT INTO MONDAY. LEE SIDE TROUGH ADVERTISED TO DRIFT NORTHEAST ONCE AGAIN WITH ANOTHER NORTHERN STREAM COOL FRONT HEADING SOUTHEAST TOWARD IOWA MONDAY. THE COMBINATION OF THESE TWO SYSTEMS /SHOULD/ RESULT IN THUNDERSTORMS BUT LIKE LAST NIGHT...SIMILAR WEAKENING OF THE SOUTHERN STREAM WAVE AND LIGHT WINDS AT H850 MAY RESULT IN A MORE NARROW BAND OF THUNDERSTORMS SOUTH OF THE REGION...THOUGH COVERAGE ACROSS THE SOUTHEAST SHOULD INCREASE LATER TONIGHT AS WEAK LOW LEVEL JET FORMS OVER MISSOURI. FOR NOW HAVE CUT BACK ON CHANCES NORTH WITH FOCUS CLOSER TO THE SOUTH THIRD OF IOWA TOWARD THE MISSOURI BORDER LATER TONIGHT INTO EARLY MONDAY. AS THE COOL FRONT APPROACHES NORTHWEST IOWA LATE TONIGHT INTO EARLY MONDAY...LIKELY THAT ONLY SHOWERS AND ISO THUNDER WILL OCCUR NORTH UNTIL MONDAY AFTERNOON... WHEN ACROSS THE SOUTH THE BOUNDARY BECOMES MORE ACTIVE WITH DAYTIME HEATING AND MORE WIDESPREAD COVERAGE OF SHOWERS AND THUNDER RETURNS. AT THIS TIME AM NOT LOOKING FOR MUCH IN TERMS OF WIDESPREAD HEAVY RAINFALL IN THE NEXT 36 HOURS SO WILL NOT NEED HEADLINES. THOUGH STORMS MAY BE SLOW MOVERS...LIKELY THAT WIND FIELDS WILL BE WEAK ENOUGH TO KEEP STORMS FROM ORGANIZING. PER PREVIOUS FORECASTS...TUESDAY LOOKS COOLER AND LESS HUMID OVERALL WITH ABOUT A DAY OF MAINLY DRY CONDITIONS BEFORE ANOTHER WAVE APPROACHES FROM THE WEST. ONCE THE HIGH RETREATS EAST TUESDAY NIGHT...A NORTHERN STREAM SHORT WAVE WILL INDUCE A LEE SIDE LOW AND ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS WEDNESDAY. FINALLY TOWARD THE VERY END OF THE PERIOD A MORE SIGNIFICANT NORTHERN STREAM SYSTEM SHOULD ARRIVE LATE IN THE WEEK. TIMING IS STILL IN QUESTION BUT THE MODELS TODAY ARE IN BETTER AGREEMENT FOR FRIDAY INTO SATURDAY. AHEAD OF THE SYSTEM SOME MUCH WARMER TEMPERATURES WILL BE BUILDING INTO THE REGION...POSSIBLY SOME UPPER 80S TO LOWER 90S AGAIN BY FRIDAY AND SATURDAY. A LOT DEPENDS ON CONVECTIVE DEBRIS AND IF A H700 CAP INDEED FORMS. WITH A BAND OF MUCH STRONGER WESTERLIES INTERACTING WITH THE VERY WARM AND MOIST AIRMASS BY SATURDAY INTO SUNDAY...THE STAGE SHOULD BE SET FOR AN ACTIVE PERIOD OF SUMMER STORMS BEFORE MUCH COOLER AIR ARRIVES ON SUNDAY. SOME TIMING ISSUES ARE EXPECTED AT THIS RANGE...BUT THE SIGNAL FOR MORE SIGNIFICANT TROUGH CROSSING THE NORTHERN PLAINS IS BECOMING MORE APPARENT. && .AVIATION...14/06Z ISSUED AT 1147 PM CDT SAT JUN 13 2015 VCSH WILL CONTINUE TO AFFECT KOTM FOR BEGINNING OF PERIOD BEFORE DISSIPATING. AMPLE LOW LEVEL MOISTURE WILL ALLOW FOR SITES TO DROP TO MVFR OR IFR VISIBILITIES AT TIMES NEAR 12Z...WITH MVFR CEILINGS ALSO POSSIBLE. CONDITIONS WILL QUICKLY IMPROVE AFTER 12Z...WITH WINDS BEING SOUTHERLY THROUGH MUCH OF PERIOD. LATE IN PERIOD MAY SEE SHRA/TSRA AT SOUTHERN SITES KDSM/KOTM BUT HAVE NOT INCLUDED MENTION ATTM DUE TO UNCERTAINTIES IN TIMING/PLACEMENT. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...AWB  FXUS63 KDMX 142045 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 345 PM CDT SUN JUN 14 2015 .SHORT TERM /TONIGHT/... ISSUED AT 312 PM CDT SUN JUN 14 2015 SEVERAL THINGS WILL AFFECT THE FORECAST TONIGHT. FIRST A TROUGH OVER THE SOUTHERN PLAINS WILL CONTINUE TO EJECT WEAK SHORTWAVES ACROSS MAINLY THE SOUTHERN PORTION OF THE FORECAST AREA. COINCIDENT WITH THIS...AN OUTFLOW BOUNDARY FROM THE MORNING CONVECTION OVER THE NORTHERN PLAINS IS SLOWLY DROPPING SOUTHEAST AND WEAKENING. I BELIEVE IT WILL STILL IMPACT NEBRASKA AND A PART OF WEST CENTRAL INTO SOUTHWEST IOWA GIVEN THE MODEST INSTABILITY IN PLACE AND THE PASSING OF THESE SHORTWAVES ACROSS THE AREA. UNCAPPED CAPES OF AROUND 1000-1500 J/KG ARE FORECAST TO REMAIN ACROSS THE SOUTHERN HALF OF IOWA THROUGH MID EVENING AND GIVEN THE SCATTERED TO WIDELY SCATTERED NATURE OF THE STORMS ON RADAR CURRENTLY OVER MUCH OF THE REGION WE WILL HAVE NO TROUBLE CONVECTING SO THE PROBLEM WILL BE ONE OF TIMING. I EXPECT WE WILL SEE PERIODS OF SHOWERS/STORMS THROUGH PEAK HEATING INTO EARLY EVENING BEFORE A LULL. THANKFULLY SHEAR IS PATHETIC SO WE WILL NOT BE LOOKING AT A SEVERE POTENTIAL FROM THE EVENING CONVECTION BUT WARM CLOUD DEPTHS ARE WELL IN EXCESS OF 12K FT AND PWATS ARE IN EXCESS OF 1.75 INCHES. THESE SHOWERS/STORMS WILL BE EFFICIENT RAIN PRODUCERS. THIS WAS SHOWN BY THE BRIEF SHOWERS THAT PASSES OVER THE OFFICE AND PRODUCED .40 INCHES OF PRECIP IN 15 MINUTES. THE SCATTERED NATURE OF THE STORMS IS NOT PARTICULARLY CONCERNING FOR A FLOODING POTENTIAL BUT THIS WILL STILL NEED TO BE MONITORED...ESPECIALLY LATE TONIGHT WHEN A STRONGER WAVE APPEARS TO BE AFFECTING SOUTHEAST IOWA. LATE TONIGHT AND THROUGH THE OVERNIGHT ATTENTION TURNS TO THE NORTH AND WEST AS A COLD FRONT SAGS SOUTHEAST ACROSS THE AREA. THE FRONT SHOULD BE INTO THE NORTHWEST AROUND 06Z AND ABOUT HALF WAY THROUGH THE STATE BY 12Z. INSTABILITY ACROSS NORTHWEST IOWA AT 06Z IS PRETTY IMPRESSIVE WITH 1800 J/KG FORECAST BUT BY THE TIME THE FRONT GETS MUCH INTO THE FORECAST AREA IT OUTRUNS THE BEST INSTABILITY. THE BEST SHEAR REMAINS POST FRONTAL THROUGH TONIGHT SO WHILE THERE MAY BE AN ISOLATED STRONG WIND GUST ACROSS THE NORTHWEST...MOST OF THE STORMS SHOULD REMAIN BELOW SEVERE LIMITS. WARM CLOUD DEPTHS REMAIN ABOVE 12-13KFT WITH PWATS AOA 1.75 AT FORT DODGE, DES MOINES AND OTTUMWA SO THE HEAVIEST RAINFALL SHOULD BE IN THIS AREA...STILL FOCUSING ON SOUTHEAST IOWA AS THE MOST FAVORED. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 312 PM CDT SUN JUN 14 2015 A SHORTWAVE THROUGH WILL MOVE THROUGH IOWA MONDAY INTERACTING WITH A WEAK FRONTAL BOUNDARY. OCCASIONAL SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGHOUT THE DAY AIDED BY DAY TIME HEATING. THUNDERSTORMS WILL BE EFFECIENT RAIN PRODUCERS WITH PRECIPITABLE WATER VALUES NEAR 1.5 INCHES. LOCALIZED FLOODING WILL BE POSSIBLE NEAR STRONGER UPDRAFTS/DOWNDRAFTS AND WHERE THUNDERSTORMS MOVE OVER THE SAME AREAS. PRECIPITATION WILL TAPER FROM NORTHWEST TO SOUTHEAST ACROSS IOWA BY EARLY MONDAY EVENING. SURFACE HIGH PRESSURE BUILDS ACROSS MINNESOTA ON TUESDAY. MUCH OF CENTRAL IOWA WILL REMAIN DRY ON TUESDAY BUT THERE WILL STILL BE SLIGHT CHANCES FOR PRECIPITAITON ACROSS SOUTHERN IOWA WITH A WEAK FRONT AND DAY TIME HEATING AIDING DEVELOPMENT OF A FEW SHOWERS AND THUNDERSTORMS. A SHORTWAVE MOVING THROUGH THE STRONGER WESTERLIES ALOFT ON WEDNESDAY WILL NUDGE ANOTHER FRONT SOUTH INTO IOWA BRINGING YET ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS MID WEEK. THE UPPER RIDGE BUILDS ACROSS THE PLAINS AND THE MIDWEST LATE IN THE WEEK WITH THE PERSISTENT SUBTROPICAL HIGH PRESSURE PREVIOUSLY ANCHORED IN THE SOUTHEAST U.S. MOVING OFFSHORE. THE HEAT WILL BUILD IN THE PLAINS AND THE MIDWEST WITH A SURFACE LOW DEPENING IN THE DAKOTAS AND SOUTH AND SOUTHWEST FLOW RETURNING. SCATTERED THUNDERSTORMS WILL BE POSSIBLE ACROSS NORTH CENTRAL IOWA LATE IN THE WEEK WITH SHORTWAVES MOVING THROUGH THE WESTERLY FLOW AROUND THE RIDGE. && .AVIATION...14/18Z ISSUED AT 100 PM CDT SUN JUN 14 2015 SCT SHRA SHOULD OCCUR OVER THE SOUTHERN TAF LOCATIONS THROUGH MUCH OF THE AFTERNOON WITH A POSSIBLE BREAK IN THE EARLY EVENING THEN CHANCES INCREASE TOWARDS 06Z. WE WILL HAVE AN UPPER LEVEL FEATURE PASS OVERNIGHT BRINGING A POTENTIAL FOR TSRA WITH HEAVY RAINFALL THEN LATE IN THE PERIOD A COLD FRONT WILL SAG SOUTH ACROSS TAF SITES. OCNL MVFR CONDITIONS WITH PERIODS OF RAIN AND THUNDERSTORMS ACROSS MAINLY SRN TAF LOCATIONS IS ABOUT THE EASIEST WAY TO SUM UP CONDITIONS THROUGH THIS TAF FORECAST PD. SFC WND WILL GENERALLY BE SOUTHERLY AT 5-15KTS SWITCHING TO THE W AND NW WITH THE FROPA FROM NW TO SE ACROSS THE STATE BEGINNING AFT 14Z. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...FAB LONG TERM...ANGLE AVIATION...FAB  FXUS63 KDMX 150905 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 405 AM CDT MON JUN 15 2015 .SHORT TERM /TODAY/... ISSUED AT 345 AM CDT MON JUN 15 2015 PERIODS OF SHOWERS AND THUNDERSTORMS REMAIN THE FOCUS TODAY WITH THE MAIN THREAT OF LOCALLY HEAVY RAIN LEADING TO ISOLATED AREAS OF FLASH FLOODING. COLD FRONT HAS MEANDERED INTO NORTHWEST IOWA AND WILL CONTINUE TO SLOWLY MOVE SOUTHEAST THROUGH THE STATE TODAY. AHEAD OF THE FRONT THERE IS PLENTY OF MOISTURE TRANSPORT AND ISENTROPIC LIFT ALONG THE 305-320 K SURFACE PERSISTS INTO THE CENTRAL AND SOUTHERN SECTIONS OF THE FORECAST AREA TODAY. THERE IS A BROAD AND WEAK AREA OF FORCING ALONG AND AHEAD OF THR FRONT AND EXPECTING THE ISOLATED TO SCATTERED STORMS TO PERSIST THROUGH THE AFTERNOON. PRECIPITABLE WATER VALUES RANGE FROM 1.5 TO 2 INCHES AND THE WARM LAYER CLOUD DEPTHS REMAIN IN THE 3800 TO 4100 METERS. THE UPWIND PROPAGATION VECTOR OVER CENTRAL IOWA REMAIN WEAK AND THUS THESE STORMS/SHOWERS WILL BE SLOW TO MOVE AND CONTINUE TO BE VERY EFFICIENT RAIN PRODUCERS. HOWEVER...THE HEAVIEST RAINFALL REMAINS ISOLATED AND SHORT-LIVED IN NATURE AND HAVE LOW CONFIDENCE WITH ISSUING A FLASH FLOOD WATCH ATTM. THAT BEING SAID...THERE HAS ALREADY BEEN SOME FLASH FLOODING ISSUES IN ANKENY DUE TO LOCALLY HEAVY RAIN AND EXPECT THE VERY ISOLATED FLASH FLOODING POTENTIAL TO REMAIN POSSIBLE THROUGH AT LEAST MIDDAY OVER CENTRAL TO SOUTHERN IOWA...MAINLY OVER URBAN AREAS. THE LATEST HRRR (15.07Z) HAS A DECENT HANDLE ON OVERALL RADAR TRENDS...BUT THINK IT IS SLIGHTLY TOO FAR NORTH WITH THE PROGRESSION OF THE HEAVIEST RAIN TODAY. LEANED TOWARD A RUC/HRRR BLEND FOR POPS UNTIL 18Z AND THEN NAM12 THIS AFTERNOON. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 345 AM CDT MON JUN 15 2015 BY THIS EVENING THE FRONT AND ASSOCIATED FORCING WILL BE MOVING OUT OF THE AREA. LINGERING SHOWERS AND POSSIBLE THUNDERSTORMS WILL CONTINUE PRIOR TO 06Z SOUTH WITH MOST OF THE AREA DONE WITH THE RAINFALL. THE ONLY EXCEPTION WILL BE THE NEAR THE IOWA MISSOURI BORDER WHERE SOME RAIN MAY LINGER ON TUESDAY. FEEL THAT MOST OF THE RAIN WILL BE SOUTH OF THE BORDER...BUT HAVE INCLUDED A SMALL AREA ALONG THE BORDER AS FRONT MAY STALL AND DRIFT SLIGHTLY NORTH DURING THE DAY. AS THE HIGH RETREATS EAST ON TUESDAY...RETURN FLOW OVER THE ROCKIES WILL DIRECT ADDITIONAL SHORTWAVE ENERGY ACROSS THE DAKOTAS AND MN THROUGH 06Z. THIS WILL INDUCE A SFC LOW AND INCREASE THUNDER CHANCES NORTHWEST TOWARD MORNING WITH SLIGHT CHANCES ELSEWHERE. THIS NEXT SYSTEM IS PROGGED TO CROSS THE REGION BY 12Z THURSDAY AS REMNANTS OF A TROPICAL SYSTEM PASS JUST SOUTH OF THE AREA. TEMPERATURES OVER THE NEXT SEVERAL DAYS WILL NOT VARY MUCH WITH HIGHS GENERALLY IN THE 70S TO LOWER 80S AND LOWS IN THE 60S TO NEAR 70. BY FRIDAY A STRONGER STORM SYSTEM IS STILL ANTICIPATED TO FORM OVER THE NORTHERN ROCKIES WITH WESTERLIES ALOFT INCREASING ACROSS THE NORTHERN PLAINS. THE AIRMASS OVER THE CENTRAL PLAINS WILL STILL BE HAVE ABUNDANT AVAILABLE MOISTURE WITH PRECIPITABLE WATER FORECAST OVER 2 INCHES BY SATURDAY AFTERNOON/EVENING. WARM CLOUD DEPTHS WILL BE OVER 13KFT. WITH THE SYSTEM INCREASING WARM AIR ADVECTION OVER THE AREA...LIKELY THAT HIGHS WILL BE IN THE UPPER 80S TO LOWER 90S EACH DAY FRIDAY AND SATURDAY BEFORE A STRONG COLD FRONT DROPS TEMPERATURES SUNDAY AND MONDAY BACK INTO THE 70S WITH LOWS IN THE 50S. AS MENTIONED IN PREVIOUS DISCUSSIONS...POTENTIAL FOR A MORE SIGNIFICANT PERIOD OF ACTIVE WEATHER LOOKS TO BE IN STORE FOR THE AREA SATURDAY AFTERNOON/EVENING INTO EARLY SUNDAY. ONCE THE MAIN FRONT PASSES...THE CHANCES OF SHOWERS AND THUNDERSTORMS WILL REMAIN ON SUNDAY...THOUGH THEY WILL BE DIMINISHING THROUGH THE MORNING AND AFTERNOON HOURS AS NORTHWEST WINDS AND DRIER AIR WORKS BACK INTO THE STATE. MONDAY WILL BE MUCH COOLER WITH HIGHS ONLY IN THE 70S WITH LOWS IN THE 50S TO LOWER 60S. && .AVIATION...15/06Z ISSUED AT 1154 PM CDT SUN JUN 14 2015 WIDESPREAD TSRA/SHRA WILL AFFECT SITES THROUGH MUCH OF THE PERIOD...ESPECIALLY SOUTHERN SITES KFOD/KDSM/KOTM. TSRA MAY BRING CEILINGS AND VISIBILITIES TO MVFR OR LOWER. LIFR CONDITIONS WILL BE POSSIBLE BRIEFLY WITH TSRA AT SITES AND HEAVY RAIN POSSIBLE. WILL SEE BOUNDARY BEGIN TO PUSH SE...PUSHING TSRA/SHRA SE AS WELL THROUGH THE AFTERNOON...CLEARING STIES NEAR.AFTER 00Z. WINDS WILL SHIFT TO THE NORTH BEHIND BOUNDARY. && .HYDROLOGY... ISSUED AT 345 AM CDT MON JUN 15 2015 LOCALLY HEAVY RAINFALL CONTINUES OVER THE AREA EARLY THIS MORNING. MONITORING FOR LOCALIZED FLASH FLOODING AND POTENTIALLY A FEW RIVERS GOING ABOVE MINOR FLOOD STAGE TODAY OR TUESDAY. RAINFALL RATES HAVE BEEN IMPRESSIVE...WITH STREET FLOODING REPORTED IN ANKENY ABOUT 3 AM CDT THIS MORNING...WITH UP TO A HALF DOZEN INTERSECTIONS CLOSED AND A FEW CARS STRANDED. SEVERAL ADDITIONAL ROUNDS OF RAIN MOVING NORTHEAST TOWARD THE AREA YET THROUGH THIS AFTERNOON. WILL MONITOR FOR POSSIBLE FLASH FLOOD WATCH HEADLINES... THOUGH MORE LOCALIZED POCKETS OF HEAVY RAINFALL SO FAR HAVE LIMITED THE COVERAGE OF PROBLEM AREAS. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...AWB HYDROLOGY...REV  FXUS63 KDMX 151748 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1248 PM CDT MON JUN 15 2015 .SHORT TERM /TODAY/... ISSUED AT 345 AM CDT MON JUN 15 2015 PERIODS OF SHOWERS AND THUNDERSTORMS REMAIN THE FOCUS TODAY WITH THE MAIN THREAT OF LOCALLY HEAVY RAIN LEADING TO ISOLATED AREAS OF FLASH FLOODING. COLD FRONT HAS MEANDERED INTO NORTHWEST IOWA AND WILL CONTINUE TO SLOWLY MOVE SOUTHEAST THROUGH THE STATE TODAY. AHEAD OF THE FRONT THERE IS PLENTY OF MOISTURE TRANSPORT AND ISENTROPIC LIFT ALONG THE 305-320 K SURFACE PERSISTS INTO THE CENTRAL AND SOUTHERN SECTIONS OF THE FORECAST AREA TODAY. THERE IS A BROAD AND WEAK AREA OF FORCING ALONG AND AHEAD OF THE FRONT AND EXPECTING THE ISOLATED TO SCATTERED STORMS TO PERSIST THROUGH THE AFTERNOON. PRECIPITABLE WATER VALUES RANGE FROM 1.5 TO 2 INCHES AND THE WARM LAYER CLOUD DEPTHS REMAIN IN THE 3800 TO 4100 METERS. THE UPWIND PROPAGATION VECTOR OVER CENTRAL IOWA REMAIN WEAK AND THUS THESE STORMS/SHOWERS WILL BE SLOW TO MOVE AND CONTINUE TO BE VERY EFFICIENT RAIN PRODUCERS. HOWEVER...THE HEAVIEST RAINFALL REMAINS ISOLATED AND SHORT-LIVED IN NATURE AND HAVE LOW CONFIDENCE WITH ISSUING A FLASH FLOOD WATCH ATTM. THAT BEING SAID...THERE HAS ALREADY BEEN SOME FLASH FLOODING ISSUES IN ANKENY DUE TO LOCALLY HEAVY RAIN AND EXPECT THE VERY ISOLATED FLASH FLOODING POTENTIAL TO REMAIN POSSIBLE THROUGH AT LEAST MIDDAY OVER CENTRAL TO SOUTHERN IOWA...MAINLY OVER URBAN AREAS. THE LATEST HRRR (15.07Z) HAS A DECENT HANDLE ON OVERALL RADAR TRENDS...BUT THINK IT IS SLIGHTLY TOO FAR NORTH WITH THE PROGRESSION OF THE HEAVIEST RAIN TODAY. LEANED TOWARD A RUC/HRRR BLEND FOR POPS UNTIL 18Z AND THEN NAM12 THIS AFTERNOON. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 345 AM CDT MON JUN 15 2015 BY THIS EVENING THE FRONT AND ASSOCIATED FORCING WILL BE MOVING OUT OF THE AREA. LINGERING SHOWERS AND POSSIBLE THUNDERSTORMS WILL CONTINUE PRIOR TO 06Z SOUTH WITH MOST OF THE AREA DONE WITH THE RAINFALL. THE ONLY EXCEPTION WILL BE THE NEAR THE IOWA MISSOURI BORDER WHERE SOME RAIN MAY LINGER ON TUESDAY. FEEL THAT MOST OF THE RAIN WILL BE SOUTH OF THE BORDER...BUT HAVE INCLUDED A SMALL AREA ALONG THE BORDER AS FRONT MAY STALL AND DRIFT SLIGHTLY NORTH DURING THE DAY. AS THE HIGH RETREATS EAST ON TUESDAY...RETURN FLOW OVER THE ROCKIES WILL DIRECT ADDITIONAL SHORTWAVE ENERGY ACROSS THE DAKOTAS AND MN THROUGH 06Z. THIS WILL INDUCE A SFC LOW AND INCREASE THUNDER CHANCES NORTHWEST TOWARD MORNING WITH SLIGHT CHANCES ELSEWHERE. THIS NEXT SYSTEM IS PROGGED TO CROSS THE REGION BY 12Z THURSDAY AS REMNANTS OF A TROPICAL SYSTEM PASS JUST SOUTH OF THE AREA. TEMPERATURES OVER THE NEXT SEVERAL DAYS WILL NOT VARY MUCH WITH HIGHS GENERALLY IN THE 70S TO LOWER 80S AND LOWS IN THE 60S TO NEAR 70. BY FRIDAY A STRONGER STORM SYSTEM IS STILL ANTICIPATED TO FORM OVER THE NORTHERN ROCKIES WITH WESTERLIES ALOFT INCREASING ACROSS THE NORTHERN PLAINS. THE AIRMASS OVER THE CENTRAL PLAINS WILL STILL BE HAVE ABUNDANT AVAILABLE MOISTURE WITH PRECIPITABLE WATER FORECAST OVER 2 INCHES BY SATURDAY AFTERNOON/EVENING. WARM CLOUD DEPTHS WILL BE OVER 13KFT. WITH THE SYSTEM INCREASING WARM AIR ADVECTION OVER THE AREA...LIKELY THAT HIGHS WILL BE IN THE UPPER 80S TO LOWER 90S EACH DAY FRIDAY AND SATURDAY BEFORE A STRONG COLD FRONT DROPS TEMPERATURES SUNDAY AND MONDAY BACK INTO THE 70S WITH LOWS IN THE 50S. AS MENTIONED IN PREVIOUS DISCUSSIONS...POTENTIAL FOR A MORE SIGNIFICANT PERIOD OF ACTIVE WEATHER LOOKS TO BE IN STORE FOR THE AREA SATURDAY AFTERNOON/EVENING INTO EARLY SUNDAY. ONCE THE MAIN FRONT PASSES...THE CHANCES OF SHOWERS AND THUNDERSTORMS WILL REMAIN ON SUNDAY...THOUGH THEY WILL BE DIMINISHING THROUGH THE MORNING AND AFTERNOON HOURS AS NORTHWEST WINDS AND DRIER AIR WORKS BACK INTO THE STATE. MONDAY WILL BE MUCH COOLER WITH HIGHS ONLY IN THE 70S WITH LOWS IN THE 50S TO LOWER 60S. && .AVIATION...15/18Z ISSUED AT 1248 PM CDT MON JUN 15 2015 AREA OF SHOWERS TO CONTINUE TO MOVE THROUGH THE CWA FROM NORTH TO SOUTH AS A COLD FRONTAL BOUNDARY SINKS THROUGH THE STATE. SOME ISOLATED THUNDERSTORMS EXPECTED ACROSS SOUTHERN IOWA THIS AFTERNOON EMBEDDED IN THE AREA OF SHOWERS. MAINLY VFR CIGS WITH POCKETS OF MVFR/IFR FOR A FEW MORE HOURS...THEN CONDITIONS SHOULD GO VFR FOR THE REMAINDER OF THE FORECAST PERIOD AS PRECIPITATION MOVES OUT OF THE AREA. WIND TO BE PRIMARILY NORTHWEST BEHIND THE FRONT...SHIFTING AROUND TO THE NORTHEAST FOR TUESDAY. && .HYDROLOGY... ISSUED AT 345 AM CDT MON JUN 15 2015 LOCALLY HEAVY RAINFALL CONTINUES OVER THE AREA EARLY THIS MORNING. MONITORING FOR LOCALIZED FLASH FLOODING AND POTENTIALLY A FEW RIVERS GOING ABOVE MINOR FLOOD STAGE TODAY OR TUESDAY. RAINFALL RATES HAVE BEEN IMPRESSIVE...WITH STREET FLOODING REPORTED IN ANKENY ABOUT 3 AM CDT THIS MORNING...WITH UP TO A HALF DOZEN INTERSECTIONS CLOSED AND A FEW CARS STRANDED. SEVERAL ADDITIONAL ROUNDS OF RAIN MOVING NORTHEAST TOWARD THE AREA YET THROUGH THIS AFTERNOON. WILL MONITOR FOR POSSIBLE FLASH FLOOD WATCH HEADLINES... THOUGH MORE LOCALIZED POCKETS OF HEAVY RAINFALL SO FAR HAVE LIMITED THE COVERAGE OF PROBLEM AREAS. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...BEERENDS HYDROLOGY...REV  FXUS63 KDMX 222005 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 305 PM CDT MON JUN 22 2015 .SHORT TERM /TONIGHT/... ISSUED AT 301 PM CDT MON JUN 22 2015 MAIN CONCERN IS SEVERE WEATHER POTENTIAL REMAINDER OF THE AFTERNOON AND EVENING. SOUTHERN SECTIONS BEGINNING TO DESTABILIZE WITH MLCAPE BETWEEN 2500 AND 4500 J/KG AND SBCAPE BETWEEN 3500 AND 5000 J/KG ACROSS THE SOUTH. FOCUSING MECHANISMS INCLUDE OLD OUTFLOW BOUNDARY AND APPROACHING COOL FRONT FROM THE NORTHWEST. WITH BULK SHEAR CONTINUING IN THE 55 TO 60KT RANGE...LIKELY THAT STORMS WILL ONCE AGAIN TRY TO DEVELOP THIS AFTERNOON AND EVENING OVER THE SOUTH HALF OF THE AREA. H700 CAP IS STRONG WITH TEMPS AT 14-16C OVER THE SOUTH AT THIS TIME. IF STORMS BREAK THE CAP...THEY WILL GO SEVERE QUICKLY. ALL MODES OF STORMS POSSIBLE WITH LARGE HAIL...SEVERE WIND GUSTS AND POSSIBLE TORNADOS. AFTER THE STORMS BEGIN TO MOVE SOUTHEAST THIS EVENING...ACTIVITY SHOULD BEGIN TO DIMINISH THROUGH THE LATE EVENING HOURS AND PROGRESS SOUTHEAST OF THE AREA BY 06Z. MODELS VARY ON INITIATION AND PLACEMENT OF STRONGEST CONVECTION...WITH HRRR SUGGESTING THAT CONVECTION WILL INCREASE EAST OF DES MOINES. LOWS BY MORNING WILL DROP INTO THE 50S NORTH TO THE LOWER TO MID 60S SOUTH. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 301 PM CDT MON JUN 22 2015 FORECAST WAS MAINLY FOCUSED ON CONVECTIVE AND SEVERE POTENTIAL TUESDAY NIGHT INTO WEDNESDAY AND TEMPERATURES THROUGH MUCH OF THE EXTENDED. LEANED TOWARD A BLEND OF THE NAM/ECMWF TUESDAY THROUGH WEDNESDAY NIGHT...AND CLOSER TO THE ECMWF THROUGH THE REMAINDER OF THE PERIOD. TUESDAY INTO WEDNESDAY...SURFACE HIGH LOOKS TO BUILD INTO THE STATE ON TUESDAY AND WILL SLOWLY SLIDE EAST OF THE FORECAST AREA TUESDAY NIGHT. CUT BACK ON POPS DURING THE DAY TUESDAY INTO TUESDAY EVENING...ESPECIALLY ACROSS THE NORTHERN SECTIONS OF THE FORECAST AREA AS THE SURFACE HIGH WILL SLOW THE PROGRESSION OF NEXT SHORTWAVE ENTERING SOUTHWEST IOWA. GOOD MOISTURE TRANSPORT RETURNS WITH WARM FRONT SURGING NORTH INTO SOUTHERN IOWA LATE TUESDAY NIGHT INTO WEDNESDAY MORNING AND LOOKS TO CONTINUE TO PUSH NORTH THROUGH THE DAY WEDNESDAY. DECENT DEEP LAYER SHEAR WITH WEAK TO MODERATE INSTABILITY OVERNIGHT TUESDAY INTO WEDNESDAY INTO SOUTHWEST TO CENTRAL IOWA. SEVERE POTENTIAL LOOKS MORE LIKELY WIND AND HAIL THREAT AS THE LOW LEVEL SHEAR IS FAIRLY WEAK WEDNESDAY. OTHER THREAT IS HEAVY RAIN WITH PRECIPITABLE WATER VALUES IN THE 1.5 TO 2 INCH RANGE...WARM LAYER CLOUD DEPTHS IN THE 3800-4100 METERS...AND STRONG THETA-E ADVECTION OVER CENTRAL IOWA WEDNESDAY. INCREASED QPF AMOUNTS DURING THE DAY WEDNESDAY. THURSDAY THROUGH SATURDAY...TRENDED TOWARD A DRIER FORECAST LATE WEDNESDAY NIGHT INTO THURSDAY WITH WEAK SURFACE HIGH AND SUBSIDENCE MOVING INTO IOWA DURING THIS TIME. BY FRIDAY...GFS AND ECMWF AREA REMAIN OUT OF SYNC AS GFS REMAINS DRY FRIDAY BUT ECMWF BLASTS IOWA WITH A DECENT SHORTWAVE THROUGH THE REGION. SLIGHTLY FAVORED THE ECMWF DURING THE EXTENDED AND KEPT POPS GOING ON FRIDAY. HIGHER CONFIDENCE TO GO DRY BY SATURDAY INTO SATURDAY NIGHT AND TRENDED THAT WAY...AND LOOKS TO BE DRY EVEN INTO SUNDAY PER ECMWF. && .AVIATION...22/18Z ISSUED AT 1236 PM CDT MON JUN 22 2015 VFR SHOULD PREVAIL THROUGH THE EVENING IN THE NORTHERN TAF SITES...FOD...MSC...ALO. THE SOUTHERN SITES...DSM AND OTM...WILL BE VFR UNTIL THE AFTERNOON WHEN STORMS MAY DROP CONDITIONS PERIODICALLY INTO MVFR AND VFR AND WILL RETURN TO VFR BY EARLY EVENING. LIKELY FOG DEVELOPMENT AT ALL SITES OVERNIGHT...WITH VISIBILITIES UNDER 1 MILE POSSIBLE BUT HELD OUT OF TAFS FOR NOW WITH POSSIBILITY OF HIGH ENOUGH WINDS. WINDS WILL SHIFT FROM GUSTY TO 20KTS OUT OF S AND SW TO SUSTAINED AROUND 5 TO 10KTS NW AND N THIS EVENING AND OVERNIGHT AS FRONT PASSES. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...PODRAZIK AVIATION...CURTIS  FXUS63 KDMX 242042 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 342 PM CDT WED JUN 24 2015 .SHORT TERM /TONIGHT/... ISSUED AT 341 PM CDT WED JUN 24 2015 COMPLEX SCENARIO SETTING UP ACROSS IOWA TONIGHT WITH A WARM FRONT SURGING NORTH-NORTHEAST INTO SOUTHWEST IOWA PROVIDING SOME DESTABILIZATION OVER SOUTHWEST IOWA. MUCH OF THIS AREA REMAINS CAPPED AT THE MOMENT...BUT WITH IMPRESSIVE EFFECTIVE SHEAR AND HIGH CAPE VALUES AVAILABLE...IF STORMS DEVELOP IN THIS LOCATION THEY LIKELY WILL RAPIDLY BECOME SEVERE THIS AFTERNOON AND EVENING. SUPERCELLS ARE CERTAINLY POSSIBLE ON INITIATION WITH STRONG VEERING AND DEEP LAYER SHEAR WILL PROVIDE A TORNADIC THREAT THROUGH THE MID- EVENING HOURS. HOWEVER...THINKING THIS AREA SHOULD REMAIN CAPPED UNTIL LLJ DEVELOPS TONIGHT COMBINED WITH THE TIMING OF A STRONG SHORTWAVE OVER THE HIGH PLAINS PUSH ACROSS THE STATE. EXPECTING THE WARM FRONT TO SURGE NORTH BETWEEN THE INTERSTATE 80 TO HIGHWAY 20 CORRIDOR. STORM REDEVELOPMENT THIS EVENING LOOKS TO BETWEEN 02Z TO 05Z THURSDAY OVER THIS CORRIDOR FROM WEST TO EAST AND THE FRONT SHOULD LIGHT UP ALONG THIS REGION. THE 24.19Z HRRR HAS A DECENT HANDLE ON CURRENT RADAR TRENDS...ALTHOUGH DIMINISHES THE CURRENT CONVECTION OVER CRAWFORD/CARROLL COUNTIES THIS AFTERNOON. POTENTIAL FOR STORMS TO LINGER A LITTLE LONGER THAN WHAT THE HRRR SUGGESTS BUT STILL LOOKING AT A BREAK BETWEEN REDEVELOPMENT LATER THIS EVENING. SEVERE POTENTIAL STILL EXISTS DURING THE OVERNIGHT BUT LOOKING MORE LIKELY STRAIGHT LINE WIND EVENT POTENTIAL. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 341 PM CDT WED JUN 24 2015 MAIN SHORT WAVE TO TRACK SOUTHEAST OF AREA BY 12Z...BUT RESIDUAL CONVECTION MAY LINGER OVER THE SOUTHEAST THROUGH MORNING. AS FRONT SAGS SOUTH THURSDAY...EXPECTING A BREAK FROM THE CONVECTION THROUGH LATE AFTERNOON. ANOTHER UPPER LEVEL SHORTWAVE WILL DROP SOUTHEAST ACROSS THE AREA THURSDAY NIGHT AND INTO FRIDAY WITH ENOUGH LIFT AND INSTABILITY TO PRODUCE SCT THUNDERSTORMS THROUGH THE DAY. WITH CLOUDS ACROSS THE REGION EXPECT THAT HIGHS WILL BE HELD BACK IN THE 70S FOR ALL OF THE AREA. THE TROUGH FINALLY PULLS SOUTHEAST OF THE REGION FRIDAY NIGHT WITH A PERIOD OF QUIET WEATHER FROM FRIDAY NIGHT THROUGH SATURDAY EVENING. OVER THE NEXT FEW DAYS THE PATTERN WILL SHIFT TO A NORTHWESTERLY FLOW ALOFT. THIS WILL LESSEN THE CHANCES FOR HEAVY RAINFALL AND ALSO BRING TEMPERATURES TO NEAR NORMAL OR SLIGHTLY BELOW NORMAL. ANOTHER NORTHERN STREAM SHORTWAVE AND COOL FRONT WILL DROP SOUTH SATURDAY EVENING WITH ADDITIONAL SCATTERED THUNDERSTORMS SUNDAY. HIGHS SATURDAY AND SUNDAY WILL BE SOMEWHAT COOLER WITH NORTHWEST FLOW. HIGHS WILL REMAIN IN THE UPPER 70S TO LOWER 80S. WITH THE NORTHWEST FLOW IN PLACE THROUGH MIDWEEK NEXT WEEK...EXPECT MORE OF THE SAME. THE RIDGE SHOULD REMAIN WEST OF IOWA WITH SOME CHANCES FOR SHOWERS OR THUNDERSTORMS AS COOL FRONTS DROP SOUTH INTO THE PLAINS AND GREAT LAKES. TEMPERATURES WILL CHANGE LITTLE WITH HIGHS IN THE 70S TO LOWER 80S AND LOWS IN THE 50S TO 60S. && .AVIATION...24/18Z ISSUED AT 115 PM CDT WED JUN 24 2015 STORM ACTIVITY WILL CONTINUE ACROSS CENTRAL TO NORTH-CENTRAL IOWA THIS AFTERNOON INTO THE EVENING. CERTAINLY MVFR FOR CIGS AND VIS ARE POSSIBLE AND EVEN TO IFR/LIFR CONDITIONS WITH THE HEAVY TS...BUT LOW CONFIDENCE WITH MENTIONING IFR/LIFR CONDITIONS AS DIFFICULT TO TIME AND LOCATE OF STORMS LATER THIS AFTERNOON. ONCE THIS FIRST ROUND OF STORMS MOVES EAST BY 22Z...ANOTHER ROUND LOOKS TO DEVELOP ALONG THE WARM FRONT LATER THIS EVENING. HAVE MVFR VIS OR CIGS FOR RAIN MENTIONED BY 03Z. && .HYDROLOGY... ISSUED AT 341 PM CDT WED JUN 24 2015 WILL STILL NEED TO CONSIDER FLASH FLOODING OVERNIGHT AND HAVE EXPANDED THE WATCH FARTHER WEST. VERY GOOD MOISTURE TRANSPORT... WARM LAYER CLOUD DEPTHS IN THE 13-14KFT RANGE AND PRECIPITABLE WATER VALUES WELL OVER 2 INCHES TONIGHT. FAIRLY HIGH CONFIDENCE IN WIDESPREAD FLASH FLOODING OVER THE INTERSTATE 80 TO HIGHWAY 20 CORRIDOR. RAINFALL RATES OF 2 TO 4 INCHES PER HOUR ARE LIKELY AND WITH THE RAIN THAT FELL ALREADY TODAY...IT WILL NOT TAKE MUCH TO CAUSE SOME FLASH FLOODING AND POTENTIAL SIGNIFICANT FLASH FLOODING ISSUES OVER THE AFOREMENTIONED CORRIDOR. THUS...EXPANDED THE FLASH FLOOD WATCH FURTHER WEST AND INCREASED POPS AND QPF CONSIDERABLY B/T 03-09Z THURSDAY. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR ADAIR-APPANOOSE- AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CLARKE- CRAWFORD-DALLAS-DAVIS-FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON- HARDIN-HUMBOLDT-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL- MONROE-POLK-POWESHIEK-SAC-STORY-TAMA-WAPELLO-WARREN-WEBSTER- WRIGHT. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...PODRAZIK HYDROLOGY...PODRAZIK  FXUS63 KDMX 252057 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 357 PM CDT THU JUN 25 2015 .SHORT TERM /TONIGHT/... ISSUED AT 356 PM CDT THU JUN 25 2015 MAIN FORECAST CONCERN WAS FOCUSED ON WEAK SHORTWAVE CUTTING ACROSS NEBRASKA AND POTENTIALLY BRINGING SOME LOCALLY HEAVY RAIN TO FAR SOUTHERN IOWA TONIGHT. BOUNDARY LOOKS TO BE SET UP IN NORTHERN MISSOURI AND POSSIBLY SHIFT NORTH ENOUGH TO THE IOWA BORDER TONIGHT...BUT HAVE FAIRLY HIGH CONFIDENCE THAT IS THE FARTHEST EXTENT NORTH IT WILL REACH. DECENT MOISTURE CONVERGENCE ALONG THE MO/IA BORDER WITH STILL A GOOD ATMOSPHERE FOR EFFICIENT RAIN PRODUCERS. PRECIPITABLE WATER VALUES AROUND 1.5 INCHES AND WARM LAYER CLOUD DEPTHS IN THE 3500-3800 METER RANGE. FORWARD PROPAGATION CORFIDI VECTORS ORIENTED WEST TO EAST PROVIDING SOME TRAINING POTENTIAL ALONG THE FAR SOUTH. THE 25.19Z HRRR KEEPS MUCH OF THE HEAVY CONVECTION IN MISSOURI. HOWEVER...INCREASED POPS AND QPF OVER THE SOUTHERN TIER OF COUNTIES ALONG THE MISSOURI BORDER. OTHER CONCERN WAS ANOTHER WEAK SHORTWAVE TO PROVIDE SOME ELEVATED SHOWERS AND ISOLATED THUNDERSTORM OVER THE REMAINDER OF THE FORECAST AREA. QPF AMOUNTS SHOULD REMAIN UNDER QUARTER OF AN INCH AND THUS LOW IMPACT ON ANY ONGOING FLOODING .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 356 PM CDT THU JUN 25 2015 A MUCH...MUCH QUIETER 7 DAYS AHEAD IN THIS LONG TERM FCST PERIOD. WATER VAPOR IMAGERY PICKING UP ON HIGH PRESSURE COMING ONSHORE NEAR THE OREGON COASTLINE. THIS HIGH PRESSURE WILL HAVE SIGNIFICANT INFLUENCE ON OUR WEATHER MUCH OF NEXT WEEK. FRIDAY MORNING...MODELS PICKING UP ON A SHORTWAVE CONTINUING THROUGH SOUTHERN IA/NORTHERN MO. ISENTROPIC LIFT PERSISTING INTO 12Z AS THIS SYSTEM WILL LIKELY BE CLIPPING AT LEAST THE SOUTHERN TWO TO THREE TIERS OF COUNTIES IN IA. WITH YESTERDAY/S BOUNDARY LINGERING IN NORTHERN MO...A LOT OF THE MOISTURE FROM THURSDAY/S SYSTEM STILL AROUND. MODELS FOCUSING IN ON PWATS BTX 1.5 AND 1.75 INCHES...WHICH IS AROUND +1 TO +2 STD DEV. GOOD SUPPORT ALOFT AS MID-LEVEL Q-VECTOR CONV PRESENT TO INCREASE LIFT. 0-6KM MIXING RATIOS AROUND 7 G/KG WHICH IS DECENT ENOUGH. OVERALL SOUNDING PROFILE MUCH LESS SATURATED THAN MOST OF THIS WEEK...SO THIS SYSTEM WILL NOT BE THE MOST EFFICIENT IN RAIN PRODUCTION. FRI AFTERNOON TEMPS...850MB TEMPS AROUND 12C IN OUR EAST AND 14C IN OUR WEST...ABOUT -1 TO -2 STD DEV. THURSDAY/S 850 MB TEMPS WERE AROUND 14C NE TO 17C SW. AM EXPECTING SUNSHINE TO BREAK THROUGH...BUT NOT A LOT...SO HAVE KEPT TEMPS IN THE MID 70S. FRI AFTERNOON THUNDERSTORM POTENTIAL...0-6KM MUCAPE VALUES BTX 700 AND 1000 J/KG WHICH WHICH IS MINIMAL. 0-6KM BULK SHEAR NEAR 30KTS...ALSO MINIMAL. LCL HEIGHTS ABOVE 1000M. OVERALL SOUNDING PROFILE SUGGESTS ANYTHING THAT FORMS WOULD BE ELEVATED. THUS OVERALL...AM EXPECTING NIL SVR/TOR THREAT FRI PM AND THERE MAY BE A FEW SHORT LIVED NON-SEVERE STORMS PRIMARILY IN OUR NW. FOR SATURDAY NIGHT INTO SUNDAY EVENING...MODELS CONSISTENT WITH PROPAGATING AN AREA OF LOW PRESSURE FROM NW MINNESOTA INTO SE MINNESOTA. A WEAK COLD FRONT WILL BE ATTACHED TO THIS AND PUSHING THROUGH IA DURING THE DAYTIME. THE 12Z GFS IS A FAST OUTLIER WITH THIS SYSTEM AS IT PLACES THE BOUNDARY EAST OF OUR CWA BY 12-15Z SUN. HAVE MAINLY DISREGARDED THE GFS AND WENT WITH AN AVERAGE OF OTHER MODELS. PWATS JUMP FROM AROUND 1.25 TO 1.5 INCHES AND 0-6KM MUCAPE VALUES ARE AROUND 400 TO 600 J/KG. POSITION OF FRONT DURING PEAK DAYTIME HEATING IMPORTANT FOR SVR POTENTIAL. AS OF NOW...ALL SIGNS POINT TO THIS BOUNDARY BEING WELL EAST OF THE CWA BY DAYTIME HEATING. FOR MONDAY AND THE REST OF THIS LONG TERM FCST PERIOD...PERSISTENCE BECOMES A GOOD FORECAST THROUGH MID-WEEK. AN UPPER LEVEL TROUGH OVER THE NORTHEASTERN US AND AN UPPER LEVEL RIDGE OVER THE MOUNTAIN WEST WILL KEEP THE DMX CWA IN NORTHWESTERLY FLOW SEEMING INTO THE NEXT THU/FRI/SAT TIMEFRAME. A HUGE THERMAL RIDGE WILL BUILD OVER THE MOUNTAIN WEST COINCIDENT WITH THE UPPER LEVEL HIGH. THE RIDGE WILL STAY TO OUR WEST AND 850 MB TEMPS WILL BE IN THE DMX CWA WILL BE AROUND 15C TO OUR EAST AND 18C TO THE WEST. MODELS HINTING AT THERMAL RIDGE CRASHING DOWN INTO IA SOMETIME LATER IN THE WEEK...BRINGING A RETURN TO POP CHANCES TO THE AREA. && .AVIATION...25/18Z ISSUED AT 1249 PM CDT THU JUN 25 2015 MVFR CIGS WILL PERSIST THROUGH THE AFTERNOON AT ALO/DSM/OTM BEFORE EXPECTING STRATUS TO LIFT BY 20Z-23Z. A WEAK SHORTWAVE WILL BRING SCATTERED SHOWERS OVERNIGHT INTO FRIDAY MORNING AND HAVE VCSH MENTIONED AT DSM/OTM/FOD AS LOOKS TO SKIRT OVER SOUTHWEST IOWA. MAY SEE SOME MVFR CIGS WITH THIS SYSTEM...BUT LOW CONFIDENCE IN MENTIONING ATTM DUE TO DURATION. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...KOTENBERG AVIATION...PODRAZIK  FXUS63 KDMX 012101 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 401 PM CDT WED JUL 1 2015 .SHORT TERM /TONIGHT/... ISSUED AT 400 PM CDT WED JUL 1 2015 A VERY QUIET NIGHT EXPECTED ACROSS THE DMX CWA. A VERY WEAK SHORTWAVE IS EXITING THE CWA TO THE EAST AND TAKING WITH IT - RA/VIRGA. SOUNDINGS SHOW A LOT OF DRY AIR IN THE LOW LEVELS AND...SUBSEQUENTLY...HIGH CLOUD BASES. SFC DWPT DEPRESSIONS ALSO APPROACHING 10F. ALL OF THIS EQUALS BAD NEWS FOR RAIN TRYING TO REACH THE GROUND AND WILL THUS KEEP WITH -RA/VIRGA THROUGH 02Z THU OR SO. NE FLOW FROM A SFC HIGH LOCATED IN THE NORTHWOODS OF WI WILL KEEP WITH DRY AIR ADVECTION IN LOW LEVELS OF THE ATMOS. THIS IS BEST HIGHLIGHTED AT 850 MB ON FCST SOUNDINGS/CROSS SECTIONS. AM EXPECTING MID-LEVEL TO HIGH LEVEL CLOUDS TO BE PRESENT ACROSS MOST OF CWA AS A JET STREAK IS APPROACHING FROM THE NW. THIS WILL LARGELY INHIBIT RADIATIONAL FOG OVERNIGHT. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 400 PM CDT WED JUL 1 2015 ALTHOUGH THERE ARE OTHER TOKEN PRECIP CHANCES EARLY AND AGAIN LATE...THE PRIMARY SENSIBLE WEATHER THROUGH THE PERIOD WILL BE SUNDAY NIGHT INTO MONDAY NIGHT. AT ONSET CURRENT SD AND SRN ALBERTA/SASKATCHEWAN SHORT WAVES WILL CONTINUE THEIR TREKS DOWN THE MO RIVER VALLEY REACHING OR APPROACHING IA THU MORNING. THERE WILL BE LITTLE IF ANY THERMODYNAMIC SUPPORT WITH WHAT FORCING THERE IS IN THE MID LEVELS AND STILL FAIRLY WEAK. INSTABILITY PARAMETERS INCLUDING K INDEX AND MUCAPES ARE LOW SO ANY THUNDER WOULD BE LIMITED AND CERTAINLY NO SEVERE WEATHER. THIS SCATTERED AND WEAK CONVECTION WOULD MAINLY AFFECT WRN 2/3RDS OF THE FORECAST...AND EVENTUALLY EXIT BY LATE EVENING. THERE IS LITTLE LARGE SCALE SUPPORT OR LOW LEVEL CONVERGENCE FOR PRECIP FRI OR SAT. BUFR SOUNDINGS DO SUGGEST UNCAPPED MLCAPES OVER 1K J/KG...BUT WITH WEAK FLOW AND LITTLE FOCUS FEEL ANY COVERAGE WOULD BE QUITE ISOLATED AND NOT WORTH A BLANKET SLIGHT CHANCE. THE SITUATION WILL CHANGE CONSIDERABLY BY THE END OF THE WEEKEND HOWEVER. RETURN FLOW WILL STRENGTHEN SUN WITH THE RETURN OF A MORE SEASONAL AIRMASS...BOOSTING DEWPOINTS AND INSTABILITY. MODELS ARE STILL TRYING TO COME TO A TIMING CONSENSUS INTO EARLY NEXT WEEK...ACTUALLY FLIP FLOPPING THEIR RESPECTIVE FAST VS SLOW SOLUTIONS...BUT THIS ONLY APPEARS TO RESULT IN MINOR SENSIBLE WEATHER CONCERNS. EXPECT PEAKING SURFACE BASED CONVECTION TO FIRE UPSTREAM INTO SD DURING PEAK HEATING...MOVING SE AND REACHING NW IA INTO THE NIGHT. A LOBE OF FAIRLY DEEP FORCING ASSOCIATED WITH MATURING CANADIAN LONG WAVE TROUGH WILL DIP INTO THE UPPER MS VALLEY AND SHOULD BE SUFFICIENT TO SUSTAIN THE MCS OVERNIGHT WITH DEEP MOISTURE CONVERGENCE AND EXTENDED COLD FRONT/THETA-E GRADIENT ALOFT. THIS WILL LIKELY CONTINUE INTO MON...SO WHILE THE CONVERGENCE WILL BE THERE FOR ADDITIONAL SURFACE BASED DEVELOPMENT DURING PEAK HEATING...THAT WILL BE CONDITIONAL DEPENDING ON THE AMOUNT OF CONVECTIVE DEBRIS WHICH MAY NOT BE MINIMAL. GFS/ECMWF DEEP SHEAR SEEMS WEAKER THAN YESTERDAY...SO WHILE MUCAPES WOULD BE THERE FOR STRONG TO SEVERE STORMS THE OVERALL EVENT OUTLOOK MAY BE DIMINISHING SLIGHTLY. THE SIGNAL FOR LOCALLY HEAVY RAINS HAS BEEN PERSISTENT HOWEVER WITH WARM CLOUD DEPTHS AND PWATS BOTH INCREASING. THIS SHOULD BE LIMITED TO ONLY AN EVENT OR TWO HOWEVER WITH PATTERN PROGRESSIVE WITH ONLY TOKEN LIGHTER PRECIP EXPECTED SOUTH INTO TUE AND WED...IF THAT. && .AVIATION...01/18Z ISSUED AT 1236 PM CDT WED JUL 1 2015 LIGHT SHOWERS PASSING THROUGH IA. VERY...VERY...LITTLE TO NO LIGHTNING BEING DETECTED. KEPT ALL TAF SITES IN VFR AS LOTS OF DRY AIR IN LOW LEVELS. KOTM WILL NEED TO BE WATCHED FOR BRIEF MVFR AS SLIGHTLY MORE LOW LEVEL MOISTURE IN THE SOUTH. OVERNIGHT MID LEVEL CLOUDS SHOULD PREVENT RADIATIONAL FOG FROM DEVELOPING. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...KOTENBERG LONG TERM...SMALL AVIATION...KOTENBERG  FXUS63 KDMX 020830 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 330 AM CDT THU JUL 2 2015 .SHORT TERM /TODAY/... ISSUED AT 308 AM CDT THU JUL 2 2015 WEAK UPPER LEVEL WAVE DROPPING SOUTHEASTWARD THROUGH THE WESTERN DAKOTAS...TO SLIDE THROUGH SOUTHWESTERN IOWA THIS AFTERNOON IN NORTHWEST FLOW PATTERN ALOFT. CURRENTLY AN AREA OF THUNDERSTORMS ASSOCIATED WITH THIS WAVE HAVE DEVELOPED ACROSS THE CENTRAL DAKOTAS...WITH ADDITIONAL ACTIVITY EXPECTED TO DEVELOP ACROSS SOUTHEAST SD AND WESTERN IOWA THROUGH THE DAY AS THE WAVE PUSHES THROUGH THE STATE. AREA ALSO UNDER THE INFLUENCE OF A LARGE AREA OF HIGH PRESSURE CENTERED OVER WI/ERN MN/NE IA. HIGH RES MODELS CONFINE THE MAJORITY OF THE CONVECTIVE ACTIVITY TO THE WEST OF THE CWA ACROSS ERN NE AND FAR WESTERN IOWA. THIS LOOKS LIKE A FAIRLY DECENT SOLUTION GIVEN THE TRAJECTORY OF THE UPPER WAVE AND DEALING WITH THE INFLUENCE OF THE LARGE AREA OF HIGH PRESSURE AS WELL. THEREFORE HAVE TRIMMED POPS SOME ACROSS THE CENTRAL/NORTHERN PORTIONS OF THE CWA FOR TODAY...AND CONFINED THE POPS TO THE FAR WESTERN/SOUTHWESTERN PORTIONS OF THE CWA. CLOUD COVER TO BE FAIRLY EXTENSIVE ACROSS THE CWA TODAY WITH THAT UPPER WAVE MOVING THROUGH...BUT SHOULD STILL SEE SOME PEEKS OF SUN ACROSS THE NORTHEAST. THEREFORE HAVE THE WARMEST TEMPS IN THAT AREA...WITH SLIGHTLY COOLER HIGHS WHERE CLOUD COVER IS GREATER AND CHANCES OF PRECIP AS WELL. .LONG TERM /TONIGHT THROUGH WEDNESDAY/... ISSUED AT 308 AM CDT THU JUL 2 2015 LITTLE CHANGE TO THE GOING FORECAST AS THE OVERALL PATTERN AND MODEL TRENDS REMAIN SIMILAR. A SHORTWAVE WILL DROP SOUTH/SOUTHEAST ACROSS THE STATE THIS EVENING MAINLY AFFECTING FAR WESTERN AND SOUTHERN IOWA. HOWEVER WITH WEAK INSTABILITY AND ANY DEEPER SHEAR REMAINING TO THE WEST OF IOWA OR AT LEAST CENTRAL IOWA...WE WILL MAINLY GET BRUSHED ACROSS THE WEST/SOUTHWEST THIS EVENING WITH SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM. SEVERE WEATHER POTENTIAL IS SLIM TO NONE FOR TONIGHT INTO FRIDAY. THE MAIN SHOW CONTINUES TO BE THE STRONGER SHORTWAVE AND FRONTAL PASSAGE FOR MONDAY. MODELS HAVE SLOWED THE FROPA DOWN AND NOW SUNDAY AND SUNDAY EVENING LOOK MAINLY DRY. ONE THING OF NOTE...THE MODELS BRING INCREASING INSTABILITY INTO IOWA SATURDAY INTO SUNDAY AHEAD OF THE BOUNDARY. HOWEVER WITH LACK OF APPRECIABLE SHEAR AND FORCING REMAINING WEST OF THE FORECAST AREA THROUGH SUNDAY EVENING IT STILL LOOKS MAINLY DRY FOR THE WEEKEND HOWEVER AN ISOLATED SHOWER OR STORM CANNOT BE RULED OUT. IT IS JUST TOO HIT AND MISS TO INCLUDE A SLIGHT CHANCE ANYWHERE IN THE FORECAST AREA. SO WHILE THE FORECAST REMAINS DRY THE INCREASING INSTABILITY MAY BE ENOUGH FOR AN ISOLATED SHOWER OR STORM. THE MAIN EVENT REMAINS MONDAY WITH THE FRONTAL PASSAGE EXPECTED DURING PEAK HEATING AND WARM CLOUD DEPTHS SUFFICIENT FOR HEAVY RAINFALL WE WILL BE RETURNING TO MENTIONING SEVERE CHANCES AND HEAVY RAINFALL WITH STORMS. HIGH PRESSURE WILL QUICKLY BUILD IN BEHIND THE FRONTAL PASSAGE LATE MONDAY NIGHT AND TUESDAY. LINGERING PRECIP WOULD BE CONFINED TO SOUTHEAST IOWA MONDAY EVENING AND TUESDAY AT THIS POINT LOOKS DRY. THE NEXT BEST CHANCE FOR PRECIP LOOKS TO BE FROM LATE IN THE EXTENDED AND BEYOND WITH A LOW AND WARM FRONT SETTING UP SOMEWHERE IN/NEAR IOWA. MODELS ARE NOT IN ANY SORT OF AGREEMENT AS TO TIMING AND PLACEMENT WITH THE EURO THINKING THE LOW WILL BE IN NW IA AND A FRONTAL BOUNDARY DRAPED ACROSS THE HIGHWAY 20 CORRIDOR AND THE GFS KEEPING THE LOW ACROSS OMAHA AND THE FRONT MUCH FURTHER SOUTH. THE EURO KEEPS THE STORM/SEVERE CHANCES FURTHER NORTH WHILE THE GFS SUGGEST MORE WIDESPREAD THUNDERSTORM CHANCES. && .AVIATION...02/06Z ISSUED AT 1037 PM CDT WED JUL 1 2015 HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA THURSDAY. WEAK BOUNDARY ACROSS THE DAKOTAS SOUTH TO KANSAS WILL BEGIN TO MOVE SOUTHWEST. UPPER LEVEL SYSTEM TRACKING SOUTH WILL PRODUCE AN AREA OF SHOWERS OVER THE WEST...REMAINING WEST OF I35. FOR NOW HAVE KEPT AREA GENERALLY DRY. VFR CIGS EXPECTED WITH SCT LOW LAYER AND BKN/OVC MID LEVEL. AS HIGH BACKS SOUTH AFT 18Z THURSDAY...SKC TO SCT CONDITIONS RETURN EAST HALF THROUGH END OF PERIOD. WINDS TO REMAIN LIGHT...OTHER THAN A FEW GUSTS NEAR KOTM. /REV && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BEERENDS LONG TERM...FAB AVIATION...REV  FXUS63 KDMX 030849 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 349 AM CDT FRI JUL 3 2015 .SHORT TERM /TODAY/... ISSUED AT 320 AM CDT FRI JUL 3 2015 AREA OF HIGH PRESSURE CURRENTLY STRETCHING ACROSS NORTHERN IOWA INTO SRN WI WILL CONTINUE TO DOMINATE THE REGION TODAY. THIS WILL BRING DRY CONDITIONS WITH SKIES EXPECTED TO CLEAR AS THE HIGH CLOUDS MOVE OUT OF THE STATE THROUGH THE MORNING HOURS. WARMER AIR IN PLACE TODAY ALONG WITH MORE SUN...SO HAVE HIGHS TOPPING OUT IN THE MID TO UPPER 70S. BIGGEST ISSUE WILL BE IF STILL HAVE THE HAZY CONDITIONS WITH SMOKE AROUND FROM THE CANADIAN WILDFIRES. THIS COULD ALLOW TEMPS TO BE A DEGREE OR TWO LESS AND CAUSE MORE OF A FILTERED SUNSHINE/CLOUDY LOOK TO THE SKY. WINDS WILL REMAIN LIGHT WITH THE HIGH OVERHEAD. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 320 AM CDT FRI JUL 3 2015 OVERALL THE FORECAST THINKING HAS CHANGED VERY LITTLE TODAY...EXCEPT FOR ADDRESSING SOME SUBTLE CHANGES. ON SATURDAY ALL MODELS PICK UP AND A SHORTWAVE DROPPING ACROSS THE NORTHERN PLAINS THEN PUSHING EAST THROUGH SATURDAY EVENING. WHILE SOME INSTABILITY IS PRESENT ACROSS IOWA...IT IS FAR BETTER OVER MINNESOTA SATURDAY INTO SATURDAY NIGHT. SHEAR IS WEAK TO NON- EXISTENT AND WITH NO FORCING OR BOUNDARY AROUND I CHOSE TO KEEP SATURDAY DRY. RECALL THAT YESTERDAYS CONCERN WAS THAT THERE WOULD BE ENOUGH INSTABILITY FOR SOME SHOWERS/STORMS AROUND BUT CONFIDENCE WAS LOW AS TO WHERE AND WHEN. THERE IS STILL VERY LOW CONFIDENCE IN WHERE AND WHEN BUT NOW INSTABILITY IS LOWER AS WELL SO POPS WERE STILL KEPT OUT OF THE FORECAST. HOWEVER...FAR NORTH AND NORTHEAST IOWA ARE STILL NOT COMPLETELY OUT OF THE WOODS WITH RESPECT TO A STAY SHOWER OR STORM. ATTENTION THEN TURNS TO SUNDAY NIGHT MONDAY WHEN SUFFICIENT SHEAR AND INSTABILITY WILL COINCIDE WITH A BOUNDARY NEAR NW IA SUNDAY NIGHT. THERE IS ALSO QUITE A BIT OF FORCING OVER THE DAKOTAS AND NEBRASKA. IT LOOKS LIKE THE SCENARIO IS THAT STORMS WILL FIRE IN THIS AREA AND MAY MERGE INTO AN MCS AFFECTING NORTHWEST IOWA EARLY ON AND ROLLING INTO OUR FORECAST AREA LATE. WE MAY SEE SOME LARGE HAIL AND DAMAGING WIND WITH THE STORMS INITIALLY WITH HEAVY RAIN AS WELL. ADDITIONAL STORMS ARE POSSIBLE ALONG THE FRONTAL BOUNDARY ON MONDAY AND WITH WARM CLOUD DEPTHS ABOVE 11KFT HEAVY RAINFALL IS POSSIBLE. A FEW SEVERE STORMS ARE STILL POSSIBLE ALONG THE BOUNDARY AS SOME SHEAR REMAINS FOCUSED ALONG THE BOUNDARY BUT THE BEST SHEAR WILL LAG THE BOUNDARY FOR A GOOD CHUNK OF THE DAY SO SEVERE POTENTIAL IS NOT LOOKING AS GOOD MONDAY...AT LEAST FOR A WIDESPREAD EVENT. STORMS WILL LIKELY BECOME MORE ORGANIZED BY AFTERNOON BUT BY THEN THE BOUNDARY IS OUT OR NEARLY OUT OF THE AREA AND AS SUCH...THE SEVERE THREAT WILL LIKELY BE OUT OF OR EXITING THE AREA. LINGERING STORMS ARE POSSIBLE VERY FAR SOUTH AND SOUTHEAST EARLY TUESDAY BUT HIGH PRESSURE QUICKLY RETURNS BY LATE MORNING AND WILL STAY WITH US THROUGH MID WEEK. AFTER THAT MODELS DIVERGE SOME WITH THE GFS DRIVING A SHORTWAVE ACROSS IOWA AT THE END OF THE FORECAST PERIOD AND BEYOND WHILE THE EURO BUILDS A RIDGE OVER IA. FOR NOW I KEPT CHANCE TO SLIGHT CHANCE POPS OVER CENTRAL IOWA BUT DID LOWER THE PERCENTAGES SOME. FURTHER REFINEMENT WILL COME AS MODELS COME CLOSER TO AGREEMENT IN LATER PERIODS. && .AVIATION...03/06Z ISSUED AT 1123 PM CDT THU JUL 2 2015 QUIET CONDITIONS EXPECTED THROUGH THE PERIOD. HIGH PRESSURE OVER WI/MN WILL DRIFT ACROSS THE AREA FRIDAY. VERY LIGHT WINDS AND VFR CIGS EXPECTED. FEW MID LEVEL CLOUDS TNT WILL GRADUALLY CLEAR BY 12Z MOST AREAS. WINDS REMAIN EITHER LIGHT/VAR OR LIGHT NORTHEAST. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BEERENDS LONG TERM...FAB AVIATION...REV  FXUS63 KDMX 032056 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 356 PM CDT FRI JUL 3 2015 .SHORT TERM /TONIGHT/... ISSUED AT 353 PM CDT FRI JUL 3 2015 SURFACE HIGH PRESSURE ACROSS IOWA WILL CONTINUE TO DOMINATE WEATHER THROUGH THE OVERNIGHT...WITH MAIN CONCERN BECOMING OVERNIGHT LOW TEMPERATURES. GIVEN AMOUNT OF DRY AIR AND LIGHT WINDS OVERNIGHT EXPECT TEMPERATURES TO ONCE AGAIN COOL WELL OVERNIGHT. HOWEVER...GIVEN WARMER TEMPERATURES TODAY AND WAA BEGINNING TO PUSH INTO THE NORTH HAVE KEPT TEMPERATURES UP A LITTLE. IN ADDITION...SMOKE FROM NORTHERN WILD FIRES MAY PUSH INTO IOWA OVERNIGHT...WHICH COULD AID IN KEEPING TEMPERATURES UP SLIGHTLY. SAW SOME ARES OF FOG THIS MORNING IN THE WEST AND WITH LIGHT WINDS MAY BE POSSIBLE AGAIN LATE IN THE PERIOD...BUT GIVEN DRY CONDITIONS HAVE LEFT MENTION OUT FOR THE EARLY MORNING. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 353 PM CDT FRI JUL 3 2015 MAIN CONCERN THROUGH THE PERIOD WILL BE CONVECTION SUN NIGHT INTO MON NIGHT. PROGRESSIVE PATTERN WILL PUSH OUT CURRENT OH VALLEY TROUGH WITH MATURING BROAD CANADIAN TROUGH DRIVING OUR SENSIBLE WEATHER INTO EARLY NEXT WEEK. INITIAL STORY WILL LIKELY BE INFLUENCES FROM CANADIAN FIRE SMOKE FOR THE FOURTH HOWEVER. VISIBLE SATELLITE IMAGERY NICELY SHOWS THIS SMOKE UPSTREAM ACROSS THE DAKOTAS AND MN WITH RESTRICTIONS DOWN TO SEVERAL MILES TIMES AT TIMES. DO NOT FEEL CONDITIONS WILL BE THAT POOR TOMORROW...BUT NOAA AIR QUALITY MODELS DO INDICATE VERTICALLY INTEGRATED SMOKE CONCENTRATIONS INCREASE SAT. THUS HAVE KEPT TEMPS BELOW MOS GUIDANCE WHICH IS LIKELY TOO HIGH DUE TO SMOKE AND CLIMO INFLUENCES. SHORT WAVE RIDGE PASSAGE WILL LIKELY PUSH SMOKE EASTWARD BY SUN HOWEVER. RELATIVELY MOIST GROUND SHOULD STILL KEEP TEMPS GETTING TO GUIDANCE HOWEVER SO HAVE CONTINUED TO GO JUST BELOW THOSE VALUES. RECENT BIASES HAVE BEEN ON THE WARM SIDE TOO. PRECIP CHANCES WILL INCREASE NW-SE LATE SUN NIGHT THROUGH MON NIGHT HOWEVER. LOBE OF DEEP FORCING ASSOCIATED WITH CANADIAN LONG WAVE TROUGH AND TRAILING FRONTAL BOUNDARY WILL DROP INTO THE SIOUXLAND AREA SUN NIGHT. PEAK HEATING GENESIS WILL LIKELY BE WELL REMOVED FROM OUR FORECAST AREA...BUT THE MAGNITUDE OF THE SYNOPTIC FORCING IN AN AIRMASS WITH INCREASING INSTABILITY WILL LIKELY KEEP THE MCS GOING THROUGH THE NIGHT. EXPECT RE-DEVELOPMENT DURING PEAK HEATING MON WITH FRONT PUSHING THROUGH FORECAST AREA DURING THE AFTERNOON. ALTHOUGH CONVECTIVE DEBRIS MAY LIMIT THINGS SOMEWHAT...BOTH GFS AND NAM BUFR SOUNDINGS SHOW UNCAPPED MLCAPES RANGING FROM 1800-4000 J/KG IN THE WARM SECTOR. HIGHER NAM VALUES ARE LIKELY OVERDONE...DRIVEN BY MID 70 DEWPOINTS...BUT EVEN THE LESS AGGRESSIVE GFS WOULD SUGGEST UNCAPPED DEVELOPMENT. NEITHER MODEL SHOWS MUCH IN THE WAY OF DEEP SHEAR HOWEVER WITH VALUES 30KTS OR LESS IN UNIDIRECTIONAL PROFILES. THUS EXPECT SEVERE POTENTIAL TO BE LOW. LOCALLY HEAVY RAINS MAY BE MORE OF A CONCERN WITH NAEFS SPECIFIC HUMIDITIES AND PWATS WELL THROUGH THE 90TH PERCENTILE AND PUSHING EXTREMES AT TIMES. DETERMINISTIC MODELS ALSO DEPICT WARM CLOUD DEPTHS OVER 13.5K FT. SYSTEM SHOULD BE TRANSIENT ENOUGH TO PRECLUDE WIDESPREAD HEAVY RAINS...BUT WILL HAVE TO MONITOR FLASH FLOODING POTENTIAL FOR ISOLATED AREAS. PRECIP MAY LINGER SOUTHEAST INTO THE NIGHT BUT EXIT BY TUESDAY. NEXT PRECIP CHANCES WILL BE INTO DAYS 6 AND 7 AS WEAK SHORT WAVES DRIFT THROUGH WEAK FLOW. POPS ARE LOW AT THIS POINT AS DETAILS DIFFICULT TO COME BY. ECMWF IS MORE AGGRESSIVE WITH MS VALLEY TROUGH DRIVING BAROCLINIC ZONE TO OUR SOUTH...WHILE GFS IS WEAKER RESULTING IN FRONTAL ZONE FARTHER NORTH AND POSSIBLY GETTING CONVECTION AS FAR NORTH AS IA. && .AVIATION...03/18Z ISSUED AT 1215 PM CDT FRI JUL 3 2015 HIGH PRESSURE WILL KEEP CONDITIONS VFR THROUGH PERIOD. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT...BECOMING SOUTHERLY LATE IN PERIOD AT SITES. WITH LIGHT WINDS OVERNIGHT...MAY SEE MVFR OR LOWER HZ OR BR AT SITES NEAR 12Z...BUT HAVE NOT INCLUDED MENTION ATTM. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...AWB LONG TERM...SMALL AVIATION...AWB  FXUS63 KDMX 070835 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 335 AM CDT TUE JUL 7 2015 .SHORT TERM /TODAY/... ISSUED AT 334 AM CDT TUE JUL 7 2015 UNSEASONABLY COOL TEMPERATURES AND THE POTENTIAL OF ADDITIONAL SMOKE FROM WILD FIRES IN NORTHERN CANADA IS THE FOCUS OF THE SHORT TERM FORECAST. SURFACE HIGH PRESSURE CENTERED OVER THE RED RIVER OF THE NORTH RIVER VALLEY WILL BUILD SOUTHEAST TODAY BRINGING A DRY DAY. A COOLER AND DRIER AIRMASS WILL CONTINUE TO SETTLE ACROSS THE MIDWEST. HIGH TEMPERATURES WILL BE AROUND 15 DEGREES BELOW NORMAL FOR THIS TIME OF THE YEAR. ATTENTION WILL BE FOCUSED ON A COUPLE OF SMOKE PLUMES. ONE PLUME IS OVER THE NORTHERN AND CENTRAL PLAINS AND ANOTHER SMALLER PLUME OVER THE MIDWEST. CHALLENGING FORECAST WITH REGARDS TO THE PROPAGATION AND ADVECTION OF THESE PLUMES WITH MIGRATION DEPENDENT UPON HEIGHT AND DEPTH OF THE SUSPENDED AEROSOLS...MIXING...AN INVERSION AND CHANGING WIND SPEED AND DIRECTION WITH HEIGHT. HAVE INCLUDED PATCHY SMOKE THROUGH THE MORNING AND WILL CONTINUE TO MONITOR TRENDS THROUGH THE DAY. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 334 AM CDT TUE JUL 7 2015 HIGH PRESSURE WILL BUILD SOUTH ACROSS THE REGION THROUGH TONIGHT. SOME SMOKE MAY LINGER OVER THE NEXT DAY OR SO...THOUGH THE EXTENT OF COVERAGE MAY REMAIN LOW THROUGH TONIGHT AS EARLIER PROJECTIONS SUGGESTED THE HIGH WOULD KEEP THE PLUME MORE WEST OF THE AREA. WITH COOL AIRMASS IN PLACE...H850 TEMPS REMAINING NEAR 9C BY 12Z WEDNESDAY AND RIDGE AXIS OVERHEAD...MINS WILL BE QUITE CHILLY FOR JULY ON WEDNESDAY MORNING. THOUGH RECORDS ARE NOT IN JEOPARDY WITH LOWS ABOUT 5 TO 7 DEGREES HIGHER THAN PREVIOUS RECORDS...LOWS WILL STILL DROP INTO THE UPPER 40S NORTH TO THE MID TO UPPER 50S IN THE SOUTH. DESPITE THE RECENT WET WEATHER FOG SHOULD NOT BE A PROBLEM TONIGHT AS LIGHT NORTHEAST WINDS RESULT IN LOWERING DEW POINTS OVERNIGHT. THIS SHOULD LEAD TO A THICK DEW WEDNESDAY MORNING... RATHER THAN ANY WIDESPREAD FOG. WITH THE EXCEPTION OF THE 00Z NAM...MODELS ARE NOW TRENDING SOUTH WITH THE SYSTEM ON WEDNESDAY AS THE GREAT LAKES HIGH WILL DEPART MORE SLOWLY THAN EARLIER ANTICIPATED. THIS SHOULD RESULT IN GENERALLY DRY CONDITIONS WITH MOSTLY SUNNY SKIES AND A SLIGHT WARMING TREND. BY AFTERNOON H850 TEMPERATURES RECOVER TO THE LOWER TEENS WITH NORTHEAST FLOW. THIS SHOULD HELP AFTERNOON HIGHS RECOVER TO THE LOWER 70S MOST AREAS... SOME 10 TO 15 DEGREES BELOW NORMAL FOR JULY 8TH. WITH THE BRIEF SPLIT FLOW THAT DEVELOPS WEDNESDAY INTO EARLY THURSDAY...THE NEXT BEST CHANCES FOR THUNDERSTORMS WILL RETURN LATE THURSDAY AFTERNOON INTO FRIDAY...LINGERING INTO SATURDAY. THE GFS/GEM/EURO ARE IN AGREEMENT THAT A STRONG PUSH OF THETAE ADVECTION ALONG A STRENGTHENING WARM FRONT AND LOW LEVEL JET WILL INCREASE FORCING ACROSS SOUTHWEST IOWA EARLY THURSDAY EVENING...WITH SHOWERS AND SCATTERED THUNDERSTORMS BUILDING NORTH OVERNIGHT. WITH LITTLE OVERALL CHANGES TO PERSISTENT SOUTHWEST FLOW ALOFT AND THE MOISTURE POOL OVER THE SOUTHERN PLAINS NOW...THE RATHER WATER LOADED H850 MOISTURE PLUME IS LIKELY TO BUILD BACK NORTH WITH THE ADVANCING WARM FRONT THURSDAY NIGHT. GFS PRECIPITABLE WATER FORECASTS INCREASE TO 1.75 TO 2.0 INCHES BY 12Z FRIDAY WITH WARM CLOUD DEPTHS AGAIN RISING TO 13 TO 14KFT BY 12Z FRIDAY. DEPENDING ON THE EXTENT OF NORTHEAST MOVEMENT OF THE BOUNDARY...MODERATE TO LOCALLY HEAVY RAINFALL MAY AGAIN OCCUR THROUGH EARLY FRIDAY MORNING DIMINISHING LATER IN THE MORNING. IN THE WAKE OF THE BOUNDARY THE GFS BRINGS A RATHER WARM AND MOIST AIRMASS WILL REMAIN IN PLACE THROUGH THE WEEKEND...HOWEVER CONFIDENCE IN THE WEEKEND EVOLUTION OF THE BOUNDARY IS LESSENING. THE 00Z EURO SHOWS THE BOUNDARY STALLING OVER IOWA WITH CONVECTION REFIRING AND KNOCKING THE BOUNDARY BACK SOUTH...KEEPING IT NEAR IOWA THROUGH LATE SATURDAY EVENING...THEN LIFTING IT NORTHEAST ON SUNDAY. THIS GREATLY IMPACTS TEMPERATURES AND THUNDER CHANCES...AS WELL AS IF REPEATED RAINFALL MAY OCCUR OVER THE SAME AREAS. TEMPERATURES LOOK TO WARM EITHER WAY...GIVEN THE INCREASING HEIGHT FIELDS AND H850 TEMPERATURES THROUGH THE PERIOD. THOUGH THUNDER IS POSSIBLE THROUGH AT LEAST SATURDAY...THERE IS SOME HINT THAT THE FORCING MAY BRIEFLY SHIFT NORTH/EAST FOR SUNDAY BEFORE THE FRONT COLLAPSES SOUTH AGAIN SUNDAY NIGHT AND MONDAY. GIVEN THE UPPER LEVEL WIND FIELDS...SEVERE CHANCES LOOK LIMITED THROUGH THE PERIOD THOUGH HEAVY RAINFALL MAY POSE A CHALLENGE IF THE BOUNDARY HANGS UP ACROSS THE AREA. TOO SOON FOR AN ANSWER THIS MORNING...SO WILL NEED TO MONITOR THE NEXT COUPLE OF DAYS. TEMPS SHOULD WARM INTO THE 80S TO NEAR 90 WITH LOWS IN THE 60S TO LOWER 70S. THERE APPEARS TO BE A SIGNAL FOR THE SUMMERTIME HEAT TO CONTINUE THROUGH EARLY NEXT WEEK. && .AVIATION...07/06Z ISSUED AT 1151 PM CDT MON JUL 6 2015 SHRA/TSRA HAVE CLEARED THE AREA AND LOW CLOUDS ARE FOLLOWING SUIT...WITH SOME BRIEF MVFR CIGS POSSIBLE IN THE NEXT COUPLE OF HOURS AT ALO/DSM/OTM. MEANWHILE...THE LARGE SWATH OF SMOKE/HAZE MOVING ACROSS THE REGION HAS SHOWN A CLEAR BACK EDGE THAT HAS NOW MOVED THROUGH FOD AND IS ABOUT TO MOVE THROUGH MCW. WITHIN THE SMOKE VSBYS ARE GENERALLY 2 1/2SM TO 4SM...AND HAVE ATTEMPTED TO TIME THE BACK EDGE MOVING THROUGH EACH TERMINAL LATER TONIGHT. THUS MVFR/BRIEF IFR VSBYS ARE EXPECTED AT ALO/DSM/OTM IN THE NEXT SEVERAL HOURS...BUT EVENTUALLY GIVING WAY TO VFR CONDITIONS ON TUESDAY AND TUESDAY NIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ANGLE LONG TERM...REV AVIATION...LEE  FXUS63 KDMX 072048 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 348 PM CDT TUE JUL 7 2015 .SHORT TERM /TONIGHT/... ISSUED AT 320 PM CDT TUE JUL 7 2015 CANADIAN HIGH PRESSURE WILL CONTINUE TO INFLUENCE THE WEATHER OVERNIGHT IN IOWA WITH COOL TEMPERATURES AND QUIET CONDITIONS. CURRENTLY...CU FIELD HAS OVERSPREAD MUCH OF THE EASTERN HALF OF IOWA WITH DAYTIME HEATING. THESE CLOUDS WILL DISSIPATE RAPIDLY THIS EVENING AS SUNSET APPROACHES WITH CLEAR SKIES FOR THE REMAINDER OF THE EVENING. HOWEVER...HIGH CLOUDS WILL BEGIN TO SPREAD BACK INTO THE STATE FROM THE SOUTH LATE TONIGHT AS SYSTEM IN TEXAS BEGINS TO MOVE NORTHWARD. OTHERWISE...TEMPERATURES WILL BEGIN TO DROP RAPIDLY AFTER SUNSET UNDER THE CLEAR SKIES AND WEAKENING WINDS. ANTICIPATE LOWS INTO THE 40S IN THE NORTH AND POSSIBLY THE NISHNA VALLEYS OF THE WEST AND HAVE GONE UNDERNEATH GUIDANCE IN THESE FAVORED LOCATIONS. MAY BEGIN TO SEE SHOWERS APPROACH THE FAR SOUTH TOWARD DAYBREAK BUT ANY THREAT FROM THOSE WILL WAIT UNTIL WEDNESDAY. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 320 PM CDT TUE JUL 7 2015 HIGH PRESSURE WILL CONTINUE TO PUSH EAST THROUGH THE DAY WEDNESDAY WITH LOW PRESSURE SYSTEM IN OKLAHOMA BEGINNING TO LIFT NORTH. MODELS HAVE CONTINUED SOUTHERN TREND WITH THIS SYSTEM...KEEPING LOW SOUTH OF IOWA...LIFTING NORTHEAST ACROSS MISSOURI. GIVEN STRENGTH OF RETREATING HIGH AND DRY AIR EXPECTED TO BE IN PLACE ACROSS MOST OF STATE...AGREE WITH TREND OF KEEPING PRECIPITATION CHANCES FURTHER TO THE SOUTHEAST THROUGH THE DAY...AND HAVE CONTINUED TO CUT BACK ON POPS...KEEPING THEM CONFINED TO THE SOUTHEAST IN THE AFTERNOON AND OVERNIGHT PERIOD...WITH BEST CHANCES COMING IN THE LATE AFTERNOON AND EARLY EVENING HOURS. CONCERN WILL THEN SHIFT TO THURSDAY NIGHT AS BOUNDARY LIFTS NORTH FROM SOUTHERN STATE. THIS WILL BRING BEST CHANCES FOR PRECIPITATION IN THE EXTENDED...ESPECIALLY THURSDAY NIGHT INTO FRIDAY AS BOUNDARY LIFTS NORTH. MODELS ARE NOT IN GOOD AGREEMENT WITH THE TIMING OF THIS SYSTEM...THOUGH GENERALLY HAVE A SLOWER SOLUTION...WITH NAM AND GFS BEING MOST AGGRESSIVE...AND ECMWF AND GEM BEING SLOWER. IN ADDITION...SLOWER SOLUTIONS KEEP BEST PRECIPITATION SOUTH OF IOWA AGAIN AS SYSTEM LIFT NORTH. HAVE OPTED TO KEEP PRECIPITATION TRENDS AS IS...WITH CHANCES ACROSS CENTRAL AND SOUTHERN IOWA THURSDAY NIGHT INTO FRIDAY...THOUGH WITH SLIGHTLY SLOWER TREND...MAY SEE BEST CHANCES VERY EARLY FRIDAY. COULD SEE CHANCES FOR HEAVY RAIN THURSDAY NIGHT WITH GOOD WARM CLOUD DEPTHS AND PWAT VALUES NEAR 1.8 INCHES. SYSTEM WILL LIFT NORTH WITH RIDGE BEGINNING TO BUILD INTO SOUTHERN STATES. HOWEVER...STRENGTH AND LOCATION OF RIDGE IS STILL SOMEWHAT UNCERTAIN IN MODELS WITH SYSTEMS PUSHING EAST ACROSS CANADA HELPING TO LIMIT NORTHERN EXTENT OF RIDGE. THIS WILL BE THE MAIN PLAYER THROUGH THE END OF THE EXTENDED...DRIVING PRECIPITATION CHANCES AND TEMPERATURES. GFS IS MOST AGGRESSIVE WITH RIDGE...AND BRINGS IN HOT AND HUMID CONDITIONS FOR THE WEEKEND...WITH GUIDANCE INDICATING HIGHS IN THE 90S ACROSS MUCH OF THE AREA. HOWEVER...ECMWF AND GEM KEEP MORE ACTIVE PATTERN ACROSS CENTRAL IOWA WITH VARIOUS WAVES PUSHING THROUGH FLOW...AND THEREFORE SLIGHTLY COOLER TEMPERATURES. GIVEN SUCH UNCERTAINTY AT THIS LENGTH...HAVE TRENDED TOWARDS A BLEND OF THE TWO...WITH HIGHS IN THE UPPER 80S AND LOW 90S LATE IN THE PERIOD...AND OCCASIONAL PRECIPITATION CHANCES...ESPECIALLY IN THE NORTH. && .AVIATION...07/18Z ISSUED AT 1243 PM CDT TUE JUL 7 2015 WIDESPREAD VFR CONDITIONS EXPECTED FOR THE DURATION OF THE FORECAST WITH HIGH PRESSURE MOVING ACROSS THE REGION. WILL SEE CU FIELD THIS AFTERNOON BUT CEILINGS WILL DISSIPATE THIS EVENING WITH LOSS OF DAYTIME HEATING. CLEAR SKIES OVERNIGHT WITH SOME CLOUDS INCREASING ON WEDNESDAY MORNING AS WEAK WARM ADVECTION TAKES OVER. SURFACE WINDS WILL BE NORTH TODAY BECOMING LIGHT AND VARIABLE OVERNIGHT BEFORE SWITCHING TO THE SOUTHEAST ON WEDNESDAY MORNING AS RIDGING MOVES TO THE EAST. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...COGIL LONG TERM...AWB AVIATION...COGIL  FXUS63 KDMX 080811 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 311 AM CDT WED JUL 8 2015 .SHORT TERM /TODAY/... ISSUED AT 311 AM CDT WED JUL 8 2015 TEMPERATURES THIS MORNING HAVE FALLEN TO THE 50S OVER MOST OF CENTRAL IOWA...ABOUT 10 DEGREES BELOW THE SEASONAL AVERAGES FOR THIS TIME OF THE YEAR. HIGHS TODAY WILL BE ABOUT 10 TO 15 DEGREES BELOW NORMAL. SURFACE HIGH PRESSURE CENTERED OVER THE MIDWEST WILL BUILD EAST TODAY GRADUALLY SHIFTING WINDS TO THE EAST AND THEN SOUTH. ALOFT A SHORTWAVE TROUGH WILL BE LIFTING THROUGH THE MISSOURI VALLEY PRODUCING NUMEROUS SHOWERS AND THUNDERSTORMS OVER MISSOURI. AS THIS WAVE LIFTS NORTHEAST...CLOUD COVER WILL BE ON THE INCREASE ACROSS IOWA. FORECAST MODEL SOUNDINGS DEPICT A GRADUAL SATURATION OF THE THERMAL COLUMN IN SOUTH CENTRAL IOWA TODAY. HAVE INCLUDED CHANCES FOR RAIN SHOWERS LATE THIS MORNING THROUGH THIS AFTERNOON. INSTABILITY WILL BE LIMITED AND HAVE OPTED TO REMOVE THUNDER. ANY PRECIPITATION THAT DOES DEVELOP WILL BE LIGHT AS DRY LAYER ALOFT MOISTENS WITH RAINFALL AMOUNTS LESS THAN A TENTH OF AN INCH EXPECTED. .LONG TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 311 AM CDT WED JUL 8 2015 CHALLENGES IN THE EXTENDED CONTINUE...THOUGH A FEW THEMES BEGINNING TO SHOW THROUGH THE DIFFERENCES IN SOLUTIONS TONIGHT. IN THE NEAR TERM...MODELS ARE IN AGREEMENT THAT THE SYSTEM JUST TO THE SOUTHWEST OF THE AREA SHOULD CLIP THE FAR SOUTHEAST THIS EVENING AS IT PULLS NORTHEAST. HAVE MAINTAINED A CHANCE FOR SOME LIGHT SHOWERS SOUTHEAST WITH LINGERING FORCING EARLY IN THE PERIOD. WEAK RIDGE OF HIGH PRESSURE WITH H850 BOUNDARY ALOFT SOUTH OF THE STATE THURSDAY CONTINUES TO SUGGEST THAT CONVECTION WILL BE SLOWER TO RETURN. EURO HAS BEEN THE OUTLIER THE PAST 3 MODELS RUNS WITH THE GEM/GFS/NAM ALL BUILDING THE UPPER LEVEL BOUNDARY AND SFC WARM FRONT NORTH THURSDAY AFTERNOON/EVENING WHILE THE EURO WEAKENS THURSDAYS WAVE...PRIOR TO A MORE ENERGETIC SHORT WAVE OVER THE SOUTHWEST EJECTING NORTHEAST ACROSS IOWA FRIDAY NIGHT AND SATURDAY. THE DIFFERENCES STEM FROM A VERY SMALL AMPLIFICATION OF THE WESTERN TROUGH BY THE GFS COMPARED TO THE EURO. THIS LIFTS THE FIRST TWO SYSTEMS FARTHER NORTH AND BRING THUNDER BACK FASTER TO THE REGION. CURRENTLY A LOOK AT THE WATER VAPOR IMAGE SHOWS A MOSTLY ZONAL FLOW WITH SOUTHERN STREAM WAVES EDGING TOWARD THE REGION...THEN BUILDING EAST. CURRENT PREFERENCE IS TO LEAN WITH THE EURO... THOUGH HAVE BLENDED A BIT WITH THE GFS FOR SAKE OF CONTINUITY AND COLLABORATION. WITH THAT SAID...THURSDAY NOW LOOKS MAINLY DRY WITH THE MOST LIKELY CHANCES FOR ANY THUNDER ACROSS THE FAR SOUTH THURSDAY NIGHT AND EVEN THAT HAS BEEN LESSENED FROM THE PREVIOUS PACKAGE. BY FRIDAY THE SYSTEM WILL TRACK EAST...LEAVING THE AREA WITH CHANCE STORMS. THE REAL PUSH SHOULD ARRIVE LATER ON FRIDAY EVENING INTO SATURDAY MORNING AS THE THIRD AND STRONGER WAVE PUSHES NORTHEAST AS THE H500 RIDGE OVER THE SOUTHEAST AMPLIFIES. THUNDERSTORMS FRIDAY NIGHT INTO SATURDAY MAY BRING A MARGINAL CHANCE FOR SOME SEVERE STORMS AS UPPER LEVEL WIND FIELDS ARE NOT TOO STRONG... THOUGH INSTABILITY MAY BE ENOUGH TO OFFSET WIND FIELDS. ONCE AGAIN WITH THE RETURN OF THE MOISTURE BOTH PRECIPITABLE WATER AND WARM CLOUD DEPTHS ARE SUPPORTIVE OF HEAVY RAINFALL AS THE SYSTEM PUSHES NORTH. WILL NEED TO MONITOR OVER THE NEXT COUPLE OF DAYS FOR THE FRIDAY NIGHT THROUGH SATURDAY NIGHT EVENTS AS BETTER DETAILS EMERGE. THE OTHER MAIN THEME CONTINUES TO BE WARMING TEMPERATURES. AS THE SFC BOUNDARY SOUTH OF THE REGION BEGINS TO ADVANCE NORTH AGAIN AS THE COOLER CANADIAN HIGH RECEDES...TEMPERATURES WILL BE ON THE RISE. OVER THE WEEKEND HIGHS SHOULD CLIMB BACK TO MORE SEASONAL LEVELS IN THE MID 80S BY SATURDAY AND PROBABLY ABOVE 90 BY SUNDAY AS H850 TEMPS BUILD TO 24C ACROSS THE AREA BY AFTERNOON. CONFIDENCE CONTINUES TO DROP BEYOND SUNDAY WITH EURO PULLING A RATHER STRONG SYSTEM ACROSS THE NORTHERN PLAINS TOWARD IOWA AND THE GFS SHOWING LITTLE IF ANY AMPLIFICATION FOR THE REMAINDER OF THE PERIOD. DESPITE THE UNCERTAINTIES...HEIGHT FIELDS SUGGEST THE REMAINDER OF THE FORECAST IS LEANING TOWARD SEASONAL OR SLIGHTLY ABOVE NORMAL TEMPERATURES. HIGHS WILL TOP OFF IN THE 80S WITH AN ADDITIONAL CHANCE FOR THUNDERSTORMS LATE WEEK. && .AVIATION...08/06Z ISSUED AT 1049 PM CDT TUE JUL 7 2015 MAINLY VFR CONDITIONS WILL PREVAIL FOR MOST OF THE TAF PERIOD. LOW CLOUDS MAY PRODUCE CIGS AROUND FL035-045 AT TIMES OVERNIGHT AND INTO WEDNESDAY...BUT EXPECT THEY WILL REMAIN ABOVE FL030. BY WEDNESDAY AFTERNOON AN AREA OF SHRA/TSRA WILL MOVE FROM NE MO INTO SE IA AND MAY AFFECT OTM...BUT AT THIS TIME APPEARS IT WILL STAY JUST SE OF OTM THUS HAVE NOT INCLUDED IN TAFS YET. BY WEDNESDAY EVENING MORE LOW CLOUDS AND BR MAY DEVELOP...WITH MVFR CONDITIONS BECOMING MORE LIKELY AFTER DARK AND TOWARD THE END OF THE 06Z TAF PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ANGLE LONG TERM...REV AVIATION...LEE  FXUS63 KDMX 100824 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 324 AM CDT FRI JUL 10 2015 .SHORT TERM /TODAY/... ISSUED AT 324 AM CDT FRI JUL 10 2015 MAIN FORECAST CONCERN FOR THE SHORT TERM PERIOD IS TIMING SHRA/TSRA POPS TOWARD THIS EVENING. CWA WILL FIND ITSELF IN A TRANSITION ZONE BETWEEN THE DEPARTING SURFACE PRESSURE RIDGE AND THE NEXT WX SYSTEM...APPROACHING FROM THE SW...TO AFFECT THE REGION. SOUTHERLY WINDS WILL BE SLIGHTLY HIGHER THAN THOSE ON THURSDAY...ESPECIALLY TOWARD THE END OF THE PERIOD AS THE SURFACE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO THE ARRIVING WX SYSTEM. WEAK WAA WILL CONTINUE TODAY...HOWEVER MORE CLOUD COVER THAN ON THURSDAY WILL HELP WASH IT OUT AND THUS HOLD AFTERNOON MAXES TO SIMILAR LEVELS AS WHAT WAS SEEN ON THURSDAY...WITH HIGHS AROUND 80. DEWPOINTS WILL BE HIGHER HOWEVER OWING TO THE RETURN FLOW. POPS INCREASE TOWARD EVENING AS FORCING FROM THE APPROACHING WX SYSTEM INCREASES OVER THE SW CWA. POP EVOLUTION IN THE GRIDS MAY BE ON THE AGGRESSIVE SIDE HOWEVER. EVEN BY 00Z SAT...HIGHEST ELEVATED CAPE VALUES ACROSS THE CWA ARE NO MORE THAN AROUND 500 J/KG. ALTHOUGH MOISTURE LEVELS WILL BE INCREASING...BEST FORCING REMAINS YET TO THE SW OF THE CWA. THUS POPS FROM LATE AFTERNOON TOWARD EVENING WILL HAVE TO BE WATCHED AND POSSIBLY ADJUSTED BASED ON SENSIBLE WX TRENDS GOING FORWARD. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 324 AM CDT FRI JUL 10 2015 FORECAST ON TRACK FOR THE NEXT FEW DAYS WITH MORE DETAILS NOW ABOUT THE EVOLUTION OF THE SYSTEM THROUGH THE WEEKEND. STILL SOME WRINKLES...BUT OVERALL THE FRONT IS ON TRACK TO ARRIVE OVERNIGHT TONIGHT. MODELS...GEM/NAM/GFS/EURO ALL IN DECENT AGREEMENT THAT AN MCS WILL DEVELOP OVER NEBRASKA/WESTERN IA THIS EVENING AND TRACK ALONG THE WARM FRONTAL BOUNDARY OVERNIGHT. PRECIPITABLE WATER FORECAST REMAIN CONSISTENT WITH NEARLY 2 INCHES EXPECTED TO COLLECT ALONG THE BOUNDARY. WARM CLOUD DEPTHS SUPPORT EFFICIENT RAINFALL PROCESSES...THE REAL ISSUE IS HOW FAR NORTH THE BOUNDARY GETS OVERNIGHT. BOTH THE GFS/EURO SUGGEST THAT BY 18Z SAT TO 00Z SUNDAY THE WARM FRONT WILL CUT ACROSS THE STATE FROM NW TO SOUTHEAST. THIS SUGGEST THAT THERE MAY BE SOME ADDITIONAL THUNDERSTORMS THROUGH THE DAY NORTHEAST OF THE BOUNDARY ACROSS CENTRAL TO NORTHEAST/EAST IOWA AS WELL WITH AFTERNOON CONVECTION INCREASING IN COVERAGE/INTENSITY. EARLIER RUNS OF THE EURO SUGGESTED THE FRONT MIGHT SLIP SOUTH SATURDAY NIGHT/SUNDAY. IT NOW APPEARS THAT THE BOUNDARY WILL NOT SLIP SOUTH BUT MAY HANG UP AS CONVECTION FROM SATURDAY AFTERNOON BUILDS ALONG AN OUTFLOW BOUNDARY EITHER ACROSS CENTRAL/EASTERN IOWA. THEN AS THE WAVE AT H500 WHICH IS TRIGGERING THIS CONVECTION MOVES EAST...TEMPERATURES WILL BUILD SUNDAY INTO MONDAY. AT THIS TIME...WILL NOT GO WITH ANY HEADLINES FOR RAINFALL/FLASH FLOODING POTENTIAL MAINLY BECAUSE OF SOME UNCERTAINTY AS TO THE EXTENT AND DURATION OF CONVECTION FROM TONIGHT THROUGH SATURDAY AFTERNOON AT ANY ONE LOCATION. IT APPEARS THAT THE BETTER FORCING WILL FAVOR AN AREA FROM WEST CENTRAL/SOUTHWEST TO I80 NORTH TO ABOUT US20 THROUGH SATURDAY NIGHT. CURRENTLY FFG IS RUNNING ABOUT 1.5-2.5 INCHES IN 1 HOUR ACROSS THE REGION AND 2-3 INCHES IN 3 HOURS AND 2.5-3.5 IN 6 HOURS IN THOSE AREAS. RAINFALL TOTALS WILL LIKELY AVERAGE 1 TO 2 INCHES IN HEAVIER STORMS...WITH POTENTIALLY SOME LOCATIONS RECEIVING 3 OR MORE FROM TONIGHT THROUGH SUNDAY. THE DAY SHIFT WILL NEED TO EVALUATE THE NEXT SET OF DATA TO MAKE A DETERMINATION REGARDING ANY HEADLINES TONIGHT/SATURDAY. WE HAVE HAD A FEW DAYS TO RECOVER FROM THIS PAST WEEKS EVENTS WHICH HAS HELPED US IN THE SHORT TERM. SEVERE CHANCES AGAIN REMAIN LIMITED...BUT WITH INCREASING HEAT/MOISTURE THERE WILL BE A SLIGHTLY BETTER RISK OF SOME AFTERNOON SEVERE STORMS SATURDAY AND AGAIN ON SUNDAY INTO SUNDAY NIGHT JUST EAST OF THE WARM FRONT. WITH MODELS IN BETTER AGREEMENT ON THERMAL PROFILES THROUGH THE WEEKEND...WILL FOLLOW UP WITH HEAT ON SUNDAY AND MONDAY WITH HIGHS IN THE UPPER 80S TO NEARLY MID 90S...MONDAY ESPECIALLY HOT AS HEAT INDICES REACH THE 100 TO 105 RANGE BOTH SUNDAY AND MONDAY WHICH MAY REQUIRE A HEADLINE FOR HEAT ONE OR BOTH DAYS. THERE REMAINS A SIGNAL FOR THE HEAT TO LINGER INTO TUESDAY NOW WITH THE H500 RIDGE BUILDING OVER THE SOUTHERN PLAINS THROUGH MIDWEEK. BEYOND TUESDAY THE RIDGE BEGINS TO WEAKEN OVER THE GREAT LAKES WHICH ALLOWS FOR COOLER TEMPERATURES TO BUILD SOUTH INTO THE AREA. THOUGH THE WETTEST PERIOD WILL BE FROM TONIGHT THROUGH SUNDAY...THERE WILL BE ADDITIONAL CHANCES FOR THUNDERSTORMS NEXT WEEK ESPECIALLY WEDNESDAY AND THURSDAY. && .AVIATION...10/06Z ISSUED AT 1154 PM CDT THU JUL 9 2015 WILL BE AN INCONSEQUENTIAL TAF PERIOD. VFR CONDITIONS EXPECTED THROUGHOUT...WITH ONLY SOME LIGHT FOG EXPECTED OVERNIGHT GIVEN WHAT OCCURRED LAST NIGHT AND STRONGER WINDS TONIGHT...THUS ONLY BARELY HINTED AT FOG IN THE TAFS. ALSO MENTIONED VCSH AT FOD LATE IN THE PERIOD...BUT KEPT ANY MENTION OUT OF DSM AND OTHERS. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ZOGG LONG TERM...REV AVIATION...CURTIS  FXUS63 KDMX 102021 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 321 PM CDT FRI JUL 10 2015 .SHORT TERM /TONIGHT/... ISSUED AT 321 PM CDT FRI JUL 10 2015 PRECIPITATION TRENDS WILL BE MAIN FORECAST CONCERN FOR THE PERIOD. HIGH RES MODELS HAVE DONE A GOOD JOB WITH ONGOING PRECIPITATION ACROSS THE WEST AND HAVE TRENDED TOWARDS THEM FOR EARLY IN THE FORECAST PERIOD. WEAK CAP NOTED ACROSS SOUTHWESTERN IOWA HAS HELD AND ALLOWED FOR PRECIPITATION TO DIMINISH ACROSS THE AREA. HOWEVER...SUFFICIENT FORCING FOR STORMS TO CONTINUE TO EXPAND IN KANSAS...AND MAY SEE THUNDERSTORMS IN THE FAR SOUTHWEST IN THE LATE AFTERNOON HOURS. SHEAR REMAINS MINIMAL...TOUGH CAPE WILL BE HIGHER. THEREFORE CANNOT RULE OUT A SCATTERED SEVERE STORM WITH HAIL OR WIND. FOCUS THEN BECOMES PRECIPITATION CHANCES IN THE OVERNIGHT HOURS. AS LOW PUSHES EAST BAND OF FORCING WILL BEING TO LIFT INTO SOUTHERN IOWA AND CONTINUE LIFTING ACROSS THE STATE THROUGH THE OVERNIGHT. HOWEVER...MODELS HAVE CONTINUED TO SLOW PROGRESSION AND HAVE TRENDED THIS WAY AS WELL. IN ADDITION...EXPECT MCS DEVELOPMENT ACROSS NE CLOSER TO LOW...WHICH WILL ALSO PUSH EAST OVERNIGHT. THEREFORE...EXPECT BEST PRECIPITATION CHANCES NEAR/AFTER 06Z. GENERALLY EXPECT PRECIPITATION CHANCES TO BE MAXIMIZED IN THE SOUTH AND WEST...THOUGH WILL BE WIDESPREAD ENOUGH TO WARRANT MENTION ACROSS THE AREA OVERNIGHT. CONCERN WILL BE WITH HEAVY RAIN. GOOD WARM CLOUD DEPTHS...ESPECIALLY IN THE SOUTH...AND PWAT VALUES JUST UNDER 2 INCHES WILL ALLOW FOR EFFICIENT RAINFALL RATES...AND COULD SEE HEAVY RAINFALL TOTALS. OPTING TO NOT ISSUE FLASH FLOOD HEADLINES ATTM DUE TO RELATIVELY DRY WEEK...WITH FFG VALUES GENERALLY 2 INCHES/HOUR OR HIGHER...AND CROP PROGRESS...DO NOT EXPECT WIDESPREAD FLOODING ISSUES THOUGH MAY SEE A LOCALIZED HAZARD. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 321 PM CDT FRI JUL 10 2015 BROAD UPPER RIDGING WILL BE IN PLACE THROUGHOUT THE PERIOD...WITH IT BEING MORE AMPLIFIED INITIALLY THEN BECOMING FLATTER TOWARD NEXT WEEK. IMPULSES WILL CONTINUE TO TOP THE UPPER LEVEL RIDGE AND PUSH THROUGH THE CWA BRINGING INTERMITTENT CHANCES OF THUNDERSTORMS TO THE STATE THROUGH MUCH OF THE PERIOD. INITIALLY WILL HAVE A FRONTAL BOUNDARY LIFT THROUGH THE CWA...WITH EXPECTED LINGERING ACTIVITY ONGOING EARLY SATURDAY MORNING. PARAMETERS STILL LEANING MORE TOWARD A HEAVY RAIN THREAT WITH DEEP WARM CLOUD DEPTHS AND PWATS CLOSE TO 1.8 TO 2 INCHES. THERMAL RIDGE WILL BUILD INTO THE CWA SATURDAY INTO SUNDAY...WITH SOUTHWESTERLY FLOW ALOFT. ADDITIONALLY THETA-E ADVECTION WITH LOW LEVEL MOISTURE INCREASING AS WELL. ADDITIONAL ACTIVITY IS POSSIBLE SATURDAY NIGHT INTO EARLY SUNDAY...WITH EXACT PLACEMENT SOMEWHAT SUSPECT AS TO HOW FAR THE BOUNDARY PUSHES NORTHEAST SATURDAY. NAM REMAINS MOST AGGRESSIVE SHOVING A FEW COMPLEXES FROM NORTH TO SOUTH ACROSS THE AREA OVERNIGHT WHICH SEEMS SOMEWHAT OVERDONE. NAM ALSO TRIES TO PUSH ANOTHER MCS ACROSS THE NORTH SUNDAY NIGHT. AGAIN THESE SCENARIOS ALL REMAIN LIKELY...ALTHOUGH PLACEMENT COULD WAIVER GIVEN WHERE OUTFLOW BOUNDARIES SET UP EACH DAY. WEAK COOL FRONT TO PUSH THROUGH SUNDAY NIGHT INTO MONDAY...WITH MORE NORTHWESTERLY FLOW EXPECTED MONDAY BEFORE THE RIDGE BUILDS BACK INTO ACROSS THE AREA TOWARD MID-WEEK. OTHER MAIN ISSUE BESIDES PRECIP THROUGH THE WEEKEND INTO EARLY NEXT WEEK WILL BE THE HEAT. WITH THE THERMAL RIDGE BUILDING IN...H85 TEMPS CLIMB INTO THE MID 20S CELSIUS WITH SOUTHWESTERLY TO WESTERLY FLOW ALOFT. DEWPOINTS PUSH INTO THE 70S WITH MAX TEMPS IN THE 90S. THIS WILL PUSH HEAT INDICES INTO THE 100 TO 105 RANGE ACROSS PORTIONS OF THE CWA SUNDAY AND 105-110 POSSIBLY MONDAY. && .AVIATION...10/18Z ISSUED AT 1248 PM CDT FRI JUL 10 2015 BOUNDARY WILL BRING CHANCES FOR TSRA TO SITES OVERNIGHT...GENERALLY BETWEEN 06Z-12Z. MVFR OR LOWER VISIBILITIES AND CEILINGS WILL BE POSSIBLE WITH TSRA. SYSTEM WILL PUSH EAST BEYOND 12Z...WITH CONDITIONS IMPROVING...THOUGH MVFR OR LOWER CEILINGS MAY LINGER THROUGH END OF PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...AWB LONG TERM...BEERENDS AVIATION...AWB  FXUS63 KDMX 110842 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 342 AM CDT SAT JUL 11 2015 .SHORT TERM /TODAY/... ISSUED AT 337 AM CDT SAT JUL 11 2015 FORECAST CHALLENGES FOR THE SHORT TERM PERIOD OF THE FORECAST WILL BE POPS AND THEIR PLACEMENT. SHRA/TSRA IS BLOSSOMING ACROSS THE SWRN CWA ATTM...IN AN AREA OF ISENTROPIC LIFT OWING TO WAA ALONG WITH RELATIVELY WEAK LLJ. THIS CONVECTION STRETCHES WEST-NORTHWESTWARD TO EASTERN NEBRASKA WHERE IT MEETS AN EASTWARD-MOVING ELEVATED MCS...BEING FORCED BY AN EASTWARD- ADVANCING SHORTWAVE AS WELL AS FED BY NORTH EXTENT OF LLJ. EXPECT THE CONVECTION TO CONTINUE DEVELOPING AND EXPANDING TOWARD SUNRISE AS MOISTURE TRANSPORT AND FORCING PERSIST. ANY RAINFALL WILL BE LOCALLY HEAVY GIVEN THE RELATIVELY HIGH PWATS OF AROUND 2 INCHES ALONG WITH WARM CLOUD DEPTHS OF 4 KM OR MORE. CONVECTION WILL SLIDE EASTWARD DURING THE DAY IN CONJUNCTION WITH BEST FORCING AND PERSISTING RELATIVELY WEAK LLJ. 700 MB CAP BUILDS IN FROM THE WEST DURING THE DAY HELPING TO LIMIT THE WESTWARD EXTENT OF ORGANIZED PCPN. EVEN SO...AIRMASS WILL BE QUITE UNSTABLE UNDERNEATH THE STRENGTHENING CAP...WITH MUCAPES AS HIGH AS 2500 TO 3000 J/KG BY LATE AFTERNOON. THUS THERE MAY BE SOME POCKETS OF SHRA/TSRA IN LOCAL WEAKNESSES OF THE CAP...AND HAVE CARRIED SLIGHT CHANCE POPS ACROSS ALL BUT THE FAR WESTERN CWA FOR THAT REASON. WOULD NOT EXPECT LARGE COVERAGE OF ANY CONVECTION THAT DEVELOPS GIVEN THE STRENGTHENING CAP AS WELL AS LACK OF COHERENT FORCING ASIDE FROM THE SURFACE INSTABILITY. HIGH-RES MODELS SEEM TO SUPPORT THIS IDEA. ANY STORMS THAT DO MANAGE TO DEVELOP THIS AFTERNOON WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL...AS WELL AS LOCALLY STRONG WINDS AND POSSIBLE HAIL. && .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 337 AM CDT SAT JUL 11 2015 PRETTY TYPICAL SUMMER PATTERN THROUGH THE PERIOD WITH IA BETWEEN WESTERLIES AND SRN PLAINS RIDGE. THIS LEAVES MAINLY SUBTLE CONVECTIVE TRENDS ONE OF THE PRIMARY CONCERNS...WITH THE OTHER BEING BUILDING HEAT INTO MONDAY. CONFIDENCE IS CERTAINLY NOT HIGH INITIALLY WITH CAP COMING INTO PLAY AND ANY CONVECTIVE FOCUS SOMEWHAT NEBULOUS. NAM AND GFS BOTH BUILD STRONG INSTABILITY INTO IA WITH 4000 PLUS J/KG MLCAPES. ASSOCIATED MLCINHS ARE ONLY SUFFICIENTLY REDUCED IN SMALL POCKETS HOWEVER...SO WITH WEAK LOW LEVEL CONVERGENCE DO NOT EXPECTED ANYTHING WIDESPREAD TO BE ONGOING IN THE EVENING AT ONSET. HOWEVER MODELS ARE ALL FAIRLY SIMILAR BRINING CURRENT FAR WRN CO SHORT WAVE...WHICH CONTINUES TO GENERATE CONVECTION AT THIS HOUR...INTO THE MO VALLEY DURING THE EVENING. AREAL COVERAGE MAY NOT BE WIDESPREAD...BUT WOULD EXPECT AT LEAST A FEW SMALL CONVECTIVE CLUSTERS TO BE GENERATED...AND THEN FADE WEST TO EAST INTO THE NIGHT. DEGREE OF INSTABILITY MAY SUPPORT A FEW PULSE STORMS...BUT LACK OF DEEP SHEAR SHOULD LIMIT POTENTIAL. HEAT CONCERN WILL THEN INCREASE SUN INTO MON. LOOKING AT FORECAST SOUNDINGS...THE GFS SEEMS OVERLY MIXED AND DRY BASED ON RECENT ECMWF RUNS. NAM THERMAL PROFILE MAY BE MORE REALISTIC...BUT LIKELY A TAD OVERDONE ON BOUNDARY LAYER MOISTURE/DEWPOINTS. SUBJECTIVE MODIFICATION AND BLEND OF THOSE SOUNDINGS SUPPORTS HIGHS NEAR NAM/GFS MOS CONSENSUS SUN...AND AT OR JUST BELOW THE WARMER GFS MOS VALUES MON. RAW GFS BUFR SOUNDINGS SUGGEST 100 IN SPOTS MON...BUT THAT SEEMS OVERDONE. HEAT INDICES LOOK TO EXCEED 100F IN MANY SPOTS SUN...BUT NOT QUITE TO ADVISORY CRITERIA /105F/. THE HEAT MON WILL BE MORE PROBLEMATIC WITH HEAT INDICES TO 105F OR MORE SOUTH AND EAST. HEADLINE MAY EVENTUALLY BE NEEDED DEPENDING ON CONVECTIVE TRENDS. SUN NIGHT MAY BE ONE OF THE TWO MORE LIKELY PERIODS FOR MCS DEVELOPMENT WITH SHORT WAVE CROSSING THE NRN PLAINS INTO THE UPPER MS VALLEY INTO THE NIGHT. THETA-E ADVECTION SEEMS TO BE MAXIMIZED INTO NERN IA...ESPECIALLY IN THE GFS...SO HAVE HIGHER END CHANCES POPS IN THIS AREA. LOW CONFIDENCE IN PEAK HEATING CONTINUES INTO MON. INSTABILITY WILL AGAIN BE EXTREME WITH ONLY PATCHY CINH REDUCTIONS. LARGE SCALE LIFT IS LACKING WITH SUBTLE SUBSIDENCE ON THE BACK SIDE OF AFOREMENTIONED SHORT WAVE. HOWEVER THE PASSAGE OF A SURFACE TROUGH DURING THE AFTERNOON AND EVENING MAY BE SUFFICIENT TO AID INITIATION. FLOW IS WEAK AND CONFIDENCE NOT HIGH...SO NOTHING MORE THAN LOW END POPS NORTH AND EAST ON THE EDGE OF THE THERMAL RIDGE. IF ANYTHING DOES FORM SEVERE POTENTIAL WOULD BE HIGHER HOWEVER WITH INCREASING MID LEVEL WINDS AND RESULTANT DEEP SHEAR ACCOMPANYING SHORT WAVE. THE HEAVY RAIN POTENTIAL IS SEASONALLY BUT NOT ANOMALOUSLY HIGH...AND WIDESPREAD MCS DEVELOPMENT IS NOT ANTICIPATED SO NO FLASH FLOOD HEADLINES FOR NOW. IA HAS HAD A CHANCE TO DRY OUT RECENTLY AND WE ARE AT OUR CLIMATOLOGICAL INSOLATION AND CROP DRAWING PEAK WINDOW. SHOULD SEE A FEW DRY PERIODS INTO TUE WITH TEMPS AND HUMIDITIES BACK TO LESS EXTREME VALUES. NEXT APPRECIABLE PRECIP WINDOW WILL BE SOMEWHERE AROUND WED OR THU WITH 00Z ECMWF AND GFS BOTH SHOWING DECENT SHORT WAVE AND LARGE SCALE FORCING WITH H85/H7 BAROCLINIC ZONE PUSHING SW-NE THROUGH THE AREA. MODEL CONSENSUS DIMINISHES INTO FRI BUT FLOW REMAINS ACTIVE ENOUGH THAT LOW END POPS ARE STILL WARRANTED THROUGH THE END OF THE EXTENDED. && .AVIATION...11/06Z ISSUED AT 1200 AM CDT SAT JUL 11 2015 AN UPPER LEVEL DISTURBANCE IS STILL PROGGED TO SHIFT ACROSS THE CENTRAL IOWA TONIGHT AS A WARM FRONT LIFTS ACROSS THE FORECAST AREA. THE TREND HAS BEEN FOR THE FRONT TO BE SLOWER THAN MODELS SUGGEST THEREFORE START OF PRECIP HAS BEEN LATER AND QPF HAS BEEN DIMINISHED SOME. LOW LEVEL CLOUDS HAVE BEEN MVFR AT LOCATIONS SO LOCAL MVFR CONDITIONS ARE LIKELY AND WILL BECOME MORE WIDESPREAD IN TSRA. LOCATION OF FRONTAL BOUNDARY WILL BE KEY TO STORMS AFT 18Z AS THE NEXT SHORTWAVE DROPS SOUTHEAST ACROSS THE FORECAST AREA. STORMS SHOULD DEVELOP MAINLY EAST OF TAF LOCATIONS BUT KALO AND KOTM MAY SEE STORMS BETWEEN 21Z AND 03Z. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...ZOGG LONG TERM...SMALL AVIATION...FAB  FXUS63 KDMX 122042 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 342 PM CDT SUN JUL 12 2015 .SHORT TERM /TONIGHT/... ISSUED AT 337 PM CDT SUN JUL 12 2015 MAIN ISSUE OVERNIGHT IS THE THREAT OF THUNDERSTORMS...SOME OF WHICH COULD BE SEVERE. FRONTAL BOUNDARY ALIGNS ROUGHLY WITH PERSISTENT STRATUS FIELD...AND DEWPOINTS HAVE POOLED JUST UPSTREAM FROM THIS BOUNDARY. CLOSEST ACTIVE CONVECTION IS STILL IN NORTHERN MINNESOTA...BUT SHORT WAVE TROF IS APPROACHING SOUTH DAKOTA MINNESOTA LINE AT THIS TIME AND SHOULD ENHANCE CONVECTIVE COVERAGE. MOST CONVECTIVE ALLOWING MODELS KEEP MAIN MCS EAST OF THIS FORECAST AREA BUT THE HRRR HAS BEEN INDICATING A POSSIBILITY OF ISOLATED STORMS ALONG THE SOUTHWESTERN END OF THE ADVANCING CONVECTION. IF THESE FORM IT WILL QUICKLY GO SEVERE WITH LARGE HAIL AND WIND THE PRIMARY THREAT. MAIN MCS SHOULD MOVE PAST THE AREA BY 12 UTC AND FRONT DOESNT REALLY MOVE MUCH BY THEN. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 337 PM CDT SUN JUL 12 2015 HOT AND HUMID CONDITIONS CONTINUE ON MONDAY OVER THE SOUTHERN HALF OF THE FORECAST AREA AND RAIN CHANCES WEDNESDAY NIGHT INTO THURSDAY WERE THE MAIN ISSUES DURING THE EXTENDED PERIOD. LEANED TOWARD A NAM12/ECMWF BLEND FOR TEMPS MONDAY INTO TUESDAY AND CLOSER TO THE ECMWF/GFS THROUGH NEXT WEEKEND. MONDAY AND TUESDAY...TWEAKED MAX TEMPS UP SLIGHTLY ALONG WITH DEW POINTS OVER CENTRAL TO SOUTHEAST PORTIONS OF THE FORECAST AREA AS THE COLD FRONT LOOKS TO BE A BIT SLOWER IN PROGRESSING ACROSS THE STATE UNTIL LATER IN THE AFTERNOON. NOT A SIGNIFICANT AMOUNT OF FORCING WITH THE FRONT...BUT ENOUGH THERE TO KEEP SLIGHT POPS GOING IN THE AFTERNOON ACROSS THE EAST. SURFACE HIGH PRESSURE AND UPPER LEVEL RIDGE HOLD IN PLACE ON TUESDAY WILL PROVIDE A MUCH LESS HUMID AIR MASS OVER THE STATE. SOME MIXING LOOKS TO PUSH TEMPS BACK INTO THE LOWER 90S OVER THE CENTRAL TO SOUTH TUESDAY...BUT WITH LESS HUMIDITY NOT CONCERNED WITH EXTREME HEAT INDEX VALUES. WEDNESDAY INTO THURSDAY...LARGE UPPER LEVEL RIDGE PERSISTS ACROSS THE CENTRAL U.S. THROUGH THE END OF THE WEEK. THE STRONGEST SHORTWAVE AND BEST CONFIDENCE IN ANY PRECIPITATION DURING THE EXTENDED IS WEDNESDAY NIGHT INTO THURSDAY. ECMWF AND GFS ARE IN SOMEWHAT GOOD AGREEMENT WRT TO PRECIP CHANCES DURING THE AFOREMENTIONED TIME FRAME. ANOTHER HEAVY RAIN EVENT LOOKS POSSIBLE WITH WARM LAYER CLOUD DEPTHS AS HIGH AS 4000 METERS AND PRECIPITABLE WATER NEAR 2 INCHES. LOWER CONFIDENCE WITH SEVERE POTENTIAL WITH NO SIGNIFICANT AMOUNT OF INSTABILITY AND SHEAR PRESENT. FRIDAY THROUGH SUNDAY...TRENDED DRIER FRIDAY INTO SATURDAY AS EXTENDED MODELS DO NOT HAVE A GOOD HANDLE OF TIMING AND LOCATION OF WHEN AND IF ANY SHORTWAVE RIDING THE UPPER LEVEL RIDGE WILL AFFECT THE FORECAST AREA. THUS...WENT WITH LESSER POPS LATE IN THE PERIOD. PLUS WITH THE DRIER FORECAST...TRENDED WARMER FOR HIGHS OVER THE WEEKEND AS THINKING LESS CLOUD COVER AND MODELS AT LEAST HINTING ON STRONGER WAA. && .AVIATION...12/18Z ISSUED AT 1231 PM CDT SUN JUL 12 2015 LINGERING STRATUS AFFECTING KMCW AND KALO WILL DISSIPATE TO VFR CONDITIONS WITHIN THE HOUR. LATER IN THE PERIOD INTRODUCED MENTION OF VCTS TO KALO KMCW AND KOTM WITH MAIN AREA OF CONVECTION EXPECTED TO REMAIN EAST OF TERMINALS. && .DMX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ADAIR-ADAMS- APPANOOSE-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD- DALLAS-DAVIS-DECATUR-EMMET-GREENE-GUTHRIE-HUMBOLDT-JASPER- KOSSUTH-LUCAS-MADISON-MAHASKA-MARION-MONROE-PALO ALTO-POCAHONTAS- POLK-RINGGOLD-SAC-STORY-TAYLOR-UNION-WAPELLO-WARREN-WAYNE- WEBSTER. HEAT ADVISORY FROM NOON TO 7 PM CDT MONDAY FOR ADAIR-ADAMS- APPANOOSE-AUDUBON-BOONE-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS- DAVIS-DECATUR-GREENE-GUTHRIE-JASPER-LUCAS-MADISON-MAHASKA-MARION- MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION- WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...HARDING LONG TERM...PODRAZIK AVIATION...HARDING  FXUS63 KDMX 130917 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 417 AM CDT MON JUL 13 2015 .SHORT TERM /TODAY/... ISSUED AT 414 AM CDT MON JUL 13 2015 MAIN FOCUS TODAY ON THE HEAT AND STORM CHANCES. STRONGER STORMS OFF TO THE NORTHEAST SHOULD REMAIN EAST OF THE AREA EARLY THIS MORNING WITH A SMALL COMPLEX OF ELEVATED STORMS ACROSS SE SD AND NE NE. THESE HAVE ALL BEEN WEAKENING...BUT MAY PUSH FAR ENOUGH EAST TO IMPACT THE FAR NW/WC CWA THIS MORNING. OTHERWISE WEAK COOL FRONT/DRYLINE FEATURE TO PUSH THROUGH THE CWA TODAY...WITH EXPECTED PLACEMENT FROM ERN IOWA INTO NW MO BY AROUND 00Z THIS EVENING. COULD SEE SOME THUNDERSTORM DEVELOPMENT ALONG THIS BOUNDARY BY LATE AFTERNOON...HOWEVER THE BEST CHANCES WILL BE EAST OF THE CWA SO STUCK WITH SMALL POPS. MOISTURE TO POOL AHEAD OF THE BOUNDARY...WITH ANOTHER HOT AND HUMID DAY EXPECTED ESPECIALLY ACROSS THE SOUTHERN HALF OF IOWA. DEWPOINTS IN THE MID TO UPPER 70S TO CONTINUE THROUGH THE DAY POSSIBLY EVEN NEAR 80 IN THE FAR SOUTH. H85 TEMPS IN THE MID 20S CELSIUS DROPPING TO THE LOWER 20S CELSIUS BEHIND THE FRONT. THIS SHOULD YIELD MAX TEMPS A FEW DEGREES WARMER THAN READINGS FROM SUNDAY...WITH HIGHS IN THE MID 90S ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHTLY COOLER IN THE LOWER 90S ACROSS THE NORTH. WITH THE HEAT AND HUMIDITY...HEAT INDICES WILL PUSH INTO THE 105 RANGE AGAIN ACROSS MUCH OF CENTRAL IOWA AND AROUND 110-115 IN THE FAR SOUTHEASTERN CWA. THEREFORE WILL UPGRADE A PORTION OF THE HEAT ADVISORY TO A HEAT WARNING FOR THIS AFTERNOON. OTHERWISE WILL KEEP THE HEAT ADVISORY AS IS FOR THE AFTERNOON. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 414 AM CDT MON JUL 13 2015 LESS CONCERNS VERSUS LAST FEW DAYS WITH TEMP/DEWPOINT TRENDS AND MID WEEK PRECIP EVENT ONLY REAL SENSIBLE WEATHER ITEMS OF NOTE. AT ONSET FOCUS WAS ON WHETHER DEPARTING TROUGH AND ASSOCIATED CONVERGENCE WOULD BE CLOSE ENOUGH FOR CONVECTION TO EFFECT ERN FORECAST AREA...HOWEVER NEARLY ALL OF THE 00Z DETERMINISTIC AND ENSEMBLE SUITE HAS THIS ALONG THE MS RIVER BY 00Z. THE ONLY OUTLIER SEEMS TO BE THE SLOWER 06Z NAM...BUT EVEN THAT SEEMS FAR ENOUGH EAST TO KEEP ANYTHING OUT OF THE AREA BY EARLY EVENING. SUBSIDENCE WILL FOLLOW INTO TUE AS CYCLONIC LOW LEVEL FLOW SETTLES IN SLIGHTLY LOWERING TEMPS AND DEWPOINTS. AIRMASS CHANGE IS NOT APPRECIABLE...BUT SUFFICIENT TO DROP HEAT INDICES OUT OF ADVISORY CRITERIA. ALTHOUGH POTENTIAL IS LOW...THERE IS SOME CONCERN OF PEAK HEATING CONVECTION DEVELOPING ALONG WEAK 0-1KM MOISTURE CONVERGENCE AXIS ACROSS FAR ERN PORTIONS. FEEL POTENTIAL IS NOT GREAT ENOUGH TO MENTION AT THE MOMENT...BUT SOMETHING TO KEEP AN EYE ON. CURRENT ROCKIES RIDGE WILL THEN BUILD EASTWARD INTO IA BY WED KEEPING FAIR WEATHER IN THE FORECAST INTO MIDWEEK. ECMWF AND GFS HAVE BEEN CONSISTENT WITH SHORT WAVE IMMEDIATELY FOLLOWING THIS RIDGE AXIS HOWEVER. TIMING IS STILL SOMEWHAT OF A CONCERN...WITH GFS STILL ON THE FASTER END...BUT CONFIDENCE IS INCREASING FOR A PERIOD OF CONVECTION SOMEWHERE FROM LATE WED INTO THU. PRIMARY CONCERN WITH THIS EVENT WOULD BE HEAVY RAIN MORE THAN SEVERE WITH DEEP SHEAR FAIRLY WEAK AND INSTABILITY NOT EXTREME. PWATS INCREASE TO 2 INCHES...WARM CLOUD DEPTHS 4-4.5KM WITH FAIRLY STRONG LOW LEVEL MOISTURE TRANSPORT. CORFIDI VECTORS AND MEAN WINDS ARE WEAK AS WELL SO SLOW MOVING EFFICIENT RAINFALL PRODUCTION SEEMS LIKELY AND WILL NEED TO BE MONITORED. THINGS SHOULD DRY OUT INTO FRI WITH LITTLE IN THE WAY OF SYNOPTIC LIFT OR LOW LEVEL FOCUS AS UPPER RIDGE BUILDS INTO IA WHICH WILL INCREASE HEAT AND HUMIDITY SOMEWHAT. POPS WILL RETURN LATE IN THE WEEKEND WITH THE PASSAGE OF THE NRN STREAM WAVE. ITS TIMING AND STRENGTH IS UNCERTAIN FOR NOW HOWEVER WITH ECMWF FASTER AND MUCH STRONGER. && .AVIATION...13/06Z ISSUED AT 1132 PM CDT SUN JUL 12 2015 MAINLY VFR CONDITIONS EXPECTED ACROSS TAF LOCATIONS BUT THERE WILL BE PATCHY FOG AND ISOLD TSRA POSSIBLE INVOF KMCW AND KALO TAF SITES BTWN 09Z AND 11Z. && .DMX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR ADAIR- ADAMS-AUDUBON-BOONE-CARROLL-CASS-CRAWFORD-DALLAS-GREENE-GUTHRIE- JASPER-MADISON-MARSHALL-POLK-POWESHIEK-RINGGOLD-STORY-TAMA- TAYLOR-UNION. EXCESSIVE HEAT WARNING FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR APPANOOSE-CLARKE-DAVIS-DECATUR-LUCAS-MAHASKA-MARION-MONROE- WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...BEERENDS LONG TERM...SMALL AVIATION...FAB  FXUS63 KDMX 032126 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 326 PM CST THU DEC 3 2015 .SHORT TERM /TONIGHT/... ISSUED AT 324 PM CST THU DEC 3 2015 CLEAR SKIES AND QUIET WEATHER WILL CONTINUE THE REMAINDER OF TODAY AND WELL BEYOND THE SHORT TERM PERIOD. THE MAIN PLAYER IN THE SHORT TERM WILL BE THE HIGH PRESSURE SOUTH OF THE STATE MOVING EASTWARD. AS A RESULT...WINDS MAY GO CALM PERIODICALLY IN THE EVENING...ESPECIALLY ACROSS THE SOUTH...PRIOR TO BECOMING SOUTHERLY AND SOUTHWESTERLY. FOR TONIGHT GUIDANCE SEEMS A BIT WARM WITH TEMPERATURES GIVEN WHAT HAPPENED TO SITES UNDER CLEAR SKIES THIS MORNING. WHILE THE SOUTHERLY/SOUTHWEST WINDS WILL SURELY KEEP TEMPS A BIT WARMER TONIGHT...I HAVE STILL DROPPED TEMPS A COUPLE OF DEGREES OVER THE SNOW PACK IN NORTHWEST IOWA IN ANTICIPATION THAT EVEN A SHORT WINDOW OF LIGHT TO CALM WINDS WOULD RESULT IN CRASHING TEMPS. THERE IS ALSO OPPORTUNITY FOR FOG WITH THE RELATIVELY LIGHT FLOW...CLEAR SKIES...AND LOW LEVEL MOISTURE. THE MELTING SNOW PACK AND AREAS THAT CAN ACHIEVE CALM/NEAR-CALM WINDS TO LIMIT MIXING IN THE AMPLE DRY AIR ABOVE THE SURFACE WILL BE PRIME CANDIDATES. HI-RES GUIDANCE DOES NOT HAVE A GREAT HANDLE ON EXTENT AND SEVERITY...BUT SUGGESTS THE POSSIBILITY OF SOME PATCHY DENSE FOG. HAVE ENTERED PATCHY FOG ACROSS THE CWA FROM 3Z AND THROUGH THE OVERNIGHT WITHOUT DENSE MENTION FOR THE TIME BEING. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 324 PM CST THU DEC 3 2015 HAZARDOUS WEATHER THREATS ARE GENERALLY LOW IN THIS LONG TERM FCST PERIOD. WARMER TEMPERATURES WILL BE THE MAIN SENSIBLE WEATHER IMPACTS OVER THE NEXT SEVEN DAYS. FRIDAY INTO SATURDAY... AFTER SPENDING MUCH OF THE PVS WEEK BELOW ZERO...850MB TEMPS WILL BE WARMING TO THE +6C RANGE FOR FRIDAY...WHICH IS 1 TO 2 STD DEV ABOVE NORMAL FOR THIS TIME OF YEAR. WITH HIGH PRESSURE OVER THE OHIO VALLEY REGION AND A SHORTWAVE NEAR THE OKLAHOMA PANHANDLE...IOWA WILL BE IN SSW FLOW...AIDING WAA. WITH NO DRIVERS FOR CLOUD COVER...EXPECT FRIDAY TO BE ANOTHER DAY OF BLUE SKIES...THOUGH FROM 12 TO ABOUT 14Z FRI...THERE MAY BE SOME PATCHY LINGERING FOG PRESENT BEFORE DAYTIME HEATING TAKES OVER. MODELS UNDERDOING SFC MOISTURE FROM SOURCE REGION OF NORTHERN MO/EASTERN KS. THURSDAY MORNING NOHRSC SNOW DEPTH ANALYSIS SHOWS BTX 4 AND 8 INCHES IN THE NW PORTION OF THE DMX CWA. THIS SNOW PACK WILL HELP KEEP TEMPERATURES DOWN A FEW DEGREES RELATIVE TO THE REST OF THE CWA. BUT AS THIS SNOW MELTS...THE TEMPERATURE DIFFERENCE WILL WANE. SATURDAY INTO SUNDAY... SATURDAY MORNING INTO THE AFTERNOON SHOULD FEATURE MINIMAL SENSIBLE WEATHER CHANGES FROM FRIDAY...APART FROM A GRADUAL INCREASE IN UPPER LEVEL CLOUDS. OVERNIGHT INTO SUNDAY MORNING...THE AFOREMENTIONED SHORTWAVE WILL MAKE ITS WAY INTO IOWA. THE GFS SEEMS TO BE A SLOW OUTLIER WITH THIS SYSTEM. THE 12Z EURO IS THE FASTEST...WITH THE 12Z NAM AND THE 12Z GEM IN BTX THE GFS AND EURO...BUT LEANING TOWARDS THE NAM. THE 12Z GFS ALSO MAKES THIS MORE OF A PRONOUNCED 500MB CLOSED OFF LOW AND STALLS IT OVER THE MO/IL BORDER INTO MONDAY...WHICH NONE OF THE OTHER MODELS SEEM TO DO. GIVEN THE STRONG RIDGING IN THE WAKE OF THIS LOW AND THE FACT THAT THE LOW IS NOT ALL THAT STRONG...EURO/GEM SOLN SEEMS MORE REASONABLE THAN GFS. THUS HAVE STRONGLY DISCOUNTED THE GFS HANDLING OF THIS OVERALL SYSTEM. SUNDAY AM FCST SOUNDINGS ACROSS DMX CWA KEEP PROFILE GENERALLY ABOVE ZERO AT TIME OF PRECIP. THUS HAVE KEEP PRECIP IN ALL RAIN. REGARDLESS OF WHETHER UNEXPECTED COOLING ARRIVES...GIVEN LIGHT NATURE OF PRECIP...CHANCE OF SIGNIFICANT IMPACTS ESSENTIALLY NIL. MONDAY THROUGH WEDNESDAY... WX PATTERN LOOKS QUIET OVERALL. 850 MB TEMPS HOVER IN THE +4 TO +6 RANGE...WHICH IS A SOLID +1 TO +2 STD DEV. GIVEN SUNSHINE AND THAT SNOW COVER SHOULD BE GONE...KEPT TEMPS ON WARMER SIDE OF GUIDANCE. WEDNESDAY AND BEYOND... MODELS ARE TRYING TO PUSH ANOTHER WEAK WAVE THROUGH IOWA WEDNESDAY. THIS SYSTEM LOOKS VERY SIMILAR TO THE SYSTEM EXPECTED SUNDAY THE 6TH...EXCEPT WITH LESS MOISTURE AND LESS FORCING TO WORK WITH. GIVEN THE AMOUNT OF DRY AIR IN THE LOW TO MID LEVELS...PLUS SHALLOW SATURATED CLOUD DEPTHS...DIFFICULT TO INTRODUCE ANYTHING BEYOND DRIZZLE. GIVEN ITS A DAY 6 FCST...HAVE LEFT POPS OUT OF FCST FOR NOW UNTIL CONFIDENCE CAN INCREASE. LONG RANGE MODELS TRYING TO SUGGEST SOME SORT OF A TROUGH PUSHING THROUGH TOWARDS THE END OF NEXT WEEK INTO THE WEEKEND. NO STRONG SIGNALS AT THIS POINT IN ANY DIRECTION. AS OF NOW...THIS APPEARS TO BE OUR NEXT WINDOW OF PRECIP AFTER SUNDAY THE 6TH...SO WE HAVE A DRY WEEK AHEAD. && .AVIATION...03/18Z ISSUED AT 1126 AM CST THU DEC 3 2015 IFR OUT OF ALL BUT ALO AND OTM...AND SHOULD EXIT ALO BY OR SHORTLY AFTER 18Z AND OTM BY AROUND 20Z. VFR EXPECTED AFTERWARDS WITH POTENTIAL FOR BR/FG OVERNIGHT WITH CALMER WINDS...SOME MOISTURE RETURN AND HI- RES MODELS HITTING ON ITS DEVELOPMENT WITH POTENTIAL TO BE DENSE. EXTENT AND SEVERITY OF BR/FG A BIT UNKNOWN...THEREFORE HAVE NOT CRASHED VSBY WITH THIS ISSUANCE. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CURTIS LONG TERM...KOTENBERG AVIATION...CURTIS  FXUS63 KDMX 050857 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 357 AM CDT SAT SEP 5 2015 .SHORT TERM /TODAY/... ISSUED AT 356 AM CDT SAT SEP 5 2015 ONGOING PRECIPITATION ACROSS WESTERN CWA WILL PERSIST THROUGH THE EARLY MORNING HOURS AS FORCING REMAINS MAXIMIZED. FORCING WILL BEGIN TO LIFT NORTH AND DIMINISH AFTER SUNRISE WITH DECREASING SUPPORT FROM LLJ...AND EXPECT PRECIPITATION TO BEGIN TO DIMINISH AS WELL. HIGH RES MODELS KEEP PRECIPITATION ACROSS NORTHERN CWA THROUGH ABOUT 18Z...AND HAVE HELD ONTO CHANCE POPS ACROSS THE AREA A BIT LONGER. OTHERWISE...EXPECT PRECIPITATION CHANCES TO REMAIN WEST OF CWA...AND HAVE LEFT FORECAST DRY THROUGH THE AFTERNOON. WILL SEE ANOTHER HOT AND HUMID DAY ACROSS THE AREA. TEMPERATURES WILL BE SIMILAR TO YESTERDAY...WITH SLIGHTLY COOLER TEMPS IN THE NORTH AND NORTHEAST WHERE CLOUDS WILL HELP KEEP TEMPERATURES DOWN. HOWEVER...WITH HUMIDITY WILL SEE HEAT INDEX VALUES ONCE AGAIN IN THE 90S...WITH WARMER READINGS IN THE SOUTH. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 356 AM CDT SAT SEP 5 2015 THUNDERSTORM CHANCES SUNDAY INTO MONDAY AND TUESDAY ARE THE PRIMARY FOCUS THROUGH THE PERIOD. THE PACIFIC NORTHWEST UPPER LOW HAS BEEN TRENDING FURTHER NORTH AS IT EJECTS OUT TO THE EAST/NORTHEAST. THE IMPACT OF THIS IS THE SUBTROPICAL HIGH BUBBLE WILL NOT BE SUPPRESSED AS FAR SOUTH AS PREVIOUSLY EXPECTED BY MONDAY WITH THE SFC BOUNDARY LIKELY TO STALL OVER CENTRAL TO SOUTHERN IOWA. THE BOUNDARY WILL LIFT BACK NORTH A BIT ON MONDAY BEFORE A COLD FRONT MOVES THROUGH MONDAY NIGHT INTO TUESDAY. THE TROPICAL CONNECTION HAS BEEN STRENGTHENING THIS MORNING WITH MID LEVEL MOISTURE ADVECTION SURGING NORTH IN THE INCREASING MONSOONAL FLOW. THE INITIAL SURGE OF THIS MOISTURE WILL PASS JUST NORTHWEST OF THE FORECAST AREA LATE THIS AFTERNOON AND TONIGHT. THIS FLOW WILL VEER SUNDAY INTO SUNDAY NIGHT AND BECOME MORE FOCUSED INTO CENTRAL IOWA. IN ADDITION...LOWER LEVEL GULF MOISTURE WILL BE STREAMING NORTH INTO THE STATE DURING THIS PERIOD AND THE COMBINATION OF THE PACIFIC AND GULF MOISTURE WILL PUSH PWAT VALUES IN EXCESS OF 2 INCHES LATE SUNDAY INTO MONDAY. THE PWATS IN CONJUNCTION WITH DEEP WARM CLOUD DEPTHS AND STORM MOTIONS OF 25 KTS OR LESS WILL BE FAVORABLE FOR EFFICIENT RAIN PRODUCING STORMS. STORM MOTIONS NEARLY PARALLEL TO THE BOUNDARY WILL LEAD TO POTENTIAL TRAINING STORMS. THE GREATEST THREAT WITH THIS SYSTEM IS SWITCHING TO A HEAVY TO VERY HEAVY RAIN THREAT. SEVERE WEATHER IS ALSO POSSIBLE ESPECIALLY WITH PEAK HEATING STORMS AS MLCAPES OF 2500 J/KG OR GREATER DEVELOP. A FEW SUPERCELLS MAY DEVELOP WITH THE INITIAL ACTIVITY SUNDAY AFTERNOON WITH EFFECTIVE SHEAR VALUES OF 30 TO 35 KTS. THE EFFECTIVE SRH IS NOT PROJECTED TO BE AS HIGH AS THE PREVIOUS NIGHTS GUIDANCE THUS THE PRIMARY THREATS WILL BE LARGE HAIL AND DAMAGING WIND GUSTS WITH UPPER LEVEL WIND PROFILES BECOMING UNIDIRECTIONAL. THE BOUNDARY WILL PUSH SOUTH MONDAY NIGHT THOUGH A FEW THUNDERSTORMS WILL LINGER INTO SOUTHERN IOWA ON TUESDAY. ANOTHER SYSTEM ARRIVES THURSDAY WITH ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS. THIS SYSTEM WILL DRIVE EVEN COOLER WEATHER INTO THE AREA WITH HIGHS IN THE 60S TO LOWER 70S BY FRIDAY WHICH IS A BIG SWITCH FROM THE 80S TO LOWER 90S EXPECTED ON SUNDAY. && .AVIATION...04/18Z ISSUED AT 1154 PM CDT FRI SEP 4 2015 WEAK ELEVATED CONVECTION WILL PERSIST OVER NRN SITES /KFOD/KMCW/KALO/ INTO THE EARLY MORNING HOURS BUT FAIRLY HIGH CONFIDENCE THAT THEY WILL REMAIN VFR. THERE COULD BE ANOTHER BRIEF PERIOD OF RADIATION FOG NEAR KMCW AS WELL...POSSIBLY DOWN TO IFR FOR AN HOUR OR TWO. OTHERWISE EXPECT CONTINUED VFR CONDITIONS AT KDSM/KOTM WITH MAINLY SCT/BKN MID CLOUDS AND WEAK GUSTS. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AWB LONG TERM...DONAVON AVIATION...SMALL  FXUS63 KDMX 052033 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 333 PM CDT SAT SEP 5 2015 .SHORT TERM /TONIGHT/... ISSUED AT 333 PM CDT SAT SEP 5 2015 SUBJECTIVE SFC ANALYSIS SHOWS LOW PRESSURE OVER SOUTHWEST SOUTH DAKOTA WITH WARM FRONT NOW OVER SOUTHERN MN MOVING NORTHEAST WITH TIME. FOCUS FOR ANY LINGERING SHOWERS AND THUNDERSTORMS WILL REMAIN NORTH OF THE BOUNDARY THIS AFTERNOON AND EVENING. DEW POINTS CONTINUE IN THE UPPER 60S TO LOWER 70S AND WILL REMAIN HIGH OVERNIGHT. HEAT INTO THE EARLY EVENING HOURS WILL BE THE MAIN CONCERN...WITH HEAT INDICES STILL PUSHING NEAR 90 TO 95 F THROUGH 7 PM. OTHERWISE ...AN EXCEPTIONALLY WARM NIGHT FOR EARLY SEPTEMBER WITH HUMIDITY REMAINING HIGH OVERNIGHT. WINDS TO RELAX SOMEWHAT...BUT STILL AROUND 10 MPH THROUGH EARLY MORNING. OTHERWISE...AS THE SYSTEM WEST OF US APPROACHES WESTERN IOWA BY 12Z SUNDAY THERE IS A SLIGHT CHANCE/ CHANCE FOR SHOWERS OR ISOLATED THUNDER OVER THE FAR NORTHWEST BY 12Z. OVERNIGHT MINS WILL REMAIN IN THE LOWER TO MID 70S ACROSS MUCH OF THE AREA... VERY ATYPICAL FOR EARLY SEPTEMBER AND WE MAY SEE A FEW RECORD MAX MINIMUM (RMM) TEMPERATURES TIED OR PERHAPS BROKEN BY SUNDAY MORNING. DES MOINES HAS A RMM OF 76F...WATERLOO 73F...MASON CITY 73F...AND OTTUMWA 78 F. CURRENT FORECAST MINS ARE 75/73/72/73 RESPECTIVELY. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 333 PM CDT SAT SEP 5 2015 MAIN FORECAST CONCERN WAS FOCUSED ON HEAVY RAIN AND SEVERE WEATHER POTENTIAL SUNDAY NIGHT INTO MONDAY...AND ANOTHER ROUND POSSIBLE MONDAY NIGHT INTO TUESDAY. LEANED TOWARD A BLEND OF THE NAM/ECMWF FOR SUNDAY INTO TUESDAY AND THEN TOWARDS THE ECMWF THROUGH THE REMAINDER OF THE FORECAST PACKAGE. SUNDAY INTO MONDAY...ANOTHER HOT AND HUMID DAY IN STORE FOR SUNDAY WITH MAX TEMPS RISING TO THE UPPER 80S/LOWER 90S AND WITH DEW POINTS RISING INTO THE LOWER 70S. NUDGED UP MAX TEMPS OVER MUCH OF THE AREA SUNDAY WITH SLIGHTLY BETTER MIXING AND A WARM START TO THE DAY SUNDAY MORNING. HEAT INDEX VALUES LOOK TO TOP THE 100 DEGREE MARK FOR A SHORT STINT IN THE AFTERNOON. HOWEVER...MAY SEE SOME HIGH CLOUDS ADVECT INTO CENTRAL IOWA FROM POTENTIAL CONVECTION IN EASTERN NEBRASKA/FAR WESTERN IOWA TOMORROW MORNING. LARGE UPPER LEVEL TROUGH DIGS INTO THE WESTERN UNITED STATES AND CONTINUES TO KEEP IOWA WITHIN THE SOUTHWEST FLOW ALOFT SUNDAY INTO TUESDAY. THE CENTER OF THE LOW GRADUALLY MEANDERS ACROSS SOUTHERN SASKATCHEWAN INTO MANITOBA SUNDAY NIGHT THROUGH EARLY TUESDAY. A COLD FRONT AND ASSOCIATED SURFACE LOW PRESSURE LOOKS TO BE THE FOCUS FOR THUNDERSTORM DEVELOPMENT SUNDAY AFTERNOON/EVENING OVER WEST-CENTRAL TO NORTHWEST IOWA AND THEN ACROSS MUCH OF THE FORECAST AREA SUNDAY EVENING INTO EARLY MONDAY MORNING AS THE FRONT SAGS SOUTHEAST OVERNIGHT. STRONG MOISTURE CONVERGENCE AND DECENT MID-LEVEL FRONTOGENETICAL FORCING SUNDAY EVENING ALONG THE AFOREMENTIONED FRONT ORIENTED FROM SOUTHWEST TO NORTHEAST ACROSS THE FORECAST AREA. AN IMPRESSIVE ATMOSPHERIC RIVER FEEDS INTO THE STATE AND REALLY DOES NOT SHUT OFF UNTIL A SHARPER COLD FRONT AND UPPER LEVEL TROUGH PUSH ACROSS THE REGION TUESDAY NIGHT. STRONG MOISTURE TRANSPORT AND THETA-E ADVECTION SUNDAY NIGHT INTO MONDAY INTO CENTRAL IOWA WITHIN THE WARM SECTOR. WELL ABOVE NORMAL PWATS FOR THIS TIME OF YEAR AS THE NAM12/GFS20 DEPICT 2.0 TO 2.4 INCHES WHICH PUTS THESE VALUES WELL ABOVE THE 90TH PERCENTILE VALUE OF 1.46 INCHES PER 00Z OAX SOUNDING ARCHIVE. HIGHLY FAVORABLE ENVIRONMENT FOR EFFICIENT RAIN PRODUCERS AS WARM LAYER CLOUD DEPTHS OF 13000 TO 14500 FEET. THIS COMBINED WITH CORFIDI VECTORS SOMEWHAT IN LINE WITH THE MEAN STORM MOTION...SO TRAINING ALONG WITH THE EFFICIENT RAIN PRODUCERS ARE HIGHLY LIKELY. RAINFALL RATES IN EXCESS OF 2-4 INCHES PER HOUR ARE LIKELY WITH LOCALLY HIGHER RAINFALL RATES POSSIBLE. INTRODUCED THE MENTION OF HEAVY RAIN SUNDAY NIGHT INTO THE OVERNIGHT HOURS MONDAY MORNING. HELD OFF ON ISSUANCE OF FLASH FLOOD WATCH ATTM DUE TO SOME UNCERTAINTY WHERE THE HEAVIEST RAINFALL WILL OCCUR. THE SEVERE POTENTIAL SUNDAY AFTERNOON INTO EARLY EVENING HAS A SHORT WINDOW BEFORE STORMS TRANSITION INTO THE HEAVY RAIN PRODUCERS. PLENTY OF INSTABILITY AVAILABLE BUT CONDITIONS REMAIN CAPPED UNTIL THE FRONT MOVES INTO NORTHWEST TO WESTERN IOWA LATE IN THE AFTERNOON SUNDAY. WITH THE STRONG LOW LEVEL LAPSE RATES AND DECENT SHEAR IN THE MID-LEVELS...THIS SHOULD BE ENOUGH TO BE CONCERNED OF LARGE HAIL AND EVEN DAMAGING WIND GUSTS. MONDAY NIGHT INTO TUESDAY...MODELS ARE IN DISAGREEMENT WITH WHERE THE FRONTAL BOUNDARY STALLS MONDAY NIGHT...THE GFS THE FURTHEST NORTH AND THE NAM THE FURTHEST SOUTH...AND THE ECMWF IS SORT OF A BLEND OF THE TWO AND SEEMS TO BE THE MOST LIKELY SCENARIO. IT STALLS THE FRONT OVER SOUTHERN IOWA AND SETS UP ANOTHER ROUND OF HEAVY RAIN MONDAY NIGHT INTO TUESDAY. THE AIRMASS SOUTH OF THE FRONT LOOKS TO BE RELATIVELY UNCHANGED FROM WRITTEN ABOVE WRT TO HEAVY RAIN POTENTIAL. THE MAIN DIFFERENCE BEING SLIGHTLY LOWER PWATS AVAILABLE. HOWEVER...THE CORFIDI VECTORS MATCH UP EVEN BETTER WITH THE STORM MOTION AND THUS ENHANCING THE TRAINING POTENTIAL AND FLASH FLOOD THREAT MONDAY NIGHT OVER THE SOUTHERN HALF OF THE FORECAST AREA. PLUS...WITH THE SUNDAY NIGHT BEING THE 'PRIMER'...IT WILL NOT TAKE MUCH HEAVY RAIN TO CAUSE FLASH FLOODING ISSUES. WEDNESDAY THROUGH SATURDAY...LEANED TOWARD THE 05.12Z ECMWF DURING THIS PERIOD WITH THE 05.12Z GFS MUCH SLOWER IN MOVING THE FRONT SOUTH AND EAST OF THE AREA. THE GFS HAS ANOTHER ROUND OF HEAVY RAIN SETTING UP TUESDAY NIGHT BUT THE ECMWF/NAM ARE FURTHER SOUTHEAST WITH THE NEXT WAVE MOVING ACROSS MISSOURI. THE GFS IS ABOUT A DAY LATE WITH THE STRONGER PUSH OF COLD AIR THAN THE ECMWF AS THE ECMWF MOVES IT ACROSS THE STATE WEDNESDAY NIGHT INTO THURSDAY. REGARDLESS...MODELS DO AGREE ON MUCH COLDER TEMPERATURES LATE IN THE WEEK AND INTO NEXT WEEKEND. SOME RAIN SHOWER CHANCES WITH THE FRONT AND CAA EXPECTED ON THURSDAY AND THURSDAY NIGHT. && .AVIATION...05/18Z ISSUED AT 1251 PM CDT SAT SEP 5 2015 WARM FRONT LIFTING NORTH INTO SOUTHERN MN NOW WITH ISO SHOWERS ALONG THE BORDER...MAINLY VFR CONDITIONS THIS AFTERNOON THOUGH WINDS SSW WINDS TO MIX THROUGH 23Z BEFORE RELAXING. OVERNIGHT CLOUDS INCREASE WEST TO EAST WITH MID TO HIGH LEVEL OVERCAST BY 12Z-18Z. WINDS INCREASE AGAIN AFT 15Z SUNDAY WITH GUSTS 20KTS. MAIN SYSTEM TO HOLD OFF UNTIL AFT 18Z SUNDAY WITH INCREASING LIKELIHOOD OF THUNDER/HVY RAIN/LOWER CIGS/VSBY AFT 00Z MON. /REV && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...PODRAZIK AVIATION...REV  FXUS63 KDMX 060856 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 356 AM CDT SUN SEP 6 2015 .SHORT TERM /TODAY/... ISSUED AT 355 AM CDT SUN SEP 6 2015 ACTIVE FORECAST FOR TODAY WITH CONTINUED HOT AND HUMID CONDITIONS AND PRECIPITATION CHANCES. ONGOING PRECIPITATION ACROSS NORTHWESTERN IOWA WILL PERSIST THROUGH THE MORNING HOURS AND EXPAND SOUTHWARD...BEGINNING TO PUSH EAST AFTER 12Z. HOWEVER...FORCING WILL ALSO BEGIN TO DIMINISH NEAR 12Z...AND EXPECT PRECIPITATION TO BECOME MORE SCATTERED AFTER. EXPECT BEST CHANCES FOR THUNDERSTORMS TO BEGIN TO DEVELOP IN THE LATE AFTERNOON WITH DIURNAL DESTABILIZATION...AND MAY BE TOO AGGRESSIVE WITH PRECIPITATION CHANCES ACROSS THE NORTH THROUGH MID AFTERNOON. HOWEVER...HIGH RES MODELS BRING PRECIPITATION ACROSS CENTRAL IOWA THROUGH THE DAY AHEAD OF APPROACHING BOUNDARY. THIS CORRESPONDS WITH FORCING NOTED IN ISENTROPIC ANALYSIS...AND HAVE THEREFORE KEPT GENERAL CHANCE POPS THROUGH THE LATE AFTERNOON. BOUNDARY WILL BEGIN TO PUSH SOUTHEAST INTO NORTHWESTERN IOWA LATE IN THE AFTERNOON AND EXPECT THUNDERSTORMS TO BECOME MORE NUMEROUS. SOUNDINGS INDICATE GOOD INSTABILITY...NEAR 1500-2000 J/KG BY LATE IN THE PERIOD...AND INVERTED V PROFILES ALONG WITH STEEP LAPSE RATES. THEREFORE...SEVERE WEATHER WILL BE POSSIBLE WITH HAIL AND WIND THE MAIN THREATS. WHILE SHEAR IS NOT MAXIMIZED...SHEAR WILL BE SUFFICIENT TO ALLOW FOR STORMS TO PERSIST...AND CANNOT RULE OUT TORNADO THREAT WITH LOW LEVEL HELICITY REMAINING STRONG. PWAT VALUES WILL INCREASE THROUGHOUT THE DAY...REACHING 2 INCHES OR HIGHER BY EVENING. WITH DEEP WARM CLOUD DEPTHS HEAVY RAIN WILL BE POSSIBLE WITH STORMS. SURFACE SOUTHERLY FLOW AHEAD OF SYSTEM WILL KEEP HOT AND HUMID AIRMASS IN PLACE ACROSS CWA FOR THE DAY. CLOUD COVER AND EARLY MORNING PRECIPITATION WILL PLAY A KEY ROLE IN TEMPERATURE TRENDS THROUGH THE DAY TODAY...ESPECIALLY IN THE NORTH. HOWEVER...FURTHER SOUTH HAVE BETTER CONFIDENCE IN HIGH TEMPERATURES REACHING THE LOW 90S WITH GOOD MIXING. AS DEW POINTS INCREASE EXPECT YET ANOTHER DAY OF PERSISTENT HEAT AND HUMIDITY...WITH HEAT INDEX VALUES NEAR 100 OR HIGHER AT TIMES IN THE AFTERNOON. GIVEN THE PAST SEVERAL DAYS OF SIMILAR CONDITIONS WITH OVERNIGHT LOWS ONLY COOLING INTO THE 70S...COULD SEE THE NEED FOR HEAR HEADLINES TODAY. HOWEVER GIVEN HEAT ADVISORY CRITERIA HAS YET TO BE MET...AND UNCERTAINTY IN TEMPERATURE TRENDS FOR TODAY WITH CLOUDS AND EARLY MORNING PRECIPITATION...WILL NOT ISSUE ANYTHING ATTM. .LONG TERM /TONIGHT THROUGH SATURDAY/... ISSUED AT 355 AM CDT SUN SEP 6 2015 EVENT THAT WE HAVE BEEN TRACKING FOR SEVERAL DAYS IS CONTINUING TO UNFOLD AS EXPECTED. THE MID LEVEL MONSOON CONNECTION IS NOW WELL ESTABLISHED AS THE SUBTROPICAL HIGH HAS RETROGRADED WEST INTO TEXAS AND NEW MEXICO. THE GULF MOISTURE FEED IS ALSO ESTABLISHED WITH SFC HIGH PRESSURE OVER THE EASTERN CONUS ALLOWING FOR SOUTHERLY FLOW FROM THE GULF TO STREAM NORTH. THIS WILL PUSH PWATS EXTREMELY HIGH AND TO NEAR 2.25 INCHES TONIGHT OVER CENTRAL AND SOUTHERN IOWA...WHICH IS OVER 200 PERCENT ABOVE NORMAL FOR EARLY SEPTEMBER. THUNDERSTORMS WILL BECOME WIDESPREAD IN ADVANCE OF A BOUNDARY DROPPING INTO THE STATE. THIS BOUNDARY WILL SETTLE SLOWLY SOUTH BEFORE STALLING OVER FAR SOUTHERN IOWA. THE HIGH PWATS AND DEEP WARM CLOUD DEPTHS NEAR 13500 FT OR GREATER WILL PROMOTE EXTREMELY EFFICIENT RAIN PRODUCING STORMS. TRAINING OF STORMS IS LIKELY WITH MULTICELL STORM MOTIONS NEARLY PARALLEL TO THE BOUNDARY. THE LOW LEVEL JET POSITION SHOULD PROMOTE THE POTENTIAL FOR BACKBUILDING STORMS AS WELL WITH NUMEROUS ROUNDS POSSIBLE DURING THE NIGHT...ESPECIALLY OVER THE SOUTHERN HALF OF THE AREA. THE DYNAMICS AND CONVERGENCE SHOULD DIMINISH A BIT MONDAY MORNING FOR THE AREA COVERAGE IN STORMS TO DECREASE. REDEVELOPMENT IS LIKELY AGAIN BY LATER MONDAY AFTERNOON AND MONDAY NIGHT AS THE SFC BOUNDARY LIFTS BACK NORTH INTO CENTRAL IOWA AND ANOTHER ROUND OF MOISTURE ADVECTION ARRIVES. PWATS WILL AGAIN INCREASE TO 2 INCHES OR GREATER AND MAY HAVE ANOTHER ROUND OF HEAVY RAINFALL. WILL BE ISSUING A FLASH FLOOD WATCH FOR PORTIONS OF CENTRAL AND SOUTHERN IOWA FOR TONIGHT INTO MONDAY MORNING. LIKELY WILL NEED ANOTHER HEADLINE MONDAY NIGHT INTO TUESDAY MORNING HOWEVER WITH AN EXPECTED BREAK DURING A PORTION OF MONDAY...WILL NOT LUMP THE TWO EVENTS TOGETHER. THE EVENT TUESDAY NIGHT MAY BE THE MORE IMPACTFUL OF THE TWO ESPECIALLY IF IT OCCURS OVER AREAS HIT HARD TONIGHT. THERE IS SOME SEVERE WEATHER THREAT TONIGHT WITH THE PRIMARY THREAT OF DAMAGING WINDS. THE HAIL THREAT WILL BE MINIMIZED DUE TO MANY OF THE FACTORS PREVIOUSLY MENTIONED THAT AREA FAVORABLE FOR HEAVY RAIN. THERE IS A LOW CHANCE FOR AN ISOLATED TORNADO WITH THE LOW LEVEL SRH AROUND 200 M2/S2. THUNDERSTORM CHANCES WILL CONTINUE INTO EARLY TUESDAY BEFORE THE BOUNDARY FINALLY BEGINS TO SHIFT SOUTH AND DRIER AIR ARRIVES FOR THE NORTH. HIGH PRESSURE WILL BUILD IN TUESDAY NIGHT AND WEDNESDAY. HIGH TEMPERATURES BY WEDNESDAY WILL BE PLEASANT WITH HIGHS IN THE 70S TO LOWER 80S. ANOTHER SYSTEM PASSING THROUGH THE PROGRESSIVE ZONAL FLOW WILL ARRIVE WEDNESDAY NIGHT INTO EARLY THURSDAY FOLLOWED BY CANADIAN HIGH PRESSURE TO END THE PERIOD. THIS SYSTEM WILL BRING EVEN COOLER TEMPERATURES TO THE STATE WITH HIGHS IN THE 60S TO LOWER 70S AND LOWS IN THE 40S TO LOWER 50S TO END THE PERIOD. A VERY LOW CHANCE FOR PRECIPITATION AS THE SYSTEM MOVES WITH MOISTURE LIMITED. && .AVIATION...06/06Z ISSUED AT 1055 PM CDT SAT SEP 5 2015 HIGH CLOUDS TO CONTINUE AHEAD OF A FRONTAL BOUNDARY TO DROP THROUGH THE AREA SUNDAY INTO SUNDAY NIGHT. SOME ISOLATED SHOWERS/STORMS EXPECTED EARLY SUNDAY BUT CONFIDENCE THAT THEY WILL MAKE THEIR WAY TO ONE OF THE NORTHERN TAF SITES IS LOW...SO HAVE LEFT DRY. MUCH GREATER CHANCES FOR STORMS AT ALL TAF SITES INCREASE THROUGH THE AFTERNOON INTO SUNDAY NIGHT...AS A COLD FRONT SINKS THROUGH IOWA. FRONT TO STALL OUT ACROSS SOUTHERN IOWA INTO MONDAY. SOME LOW CLOUDS AND MAYBE FOG/SHOWERS POSSIBLE ACROSS THE NORTH BEHIND THE FRONT. && .HYDROLOGY... ISSUED AT 355 AM CDT SUN SEP 6 2015 AS REFERENCED IN THE LONG TERM SECTION...TWO HEAVY RAINFALL EVENTS ARE POSSIBLE FROM TONIGHT THROUGH TUESDAY MORNING WITH THE FOCUS OVER CENTRAL AND SOUTHERN IOWA. WIDESPREAD RAINFALL AMOUNTS OF 1 TO 3 INCHES IS EXPECTED WITH AMOUNTS EXCEEDING 5 INCHES POSSIBLE DURING THIS PERIOD. EFFICIENT RAIN PRODUCING STORMS WILL PRODUCE HEAVY RAINFALL OVER A SHORT PERIOD OF TIME. SIGNIFICANT RUNOFF AND/OR PONDING OF WATER IS LIKELY IN SOME AREAS LEADING TO A FLASH FLOOD THREAT. THE EVENT MAY EVOLVE INTO A RIVER FLOODING THREAT THROUGH MID TO LATE WEEK AS THE RUNOFF REACHES THE LARGER STREAMS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BOONE-CASS-CLARKE-DALLAS-DAVIS- DECATUR-GREENE-GUTHRIE-JASPER-LUCAS-MADISON-MAHASKA-MARION- MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION- WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...AWB LONG TERM...DONAVON AVIATION...BEERENDS HYDROLOGY...DONAVON  FXUS63 KDMX 062005 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 305 PM CDT SUN SEP 6 2015 .SHORT TERM /TONIGHT/... ISSUED AT 305 PM CDT SUN SEP 6 2015 STILL SOME UNCERTAINTY ABOUT EVOLUTION OF SYSTEM TONIGHT. VARIOUS MODEL SOLUTIONS BEGINNING TO EITHER POINT TOWARD SLIGHTLY MORE PROGRESSIVE EVOLUTION OF CONVECTION OVERNIGHT...OR SLIGHTLY MORE NORTH PLACEMENT OF MAX. SO FAR CONVECTIVE TRENDS HAVE BEEN RAMPING UP SLOWLY DUE TO H700 TEMPS SITTING ABOVE 11-12C THIS AFTERNOON. BUT AS FRONT ENTERS NW/W IA EARLY THIS EVENING AND AREA BECOMES UNCAPPED AND H700 TEMPS COOL A COUPLE OF DEGREES...A RAPID INCREASE IN STORMS SHOULD OCCUR BETWEEN 4 PM AND 7 PM. DESPITE THE EXPECTED MODEL UNCERTAINTY...WE ARE IN NEAR RECORD TERRITORY FOR AVAILABLE ATMOSPHERIC MOISTURE FOR EARLY SEPTEMBER. THIS IS DUE IN PART TO A PROLONGED FETCH OF GULF MOISTURE WHICH IS FEEDING NORTHEAST INTO THE CENTRAL PLAINS AND GREAT LAKES. SECONDLY...A TROPICAL CONNECTION FROM THE SOUTHWEST US THAT RESULTED IN AN OLD TROPICAL SYSTEM EARLIER IN THE WEEK OFF THE COAST OF BAJA MEXICO BEING INGESTED IN THE MID TO UPPER LEVEL FLOW. PWAT VALUES WILL BE APPROACHING 2 TO 2.25 INCHES BETWEEN 00-06Z TONIGHT PLACING OUR VALUES IN THE 99TH/100TH PERCENTILE AND OVER 3 SDEV ABOVE NORMAL FOR THIS TIME OF YEAR. WARM CLOUD DEPTHS ARE NEAR 14.5KFT WHICH IS EXTREMELY DEEP. THERE REMAIN NUMEROUS FACTORS SUPPORTING EFFICIENT/HIGH RAINFALL RATES THIS EVENING...AND LOOKING AHEAD...AGAIN MONDAY NIGHT. BACK TO THE MODELS...CONSECUTIVE RUNS OF THE HRRR ARE SHOWING A MORE PROGRESSIVE EVOLUTION TO TONIGHTS CONVECTION WITH FORWARD PROPAGATING CORFIDI VECTORS ABOUT 20 KTS. BUT EVEN THIS IS DECEIVING IF RAINFALL RATES ARE 2-3 INCHES PER HOUR AT TIMES...AND STILL SUGGESTS A QUICK COUPLE OF INCHES OF RAIN IN THE MORE VIGOROUS CELLS. WITH ANY LOCALIZED TRAINING...STILL A POTENTIAL FOR ISOLATED 3 TO 4 INCHES AMOUNTS OVERNIGHT. THE NAM IS LEANING TOWARD THE MORE PROGRESSIVE HRRR OVERNIGHT WITH THE GFS RAMPING UP CONVECTION BETWEEN 00-06Z ON THE NOSE OF THE INCREASING LOW LEVEL JET ALONG THE INVERTED TROUGH WITHIN THE ZONE OF MAXIMUM SFC CONVERGENCE. THE QPF MAX IS CENTERED OVER HIGHWAY 30...ROUGHLY BETWEEN US 20/I80 FROM GREENE TO MARSHALL COUNTIES. WITH THAT ADDED UNCERTAINTY TONIGHT AND THE POSSIBLE NORTHERLY SHIFT BY 20 MILES OF THE QPF MAX...WILL BE ADDING ONE ROW OF COUNTIES TO TONIGHTS FFA ALONG US 20. REALIGNING THE WATCH NOW IS RISKY...DUE TO THE POSSIBILITY OF THE MODELS ARE NOT PROPERLY ACCOUNTING FOR A STRONGER OUTFLOW BOUNDARY LATER IN THE EVENING...WHICH WOULD THEN BE FEEDING OFF AN INCREASING LOW LEVEL JET OVERNIGHT. THERE MAY ACTUALLY BE TWO FAVORED AREAS OF HEAVY RAINFALL...EARLIER BETWEEN US20/30 AND LATER ALONG AND SOUTH OF I80. NONE THE LESS...THE RISK FOR FLASH FLOODING AND SUBSEQUENT ISSUES REMAINS. TIMING OF THE EVENT SUGGESTS THAT STORMS SHOULD BE IN FULL SWING BETWEEN 02-09Z WITH ACTIVITY REMAINING STRONG BUT SLOWLY DIMINISHING BETWEEN 09-13Z MONDAY OVER THE SOUTH/SOUTHEAST. LOWS TONIGHT WILL FALL TO THE LOWER 70S SOUTH TO NEAR 60 OVER THE FAR NORTHWEST AS THE COOLER AIR BEGINS TO FILTER INTO THE REGION TONIGHT. TONIGHTS RAINFALL WILL PRIME THE REGION FOR A MORE SIGNIFICANT RISK OF FLOODING MONDAY NIGHT AND THIS IS COVERED IN THE EXTENDED DISCUSSION. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 305 PM CDT SUN SEP 6 2015 A POTENTIALLY SIGNIFICANT HEAVY RAIN AND FLOODING EVENT MAY BE SHAPING UP EARLY THIS WEEK. THE COLD FRONT SAGGING DOWN INTO IOWA TONIGHT...AS DISCUSSED IN THE SHORT TERM SECTION ABOVE...WILL LIKELY STALL ACROSS SOUTHERN IOWA BY MONDAY MORNING THEN RETREAT BACK NORTHWARD A BIT TOWARD CENTRAL IOWA DURING THE DAY. DESTABILIZATION WILL BE LIMITED BY DEBRIS CLOUDS AND A LACK OF LOW LEVEL WARM AIR ADVECTION OVER MOST OF THE FORECAST AREA...PLUS THERE WILL BE NO LARGE SCALE FORCING MECHANISM FOR CONVECTION FOR MOST OF THE DAY. NEVERTHELESS THE AIRMASS WILL BE JUICED ENOUGH WITH THE BOUNDARY WOBBLING AROUND THAT LOW POPS ARE MAINTAINED ON MONDAY. BEGINNING LATE MONDAY AFTERNOON AND ESPECIALLY ON MONDAY NIGHT THE ATMOSPHERE APPEARS TO BE SETTING UP FOR A SIGNIFICANT...POSSIBLY EXTREME HEAVY RAINFALL EVENT. ALONG AND SOUTH OF THE NEARLY STATIONARY FRONTAL ZONE PWAT VALUES WILL BE NEAR RECORDS WITH SUBSTANTIAL MOISTURE TRANSPORT CONTINUING FROM THE GULF ESPECIALLY AS THE NOCTURNAL LOW LEVEL JET KICKS IN AFTER DARK. CONCURRENTLY...A SECOND FAIRLY ROBUST MID LEVEL SHORTWAVE WILL ROUND THE BASE OF BROAD CYCLONIC FLOW ALOFT AND PROVIDE A TRIGGER FOR WIDESPREAD THUNDERSTORM DEVELOPMENT. WITH WARM CLOUD DEPTHS IN EXCESS OF 15 KFT IN FORECAST SOUNDINGS AND THE COMBINATION OF OTHER FACTORS...WE WILL BE PRIMED FOR VERY EFFICIENT RAINFALL RATES AND POTENTIALLY TRAINING OR SLOW MOVING STORMS NEAR THE FRONTAL ZONE. THIS COULD LEAD TO WIDESPREAD RAINFALL AMOUNTS IN THE 2 TO 3 INCH RANGE WITHIN A BROAD SWATH ACROSS THE AREA...AND LOCALIZED AMOUNTS OF 6 INCHES OR MORE ARE DEFINITELY CONCEIVABLE. IN TERMS OF THE FLOODING EFFECTS OF SUCH RAINFALL...MUCH WILL DEPEND ON WHERE IT FALLS AND WHETHER IT OCCURS IN THE SAME AREA AS THE HEAVIEST RAINFALL TONIGHT...WHICH IS IN TURN DEPENDENT ON THE DIFFICULT TO PREDICT MOTIONS AND LOCATION OF THE FRONTAL BOUNDARY BY MONDAY EVENING. IT IS LIKELY...IN ANY EVENT...THAT A SECOND FLASH FLOOD WATCH WILL BE NEEDED AFTER TONIGHTS RAINFALL PANS OUT...AND THAT IT MAY NEED TO HAVE EVEN STRONGER WORDING FOR THE POTENTIAL EFFECTS MONDAY NIGHT INTO TUESDAY MORNING. SCATTERED THUNDERSTORMS MAY CONTINUE TO FESTER ACROSS OUR SOUTHERN COUNTIES ON TUESDAY AS THE FRONTAL ZONE LINGERS NEAR THE IOWA/MISSOURI BORDER...BUT THEN ANOTHER SHORTWAVE TROUGH WILL MOVE OVERHEAD AROUND TUESDAY EVENING AND FINALLY CLEAR OUT THE WET AIRMASS TO OUR SOUTH. THIS WILL BRING AN END OF ANY HEAVY RAIN THREAT FOR THE REMAINDER OF THE SEVEN DAY FORECAST...ALONG WITH NOTABLY COOLER AND DRIER WEATHER ACROSS IOWA. THERE WILL BE A CHANCE FOR SCATTERED SHOWERS AND STORMS AROUND THURSDAY AS A REINFORCING COLD FRONT SURGES ACROSS THE STATE...USHERING IN THE FIRST TRULY AUTUMNAL WEATHER OF THE SEASON AT THE END OF THIS WEEK WITH FRIDAY HIGHS IN THE 60S AND FRIDAY NIGHT LOWS IN THE 40S STATEWIDE. && .AVIATION...06/18Z ISSUED AT 1256 PM CDT SUN SEP 6 2015 WITH THE COLD FRONT APPROACHING IOWA THIS EVENING...CONDITIONS WILL CONTINUE TO DETERIORATE WITH INCREASING AREAL COVERAGE OF THUNDERSTORMS FROM 00 TO 06Z ALONG WITH MODERATE TO HEAVY RAINFALL SOUTH OF US 20 TO THE IOWA MISSOURI BORDER. THOUGH SOME SEVERE THREAT EXISTS...THE BIGGER THREAT WILL BE SEVERE WIND GUSTS WHICH MAY ACCOMPANY THE STORMS THAT ROLL THROUGH THE REGION BETWEEN 21Z AND 02Z. WITH THE PASSAGE OF THE STORMS AFT 04Z NORTHWEST TO 11Z SOUTHEAST...CIGS WILL DROP TO IFR/MVFR CATEGORIES WITH POTENTIAL FOR LIFR CIGS AND VSBY. EXPECTING A RECOVERY TO ONLY MVFR CONDITIONS BETWEEN 14-18Z MON PRIOR TO NEXT UPSTREAM APPROACHING WAVE. FOR PLANNING PURPOSES...HEAVY RAINFALL/STORM COVERAGE/POOR CONDITIONS EXPECTED TO RETURN AGAIN AFT 08/00Z TUES FOR MOST SITES SOUTH OF US20./REV && .HYDROLOGY... ISSUED AT 305 PM CDT SUN SEP 6 2015 AS REFERENCED IN THE PREVIOUS DISCUSSIONS...TWO HEAVY RAINFALL EVENTS ARE POSSIBLE TONIGHT THROUGH TUESDAY MORNING WITH THE FOCUS FROM NORTH CENTRAL TO SOUTHERN IOWA. WIDESPREAD RAINFALL AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED WITH AMOUNTS EXCEEDING 5 INCHES POSSIBLE DURING THIS PERIOD. MONDAY NIGHTS EVENT IS STILL EXPECTED TO BE OF GREATER MAGNITUDE...SO SOME REEVALUATION OF THE WATCH OUTLINE WILL OCCUR BETWEEN THIS EVENING AND TOMORROW MORNING AFTER TONIGHTS RAINFALL REPORTS ARE GATHERED. IN BOTH EVENTS...EFFICIENT RAIN PRODUCING STORMS WILL PRODUCE HEAVY RAINFALL OVER A SHORT PERIOD OF TIME. SIGNIFICANT RUNOFF AND/OR PONDING OF WATER IS LIKELY IN SOME AREAS LEADING TO A FLASH FLOOD THREAT. THE EVENT MAY EVOLVE INTO A RIVER FLOODING THREAT THROUGH MID TO LATE WEEK AS THE RUNOFF REACHES THE LARGER STREAMS. THE MAGNITUDE OF RIVER FLOODING ON ANY GIVEN MAINSTEM RIVER WILL DEPEND ON BOTH RAINFALL AMOUNTS AND BASIN COVERAGE IN THE NEXT 48 TO 60 HOURS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH MONDAY MORNING FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-CASS- CLARKE-DALLAS-DAVIS-DECATUR-GREENE-GRUNDY-GUTHRIE-HAMILTON- HARDIN-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POLK- POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...REV LONG TERM...LEE AVIATION...REV HYDROLOGY...REV  FXUS63 KDMX 062040 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 340 PM CDT THU AUG 6 2015 .SHORT TERM /TONIGHT/... ISSUED AT 339 PM CDT THU AUG 6 2015 MAIN FORECAST CONCERNS INCLUDE SHRA/TSRA CHANCES TONIGHT...ESPECIALLY ITS SOUTHWARD EXTENT. SPLIT UPPER LEVEL FLOW REGIME EXISTS FROM THE NORTHERN U.S. INTO CANADA. A RIDGE STRETCHES FROM SOUTH CENTRAL INTO NORTHERN CANADA. RELATIVELY ZONAL FLOW EXISTS ON THE SOUTHERN PERIPHERY OF THE RIDGE...FROM THE NORTHERN U.S. ROCKIES EASTWARD TO OUR REGION...WHERE IT TURNS SOUTHEASTWARD TOWARD LOW OVER THE LOWER TO MIDDLE OHIO RIVER VALLEY. A SHORTWAVE EXTENDING FROM NORTHERN NORTH DAKOTA INTO NEBRASKA...AND SURFACE COLD FRONTAL BOUNDARY...WILL HELP FACILITATE THE DEVELOPMENT OF CONVECTION FROM SOUTH DAKOTA INTO NORTHERN/NORTHEASTERN NEBRASKA LATER THIS AFTN/EVENING. PARAMETERS SUGGEST SVR WX WILL BE POSSIBLE IN THAT REGION ESPECIALLY INITIALLY...WITH THE CONVECTION GROWING UPSCALE INTO THE EVENING AS IT TRACKS EASTWARD. BEST KINEMATIC FORCING TONIGHT WILL EXIST FROM SOUTH DAKOTA EASTWARD INTO MINNESOTA...GRAZING OUR NORTHERN CWA. THERMODYNAMIC PARAMETERS ARE ALSO MAXIMIZED IN THIS SAME GENERAL AREA. QUESTION IS HOW FAR SOUTH THE CONVECTION WILL DEVELOP IN OUR CWA. ATTM...THERMODYNAMIC FORCING IS EXPECTED TO BE SUFFICIENT TO ALLOW FOR CONVECTION AT LEAST AS FAR SOUTH AS THE I-80 / US 30 CORRIDORS...THUS HAVE PUSHED CHANCE POPS THAT FAR SOUTH...WITH SLIGHT CHANCE ALL THE WAY TO THE MO BORDER. AS FOR SVR WX POTENTIAL...PARAMETERS MOST FAVOR SOUTH DAKOTA INTO MINNESOTA...HOWEVER CANNOT RULE OUT THE POTENTIAL FOR OUR NORTHERN CWA...WHERE DEEP-LAYER SHEAR PARAMETERS ARE 40+ KTS FROM U.S. 20 NORTHWARD. PRIMARY THREAT WILL BE LARGE HAIL...WITH DAMAGING WINDS A SECONDARY THREAT. ALTHOUGH TORNADO POTENTIAL CANNOT BE RULED OUT ACROSS THE FAR NORTHERN CWA...CLIMATOLOGY WOULD NOT FAVOR THEM OVERNIGHT. NOT OVERLY CONCERNED ABOUT HEAVY RAINFALL POTENTIAL...GIVEN RELATIONSHIP OF ANTICIPATED STORM MOTION VECTORS AS WELL AS CORFIDI VECTORS. MOISTURE TRANSPORT VECTORS DO BRING ENOUGH MOISTURE IN...HOWEVER...SUCH THAT BRIEF HEAVY RAINFALL WILL BE POSSIBLE. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 339 PM CDT THU AUG 6 2015 STILL SOME SIGNIFICANT UNCERTAINTIES WITH CONVECTION OVER THE WEEKEND PARTICULARLY WRT TIMING AND LOCATION OF SUBSEQUENT SHORTWAVES TO IMPACT CENTRAL IOWA. LEANED MORE TOWARD THE ECMWF AS IT REMAINS THE MOST CONSISTENT FROM PREVIOUS MODELS RUNS FOR THE WEEKEND SOLUTION. FRIDAY...SHORTWAVE QUICKLY EXITS THE STATE BY FRIDAY MORNING AND BEHIND IT DECENT MIXING AND DOWNSLOPE DEVELOP BY THE AFTERNOON. NUDGED UP MAX TEMPS SLIGHTLY FOR FRIDAY AFTERNOON WITH MODELS TRENDING TOWARDS UPPER 80S TO NEAR 90 AND PER SLIGHTLY DRIER DEW POINTS. SATURDAY THROUGH MONDAY...LARGE UPPER LEVEL RIDGE REMAINS DOMINANT OVER THE SOUTH CENTRAL U.S. THROUGH THE WEEKEND. SEVERAL SHORTWAVES EMBEDDED IN THE 500MB FLOW FOLLOW ONE ANOTHER BEGINNING LATE FRIDAY NIGHT AND CONTINUING INTO EARLY MONDAY. THE FIRST SHORTWAVE TRACKS EAST ACROSS NEBRASKA INTO WESTERN IOWA OVERNIGHT FRIDAY NIGHT INTO EARLY SATURDAY. SURFACE LOW PRESSURE DEVELOPS OVER KANSAS AND BECOMES THE MORE DOMINANT LOW PRESSURE CENTER THROUGH SATURDAY NIGHT. A SURFACE AND 850MB BOUNDARY SET UP ACROSS THE STATE FROM WEST TO EAST RESULTING IN THE FOCUS FOR CONVECTION OVER THE FORECAST AREA EARLY SATURDAY AND AGAIN SATURDAY NIGHT INTO SUNDAY. THE BEST FRONTOGENETICAL FORCING AND MOISTURE CONVERGENCE LOOKS TO BE OVER WESTERN PORTIONS OF IOWA FROM 09-18Z SATURDAY BEFORE QUICKLY TRANSITIONING EAST DURING THE AFTERNOON AS THE SHORTWAVE PUSHES INTO ILLINOIS. EXPECTING A BREAK IN STORMS SATURDAY AFTERNOON AND HAVE SLIGHTLY LOWERED POPS DURING THIS TIME FRAME AS SUBSIDENCE SETTLES INTO CENTRAL IOWA. THIS LULL SHOULD ALLOW FOR THE ATMOSPHERE TO DESTABILIZE SATURDAY AFTERNOON AHEAD OF NEXT SHORTWAVE MOVING ACROSS IOWA SATURDAY NIGHT. STORMS LOOK TO DEVELOP ALONG THE AFOREMENTIONED FRONTAL BOUNDARY IN RESPONSE TO THE LLJ INCREASING LATE SATURDAY NIGHT INTO SUNDAY MORNING. THE BEST THETA-E ADVECTION AND MOISTURE TRANSPORT ARE SOUTH OF THE FRONT SATURDAY NIGHT AND BRING THE POTENTIAL FOR POCKETS OF HEAVY RAIN OVER THIS AREA. INCREASED QPF AND POPS DURING THIS TIME FRAME WITH THE WARM LAYER CLOUD DEPTHS WELL OVER 4000 METERS AND PRECIPITABLE WATER VALUES IN THE 2-2.4 INCH RANGED BY 06Z SUNDAY. LOW CONFIDENCE WITH WIDESPREAD SEVERE POTENTIAL...BUT CANNOT RULE OUT COMPLETELY THE WIND AND HAIL THREAT FOR SATURDAY NIGHT WITH THE DECENT CAPE AND SHEAR PRESENT. FINALLY BY MONDAY A COLD FRONT AND UPPER TROUGH PUSH ACROSS THE REGION AND PROVIDE ANOTHER ROUND OF STORMS LATE SUNDAY INTO MONDAY. MOISTURE IS LIMITED WITH THIS SYSTEM AND HAVE LOW CHANCE POPS GOING DURING THE AFOREMENTIONED TIME FRAME. TUESDAY INTO THURSDAY...LARGE SURFACE HIGH PRESSURE BUILDS INTO THE REGION AND PROVIDES COOLER TEMPS AND DRY CONDITIONS. && .AVIATION...06/18Z ISSUED AT 125 PM CDT THU AUG 6 2015 ADDITIONAL SHRA/TSRA ARE POSSIBLE MAINLY ACROSS THE NORTHERN HALF OF THE STATE TONIGHT. HAVE INTRODUCED VCTS FOR THE KFOD...KMCW AND KALO TERMINALS DURING THE MOST LIKELY PERIOD...AND CAN BE REFINED IN LATER UPDATES. BRIEF MVFR CONDITIONS ARE POSSIBLE IN THE STRONGER THUNDERSTORMS. A PERIOD OF MVFR FOG IS POSSIBLE AFTER THE RAIN MOVES OUT...AND HAVE INTRODUCED THIS AS WELL INTO THE TAFS. FOG IS EXPECTED TO DISSIPIATE WITHIN A COUPLE HOURS OF SUNRISE ON FRIDAY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...ZOGG LONG TERM...PODRAZIK AVIATION...ZOGG  FXUS63 KDMX 062324 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 624 PM CDT SUN SEP 6 2015 .SHORT TERM /TONIGHT/... ISSUED AT 305 PM CDT SUN SEP 6 2015 STILL SOME UNCERTAINTY ABOUT EVOLUTION OF SYSTEM TONIGHT. VARIOUS MODEL SOLUTIONS BEGINNING TO EITHER POINT TOWARD SLIGHTLY MORE PROGRESSIVE EVOLUTION OF CONVECTION OVERNIGHT...OR SLIGHTLY MORE NORTH PLACEMENT OF MAX. SO FAR CONVECTIVE TRENDS HAVE BEEN RAMPING UP SLOWLY DUE TO H700 TEMPS SITTING ABOVE 11-12C THIS AFTERNOON. BUT AS FRONT ENTERS NW/W IA EARLY THIS EVENING AND AREA BECOMES UNCAPPED AND H700 TEMPS COOL A COUPLE OF DEGREES...A RAPID INCREASE IN STORMS SHOULD OCCUR BETWEEN 4 PM AND 7 PM. DESPITE THE EXPECTED MODEL UNCERTAINTY...WE ARE IN NEAR RECORD TERRITORY FOR AVAILABLE ATMOSPHERIC MOISTURE FOR EARLY SEPTEMBER. THIS IS DUE IN PART TO A PROLONGED FETCH OF GULF MOISTURE WHICH IS FEEDING NORTHEAST INTO THE CENTRAL PLAINS AND GREAT LAKES. SECONDLY...A TROPICAL CONNECTION FROM THE SOUTHWEST US THAT RESULTED IN AN OLD TROPICAL SYSTEM EARLIER IN THE WEEK OFF THE COAST OF BAJA MEXICO BEING INGESTED IN THE MID TO UPPER LEVEL FLOW. PWAT VALUES WILL BE APPROACHING 2 TO 2.25 INCHES BETWEEN 00-06Z TONIGHT PLACING OUR VALUES IN THE 99TH/100TH PERCENTILE AND OVER 3 SDEV ABOVE NORMAL FOR THIS TIME OF YEAR. WARM CLOUD DEPTHS ARE NEAR 14.5KFT WHICH IS EXTREMELY DEEP. THERE REMAIN NUMEROUS FACTORS SUPPORTING EFFICIENT/HIGH RAINFALL RATES THIS EVENING...AND LOOKING AHEAD...AGAIN MONDAY NIGHT. BACK TO THE MODELS...CONSECUTIVE RUNS OF THE HRRR ARE SHOWING A MORE PROGRESSIVE EVOLUTION TO TONIGHTS CONVECTION WITH FORWARD PROPAGATING CORFIDI VECTORS ABOUT 20 KTS. BUT EVEN THIS IS DECEIVING IF RAINFALL RATES ARE 2-3 INCHES PER HOUR AT TIMES...AND STILL SUGGESTS A QUICK COUPLE OF INCHES OF RAIN IN THE MORE VIGOROUS CELLS. WITH ANY LOCALIZED TRAINING...STILL A POTENTIAL FOR ISOLATED 3 TO 4 INCHES AMOUNTS OVERNIGHT. THE NAM IS LEANING TOWARD THE MORE PROGRESSIVE HRRR OVERNIGHT WITH THE GFS RAMPING UP CONVECTION BETWEEN 00-06Z ON THE NOSE OF THE INCREASING LOW LEVEL JET ALONG THE INVERTED TROUGH WITHIN THE ZONE OF MAXIMUM SFC CONVERGENCE. THE QPF MAX IS CENTERED OVER HIGHWAY 30...ROUGHLY BETWEEN US 20/I80 FROM GREENE TO MARSHALL COUNTIES. WITH THAT ADDED UNCERTAINTY TONIGHT AND THE POSSIBLE NORTHERLY SHIFT BY 20 MILES OF THE QPF MAX...WILL BE ADDING ONE ROW OF COUNTIES TO TONIGHTS FFA ALONG US 20. REALIGNING THE WATCH NOW IS RISKY...DUE TO THE POSSIBILITY OF THE MODELS ARE NOT PROPERLY ACCOUNTING FOR A STRONGER OUTFLOW BOUNDARY LATER IN THE EVENING...WHICH WOULD THEN BE FEEDING OFF AN INCREASING LOW LEVEL JET OVERNIGHT. THERE MAY ACTUALLY BE TWO FAVORED AREAS OF HEAVY RAINFALL...EARLIER BETWEEN US20/30 AND LATER ALONG AND SOUTH OF I80. NONE THE LESS...THE RISK FOR FLASH FLOODING AND SUBSEQUENT ISSUES REMAINS. TIMING OF THE EVENT SUGGESTS THAT STORMS SHOULD BE IN FULL SWING BETWEEN 02-09Z WITH ACTIVITY REMAINING STRONG BUT SLOWLY DIMINISHING BETWEEN 09-13Z MONDAY OVER THE SOUTH/SOUTHEAST. LOWS TONIGHT WILL FALL TO THE LOWER 70S SOUTH TO NEAR 60 OVER THE FAR NORTHWEST AS THE COOLER AIR BEGINS TO FILTER INTO THE REGION TONIGHT. TONIGHTS RAINFALL WILL PRIME THE REGION FOR A MORE SIGNIFICANT RISK OF FLOODING MONDAY NIGHT AND THIS IS COVERED IN THE EXTENDED DISCUSSION. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 305 PM CDT SUN SEP 6 2015 A POTENTIALLY SIGNIFICANT HEAVY RAIN AND FLOODING EVENT MAY BE SHAPING UP EARLY THIS WEEK. THE COLD FRONT SAGGING DOWN INTO IOWA TONIGHT...AS DISCUSSED IN THE SHORT TERM SECTION ABOVE...WILL LIKELY STALL ACROSS SOUTHERN IOWA BY MONDAY MORNING THEN RETREAT BACK NORTHWARD A BIT TOWARD CENTRAL IOWA DURING THE DAY. DESTABILIZATION WILL BE LIMITED BY DEBRIS CLOUDS AND A LACK OF LOW LEVEL WARM AIR ADVECTION OVER MOST OF THE FORECAST AREA...PLUS THERE WILL BE NO LARGE SCALE FORCING MECHANISM FOR CONVECTION FOR MOST OF THE DAY. NEVERTHELESS THE AIRMASS WILL BE JUICED ENOUGH WITH THE BOUNDARY WOBBLING AROUND THAT LOW POPS ARE MAINTAINED ON MONDAY. BEGINNING LATE MONDAY AFTERNOON AND ESPECIALLY ON MONDAY NIGHT THE ATMOSPHERE APPEARS TO BE SETTING UP FOR A SIGNIFICANT...POSSIBLY EXTREME HEAVY RAINFALL EVENT. ALONG AND SOUTH OF THE NEARLY STATIONARY FRONTAL ZONE PWAT VALUES WILL BE NEAR RECORDS WITH SUBSTANTIAL MOISTURE TRANSPORT CONTINUING FROM THE GULF ESPECIALLY AS THE NOCTURNAL LOW LEVEL JET KICKS IN AFTER DARK. CONCURRENTLY...A SECOND FAIRLY ROBUST MID LEVEL SHORTWAVE WILL ROUND THE BASE OF BROAD CYCLONIC FLOW ALOFT AND PROVIDE A TRIGGER FOR WIDESPREAD THUNDERSTORM DEVELOPMENT. WITH WARM CLOUD DEPTHS IN EXCESS OF 15 KFT IN FORECAST SOUNDINGS AND THE COMBINATION OF OTHER FACTORS...WE WILL BE PRIMED FOR VERY EFFICIENT RAINFALL RATES AND POTENTIALLY TRAINING OR SLOW MOVING STORMS NEAR THE FRONTAL ZONE. THIS COULD LEAD TO WIDESPREAD RAINFALL AMOUNTS IN THE 2 TO 3 INCH RANGE WITHIN A BROAD SWATH ACROSS THE AREA...AND LOCALIZED AMOUNTS OF 6 INCHES OR MORE ARE DEFINITELY CONCEIVABLE. IN TERMS OF THE FLOODING EFFECTS OF SUCH RAINFALL...MUCH WILL DEPEND ON WHERE IT FALLS AND WHETHER IT OCCURS IN THE SAME AREA AS THE HEAVIEST RAINFALL TONIGHT...WHICH IS IN TURN DEPENDENT ON THE DIFFICULT TO PREDICT MOTIONS AND LOCATION OF THE FRONTAL BOUNDARY BY MONDAY EVENING. IT IS LIKELY...IN ANY EVENT...THAT A SECOND FLASH FLOOD WATCH WILL BE NEEDED AFTER TONIGHTS RAINFALL PANS OUT...AND THAT IT MAY NEED TO HAVE EVEN STRONGER WORDING FOR THE POTENTIAL EFFECTS MONDAY NIGHT INTO TUESDAY MORNING. SCATTERED THUNDERSTORMS MAY CONTINUE TO FESTER ACROSS OUR SOUTHERN COUNTIES ON TUESDAY AS THE FRONTAL ZONE LINGERS NEAR THE IOWA/MISSOURI BORDER...BUT THEN ANOTHER SHORTWAVE TROUGH WILL MOVE OVERHEAD AROUND TUESDAY EVENING AND FINALLY CLEAR OUT THE WET AIRMASS TO OUR SOUTH. THIS WILL BRING AN END OF ANY HEAVY RAIN THREAT FOR THE REMAINDER OF THE SEVEN DAY FORECAST...ALONG WITH NOTABLY COOLER AND DRIER WEATHER ACROSS IOWA. THERE WILL BE A CHANCE FOR SCATTERED SHOWERS AND STORMS AROUND THURSDAY AS A REINFORCING COLD FRONT SURGES ACROSS THE STATE...USHERING IN THE FIRST TRULY AUTUMNAL WEATHER OF THE SEASON AT THE END OF THIS WEEK WITH FRIDAY HIGHS IN THE 60S AND FRIDAY NIGHT LOWS IN THE 40S STATEWIDE. && .AVIATION...07/00Z ISSUED AT 624 PM CDT SUN SEP 6 2015 LINE OF THUNDERSTORMS STRETCHING FROM KDNS TO KMCW TO CONTINUE TO MOVES ESE THROUGH THE STATE DURING THE EVENING AND OVERNIGHT HOURS. LOW CLOUDS AND SOME FOG POSSIBLE ACROSS THE NORTHERN TAFS BEHIND THE THUNDERSTORMS. MVFR TO POSSIBLY IFR VSBYS POSSIBLE WITH THE STORMS IN ESPECIALLY OVERNIGHT DUE TO HEAVY RAINFALL. HAIL ALSO POSSIBLE AND DAMAGING WINDS WITH ANY POTENTIAL SEVERE STORMS. && .HYDROLOGY... ISSUED AT 305 PM CDT SUN SEP 6 2015 AS REFERENCED IN THE PREVIOUS DISCUSSIONS...TWO HEAVY RAINFALL EVENTS ARE POSSIBLE TONIGHT THROUGH TUESDAY MORNING WITH THE FOCUS FROM NORTH CENTRAL TO SOUTHERN IOWA. WIDESPREAD RAINFALL AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED WITH AMOUNTS EXCEEDING 5 INCHES POSSIBLE DURING THIS PERIOD. MONDAY NIGHTS EVENT IS STILL EXPECTED TO BE OF GREATER MAGNITUDE...SO SOME REEVALUATION OF THE WATCH OUTLINE WILL OCCUR BETWEEN THIS EVENING AND TOMORROW MORNING AFTER TONIGHTS RAINFALL REPORTS ARE GATHERED. IN BOTH EVENTS...EFFICIENT RAIN PRODUCING STORMS WILL PRODUCE HEAVY RAINFALL OVER A SHORT PERIOD OF TIME. SIGNIFICANT RUNOFF AND/OR PONDING OF WATER IS LIKELY IN SOME AREAS LEADING TO A FLASH FLOOD THREAT. THE EVENT MAY EVOLVE INTO A RIVER FLOODING THREAT THROUGH MID TO LATE WEEK AS THE RUNOFF REACHES THE LARGER STREAMS. THE MAGNITUDE OF RIVER FLOODING ON ANY GIVEN MAINSTEM RIVER WILL DEPEND ON BOTH RAINFALL AMOUNTS AND BASIN COVERAGE IN THE NEXT 48 TO 60 HOURS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH MONDAY MORNING FOR ADAIR-ADAMS- APPANOOSE-AUDUBON-BLACK HAWK-BOONE-CASS-CLARKE-DALLAS-DAVIS- DECATUR-GREENE-GRUNDY-GUTHRIE-HAMILTON-HARDIN-JASPER-LUCAS- MADISON-MAHASKA-MARION-MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD- STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...REV LONG TERM...LEE AVIATION...BEERENDS HYDROLOGY...REV  FXUS63 KDMX 062331 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 631 PM CDT THU AUG 6 2015 .SHORT TERM /TONIGHT/... ISSUED AT 339 PM CDT THU AUG 6 2015 MAIN FORECAST CONCERNS INCLUDE SHRA/TSRA CHANCES TONIGHT...ESPECIALLY ITS SOUTHWARD EXTENT. SPLIT UPPER LEVEL FLOW REGIME EXISTS FROM THE NORTHERN U.S. INTO CANADA. A RIDGE STRETCHES FROM SOUTH CENTRAL INTO NORTHERN CANADA. RELATIVELY ZONAL FLOW EXISTS ON THE SOUTHERN PERIPHERY OF THE RIDGE...FROM THE NORTHERN U.S. ROCKIES EASTWARD TO OUR REGION...WHERE IT TURNS SOUTHEASTWARD TOWARD LOW OVER THE LOWER TO MIDDLE OHIO RIVER VALLEY. A SHORTWAVE EXTENDING FROM NORTHERN NORTH DAKOTA INTO NEBRASKA...AND SURFACE COLD FRONTAL BOUNDARY...WILL HELP FACILITATE THE DEVELOPMENT OF CONVECTION FROM SOUTH DAKOTA INTO NORTHERN/NORTHEASTERN NEBRASKA LATER THIS AFTN/EVENING. PARAMETERS SUGGEST SVR WX WILL BE POSSIBLE IN THAT REGION ESPECIALLY INITIALLY...WITH THE CONVECTION GROWING UPSCALE INTO THE EVENING AS IT TRACKS EASTWARD. BEST KINEMATIC FORCING TONIGHT WILL EXIST FROM SOUTH DAKOTA EASTWARD INTO MINNESOTA...GRAZING OUR NORTHERN CWA. THERMODYNAMIC PARAMETERS ARE ALSO MAXIMIZED IN THIS SAME GENERAL AREA. QUESTION IS HOW FAR SOUTH THE CONVECTION WILL DEVELOP IN OUR CWA. ATTM...THERMODYNAMIC FORCING IS EXPECTED TO BE SUFFICIENT TO ALLOW FOR CONVECTION AT LEAST AS FAR SOUTH AS THE I-80 / US 30 CORRIDORS...THUS HAVE PUSHED CHANCE POPS THAT FAR SOUTH...WITH SLIGHT CHANCE ALL THE WAY TO THE MO BORDER. AS FOR SVR WX POTENTIAL...PARAMETERS MOST FAVOR SOUTH DAKOTA INTO MINNESOTA...HOWEVER CANNOT RULE OUT THE POTENTIAL FOR OUR NORTHERN CWA...WHERE DEEP-LAYER SHEAR PARAMETERS ARE 40+ KTS FROM U.S. 20 NORTHWARD. PRIMARY THREAT WILL BE LARGE HAIL...WITH DAMAGING WINDS A SECONDARY THREAT. ALTHOUGH TORNADO POTENTIAL CANNOT BE RULED OUT ACROSS THE FAR NORTHERN CWA...CLIMATOLOGY WOULD NOT FAVOR THEM OVERNIGHT. NOT OVERLY CONCERNED ABOUT HEAVY RAINFALL POTENTIAL...GIVEN RELATIONSHIP OF ANTICIPATED STORM MOTION VECTORS AS WELL AS CORFIDI VECTORS. MOISTURE TRANSPORT VECTORS DO BRING ENOUGH MOISTURE IN...HOWEVER...SUCH THAT BRIEF HEAVY RAINFALL WILL BE POSSIBLE. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 339 PM CDT THU AUG 6 2015 STILL SOME SIGNIFICANT UNCERTAINTIES WITH CONVECTION OVER THE WEEKEND PARTICULARLY WRT TIMING AND LOCATION OF SUBSEQUENT SHORTWAVES TO IMPACT CENTRAL IOWA. LEANED MORE TOWARD THE ECMWF AS IT REMAINS THE MOST CONSISTENT FROM PREVIOUS MODELS RUNS FOR THE WEEKEND SOLUTION. FRIDAY...SHORTWAVE QUICKLY EXITS THE STATE BY FRIDAY MORNING AND BEHIND IT DECENT MIXING AND DOWNSLOPE DEVELOP BY THE AFTERNOON. NUDGED UP MAX TEMPS SLIGHTLY FOR FRIDAY AFTERNOON WITH MODELS TRENDING TOWARDS UPPER 80S TO NEAR 90 AND PER SLIGHTLY DRIER DEW POINTS. SATURDAY THROUGH MONDAY...LARGE UPPER LEVEL RIDGE REMAINS DOMINANT OVER THE SOUTH CENTRAL U.S. THROUGH THE WEEKEND. SEVERAL SHORTWAVES EMBEDDED IN THE 500MB FLOW FOLLOW ONE ANOTHER BEGINNING LATE FRIDAY NIGHT AND CONTINUING INTO EARLY MONDAY. THE FIRST SHORTWAVE TRACKS EAST ACROSS NEBRASKA INTO WESTERN IOWA OVERNIGHT FRIDAY NIGHT INTO EARLY SATURDAY. SURFACE LOW PRESSURE DEVELOPS OVER KANSAS AND BECOMES THE MORE DOMINANT LOW PRESSURE CENTER THROUGH SATURDAY NIGHT. A SURFACE AND 850MB BOUNDARY SET UP ACROSS THE STATE FROM WEST TO EAST RESULTING IN THE FOCUS FOR CONVECTION OVER THE FORECAST AREA EARLY SATURDAY AND AGAIN SATURDAY NIGHT INTO SUNDAY. THE BEST FRONTOGENETICAL FORCING AND MOISTURE CONVERGENCE LOOKS TO BE OVER WESTERN PORTIONS OF IOWA FROM 09-18Z SATURDAY BEFORE QUICKLY TRANSITIONING EAST DURING THE AFTERNOON AS THE SHORTWAVE PUSHES INTO ILLINOIS. EXPECTING A BREAK IN STORMS SATURDAY AFTERNOON AND HAVE SLIGHTLY LOWERED POPS DURING THIS TIME FRAME AS SUBSIDENCE SETTLES INTO CENTRAL IOWA. THIS LULL SHOULD ALLOW FOR THE ATMOSPHERE TO DESTABILIZE SATURDAY AFTERNOON AHEAD OF NEXT SHORTWAVE MOVING ACROSS IOWA SATURDAY NIGHT. STORMS LOOK TO DEVELOP ALONG THE AFOREMENTIONED FRONTAL BOUNDARY IN RESPONSE TO THE LLJ INCREASING LATE SATURDAY NIGHT INTO SUNDAY MORNING. THE BEST THETA-E ADVECTION AND MOISTURE TRANSPORT ARE SOUTH OF THE FRONT SATURDAY NIGHT AND BRING THE POTENTIAL FOR POCKETS OF HEAVY RAIN OVER THIS AREA. INCREASED QPF AND POPS DURING THIS TIME FRAME WITH THE WARM LAYER CLOUD DEPTHS WELL OVER 4000 METERS AND PRECIPITABLE WATER VALUES IN THE 2-2.4 INCH RANGED BY 06Z SUNDAY. LOW CONFIDENCE WITH WIDESPREAD SEVERE POTENTIAL...BUT CANNOT RULE OUT COMPLETELY THE WIND AND HAIL THREAT FOR SATURDAY NIGHT WITH THE DECENT CAPE AND SHEAR PRESENT. FINALLY BY MONDAY A COLD FRONT AND UPPER TROUGH PUSH ACROSS THE REGION AND PROVIDE ANOTHER ROUND OF STORMS LATE SUNDAY INTO MONDAY. MOISTURE IS LIMITED WITH THIS SYSTEM AND HAVE LOW CHANCE POPS GOING DURING THE AFOREMENTIONED TIME FRAME. TUESDAY INTO THURSDAY...LARGE SURFACE HIGH PRESSURE BUILDS INTO THE REGION AND PROVIDES COOLER TEMPS AND DRY CONDITIONS. && .AVIATION...07/00Z ISSUED AT 625 PM CDT THU AUG 6 2015 APPROACHING BOUNDARY ACROSS THE NORTH WILL BRING CHANCES FOR TSRA AND SHRA TO SITES OVERNIGHT. HAVE ONLY INCLUDED VC MENTION ATTM WITH UNCERTAINTIES IN TIMING AND PLACEMENT. HOWEVER...TSRA MAY BRING MVFR OR LOWER CEILINGS AND VISIBILITIES TO AFFECTED SITES. IN ADDITION...WITH INCREASING MOISTURE HAVE INCLUDED MVFR BR AT SITES NEAR 12Z. BEHIND SYSTEM WINDS WILL SHIFT TO THE NORTHEAST AND MAY BE GUSTY BEYOND 18Z...THOUGH VFR CONDITIONS WILL PREVAIL. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ZOGG LONG TERM...PODRAZIK AVIATION...AWB  FXUS63 KDMX 070522 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1222 AM CDT MON SEP 7 2015 .SHORT TERM /TONIGHT/... ISSUED AT 305 PM CDT SUN SEP 6 2015 STILL SOME UNCERTAINTY ABOUT EVOLUTION OF SYSTEM TONIGHT. VARIOUS MODEL SOLUTIONS BEGINNING TO EITHER POINT TOWARD SLIGHTLY MORE PROGRESSIVE EVOLUTION OF CONVECTION OVERNIGHT...OR SLIGHTLY MORE NORTH PLACEMENT OF MAX. SO FAR CONVECTIVE TRENDS HAVE BEEN RAMPING UP SLOWLY DUE TO H700 TEMPS SITTING ABOVE 11-12C THIS AFTERNOON. BUT AS FRONT ENTERS NW/W IA EARLY THIS EVENING AND AREA BECOMES UNCAPPED AND H700 TEMPS COOL A COUPLE OF DEGREES...A RAPID INCREASE IN STORMS SHOULD OCCUR BETWEEN 4 PM AND 7 PM. DESPITE THE EXPECTED MODEL UNCERTAINTY...WE ARE IN NEAR RECORD TERRITORY FOR AVAILABLE ATMOSPHERIC MOISTURE FOR EARLY SEPTEMBER. THIS IS DUE IN PART TO A PROLONGED FETCH OF GULF MOISTURE WHICH IS FEEDING NORTHEAST INTO THE CENTRAL PLAINS AND GREAT LAKES. SECONDLY...A TROPICAL CONNECTION FROM THE SOUTHWEST US THAT RESULTED IN AN OLD TROPICAL SYSTEM EARLIER IN THE WEEK OFF THE COAST OF BAJA MEXICO BEING INGESTED IN THE MID TO UPPER LEVEL FLOW. PWAT VALUES WILL BE APPROACHING 2 TO 2.25 INCHES BETWEEN 00-06Z TONIGHT PLACING OUR VALUES IN THE 99TH/100TH PERCENTILE AND OVER 3 SDEV ABOVE NORMAL FOR THIS TIME OF YEAR. WARM CLOUD DEPTHS ARE NEAR 14.5KFT WHICH IS EXTREMELY DEEP. THERE REMAIN NUMEROUS FACTORS SUPPORTING EFFICIENT/HIGH RAINFALL RATES THIS EVENING...AND LOOKING AHEAD...AGAIN MONDAY NIGHT. BACK TO THE MODELS...CONSECUTIVE RUNS OF THE HRRR ARE SHOWING A MORE PROGRESSIVE EVOLUTION TO TONIGHTS CONVECTION WITH FORWARD PROPAGATING CORFIDI VECTORS ABOUT 20 KTS. BUT EVEN THIS IS DECEIVING IF RAINFALL RATES ARE 2-3 INCHES PER HOUR AT TIMES...AND STILL SUGGESTS A QUICK COUPLE OF INCHES OF RAIN IN THE MORE VIGOROUS CELLS. WITH ANY LOCALIZED TRAINING...STILL A POTENTIAL FOR ISOLATED 3 TO 4 INCHES AMOUNTS OVERNIGHT. THE NAM IS LEANING TOWARD THE MORE PROGRESSIVE HRRR OVERNIGHT WITH THE GFS RAMPING UP CONVECTION BETWEEN 00-06Z ON THE NOSE OF THE INCREASING LOW LEVEL JET ALONG THE INVERTED TROUGH WITHIN THE ZONE OF MAXIMUM SFC CONVERGENCE. THE QPF MAX IS CENTERED OVER HIGHWAY 30...ROUGHLY BETWEEN US 20/I80 FROM GREENE TO MARSHALL COUNTIES. WITH THAT ADDED UNCERTAINTY TONIGHT AND THE POSSIBLE NORTHERLY SHIFT BY 20 MILES OF THE QPF MAX...WILL BE ADDING ONE ROW OF COUNTIES TO TONIGHTS FFA ALONG US 20. REALIGNING THE WATCH NOW IS RISKY...DUE TO THE POSSIBILITY OF THE MODELS ARE NOT PROPERLY ACCOUNTING FOR A STRONGER OUTFLOW BOUNDARY LATER IN THE EVENING...WHICH WOULD THEN BE FEEDING OFF AN INCREASING LOW LEVEL JET OVERNIGHT. THERE MAY ACTUALLY BE TWO FAVORED AREAS OF HEAVY RAINFALL...EARLIER BETWEEN US20/30 AND LATER ALONG AND SOUTH OF I80. NONE THE LESS...THE RISK FOR FLASH FLOODING AND SUBSEQUENT ISSUES REMAINS. TIMING OF THE EVENT SUGGESTS THAT STORMS SHOULD BE IN FULL SWING BETWEEN 02-09Z WITH ACTIVITY REMAINING STRONG BUT SLOWLY DIMINISHING BETWEEN 09-13Z MONDAY OVER THE SOUTH/SOUTHEAST. LOWS TONIGHT WILL FALL TO THE LOWER 70S SOUTH TO NEAR 60 OVER THE FAR NORTHWEST AS THE COOLER AIR BEGINS TO FILTER INTO THE REGION TONIGHT. TONIGHTS RAINFALL WILL PRIME THE REGION FOR A MORE SIGNIFICANT RISK OF FLOODING MONDAY NIGHT AND THIS IS COVERED IN THE EXTENDED DISCUSSION. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 305 PM CDT SUN SEP 6 2015 A POTENTIALLY SIGNIFICANT HEAVY RAIN AND FLOODING EVENT MAY BE SHAPING UP EARLY THIS WEEK. THE COLD FRONT SAGGING DOWN INTO IOWA TONIGHT...AS DISCUSSED IN THE SHORT TERM SECTION ABOVE...WILL LIKELY STALL ACROSS SOUTHERN IOWA BY MONDAY MORNING THEN RETREAT BACK NORTHWARD A BIT TOWARD CENTRAL IOWA DURING THE DAY. DESTABILIZATION WILL BE LIMITED BY DEBRIS CLOUDS AND A LACK OF LOW LEVEL WARM AIR ADVECTION OVER MOST OF THE FORECAST AREA...PLUS THERE WILL BE NO LARGE SCALE FORCING MECHANISM FOR CONVECTION FOR MOST OF THE DAY. NEVERTHELESS THE AIRMASS WILL BE JUICED ENOUGH WITH THE BOUNDARY WOBBLING AROUND THAT LOW POPS ARE MAINTAINED ON MONDAY. BEGINNING LATE MONDAY AFTERNOON AND ESPECIALLY ON MONDAY NIGHT THE ATMOSPHERE APPEARS TO BE SETTING UP FOR A SIGNIFICANT...POSSIBLY EXTREME HEAVY RAINFALL EVENT. ALONG AND SOUTH OF THE NEARLY STATIONARY FRONTAL ZONE PWAT VALUES WILL BE NEAR RECORDS WITH SUBSTANTIAL MOISTURE TRANSPORT CONTINUING FROM THE GULF ESPECIALLY AS THE NOCTURNAL LOW LEVEL JET KICKS IN AFTER DARK. CONCURRENTLY...A SECOND FAIRLY ROBUST MID LEVEL SHORTWAVE WILL ROUND THE BASE OF BROAD CYCLONIC FLOW ALOFT AND PROVIDE A TRIGGER FOR WIDESPREAD THUNDERSTORM DEVELOPMENT. WITH WARM CLOUD DEPTHS IN EXCESS OF 15 KFT IN FORECAST SOUNDINGS AND THE COMBINATION OF OTHER FACTORS...WE WILL BE PRIMED FOR VERY EFFICIENT RAINFALL RATES AND POTENTIALLY TRAINING OR SLOW MOVING STORMS NEAR THE FRONTAL ZONE. THIS COULD LEAD TO WIDESPREAD RAINFALL AMOUNTS IN THE 2 TO 3 INCH RANGE WITHIN A BROAD SWATH ACROSS THE AREA...AND LOCALIZED AMOUNTS OF 6 INCHES OR MORE ARE DEFINITELY CONCEIVABLE. IN TERMS OF THE FLOODING EFFECTS OF SUCH RAINFALL...MUCH WILL DEPEND ON WHERE IT FALLS AND WHETHER IT OCCURS IN THE SAME AREA AS THE HEAVIEST RAINFALL TONIGHT...WHICH IS IN TURN DEPENDENT ON THE DIFFICULT TO PREDICT MOTIONS AND LOCATION OF THE FRONTAL BOUNDARY BY MONDAY EVENING. IT IS LIKELY...IN ANY EVENT...THAT A SECOND FLASH FLOOD WATCH WILL BE NEEDED AFTER TONIGHTS RAINFALL PANS OUT...AND THAT IT MAY NEED TO HAVE EVEN STRONGER WORDING FOR THE POTENTIAL EFFECTS MONDAY NIGHT INTO TUESDAY MORNING. SCATTERED THUNDERSTORMS MAY CONTINUE TO FESTER ACROSS OUR SOUTHERN COUNTIES ON TUESDAY AS THE FRONTAL ZONE LINGERS NEAR THE IOWA/MISSOURI BORDER...BUT THEN ANOTHER SHORTWAVE TROUGH WILL MOVE OVERHEAD AROUND TUESDAY EVENING AND FINALLY CLEAR OUT THE WET AIRMASS TO OUR SOUTH. THIS WILL BRING AN END OF ANY HEAVY RAIN THREAT FOR THE REMAINDER OF THE SEVEN DAY FORECAST...ALONG WITH NOTABLY COOLER AND DRIER WEATHER ACROSS IOWA. THERE WILL BE A CHANCE FOR SCATTERED SHOWERS AND STORMS AROUND THURSDAY AS A REINFORCING COLD FRONT SURGES ACROSS THE STATE...USHERING IN THE FIRST TRULY AUTUMNAL WEATHER OF THE SEASON AT THE END OF THIS WEEK WITH FRIDAY HIGHS IN THE 60S AND FRIDAY NIGHT LOWS IN THE 40S STATEWIDE. && .AVIATION...07/06Z ISSUED AT 1222 AM CDT MON SEP 7 2015 SOME STORMS TO STILL IMPACT KOTM KDSM AND KALO THROUGH THE OVERNIGHT HOURS...WITH FOG CHANCES AT THE NORTHERN SITES LOOKING SOMEWHAT UNCERTAIN. WINDS TO SHIFT AROUND TO THE SOUTHEAST TO SOUTH AGAIN LATE IN THE FORECAST PERIOD...WITH ANOTHER ROUND OF STORMS POSSIBLE BEGINNING LATE MONDAY AFTERNOON INTO MONDAY NIGHT. CIGS TO BE IN THE MVFR TO LOW VFR RANGE...BUT MAY DIP INTO IFR IF FOG DEVELOPS. && .HYDROLOGY... ISSUED AT 305 PM CDT SUN SEP 6 2015 AS REFERENCED IN THE PREVIOUS DISCUSSIONS...TWO HEAVY RAINFALL EVENTS ARE POSSIBLE TONIGHT THROUGH TUESDAY MORNING WITH THE FOCUS FROM NORTH CENTRAL TO SOUTHERN IOWA. WIDESPREAD RAINFALL AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED WITH AMOUNTS EXCEEDING 5 INCHES POSSIBLE DURING THIS PERIOD. MONDAY NIGHTS EVENT IS STILL EXPECTED TO BE OF GREATER MAGNITUDE...SO SOME REEVALUATION OF THE WATCH OUTLINE WILL OCCUR BETWEEN THIS EVENING AND TOMORROW MORNING AFTER TONIGHTS RAINFALL REPORTS ARE GATHERED. IN BOTH EVENTS...EFFICIENT RAIN PRODUCING STORMS WILL PRODUCE HEAVY RAINFALL OVER A SHORT PERIOD OF TIME. SIGNIFICANT RUNOFF AND/OR PONDING OF WATER IS LIKELY IN SOME AREAS LEADING TO A FLASH FLOOD THREAT. THE EVENT MAY EVOLVE INTO A RIVER FLOODING THREAT THROUGH MID TO LATE WEEK AS THE RUNOFF REACHES THE LARGER STREAMS. THE MAGNITUDE OF RIVER FLOODING ON ANY GIVEN MAINSTEM RIVER WILL DEPEND ON BOTH RAINFALL AMOUNTS AND BASIN COVERAGE IN THE NEXT 48 TO 60 HOURS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR ADAIR-ADAMS- APPANOOSE-AUDUBON-BOONE-CASS-CLARKE-DALLAS-DAVIS-DECATUR-GREENE- GUTHRIE-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POLK- POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...REV LONG TERM...LEE AVIATION...BEERENDS HYDROLOGY...REV  FXUS63 KDMX 071002 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 502 AM CDT MON SEP 7 2015 .SHORT TERM /TODAY/... ISSUED AT 459 AM CDT MON SEP 7 2015 THUNDERSTORMS HAVE PERSISTED THROUGHOUT THE NIGHT ALONG A BOUNDARY FROM SOUTHERN NE TO EASTERN IOWA. SYSTEM WILL CONTINUE TO PUSH SLOWLY SOUTH/SOUTHEAST THROUGH THE EARLY MORNING HOURS...WITH PRECIPITATION PERSISTING IN THE SOUTHERN AND SOUTHEASTERN PORTIONS OF THE CWA. WHILE WILL GENERALLY SEE A DOWNWARD TREND IN PRECIPITATION INTENSITY AS SYSTEM PUSHES SOUTH...THUNDERSTORMS WILL REMAIN CAPABLE OF HEAVY RAINFALL AND MAY CONTINUE TO TRACK OVER AREAS WHICH HAVE ALREADY SEEN HEAVY RAINFALL TOTALS TONIGHT. THEREFORE...WILL KEEP FLASH FLOOD WATCH FOR SOUTHERN PORTIONS OF THE CWA...AND WILL LET GO FOR NORTHERN PORTIONS OF THE WATCH AREA WHERE ADDITIONAL HEAVY PRECIPITATION IS NOT EXPECTED THIS MORNING. FOCUS WILL THEN TURN TO PRECIPITATION TRENDS FOR TODAY. BOUNDARY WILL BEGIN TO LIFT BACK NORTH...AND EXTENT OF NORTHERN PUSH WILL HAVE MAJOR IMPACT ON FORECAST FOR REMAINDER OF DAY. MODELS HAVE GENERALLY NOT HAD A GOOD HANDLE ON OVERNIGHT CONVECTION...WITH GFS SEEMING TO PERFORM THE BEST...AND ECMWF COMING MORE IN LINE WITH GFS. THEREFORE HAVE TRENDED TOWARDS GFS FOR REMAINDER OF THE FORECAST...WHICH BRINGS BOUNDARY BACK INTO SOUTHERN IOWA LATE IN THE PERIOD. WITH BOUNDARY LINGERING CLOSE TO SOUTHERN IOWA HAVE KEPT CHANCE POPS THROUGH THE DAY...THOUGH DO NOT HAVE HIGH CONFIDENCE. EXPECT BEST CHANCE FOR THUNDERSTORMS TO COME WITH AFTERNOON DESTABILIZATION WITH THUNDERSTORMS FIRING ALONG BOUNDARY...WITH BEST CHANCES ACROSS THE WEST WITH BETTER RECOVERY BEHIND MORNING PRECIPITATION. GIVEN UNCERTAINTY IN PLACEMENT OF BOUNDARY...STILL DO NOT HAVE HIGH CONFIDENCE IN PRECIPITATION. IF STORMS DO PUSH INTO IOWA COULD SEE SEVERE WITH CAPE VALUES NEAR 2000 J/KG. WITH SOMEWHAT LACKLUSTER SHEAR...BIGGEST THREAT FOR SEVERE HAZARDS WOULD BE HAIL AND WINDS...AND FEEL SPC MARGINAL OUTLOOK IS SUFFICIENT FOR NOW. PWAT VALUES WILL REMAIN HIGH...NEAR OR ABOVE 2 INCHES...THROUGH THE DAY AND THUNDERSTORMS WILL BE CAPABLE OF ADDITIONAL HEAVY RAINFALL. THEREFORE...IF THUNDERSTORMS DEVELOP IN CENTRAL IOWA IN THE LATE AFTERNOON...MAY NEED TO CHANGE START TIME OF TONIGHT/S FLASH FLOOD WATCH EARLIER. TEMPERATURES WILL NOT BE AS WARM AS PREVIOUS DAYS. HAVE INCREASED TEMPS IN THE SOUTH...THOUGH PRECIPITATION TRENDS COULD HAMPER WARMING. HOWEVER...WITH AMPLE MOISTURE AROUND HUMID CONDITIONS WILL AGAIN PREVAIL WITH HEAT INDEX VALUES IN THE 90S IN THE SOUTHERN PORTIONS OF THE CWA. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 459 AM CDT MON SEP 7 2015 PRIMARY CONCERN OBVIOUSLY REMAINS CONVECTIVE TRENDS AND ADDITIONAL HEAVY RAINS TONIGHT INTO EARLY TUESDAY MORNING. SYNOPTIC SITUATION WILL TRY TO CHANGE BRIEFLY HEADING INTO TONIGHT AS CURRENT NE/KS 1- 3KM RIDGE TRIES TO PUSH THE FRONTAL BOUNDARY AND ASSOCIATED CONVERGENCE ZONE A BIT FARTHER SOUTH. THE RIDGE WILL BE MOVING ACROSS IA DURING THE AFTERNOON HOWEVER RESULTING IN ANOTHER SURGE OF MOISTURE TRANSPORT AND THETA-E ADVECTION AROUND 00Z AND LASTING INTO THE NIGHT. FLOW WILL NOT BE EXTREME...AS NOTED BY ONLY 25-30KT WINDS ALONG 305K ISENT SURFACE...BUT ENVIRONMENT MAY OFFSET THIS INFLOW DEFICIENCY WITH CONDITIONS STILL VERY FAVORABLE FOR EFFICIENT HEAVY RAINS. THE SITUATION BY 06Z SHOULD MIRROR WHAT OCCURRED OVERNIGHT WITH WARM CLOUD DEPTHS 4KM OR MORE...PWATS OVER 2 INCHES AND SIMILAR MOISTURE TRANSPORT. CLIMATOLOGICALLY THE SCENARIO IS NOTABLE WITH 00Z NAEFS PWATS...LOW LEVEL SPECIFIC HUMIDITY AND INTEGRATED MOISTURE TRANSPORT ALL WELL INTO THE 90TH PERCENTILE AND OFTEN PUSHING ALL TIME EXTREMES. MANY AREAS HAVE BEEN WELL PRIMED BY HEAVY RAINS OVERNIGHT SO HAVE EXPANDED CURRENT FLASH FLOODING IN SPACE AND TIME...NOW INTO TONIGHT AND INCLUDING ALL AREAS ALONG AND SOUTH OF HIGHWAY 30. THERE IS SOME SPREAD IN THE DETERMINISTIC AND ENSEMBLE SOLUTIONS LATITUDINALLY...BUT THE CONSENSUS FAVORS THE SRN HALF OF IOWA AND THIS MAKES SENSE CONSIDERING THE CURRENT PLACEMENT OF THE MCS. CANNOT SEE CONVERGENCE AND BAROCLINIC ZONE JUMPING THAT FAR NORTH IN LESS THAN 24 HOURS. BOTH THE 00Z NCAR HI RES ENSEMBLE AND 21Z SREF CONSENSUS SUPPORTS THIS AS WELL. ALTHOUGH OVERNIGHT HEAVY RAINS WERE NOT WIDESPREAD...LOCALIZED AREAS THAT SAW THREE TO SEVEN INCHES OF RAIN OVERNIGHT AND PRIMED FOR SERIOUS FLASH FLOODING IF THEY ARE HIT ONCE AGAIN. HEAVY RAINS MAY BLEED INTO TUE AS SECONDARY AREA OF FORCING ASSOCIATED WITH SHORT WAVE OFF THE BC COAST REACHES IA. GFS IS MORE AGGRESSIVE WITH THIS THAN THE ECMWF...WHICH PUSHES BOUNDARY THROUGH FASTER...SO HEADLINE MAY NEED TO BE EXPANDED IF GFS SOLUTION MATERIALIZES BUT CONFIDENCE IS NOT GREAT ENOUGH FOR THIRD PERIOD WATCH AT THIS TIME. AIRMASS WILL THEN FINALLY CHANGE CONSIDERABLY ONCE THE FRONT FINALLY PUSHES THROUGH THE MUCH DRIER CONDITIONS AND DEWPOINTS. RELATIVELY WEAK BUT BROAD CENTRAL CONUS TROUGH WILL SETTLE IN TO START THE EXTENDED PERIOD...BUT BECOME MORE AMPLIFIED WITH TIME LEADING TO SOME FORM OF GREAT LAKES/NRN OH VALLEY TROUGH FOR THE WEEKEND. THIS WILL KEEP THE FORECAST COOLER WITH MUCH LESS SIGNIFICANT PRECIP CHANCES. THIS FIRST WILL BE WITH NRN STREAM SHORT WAVE AROUND THU...AND THEN AGAIN INTO THE WEEKEND WITH WARM ADVECTION RETURNING AGAIN. && .AVIATION...07/06Z ISSUED AT 1222 AM CDT MON SEP 7 2015 SOME STORMS TO STILL IMPACT KOTM KDSM AND KALO THROUGH THE OVERNIGHT HOURS...WITH FOG CHANCES AT THE NORTHERN SITES LOOKING SOMEWHAT UNCERTAIN. WINDS TO SHIFT AROUND TO THE SOUTHEAST TO SOUTH AGAIN LATE IN THE FORECAST PERIOD...WITH ANOTHER ROUND OF STORMS POSSIBLE BEGINNING LATE MONDAY AFTERNOON INTO MONDAY NIGHT. CIGS TO BE IN THE MVFR TO LOW VFR RANGE...BUT MAY DIP INTO IFR IF FOG DEVELOPS. && .HYDROLOGY... ISSUED AT 459 AM CDT MON SEP 7 2015 HEAVY RAINS OVERNIGHT WERE EXTREME...BUT FAIRLY LOCALIZED IN THE RACCOON RIVER BASIN SO LATEST FORECASTS INCORPORATING THAT RUNOFF ONLY EXPECT WITHIN BANK RISES OR MINOR FLOODING FOR THE TIME BEING. THIS MAY CHANGE INTO TONIGHT HOWEVER DEPENDING ON WHERE ADDITIONAL HEAVY RAINS FALL. THUS HAVE OPTED FOR HYDROLOGIC OUTLOOKS RATHER THAN FLOOD WARNINGS UNTIL CONFIDENCE INCREASES. SIMILAR THINKING FOR SRN IOWA SITES WHICH SAW LESSER...BUT STILL FAIRLY HEAVY RAINS. ADDITIONAL RIVER FORECASTS THIS MORNING WILL BE HEAVILY INFLUENCED BY FORECAST RAINFALL...WITH BASIN AVERAGE RAINS TWO TO THREE INCHES SOUTH OF I80. THIS MAY LEAD AGGRESSIVE FLOODING FORECASTS FOR THOSE LOCATIONS...BUT AGAIN LOW CONFIDENCE AS THOSE BASINS ARE SMALLER AND RAINFALL AMOUNTS COULD BE QUITE VARIABLE IN SPACE. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM THIS EVENING THROUGH TUESDAY MORNING FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BOONE-CARROLL-CASS-CLARKE-CRAWFORD- DALLAS-DAVIS-DECATUR-GREENE-GUTHRIE-JASPER-LUCAS-MADISON-MAHASKA- MARION-MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR- UNION-WAPELLO-WARREN-WAYNE. FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING AND THEN AGAIN TONIGHT FOR ADAMS-APPANOOSE-CLARKE-DAVIS-DECATUR-LUCAS-MAHASKA- MONROE-RINGGOLD-TAYLOR-UNION-WAPELLO-WAYNE. && $$ SHORT TERM...AWB LONG TERM...SMALL AVIATION...BEERENDS HYDROLOGY...SMALL  FXUS63 KDMX 072028 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 328 PM CDT MON SEP 7 2015 .SHORT TERM /TONIGHT/... ISSUED AT 327 PM CDT MON SEP 7 2015 HEAVY RAIN REMAINS THE CONCERN OF THE OVERNIGHT FORECAST. OVERNIGHT CONVECTION HAS LAID OUT AN OUTFLOW BOUNDARY OVER NORTHERN MISSOURI WHICH IS TIED BACK INTO THE LOW OVER KANSAS. THE SYNOPTIC BOUNDARY IS STILL OVER IOWA...STRETCHING FROM NEAR PRAIRIE DU CHIEN BACK WEST TO NEAR DENISON. H850 FRONT IS ALSO SITUATED OVER IOWA NOW. THE MODELS ARE HAVING DIFFICULTY WITH THE EVOLUTION OF THE CONVECTION TONIGHT...BUT AN OVERALL CONSENSUS IS FOR THE CENTRAL AND SOUTH TO RECEIVE THE BALANCE OF THE FORCING AND THUS...RAINFALL. THE NAM WAS FARTHER SOUTH WITH THE MAIN QPF AXIS TONIGHT...WHILE THE GFS LOOKS VERY SIMILAR TO LAST NIGHTS FARTHER NORTH PLACEMENT OVER IOWA...THIS TIME RIGHT OVER THE I80 CORRIDOR. THE OTHER MESO MODELS SHOW A VARIETY OF SOLUTIONS...WITH THE HIRES ARW HAVING A FOCUS FOR TWO AREAS OF HEAVY RAINFALL...ONE NEARER THE IA/MO BORDER AND ONE ALONG THE I80 CORRIDOR. THE LATEST HRRR RUN IS SHOWING TWO MAXIMA AS WELL...WITH A LESS ORGANIZED CLUSTERING THAN THE OTHER MODELS MENTIONED. A NUMBER OF FACTORS ARE POINTING TOWARD TWO MAXIMA...ONE THE H850 BOUNDARY IS ALREADY BECOMING ACTIVE OVER CENTRAL NEBRASKA AND THERE IS ALSO SOME DEVELOPMENT ALONG THE TRIPLE POINT IN SOUTHEAST NEBRASKA NEARER THE SFC LOW...COOL FRONT...AND OUTFLOW BOUNDARY INTERSECTION. THE SOUTHERN CLUSTER WILL FOLLOW THE BOUNDARY UNTIL IT IS LIFTED NORTH THIS EVENING...WHILE THE NORTHERN AREA WILL CONTINUE TO FILL IN THROUGH THE EVENING HOURS. AS THE LOW LEVEL JET KICKS IN BETWEEN 02-03Z THIS EVENING...THE COVERAGE AND INTENSITY OF THE CONVECTION SHOULD INCREASE. NOTHING MUCH HAS CHANGED WITH REGARD TO THE AVAILABLE MOISTURE...STILL RUNNING ABOUT 2.30 INCH PWATS AT 06Z OVER THE SOUTH THIRD WITH WARM CLOUD DEPTHS PUSHING 13.8 KFT AT OVERNIGHT. THE SCENARIO IS PRETTY MUCH THE SAME FOR EFFICIENT RAINFALL PROCESSES TONIGHT...SO HAVE GENERALLY GONE ABOUT 1 TO 2 INCHES ACROSS THE SOUTH WITH THE EXPECTATION THAT THERE MAY BE SOME TOTALS IN THE 4 TO 5 INCH RANGE BY MORNING. AS THE LOW PUNCHES NORTH THIS EVENING...LOWS WILL REMAIN WARM SOUTH/SOUTHEAST WITH SLIGHTLY COOLER NORTHWEST. SHOWERS WILL HOLD ON IN THE SOUTHEAST. WITH LIGHT WINDS IN THE MORNING...PATCHY TO AREAS OF FOG MAY ALSO DEVELOP. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 327 PM CDT MON SEP 7 2015 THE LONG TERM FORECAST GROWS GENERALLY MORE AUTUMNAL AS A SERIES OF NORTHERN STREAM MID/UPPER LEVEL TROUGHS ROUNDING BROAD CYCLONIC FLOW KEEP THE MORE SUMMERLIKE WEATHER BENEATH A LARGE RIDGE SHUNTED OFF TO OUR SOUTH AND WEST. THE FIRST OF THESE TROUGHS WILL MOVE OVERHEAD ON TUESDAY...POSSIBLY GENERATING SOME ELEVATED SHOWERS AND THUNDERSTORMS MAINLY ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. HOWEVER...THE SURFACE FRONT SHOULD BE BLOWN THROUGH INTO MISSOURI BY TONIGHTS CONVECTION AND ANY SEVERE WEATHER OR HEAVY RAIN THREAT WILL BE SOMEWHAT DIMINISHED TOMORROW. THIS INITIAL TROUGH WILL ALSO FINALLY SCOUR OUT OUR WARM AND JUICY AIRMASS OUT OF IOWA...WITH A COOL AREA OF HIGH PRESSURE BRINGING DRY AND PLEASANT WEATHER BY WEDNESDAY. THE SECOND...SUBSTANTIALLY STRONGER MID/UPPER LEVEL TROUGH WILL DEEPEN AS IT MOVES OVER MINNESOTA AND WISCONSIN AROUND THURSDAY NIGHT AND FRIDAY. THIS WILL PUSH A MORE PRONOUNCED REINFORCING COLD FRONT ACROSS IOWA DURING THIS TIME FRAME...BRINGING CONSIDERABLY COOLER WEATHER FROM FRIDAY INTO SATURDAY. THE PASSAGE OF THE FRONT WILL LIKELY GENERATE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS AROUND THURSDAY NIGHT...BUT TIMING DIFFERENCES AMONG THE MODELS PROHIBIT GOING HIGHER THAN 20 OR 30 POPS AT THIS TIME. WHILE THE FORCING AND WIND FIELDS ASSOCIATED WITH THE PASSAGE OF THIS SYSTEM MAY BE ROBUST...INSTABILITY SHOULD BE LIMITED MITIGATING ANY SEVERE WEATHER THREAT. THE ALTERNATING PATTERN OF TROUGHS AND RIDGES WILL CONTINUE FROM THE WEEKEND INTO NEXT WEEK WITH SUNSHINE AND RECOVERING TEMPERATURES ON SUNDAY FOLLOWED BY ANOTHER COLD FRONT ON MONDAY OR MONDAY NIGHT...AND POSSIBLY ANOTHER AROUND WEDNESDAY OR THURSDAY OF NEXT WEEK THOUGH THAT IS BEYOND THE SEVEN DAY FORECAST PERIOD. OUTSIDE OF SOME LINGERING POTENTIAL FOR STRONG STORMS OR HEAVY RAIN ON TUESDAY...WHICH SHOULD BE AN ISOLATED THREAT...AND THE LOW POSSIBILITY OF PERHAPS A COUPLE OF BRIEFLY STRONG STORMS WITH THE FRONT AROUND THURSDAY NIGHT...THERE IS LITTLE IN THE WAY OF HAZARDOUS OR HEADLINE INDUCING WEATHER DURING THE NEXT SEVEN DAYS. OVERALL IT WILL BE COOLER...DRY...AND STARTING TO FEEL LIKE FALL ACROSS IOWA. && .AVIATION...07/18Z ISSUED AT 104 PM CDT MON SEP 7 2015 CHALLENGES REMAIN FOR TONIGHT...PARTICULARLY WITH THE PLACEMENT OF HEAVIEST THUNDERSTORMS AND SOMEWHAT ON TIMING. MESO MODELS HAVE SLOWED DEVELOPMENT/EASTWARD PROGRESSION A BIT...BUT CURRENT TRENDS OVER NEBRASKA SUGGEST THE GFS HAS A HANDLE ON DEVELOPMENT. HAVE TAKEN A BLENDED APPROACH FOR NOW. LOW STRATUS TRYING TO BREAK NORTH AND HAVE LIFTED DECK AFT 20Z FOR A FEW HOURS. EXPECT A ROUND OF HEAVY RAINFALL AGAIN TONIGHT...FOCUSED BETWEEN I80 AND IA/MO BORDER AFFECTING MAINLY KDSM AND KOTM. CIGS WILL LOWER SIGNIFICANTLY BY 11Z MOST AREAS WITH BF/FG FORMING AS WELL. SOME IMPROVEMENT TOWARD 18Z AS WINDS BECOME MORE NW...BUT WILL STILL SEE SOME LINGERING STRATUS. /REV && .HYDROLOGY... ISSUED AT 327 PM CDT MON SEP 7 2015 EVEN WITH THE RESPITE IN RAIN TODAY...WE STILL REMAIN PRIMED FOR ADDITIONAL RISES IN RIVERS OVER THE NEXT SEVERAL DAYS. LAST NIGHTS EXTREME RAINS WERE FAIRLY LOCALIZED IN THE RACCOON RIVER BASIN AND WITH ADDITIONAL RAINFALL TONIGHT...SOME LOCATIONS MAY REACH MODERATE CATEGORY ACROSS CENTRAL IOWA. CONFIDENCE ON TONIGHTS RAINFALL IS SOMEWHAT LIMITED DUE TO LAST NIGHTS CONVECTION AND THE EXPECTED RECOVERY OF STORMS LATER TONIGHT FARTHER WEST IN NEBRASKA. IF THE STORMS FOLLOW A SIMILAR EVOLUTION TO LAST NIGHT...THE RACCOON RIVER WOULD BE FURTHER AFFECTED...ALONG WITH SOME IMPACTS FOR STREAMS AND CREEKS OVER CENTRAL AND SOUTHERN IOWA...LEADING TO LOCALIZED FLASH FLOODING OVERNIGHT AND ADDITIONAL RISES TO MAIN STEM RIVERS AND POSSIBLE RIVER FLOOD WARNINGS IN THE NEXT FEW DAYS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH TUESDAY MORNING FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BOONE-CARROLL-CASS- CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-GREENE-GUTHRIE-JASPER-LUCAS- MADISON-MAHASKA-MARION-MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD- STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...REV LONG TERM...LEE AVIATION...REV HYDROLOGY...REV  FXUS63 KDMX 080844 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 344 AM CDT TUE SEP 8 2015 .SHORT TERM /TODAY/... ISSUED AT 330 AM CDT TUE SEP 8 2015 FOCUS OBVIOUSLY ON WIDESPREAD CONVECTION ACROSS CENTRAL IOWA THIS MORNING AND POTENTIAL FOR HEAVY RAIN. STRONG LOW LEVEL JET AND MOISTURE TRANSPORT CONTINUES INTO IOWA EARLY THIS MORNING FEEDING EXPANDING AREA OF CONVECTION. THESE STORMS HAVE INCREASED IN COVERAGE OVER THE PAST FEW HOURS AS SHORTWAVE APPROACHES WITH STRONG MID LEVEL FORCING HELPING GENERATE ADDITIONAL LIFT. MODELS HAVE SHIFTED HEAVIEST AXIS OF PRECIPITATION FARTHER NORTH ACROSS THE STATE OVER THROUGH MIDDAY WHERE FORCING AND LOW LEVEL CONVERGENCE WILL BE STRONGEST. MAIN CONCERN GOING FORWARD WILL BE HEAVY RAIN THREAT AS SEVERE POTENTIAL WILL BE LIMITED...ALTHOUGH NOT ENTIRELY GONE AS STRONG WINDS REMAIN A THREAT. THE HEAVY RAIN DISCUSSION WILL BE COVERED IN THE HYDROLOGY SECTION BELOW. FORTUNATELY...THE WAVE WILL REMAIN PROGRESSIVE THROUGH THIS MORNING WITH BULK OF CONVECTION SLIDING EASTWARD BY MIDDAY AND HEAVY RAIN THREAT SUBSIDING. HOWEVER...SOME LINGERING CHANCES FOR ISOLD/SCT REDEVELOPMENT BEHIND THE SURFACE FRONT ACROSS THE SOUTHERN HALF/TWO- THIRDS OF FORECAST AREA THIS AFTERNOON AS SOME MID LEVEL FORCING WILL PERSIST. TEMPERATURES TO REMAIN AROUND NORMAL TODAY AS COLD ADVECTION DOESNT REALLY INCREASE UNTIL LATER THIS AFTERNOON/EVENING. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 330 AM CDT TUE SEP 8 2015 MAIN LONG TERM FORECAST CONCERNS INCLUDE LINGERING PCPN CHANCES SOUTH TONIGHT...THEN PCPN CHANCES LATER IN THE WEEK...FOLLOWED BY RENEWED PCPN CHANCES EARLY TO MIDDLE NEXT WEEK. THE ADVERTISED UPPER-LEVEL FLOW DURING THE LONG TERM PERIOD IS MORE FALL-LIKE THAN THE PAST SEVERAL DAYS...WITH PROGRESSIVE FEATURES IMPACTING THE CWA. TONIGHT...POPS DECREASE FROM NORTHWEST TO SOUTHEAST AS DEPARTING SHORTWAVE PUSHES FRONTAL BOUNDARY/BOUNDARIES THAT HAVE LINGERED INVOF THE CWA PUSH TOWARD THE SOUTHEAST. ALTHOUGH LOCALLY HEAVY RAINFALL IS POSSIBLE AGAIN...HAVE HELD OFF ON ANY FLASH FLOOD WATCH HEADLINES FOR TONIGHT AT THIS TIME. THE FRONTAL BOUNDARY IS EXPECTED TO MOVE MORE SWIFTLY LATER TODAY/TONIGHT. IN ADDITION...THE AREAS OF THE CWA MOST LIKELY TO SEE THE RAINFALL TONIGHT HAVE NOT SEEN IT THE PAST FEW DAYS...THUS CAN TAKE MORE RAINFALL BEFORE FLASH FLOODING BECOMES A CONCERN. WEDNESDAY NIGHT INTO THURSDAY NIGHT...A SHORTWAVE BRINGS A FRONTAL BOUNDARY AND RENEWED PCPN CHANCES TO THE CWA. THERE IS SOME MODEL DISAGREEMENT DURING THIS TIME FRAME...WITH THE ECMWF DEEPER/STRONGER WITH THE SHORTWAVE THAN THE GFS. BEST ISENTROPIC LIFT IS SHOWN AT THE 305K LEVEL...AND TRANSLATES FROM WEST TO EAST ACROSS THE CWA. SVR POTENTIAL WILL BE MINIMAL...DUE IN PART TO TIMING OF THE BOUNDARY...WHICH IS PROGGED TO BE IN THE FAR SOUTHEASTERN CWA BY LATE AFTN/EVENING THU. FRIDAY...HAVE SLIGHT CHANCE POPS IN THE FAR SOUTHERN CWA. THETA-E ADVECTION COMBINED WITH THE FRONTAL BOUNDARY ACROSS NORTHERN MISSOURI MAY BRING SHRA/TSRA TO THE SOUTHERN CWA. MODEL DISAGREEMENT CONTINUES...WITH THE ECMWF STILL DEEPER/STRONGER WITH THE SHORTWAVE THAN THE GFS. OVER THE WEEKEND...MODEL DIFFERENCES BECOME GREATER. THE ECMWF CARVES OUT AN UPPER-LEVEL LOW ACROSS THE LOWER TO MIDDLE OHIO RIVER VALLEY...WHILE THE GFS IS MORE PROGRESSIVE AND REFLECTS MAINLY A SHORTWAVE. MODELS COME CLOSER INTO AGREEMENT BY EARLY INTO NEXT WORK WEEK. EVEN WITH THE MODEL DIFFERENCES...WX IS EXPECTED TO BE QUIET ACROSS THE CWA. SUNDAY NIGHT INTO MONDAY NIGHT...SHORTWAVE WILL PUSH ANOTHER BOUNDARY SOUTHEASTWARD TOWARD THE CWA. BEST KINEMATIC FORCING REMAINS NORTH OF THE CWA. HOW FAR SOUTH THE PCPN DEVELOPS WILL DEPEND IN PART ON THE THERMODYANMIC FORCING...WHICH LOOKS MODEST AT BEST. TUESDAY/TUESDAY NIGHT...LIKELY THE MOST POTENT DISTURBANCE OF THE LONG TERM PERIOD /PER THE GFS/ IS PROGGED TO AFFECT THE CWA. THIS TIME THE GFS IS DEEPER/STRONGER WITH THE UPPER LEVEL FEATURES THAN IS THE ECMWF. THE SURFACE BOUNDARY FROM EARLIER IN THE WEEK IS LIFTED NORTHWARD AS A WARM FRONT IN THE WAA REGIME AHEAD OF THE SHORTWAVE. ALTHOUGH GOING BEYOND THE LONG TERM FORECAST WINDOW...BOTH KINEMATIC AND THERMODYNAMIC FORCING IS IMPRESSIVE LATE TUESDAY NIGHT INTO WEDNESDAY. TEMPERATURES DURING THE LONG TERM PERIOD WILL BE MORE FALL-LIKE THAN THOSE OF LATE...WITH HIGHS IN THE 70S AND LOWS GENERALLY IN THE 50S. THE COOLEST OVERNIGHT LOWS ARE EXPECTED ON FRIDAY NIGHT...AFTER THE PASSAGE OF THE LATE-WEEK FRONTAL BOUNDARY...WITH LOWS RANGING FROM THE MIDDLE 40S NORTH TO AROUND 50 SOUTH. && .AVIATION...08/06Z ISSUED AT 1155 PM CDT MON SEP 7 2015 COMPLICATED FORECAST WITH A STALLED BOUNDARY ACROSS CENTRAL IOWA AND AN APPROACHING SHORTWAVE WITH AN INCREASING LOW LEVEL JET. MAIN AREA OF CONVECTION WILL BE STORMS BLOSSOMING ACROSS NEBRASKA PUSHING INTO TAF LOCATIONS LATE TONIGHT...08Z-12Z. A SECOND AREA OF CONVECTION OVER FSD AREA WILL MOVE ACROSS NORTHERN IOWA. ALTHOUGH HEAVY RAIN IS POSSIBLE ANYWHERE ACROSS IOWA THE BETTER POTENTIAL WILL REMAIN ACROSS THE SOUTHERN IOWA. MVFR WITH LCL IFR CONDITIONS WILL PERSIST THROUGH 12Z-15Z WITH SLOW IMPROVEMENT NW TO SE. SFC FLOW WILL BE EAST TO SOUTHEAST THEN BECOME NORTHERLY. && .HYDROLOGY... ISSUED AT 330 AM CDT TUE SEP 8 2015 SCENARIO UNFOLDING SOMEWHAT DIFFERENTLY THAN EARLIER THOUGHT AS MONDAY EVENING CONVECTION REMAINED PRIMARILY WEST AND SOUTH OF THE FORECAST AREA. CURRENT CONVECTION IS NOW EXPANDING/INCREASING IN NORTHERN IOWA IN AREA OF INCREASING MID LEVEL LIFT AND ON NOSE OF LOW LEVEL JET AND MOISTURE TRANSPORT. FLASH FLOOD THREAT HAS SHIFTED FARTHER NORTH AND HAVE EXPANDED WATCH TO INCLUDE THE ENTIRE FORECAST AREA. MOISTURE TRANSPORT WILL CONTINUE TO SHIFT EASTWARD THROUGH THE MORNING HOURS WITH FLASH FLOOD THREAT DIMINISHING FROM WEST TO EAST THROUGH MIDDAY. PWATS CONTINUE TO BE FROM 1.75 TO 2 INCHES ACROSS MUCH OF CENTRAL IOWA THIS MORNING WITH RELATIVELY GOOD WARM CLOUD DEPTH REMAINING SUPPORTIVE OF EFFICIENT AND HEAVY RAIN FROM STORMS. GIVEN THE RELATIVELY LOW VALUES OF FLASH FLOOD GUIDANCE ACROSS THE FORECAST AREA...WATCH STILL LOOKS GOOD ALTHOUGH RAINFALL AMOUNTS IN SOUTHERN IOWA WILL LIKELY BE LESS THAN PREVIOUSLY THOUGHT. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR ADAIR-ADAMS- APPANOOSE-BLACK HAWK-BOONE-BREMER-BUTLER-CLARKE-DALLAS-DAVIS- DECATUR-FRANKLIN-GRUNDY-HAMILTON-HARDIN-JASPER-LUCAS-MADISON- MAHASKA-MARION-MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD-STORY- TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE. FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR AUDUBON- CALHOUN-CARROLL-CASS-CERRO GORDO-CRAWFORD-EMMET-GREENE-GUTHRIE- HANCOCK-HUMBOLDT-KOSSUTH-PALO ALTO-POCAHONTAS-SAC-WEBSTER- WINNEBAGO-WORTH-WRIGHT. && $$ SHORT TERM...COGIL LONG TERM...ZOGG AVIATION...FAB HYDROLOGY...COGIL  FXUS63 KDMX 082042 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 342 PM CDT SAT AUG 8 2015 .SHORT TERM /TONIGHT/... ISSUED AT 342 PM CDT SAT AUG 8 2015 A COUPLE AREAS OF CONCERN THROUGH TONIGHT. FIRST...A SURFACE LOW HAS BEEN SLOWLY DEVELOPING AND MOVING INTO NORTH CENTRAL KANSAS THIS AFTERNOON...WITH AN EFFECTIVE WARM FRONT/REMNANT OUTFLOW BOUNDARIES FROM MORNING CONVECTION EXTENDING TO NEAR THE IOWA/MISSOURI BORDER. THERE IS A STOUT CAP IN PLACE...BUT IF CONVECTIVE TEMPERATURES ARE REACHED AND STORMS INITIATE ACROSS NORTHEAST KANSAS/SOUTHEAST NEBRASKA THEY WOULD MOVE EASTWARD NEAR OUR SOUTHERN BORDER WITH A DISTINCT SEVERE WEATHER THREAT GIVEN THE AMOUNT OF INSTABILITY AND LOW LEVEL SHEAR THAT WOULD BE PRESENT. HAVE MAINTAINED MID RANGE POPS ALONG OUR SOUTHERN BORDER THIS EVENING...BUT HELD OFF ON SEVERE WORDING FOR NOW GIVEN THE CONDITIONAL NATURE OF THE THREAT. IN WAKE OF ANY EVENING CONVECTION THAT OCCURS...OR DOESNT...A FAIRLY STRONG LOW LEVEL JET DEVELOPING AFTER SUNSET WILL PROVIDE THE IMPETUS FOR EVEN MORE LIKELY THUNDERSTORM DEVELOPMENT OVERNIGHT. THERE WILL REMAIN A SEVERE WEATHER THREAT IN THE FORM OF HAIL AND WIND DURING THIS TIME...BUT THE BIGGER CONCERN WILL BE FOR HEAVY RAIN AND FLASH FLOODING. PWAT VALUES ARE VERY HIGH...WARM CLOUD DEPTHS WILL BE NEARLY 15 KFT...AND THE LINGERING OUTFLOW BOUNDARIES NEAR THE IA/MO BORDER WILL PROVIDE A FOCUS FOR POTENTIALLY BACKBUILDING/REDEVELOPING ROUNDS OF STORMS ACROSS SOUTHERN IOWA. GIVEN THAT ANTECEDENT CONDITIONS ARE FAVORABLE FOR FLASH FLOODING IN THAT PART OF THE STATE...GIVEN RECENT RAINFALLS...AND THE VERY FAVORABLE ATMOSPHERIC PARAMETERS APPARENT...HAVE ISSUED A FLASH FLOOD WATCH FOR MOST AREAS FROM I-80 SOUTHWARD OVERNIGHT. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 342 PM CDT SAT AUG 8 2015 OVERALL ACTIVE LONG TERM PERIOD IN THE NEARER TERM...WITH CONDITIONS DRYING OUT FOR THE MID/LONG RANGE. AREA OF LOW PRESSURE ACROSS KS TO SLOWLY SINK SOUTHEASTWARD INTO SUNDAY...WITH THE FRONTAL BOUNDARY REMAINING IN PLACE FROM WEST TO EAST ACROSS THE SOUTHERN CWA. SOME LINGERING STORMS MAY BE PRESENT IN THE FAR SOUTHEAST IN THE MORNING...AND DEPENDING ON WHERE THE BOUNDARY SETS UP AGAIN FOR SUNDAY MAY SEE ACTIVITY LINGER INTO THE AFTERNOON HOURS ACROSS THE FAR SOUTH. MODELS DO TRY AND PUSH THE FRONT INTO NORTHERN MISSOURI WHICH WOULD KEEP SOUTHERN IOWA MAINLY DRY FOR SUNDAY AFTER THE EARLY MORNING ACTIVITY MOVES OUT. FOCUS THEN SHIFTS TO SUNDAY NIGHT AS ANOTHER UPPER LEVEL WAVE IS PROGGED TO DROP THROUGH THE DAKOTAS AND THROUGH IOWA LATE SUNDAY NIGHT INTO MONDAY. A STRONG COLD FRONT WILL MOVE THROUGH THE STATE WITH THIS WAVE WITH STORMS EXPECTED TO FIRE ALONG THE BOUNDARY ACROSS SOUTH DAKOTA SUNDAY AFTERNOON. MODELS THEN BRING AN MCS THROUGH IOWA IN THE LATE EVENING/OVERNIGHT HOURS...WITH POST-FRONTAL SHOWERS LINGERING INTO MONDAY. ALSO EXPECT DECENT CLOUD COVER LINGERING THROUGH MUCH OF THE DAY WITH H85 TEMPS DROPPING TO AROUND +14C. THEREFORE EXPECT RELATIVELY COOLER CONDITIONS FOR MONDAY WITH HIGHS IN THE 70S TO AROUND 80. LARGE AREA OF HIGH PRESSURE TO BUILD INTO THE REGION FOR TUESDAY INTO WEDNESDAY. A WEAK COLD FRONTAL BOUNDARY WILL DROP THROUGH THE CWA THURSDAY NIGHT ASSOCIATED WITH A WAVE MOVING THROUGH SE ONTARIO. THIS CURRENTLY LOOKS LIKE A DRY FRONTAL PASSAGE WITH MUCH OF THE LIFT CLOSER TO THE PARENT SYSTEM IN CANADA. UPPER RIDGING CONTINUES TO AMPLIFY ACROSS THE CENTRAL US INTO THE WEEKEND...WITH THE THERMAL RIDGE BUILDING AND DRY CONDITIONS EXPECTED. H85 TEMPS PUSH INTO THE 20S CELSIUS BY NEXT WEEKEND...SO EXPECT HIGHS TO CLIMB BACK INTO THE MID TO UPPER 80S IF NOT WARMER. && .AVIATION...08/18Z ISSUED AT 1232 PM CDT SAT AUG 8 2015 FOR THE REST OF THIS AFTERNOON VFR CONDITIONS ARE EXPECTED...BUT THEN SHRA/TSRA WILL REDEVELOP THIS EVENING AND TONIGHT PRODUCING LOCALIZED MVFR OR LOWER CONDITIONS. IN WAKE OF THE SHRA/TSRA...FORECAST SOUNDINGS INDICATE A LARGE AREA OF FOG AND STRATUS DEVELOPING ON THE BACKSIDE OF A SURFACE LOW/TROUGH MOVING ACROSS IOWA OVERNIGHT...WITH IFR OR LOWER CIGS/VSBYS A DISTINCT POSSIBILITY TOWARD SUNRISE SUNDAY. HAVE INCLUDED LOW MVFR CIGS/VSBYS AFTER MIDNIGHT IN THE 18Z TAFS...BUT THESE MAY NEED TO LOWER FURTHER IN SUBSEQUENT UPDATES...AND SHRA/TSRA TIMING WILL ALSO NEED TO BE REFINED. && .HYDROLOGY... ISSUED AT 342 PM CDT SAT AUG 8 2015 IT IS EXPECTED THAT A DEVELOPING LOW LEVEL JET WILL INITIATE THUNDERSTORM DEVELOPMENT OVER PARTS OF IOWA AFTER SUNSET TONIGHT...ESPECIALLY DURING THE EARLY MORNING HOURS ON SUNDAY. THERE IS SOME QUESTION AS TO HOW FAR NORTH OR SOUTH THESE STORMS MAY FORM...BUT SOUTHERN IOWA APPEARS THE BEST BET GIVEN THE LOCATION OF GREATEST INSTABILITY AND NASCENT OUTFLOW BOUNDARIES NEAR THE IOWA/MISSOURI BORDER. ANY STORMS THAT DO FORM OVERNIGHT WILL DO SO WITHIN AN ENVIRONMENT THAT IS VERY FAVORABLE FOR HEAVY RAIN...WITH PWAT VALUES OVER TWO INCHES AND WARM CLOUD DEPTHS OF NEARLY 15 KFT. IN ADDITION...THE AFOREMENTIONED BOUNDARIES JUST TO OUR SOUTH WILL PROVIDE AN ANCHOR FOR CONTINUING THUNDERSTORM DEVELOPMENT AND POTENTIAL BACKBUILDING. IN ADDITION...DESPITE ABOUT SIX DAYS OF RELATIVELY DRY WEATHER...SOIL MOISTURE REMAINS VERY HIGH IN SOUTHERN IOWA GIVEN THE HEAVY RAINFALL OF JULY/EARLY AUGUST...AND FLASH FLOOD GUIDANCE IS LOWER IN THIS AREA AS A RESULT. GIVEN THIS COMBINATION OF FACTORS...HAVE ISSUED A FLASH FLOOD WATCH TO COVER THE OVERNIGHT HOURS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH SUNDAY MORNING FOR ADAIR-ADAMS-APPANOOSE-CLARKE-DALLAS-DAVIS-DECATUR- JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE-POLK-RINGGOLD-TAYLOR- UNION-WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...LEE LONG TERM...BEERENDS AVIATION...LEE HYDROLOGY...LEE  FXUS63 KDMX 082345 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 645 PM CDT SAT AUG 8 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TONIGHT/... ISSUED AT 342 PM CDT SAT AUG 8 2015 A COUPLE AREAS OF CONCERN THROUGH TONIGHT. FIRST...A SURFACE LOW HAS BEEN SLOWLY DEVELOPING AND MOVING INTO NORTH CENTRAL KANSAS THIS AFTERNOON...WITH AN EFFECTIVE WARM FRONT/REMNANT OUTFLOW BOUNDARIES FROM MORNING CONVECTION EXTENDING TO NEAR THE IOWA/MISSOURI BORDER. THERE IS A STOUT CAP IN PLACE...BUT IF CONVECTIVE TEMPERATURES ARE REACHED AND STORMS INITIATE ACROSS NORTHEAST KANSAS/SOUTHEAST NEBRASKA THEY WOULD MOVE EASTWARD NEAR OUR SOUTHERN BORDER WITH A DISTINCT SEVERE WEATHER THREAT GIVEN THE AMOUNT OF INSTABILITY AND LOW LEVEL SHEAR THAT WOULD BE PRESENT. HAVE MAINTAINED MID RANGE POPS ALONG OUR SOUTHERN BORDER THIS EVENING...BUT HELD OFF ON SEVERE WORDING FOR NOW GIVEN THE CONDITIONAL NATURE OF THE THREAT. IN WAKE OF ANY EVENING CONVECTION THAT OCCURS...OR DOESNT...A FAIRLY STRONG LOW LEVEL JET DEVELOPING AFTER SUNSET WILL PROVIDE THE IMPETUS FOR EVEN MORE LIKELY THUNDERSTORM DEVELOPMENT OVERNIGHT. THERE WILL REMAIN A SEVERE WEATHER THREAT IN THE FORM OF HAIL AND WIND DURING THIS TIME...BUT THE BIGGER CONCERN WILL BE FOR HEAVY RAIN AND FLASH FLOODING. PWAT VALUES ARE VERY HIGH...WARM CLOUD DEPTHS WILL BE NEARLY 15 KFT...AND THE LINGERING OUTFLOW BOUNDARIES NEAR THE IA/MO BORDER WILL PROVIDE A FOCUS FOR POTENTIALLY BACKBUILDING/REDEVELOPING ROUNDS OF STORMS ACROSS SOUTHERN IOWA. GIVEN THAT ANTECEDENT CONDITIONS ARE FAVORABLE FOR FLASH FLOODING IN THAT PART OF THE STATE...GIVEN RECENT RAINFALLS...AND THE VERY FAVORABLE ATMOSPHERIC PARAMETERS APPARENT...HAVE ISSUED A FLASH FLOOD WATCH FOR MOST AREAS FROM I-80 SOUTHWARD OVERNIGHT. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 342 PM CDT SAT AUG 8 2015 OVERALL ACTIVE LONG TERM PERIOD IN THE NEARER TERM...WITH CONDITIONS DRYING OUT FOR THE MID/LONG RANGE. AREA OF LOW PRESSURE ACROSS KS TO SLOWLY SINK SOUTHEASTWARD INTO SUNDAY...WITH THE FRONTAL BOUNDARY REMAINING IN PLACE FROM WEST TO EAST ACROSS THE SOUTHERN CWA. SOME LINGERING STORMS MAY BE PRESENT IN THE FAR SOUTHEAST IN THE MORNING...AND DEPENDING ON WHERE THE BOUNDARY SETS UP AGAIN FOR SUNDAY MAY SEE ACTIVITY LINGER INTO THE AFTERNOON HOURS ACROSS THE FAR SOUTH. MODELS DO TRY AND PUSH THE FRONT INTO NORTHERN MISSOURI WHICH WOULD KEEP SOUTHERN IOWA MAINLY DRY FOR SUNDAY AFTER THE EARLY MORNING ACTIVITY MOVES OUT. FOCUS THEN SHIFTS TO SUNDAY NIGHT AS ANOTHER UPPER LEVEL WAVE IS PROGGED TO DROP THROUGH THE DAKOTAS AND THROUGH IOWA LATE SUNDAY NIGHT INTO MONDAY. A STRONG COLD FRONT WILL MOVE THROUGH THE STATE WITH THIS WAVE WITH STORMS EXPECTED TO FIRE ALONG THE BOUNDARY ACROSS SOUTH DAKOTA SUNDAY AFTERNOON. MODELS THEN BRING AN MCS THROUGH IOWA IN THE LATE EVENING/OVERNIGHT HOURS...WITH POST-FRONTAL SHOWERS LINGERING INTO MONDAY. ALSO EXPECT DECENT CLOUD COVER LINGERING THROUGH MUCH OF THE DAY WITH H85 TEMPS DROPPING TO AROUND +14C. THEREFORE EXPECT RELATIVELY COOLER CONDITIONS FOR MONDAY WITH HIGHS IN THE 70S TO AROUND 80. LARGE AREA OF HIGH PRESSURE TO BUILD INTO THE REGION FOR TUESDAY INTO WEDNESDAY. A WEAK COLD FRONTAL BOUNDARY WILL DROP THROUGH THE CWA THURSDAY NIGHT ASSOCIATED WITH A WAVE MOVING THROUGH SE ONTARIO. THIS CURRENTLY LOOKS LIKE A DRY FRONTAL PASSAGE WITH MUCH OF THE LIFT CLOSER TO THE PARENT SYSTEM IN CANADA. UPPER RIDGING CONTINUES TO AMPLIFY ACROSS THE CENTRAL US INTO THE WEEKEND...WITH THE THERMAL RIDGE BUILDING AND DRY CONDITIONS EXPECTED. H85 TEMPS PUSH INTO THE 20S CELSIUS BY NEXT WEEKEND...SO EXPECT HIGHS TO CLIMB BACK INTO THE MID TO UPPER 80S IF NOT WARMER. && .AVIATION...09/00Z ISSUED AT 645 PM CDT SAT AUG 8 2015 EXPECTING VFR CONDITIONS THROUGH MUCH OF THE EVENING BEFORE STORMS LOOK TO DEVELOP OVER CENTRAL TO SOUTHERN IOWA PAST 06Z. THE LATEST RAP13 HAS GOOD HANDLE ON CURRENT RADAR TRENDS AND FORECAST THROUGH THE OVERNIGHT HOURS AND HAVE HIGH CONFIDENCE DSM/OTM WILL SEE HEAVY RAIN AND TS OVERNIGHT. FOD WILL SEE A FEW SCATTERED STORMS THROUGH 03Z AS THIS WEAK ELEVATED CONVECTION CONTINUES. EXPECTING THIS ELEVATED CONVECTION TO REMAIN SOUTH OF MCW BUT ALO MAY SEE A FEW SPRINKLES BEFORE NEXT TAF UPDATE. HOWEVER...LOW CONFIDENCE IN DURATION AND ANY FLIGHT RESTRICTIONS AND LEFT OUT MENTION ATTM. && .HYDROLOGY... ISSUED AT 342 PM CDT SAT AUG 8 2015 IT IS EXPECTED THAT A DEVELOPING LOW LEVEL JET WILL INITIATE THUNDERSTORM DEVELOPMENT OVER PARTS OF IOWA AFTER SUNSET TONIGHT...ESPECIALLY DURING THE EARLY MORNING HOURS ON SUNDAY. THERE IS SOME QUESTION AS TO HOW FAR NORTH OR SOUTH THESE STORMS MAY FORM...BUT SOUTHERN IOWA APPEARS THE BEST BET GIVEN THE LOCATION OF GREATEST INSTABILITY AND NASCENT OUTFLOW BOUNDARIES NEAR THE IOWA/MISSOURI BORDER. ANY STORMS THAT DO FORM OVERNIGHT WILL DO SO WITHIN AN ENVIRONMENT THAT IS VERY FAVORABLE FOR HEAVY RAIN...WITH PWAT VALUES OVER TWO INCHES AND WARM CLOUD DEPTHS OF NEARLY 15 KFT. IN ADDITION...THE AFOREMENTIONED BOUNDARIES JUST TO OUR SOUTH WILL PROVIDE AN ANCHOR FOR CONTINUING THUNDERSTORM DEVELOPMENT AND POTENTIAL BACKBUILDING. IN ADDITION...DESPITE ABOUT SIX DAYS OF RELATIVELY DRY WEATHER...SOIL MOISTURE REMAINS VERY HIGH IN SOUTHERN IOWA GIVEN THE HEAVY RAINFALL OF JULY/EARLY AUGUST...AND FLASH FLOOD GUIDANCE IS LOWER IN THIS AREA AS A RESULT. GIVEN THIS COMBINATION OF FACTORS...HAVE ISSUED A FLASH FLOOD WATCH TO COVER THE OVERNIGHT HOURS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH SUNDAY MORNING FOR ADAIR-ADAMS-APPANOOSE-CLARKE-DALLAS-DAVIS-DECATUR- JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE-POLK-RINGGOLD-TAYLOR- UNION-WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...LEE LONG TERM...BEERENDS AVIATION...PODRAZIK HYDROLOGY...LEE  FXUS63 KDMX 102152 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 352 PM CST THU DEC 10 2015 .SHORT TERM /TONIGHT/... ISSUED AT 352 PM CST THU DEC 10 2015 SURFACE COL WILL SHIFT ACROSS THE EASTERN DAKOTAS AND MINNESOTA TONIGHT...WITH IOWA LOCATED UNDER SHORTWAVE RIDING. THIS WILL RESULT IN CALMING WINDS AND CLEAR SKIES TO START THE EVENING. OVERRUNNING CIRRUS OVER NEBRASKA WILL WORK INTO THE STATE LATER THIS EVENING AND THICKEN BY MORNING. LOWERED MIN TEMPS IN THE NISH VALLEY SEVERAL DEGREES BELOW GUIDANCE WITH THE RIDGE AXIS AND DRY AIR IN PLACE...HOWEVER...RADIATIONAL COOLING SHOULD BE LIMITED WITH THE INCREASING HIGH CLOUDS. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 352 PM CST THU DEC 10 2015 INTENSE UPPER LEVEL SYSTEM OFF THE WASHINGTON AND OREGON COAST TODAY WILL SHIFT INLAND ON FRIDAY THEN INTO THE FOUR CORNERS REGION FOR SATURDAY. THIS WILL LEAD TO THE DEVELOPMENT OF STRONG SOUTHWEST FLOW ALOFT INTO THE STATE. AN INITIAL SURGE OF LOW LEVEL MOISTURE WILL REACH IOWA ON FRIDAY IN THE FORM OF STRATUS. SOME POTENTIAL FOR A PERIOD OF DRIZZLE TO DEVELOP BY LATE FRIDAY AFTERNOON INTO THE EVENING WITH THIS PASSAGE. LEE SIDE CYCLOGENESIS OVER THE TEXAS/OKLAHOMA PANHANDLES AS THE UPPER SYSTEM APPROACHES...WILL LEAD TO GOOD MOISTURE TRANSPORT FROM THE GULF. THIS MOISTURE WILL ARRIVE LATE SATURDAY AND ESPECIALLY SATURDAY NIGHT. DRIZZLE OR LIGHT RAIN IS POSSIBLE THROUGH THE DAY ON SATURDAY. CONVECTIVE INSTABILITY ARRIVES SATURDAY NIGHT THEREFORE EXPECT WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS INTO SUNDAY MORNING. AS THIS OCCURS...SFC DEWPOINTS IN THE MID 50S TO POSSIBLY NEAR 60 WILL LIFT INTO SOUTH CENTRAL AND SOUTHEAST IOWA LEADING OVERNIGHT TEMPERATURES 30 TO 35 DEGREES ABOVE NORMAL. PWAT VALUES NEAR 1.25 INCHES WHICH IS 350 TO 400 PERCENT ABOVE DECEMBER CLIMATOLOGY. THIS COMBINED WITH WARM CLOUD DEPTHS APPROACHING 10 KFT MAY LEAD TO HEAVY RAINFALL AND POSSIBLY SOME FLOODING. THE MOIST SOUNDINGS AND WEAK LAPSE RATES SHOULD DETER AND SEVERE HAIL THREAT. THE SFC LOW PRESSURE WILL LIFT RAPIDLY NORTHEAST SUNDAY AND SUNDAY NIGHT AND PASS ACROSS THE EASTERN PORTION OF THE STATE SUNDAY NIGHT. THIS SLOWER TIMING WILL KEEP PRECIPITATION RAIN THROUGH SUNDAY. THE PRECIPITATION WILL CHANGE TO DEFORMATION ZONE RAIN DURING THIS PROCESS WITH A GRADUAL CHANGE OVER TO SNOW OVER THE NORTHWEST. THE POTENTIAL FOR SNOW ACCUMULATIONS STILL IN QUESTION AS PRECIPITATION WILL BE NEARING AND END AS THE PRECIPITATION SWITCHES WITH DRIER AIR MOVING IN. THE OTHER CONCERN WILL BE THE POTENTIAL FOR HIGH WINDS WITH THE LOW RAPIDLY DEEPENING AND A TIGHTENING PRESSURE GRADIENT AS IT DEPARTS. WILL NEED TO MONITOR WITH GUSTS OVER 40 KTS LIKELY AND POSSIBLY 50 KTS OR MORE WHICH WOULD BE HIGH WIND CRITERIA. THE NEXT SYSTEM ARRIVES ON TUESDAY AND WILL CARVE A LARGE TROUGH OUT OVER THE CENTRAL AND NORTHERN PLAINS. THIS WILL ALLOW A STRONG PUSH OF COLD AIR TO SPILL SOUTH INTO THE REGION. THE PRIMARY PRECIPITATION WITH THE SYSTEM WILL FALL TO THE NORTH OF THE STATE BUT WILL INCLUDE SOME LIGHT SNOW POTENTIAL. WEDNESDAY WILL BE COLDER THOUGH POTENTIAL FOR MIXING TO NEAR 850 MB WHERE TEMPERATURES OF -10C TO -15C WILL BE IN PLACE. MIXING TO THIS LEVEL WILL YIELD HIGHS IN THE MID 20S TO AN OPTIMISTIC LOW 30S. THE COLDER AIR WILL LAST THROUGH THURSDAY. && .AVIATION...10/18Z ISSUED AT 1146 AM CST THU DEC 10 2015 STRONG W TO NW WINDS OF 20-30 KTS WITH GUSTS OVER 40 KTS WILL CONTINUE THROUGH THE EARLY TO MID AFTERNOON HOURS...PRIMARILY IN THE EASTERN PORTION OF THE FORECAST AREA. WINDS WILL LESSEN OVERNIGHT AND THEN BACK TO THE SOUTHEAST BY TOMORROW MORNING. PRECIP AND MVFR CIGS IN NORTHERN IOWA WILL ALSO RAPIDLY ADVANCE EASTWARD AND OUT OF THE AREA BY THE MID AFTERNOON. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SKOW LONG TERM...DONAVON AVIATION...SKOW  FXUS63 KDMX 112153 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 353 PM CST FRI DEC 11 2015 .SHORT TERM /TONIGHT/... ISSUED AT 350 PM CST FRI DEC 11 2015 UPPER LEVEL PATTERN ACROSS THE WESTERN CONUS HAS BEEN AMPLIFYING THROUGHOUT THE DAY AS A STRONG UPPER LEVEL SHORTWAVE/PV ANOMALY MAKES LANDFALL ACROSS THE WEST COAST. THIS TROUGH WILL CONTINUE TO DIG SOUTHEASTWARD INTO THE SOUTHERN COLORADO RIVER BASIN BY 12Z SAT. AT THE SURFACE...A BROAD 999MB TROUGH HAS BEEN LIFTING NORTHEASTWARD INTO NE KANSAS AND SE NEBRASKA...WITH A DEVELOPING WARM FRONT OVER NORTHERN MISSOURI AND SOUTHWEST IOWA. THIS TROUGH WILL SETTLE ACROSS THE CENTRAL AND EASTERN PORTIONS OF THE CWA FOR TONIGHT WITH THE ATTENDANT BOUNDARY BECOMING NEARLY STATIONARY ACROSS SE/E IOWA. DEWPOINTS WILL CLIMB INTO THE MID 40S ALONG AND SOUTH OF THIS BOUNDARY DURING THE OVERNIGHT. THIS MOISTURE POOLING...COMBINED WITH LIGHT WINDS ALONG THE FRONT...MAY BE ENOUGH TO GENERATE AREAS OF FOG. ALL AVAILABLE HIGH-RES GUIDANCE DEVELOP FOG SOUTH AND EAST OF DES MOINES WITH VARIATIONS IN THE NORTHERN AND WESTERN EXTENT OF THE BACK EDGE. FOG INVOF THE BOUNDARY MAY BE DENSE WITH VISIBILITIES BELOW 1/2 OF A MILE. LOWS TONIGHT IN THE SOUTHEAST WILL ONLY DROP SLIGHTLY FROM TODAY'S HIGHS GIVEN THE HIGHER MOISTURE CONTENT IN THE AIRMASS. LIGHT DRIZZLE MAY BE POSSIBLE IN EASTERN AND NORTHERN IOWA AS A LOW STRATUS SHIELD OVERSPREADS THE AREA. HOWEVER...OVERALL FORCING IS MINIMAL AT BEST ON THE ALO/MCW BUFR PROFILES AND KEPT POPS IN THE 10- 14 PERCENT RANGE. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 350 PM CST FRI DEC 11 2015 A DYNAMIC UPPER LEVEL SYSTEM THAT IS MOVING INLAND OVER CALIFORNIA WILL IMPACT THE MIDWEST OVER THE WEEKEND AND INTO MONDAY. THIS SYSTEM WILL MOVE EAST OVER ARIZONA AND NEW MEXICO...WHICH WILL CREATE STRONG SOUTHWEST FLOW INTO THE STATE. IN ADDITION...THE SFC CYCLOGENESIS AHEAD OF THE UPPER SYSTEM WILL GENERATE GOOD SOUTHERLY FLOW LEADING TO STRONG MOISTURE ADVECTION NORTHWARD FROM THE GULF. THE LEADING STRATUS ASSOCIATED WITH THIS MOISTURE SURGE WILL ARRIVE OVER SOUTHERN THEN CENTRAL IOWA SATURDAY AFTERNOON. SOME POTENTIAL FOR DRIZZLE OR VERY LIGHT RAIN WITH THIS SURGE HOWEVER THE DEEPER MOISTURE WILL NOT ARRIVE UNTIL SATURDAY NIGHT. THE DEEPER MOISTURE ARRIVAL WILL BE COINCIDENT WITH THE ARRIVAL OF STRONGER THERMODYNAMIC FORCING. THEREFORE EXPECT WIDESPREAD SHOWERS WITH EMBEDDED THUNDERSTORMS SATURDAY NIGHT INTO EARLY SUNDAY. THE SYSTEM CONTINUES TO PROJECT FURTHER TO THE NORTHWEST AS PREVIOUSLY EXPECTED AS THESE DEEPER SYSTEMS TEND TO BE SLOWER AND FURTHER NORTHWEST. PWAT VALUES SATURDAY NIGHT IN EXCESS OF 1.25 INCHES STILL ON TRACK. THESE VALUES REMAIN NEARLY 400 PERCENT ABOVE MID DECEMBER VALUES. THESE ALONG WITH WARM CLOUD DEPTHS OVER 10 KFT WILL LEAD TO AN EFFICIENT RAIN PRODUCING SYSTEM. PRECIPITATION AMOUNTS THROUGH SUNDAY OF 1.5 TO 3 INCHES ARE LIKELY ACROSS THE AREA. THESE VALUES WILL CAUSE SIGNIFICANT RISES ON LOCAL STREAMS. REFER TO THE HYDROLOGY SECTION FOR ADDITIONAL DETAILS. THE SFC LOW PRESSURE WILL LIFT INTO IOWA LATE SUNDAY AND SUNDAY NIGHT. THE POTENTIAL FOR THE DRY SLOT TO LIFT INTO CENTRAL AND SOUTHEAST IOWA SHOULD OCCUR DURING THIS TIME AND WILL LEAD TO DIMINISHING PRECIPITATION ACROSS THAT REGION WHILE A DEFORMATION ZONE DEVELOPS OVER THE NORTHWEST. A PORTION OF THE WARM CONVEYOR WILL CONTINUE TO WRAP AROUND THE SYSTEM INTO EARLY MONDAY. COLDER AIR WILL GRADUALLY WRAP IN AS WELL THEREFORE THERE WILL BE A TRANSITION TO SNOW OVER AT LEAST WESTERN IOWA WITH SOME ACCUMULATIONS POSSIBLE. ELSEWHERE...LOW LEVEL WETBULBS WILL REMAIN RELATIVELY WARM AND IN THE MID 30S OR HIGHER WHICH WILL LIMIT ANY SNOW POTENTIAL. ANOTHER SYSTEM WILL BE QUICK ON THE HEELS AND ARRIVE TUESDAY INTO WEDNESDAY. THE PRECIPITATION SHIELD WITH THIS SYSTEM WILL BE PRIMARILY TO THE NORTH OF IOWA HOWEVER GOOD COLD ADVECTION WILL ARRIVE WITH 850 MB TEMPS OF -13C TO -15C LIKELY. GOOD LOW LEVEL MIXING SHOULD KEEP TEMPERATURES FROM BOTTOMING OUT. BOTH SYSTEMS...THE DEPARTING WEEKEND SYSTEM AND THE MID WEEK SYSTEM WILL BRING STRONG AND GUSTY WINDS WITH THEM THAT MAY REQUIRE HEADLINES. && .AVIATION...11/18Z ISSUED AT 1151 AM CST FRI DEC 11 2015 VFR CIRROSTRATUS DECK WILL REMAIN IN PLACE THROUGHOUT THE DAY WITH MVFR TO IFR STRATUS WORKING INTO THE EASTERN AND SOUTHEASTERN PORTIONS OF THE AREA THIS EVENING. IFR TO LIFR CIGS WILL EXPAND ACROSS THE CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA THROUGH THE OVERNIGHT HOURS WITH VISBYS BELOW 1/2 TO 1 MILE...PRIMARILY IN THE SOUTH AND EAST. && .HYDROLOGY... ISSUED AT 350 PM CST FRI DEC 11 2015 AS MENTIONED IN THE LONG TERM SECTION...PWAT VALUES WILL INCREASE TO IN EXCESS OF 1.25 INCHES ACROSS THE AREA WHICH IS AT LEAST 400 PERCENT OF NORMAL FOR THIS TIME OF YEAR. THIS SYSTEM WILL BE AN EFFICIENT RAIN PRODUCING SYSTEM WITH CURRENT QPF ACROSS MUCH OF THE FORECAST AREA IS FROM 1.50-3.00 INCHES THROUGH MIDDAY MONDAY WHICH WOULD BE NEAR RECORD TO RECORD RAINFALL FOR A TWO DAY PERIOD FOR DECEMBER AT MANY LOCATIONS. MOST RIVERS ARE RUNNING HIGHER THAN THE 90TH PERCENTILE FOR THIS TIME OF YEAR...ALBEIT THATS NOT HORRIBLY BAD IN MID DECEMBER AS FAR AS STAGES ARE CONCERNED...BUT STILL SHOWS ITS WET. GIVEN DORMANT VEGETATIVE GROWTH AND OPEN FIELDS...RUNOFF WILL BE DECENT/EFFICIENT AND ANTICIPATE AT LEAST SOME MINOR FLOODING ON AREA STREAMS AND RIVERS SHOULD QPF MATERIALIZE. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SKOW LONG TERM...DONAVON AVIATION...SKOW HYDROLOGY...COGIL  FXUS63 KDMX 130942 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 342 AM CST FRI NOV 13 2015 .SHORT TERM /TODAY/... ISSUED AT 342 AM CST FRI NOV 13 2015 LARGE AREA OF HIGH PRESSURE WILL PUSH EAST ACROSS THE SOUTHERN US TODAY. THIS WILL BRING DRY CONDITIONS THROUGH THE DAY. AS HIGH PUSHES EAST WILL SEE WINDS BEGIN TO DIMINISH IN THE WEST...THOUGH MAY STILL BRING STRONG AND GUSTY ACROSS THE NORTHEAST WITH PERSISTENT PRESSURE GRADIENT. WILL ALSO SEE INCREASING WAA AND CLEAR SKIES AND HAVE BUMPED TEMPERATURES UP A FEW DEGREES FOR HIGHS...THOUGH AM STILL ON THE COOLER SIDE OF GUIDANCE AND IF MIXING IS STRONGER THAN EXPECTED...MAY BE TOO COOL. .LONG TERM /TONIGHT THROUGH WEDNESDAY/... ISSUED AT 342 AM CST FRI NOV 13 2015 RIDGE OF HIGH PRESSURE WILL BE PASSING EAST OF THE FORECAST AREA THIS EVENING WITH WARM ADVECTION COMMENCING ALOFT. SATURDAY WILL FEATURE BREEZY SOUTHWEST WINDS THAT WILL HELP PUSH TEMPERATURES INTO THE UPPER 50S TO LOWER 60S. VERTICAL CROSS SECTIONS FOR SATURDAY DOES HAVE SOME MOISTURE AOA 400 MB THEREFORE SOME POTENTIAL FOR CIRRUS TO MOVE OVER THE STATE. AT THIS TIME...DO NOT EXPECT THE CIRRUS TO BE OPAQUE ENOUGH TO LIMIT HIGH TEMPERATURES. A LONG WAVE TROUGH MOVING INTO THE WESTERN CONUS SATURDAY NIGHT INTO SUNDAY WILL CREATE LARGE SCALE SOUTHWEST FLOW. THIS FLOW WILL BRING MID-LEVEL PACIFIC MOISTURE ADVECTION INTO THE CENTRAL AND SOUTHERN PLAINS WHILE LOW LEVEL GULF MOISTURE STREAMS NORTH. CLOUDS WILL BEGIN TO ENTER THE STATE BY SUNDAY AFTERNOON WITH SOUTHERN PORTIONS OF IOWA POSSIBLY BECOMING MOSTLY CLOUDY BY MID TO LATE AFTERNOON. PRECIPITATION CHANCES SHOULD HOLD OFF UNTIL SUNDAY NIGHT WHEN THE FIRST SHORT WAVE LIFTS INTO THE REGION. THE WESTERN SYSTEM WILL MOVE EAST AND BECOME A CLOSED UPPER LOW NEAR THE FOUR CORNERS REGION MONDAY NIGHT THEN MOVE EAST TOWARDS THE TEXAS PANHANDLE ON TUESDAY. THE BEST POTENTIAL FOR WIDESPREAD PRECIPITATION WILL BE MONDAY NIGHT AND TUESDAY WITH THE STRONGEST MOISTURE SURGE ARRIVING. THE ATMOSPHERE WILL BECOME CONVECTIVELY UNSTABLE AS WELL BY TUESDAY AND HAVE ADDED THUNDER MENTION OVER THE SOUTHERN TWO THIRDS. PWATS NEAR 1.25 INCHES WITH SATURATED PROFILES AND WARM CLOUD DEPTHS APPROACHING 10 KFT MAY RESULT AN EFFICIENT RAIN PRODUCING SYSTEM AND SOME POTENTIAL FOR HEAVY RAINFALL. A LOT OF UNCERTAINTY REGARDING THE EVOLUTION OF THE UPPER LOW BEYOND TUESDAY. THE HANDLING OF AN ALASKAN UPPER LOW AN HOW IT EVOLVES WILL HAVE A SIGNIFICANT IMPACT ON THE OKLAHOMA AND KANSAS UPPER LOW. PREFER THE MORE PROGRESSIVE NATURE OF THE ECMWF/GEM WHICH LIFT THE SOUTHERN SYSTEM QUICKLY NORTHEAST AS THE ALASKAN LOW ENERGY SHIFTS SOUTHEAST. THE GFS SOLUTION OF KEEPING THE ALASKAN ENERGY OVER SOUTHERN CANADA AND BLOCKS THE UPPER LOW AND STALLS IT FOR SEVERAL DAYS APPEARS TO BE UNREALISTIC GIVEN THE STRENGTH OF THE UPPER JET ROUNDING THE BASE. REGARDLESS...POTENTIAL FOR SOME LIGHT SNOW OVER WESTERN IOWA BY WEDNESDAY NIGHT AS COOLER AIR SETTLES INTO THE STATE. && .AVIATION...13/06Z ISSUED AT 1127 PM CST THU NOV 12 2015 NW WIND WILL AROUND 15KTS WITH A FEW GUSTS AT TIMES. THE WIND WILL PICK UP AGAIN AFTER 15Z BUT WILL NOT BE NEAR AS STRONG AS THEY WERE TODAY. WE SHOULD SEE SUSTAINED SPEEDS AROUND 15KTS WITH SLIGHTLY HIGHER SUSTAINED SPEEDS NORTHEAST. GUSTS TO 25KTS OR SO MAINLY ACROSS THE NORTHEAST THROUGH MID AFTERNOON ARE EXPECTED. AS THE SURFACE HIGH MOVES OFF AFTER 14/00Z WINDS WILL SHIFT AROUND TO THE SOUTH. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AWB LONG TERM...DONAVON AVIATION...FAB  FXUS63 KDMX 131748 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1248 PM CDT MON JUL 13 2015 ...UPDATED FOR 18 UTC AVIATION... .SHORT TERM /TODAY/... ISSUED AT 414 AM CDT MON JUL 13 2015 MAIN FOCUS TODAY ON THE HEAT AND STORM CHANCES. STRONGER STORMS OFF TO THE NORTHEAST SHOULD REMAIN EAST OF THE AREA EARLY THIS MORNING WITH A SMALL COMPLEX OF ELEVATED STORMS ACROSS SE SD AND NE NE. THESE HAVE ALL BEEN WEAKENING...BUT MAY PUSH FAR ENOUGH EAST TO IMPACT THE FAR NW/WC CWA THIS MORNING. OTHERWISE WEAK COOL FRONT/DRYLINE FEATURE TO PUSH THROUGH THE CWA TODAY...WITH EXPECTED PLACEMENT FROM ERN IOWA INTO NW MO BY AROUND 00Z THIS EVENING. COULD SEE SOME THUNDERSTORM DEVELOPMENT ALONG THIS BOUNDARY BY LATE AFTERNOON...HOWEVER THE BEST CHANCES WILL BE EAST OF THE CWA SO STUCK WITH SMALL POPS. MOISTURE TO POOL AHEAD OF THE BOUNDARY...WITH ANOTHER HOT AND HUMID DAY EXPECTED ESPECIALLY ACROSS THE SOUTHERN HALF OF IOWA. DEWPOINTS IN THE MID TO UPPER 70S TO CONTINUE THROUGH THE DAY POSSIBLY EVEN NEAR 80 IN THE FAR SOUTH. H85 TEMPS IN THE MID 20S CELSIUS DROPPING TO THE LOWER 20S CELSIUS BEHIND THE FRONT. THIS SHOULD YIELD MAX TEMPS A FEW DEGREES WARMER THAN READINGS FROM SUNDAY...WITH HIGHS IN THE MID 90S ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHTLY COOLER IN THE LOWER 90S ACROSS THE NORTH. WITH THE HEAT AND HUMIDITY...HEAT INDICES WILL PUSH INTO THE 105 RANGE AGAIN ACROSS MUCH OF CENTRAL IOWA AND AROUND 110-115 IN THE FAR SOUTHEASTERN CWA. THEREFORE WILL UPGRADE A PORTION OF THE HEAT ADVISORY TO A HEAT WARNING FOR THIS AFTERNOON. OTHERWISE WILL KEEP THE HEAT ADVISORY AS IS FOR THE AFTERNOON. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 414 AM CDT MON JUL 13 2015 LESS CONCERNS VERSUS LAST FEW DAYS WITH TEMP/DEWPOINT TRENDS AND MID WEEK PRECIP EVENT ONLY REAL SENSIBLE WEATHER ITEMS OF NOTE. AT ONSET FOCUS WAS ON WHETHER DEPARTING TROUGH AND ASSOCIATED CONVERGENCE WOULD BE CLOSE ENOUGH FOR CONVECTION TO EFFECT ERN FORECAST AREA...HOWEVER NEARLY ALL OF THE 00Z DETERMINISTIC AND ENSEMBLE SUITE HAS THIS ALONG THE MS RIVER BY 00Z. THE ONLY OUTLIER SEEMS TO BE THE SLOWER 06Z NAM...BUT EVEN THAT SEEMS FAR ENOUGH EAST TO KEEP ANYTHING OUT OF THE AREA BY EARLY EVENING. SUBSIDENCE WILL FOLLOW INTO TUE AS CYCLONIC LOW LEVEL FLOW SETTLES IN SLIGHTLY LOWERING TEMPS AND DEWPOINTS. AIRMASS CHANGE IS NOT APPRECIABLE...BUT SUFFICIENT TO DROP HEAT INDICES OUT OF ADVISORY CRITERIA. ALTHOUGH POTENTIAL IS LOW...THERE IS SOME CONCERN OF PEAK HEATING CONVECTION DEVELOPING ALONG WEAK 0-1KM MOISTURE CONVERGENCE AXIS ACROSS FAR ERN PORTIONS. FEEL POTENTIAL IS NOT GREAT ENOUGH TO MENTION AT THE MOMENT...BUT SOMETHING TO KEEP AN EYE ON. CURRENT ROCKIES RIDGE WILL THEN BUILD EASTWARD INTO IA BY WED KEEPING FAIR WEATHER IN THE FORECAST INTO MIDWEEK. ECMWF AND GFS HAVE BEEN CONSISTENT WITH SHORT WAVE IMMEDIATELY FOLLOWING THIS RIDGE AXIS HOWEVER. TIMING IS STILL SOMEWHAT OF A CONCERN...WITH GFS STILL ON THE FASTER END...BUT CONFIDENCE IS INCREASING FOR A PERIOD OF CONVECTION SOMEWHERE FROM LATE WED INTO THU. PRIMARY CONCERN WITH THIS EVENT WOULD BE HEAVY RAIN MORE THAN SEVERE WITH DEEP SHEAR FAIRLY WEAK AND INSTABILITY NOT EXTREME. PWATS INCREASE TO 2 INCHES...WARM CLOUD DEPTHS 4-4.5KM WITH FAIRLY STRONG LOW LEVEL MOISTURE TRANSPORT. CORFIDI VECTORS AND MEAN WINDS ARE WEAK AS WELL SO SLOW MOVING EFFICIENT RAINFALL PRODUCTION SEEMS LIKELY AND WILL NEED TO BE MONITORED. THINGS SHOULD DRY OUT INTO FRI WITH LITTLE IN THE WAY OF SYNOPTIC LIFT OR LOW LEVEL FOCUS AS UPPER RIDGE BUILDS INTO IA WHICH WILL INCREASE HEAT AND HUMIDITY SOMEWHAT. POPS WILL RETURN LATE IN THE WEEKEND WITH THE PASSAGE OF THE NRN STREAM WAVE. ITS TIMING AND STRENGTH IS UNCERTAIN FOR NOW HOWEVER WITH ECMWF FASTER AND MUCH STRONGER. && .AVIATION...13/18Z ISSUED AT 1246 PM CDT MON JUL 13 2015 ALL TERMINALS WILL REMAIN VFR NEXT 24 HOURS. WIND SHIFT TO NW WINDS AFTER 00Z IS ONLY CHANGES TO ONGOING CONDITIONS. && .DMX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ADAIR-ADAMS- AUDUBON-BOONE-CARROLL-CASS-CRAWFORD-DALLAS-GREENE-GUTHRIE-JASPER- MADISON-MARSHALL-POLK-POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION. EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR APPANOOSE- CLARKE-DAVIS-DECATUR-LUCAS-MAHASKA-MARION-MONROE-WAPELLO-WARREN- WAYNE. && $$ SHORT TERM...BEERENDS LONG TERM...SMALL AVIATION...HARDING  FXUS63 KDMX 132008 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 308 PM CDT MON JUL 13 2015 .SHORT TERM /TONIGHT/... ISSUED AT 307 PM CDT MON JUL 13 2015 WEAK BOUNDARY HAS MOVED MOSTLY THROUGH THE FORECAST AREA BRINGING SIGNIFICANTLY LOWER DEWPOINTS. CURRENT HEAT ADVISORY AND WARNING EXPIRE THIS AFTERNOON AND MOST STATIONS WILL BE WELL BELOW CRITERIA BY THEN. KEPT PRECIP CHANCES OUT OF THE FORECAST FOR TONIGHT. NONE OF THE CONVECTIVE ALLOWING MODELS SHOW ANY PRECIP NOR DO THE NAM OR GFS OR EVEN THE SREF PLUMES FROM SPC. LOOKS AGAIN LIKE EVERYTHING WILL STAY EAST OF THIS FORECAST AREA OVERNIGHT. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 307 PM CDT MON JUL 13 2015 MAIN FORECAST CONCERN WAS FOCUSED ON PRECIPITATION CHANCES WEDNESDAY INTO THURSDAY AND ANOTHER ROUND OF HOT AND HUMID CONDITIONS LATE IN THE PERIOD. LEANED TOWARD A NAM12/ECMWF/SREF BLEND FOR TUESDAY AND WEDNESDAY...THEN A LITTLE MORE WEIGHT TO THE ECMWF THROUGH THE REST OF THE WEEKEND. TUESDAY INTO THURSDAY...MUCH LESS HUMIDITY IS ANTICIPATED ON TUESDAY BUT TEMPERATURES STILL LOOK TO RISE INTO THE UPPER 80S AND LOWER 90S. A FEW SPOTS MAY REACH HEAT INDEX READINGS TO AROUND 100 BUT NOTHING CLOSE TO ADVISORY LEVEL. WEDNESDAY WILL SEE INCREASING CLOUD COVER WHICH WILL HOLD TEMPERATURES IN THE 80S. DECENT SHORTWAVE TRACKS EAST-NORTHEAST ALONG THE UPPER LEVEL RIDGE BUILDING INTO THE CENTRAL U.S. WEDNESDAY NIGHT INTO THURSDAY. TIMING HAS SLOWED SLIGHTLY AND THUS DELAYED ONSET OF POPS TO WESTERN IOWA AFTER 18Z WEDNESDAY AND ACROSS THE ENTIRE FORECAST AREA AFTER 00Z THURSDAY. ECMWF/NAM ARE SLIGHTLY FURTHER SOUTH WITH THE SHORTWAVE TRACK AND WITH THE HEAVIEST RAIN THAN THE GFS. ECMWF HAS BEEN A LITTLE MORE CONSISTENT BETWEEN MODEL RUNS AND LIKENED THE SOLUTION WHICH RESULTED IN INCREASING POPS OVERNIGHT WEDNESDAY NIGHT INTO THURSDAY. HEAVY RAIN LOOKS TO BE THE MAIN THREAT AS PRECIPITABLE WATER VALUES IN THE RANGE OF 1.5 TO 2.0 INCHES WITH STRONG MOISTURE TRANSPORT AND THETA-E ADVECTION INTO THE STATE PAST 06Z THURSDAY. WARM LAYER CLOUD DEPTHS RANGE FROM 13KFT TO 14KT FEET INTO THURSDAY MORNING SO CERTAINLY SOME EFFICIENT RAIN PRODUCERS CAN BE EXPECTED. INCREASED QPF AMOUNTS BETWEEN 00-12Z THURSDAY. SEVERE POTENTIAL IS LOW WITH MINIMAL INSTABILITY AND SHEAR AVAILABLE WEDNESDAY NIGHT INTO THURSDAY. FRIDAY INTO MONDAY...UPPER LEVEL RIDGE PERSISTS THROUGH THE WEEKEND WITH SOUTHWEST FLOW RETURNING TO THE STATE BY SATURDAY. TRENDED WARMER FOR MAX TEMPS ON SATURDAY WITH DECENT MIXING AND 850MB TEMPS TO +22C TO +23C. DEW POINTS LOOKS TO RISE BACK INTO THE MIDDLE 70S AND MAY HAVE ANOTHER HOT AND HUMID DAY SATURDAY. COLD FRONT/TROUGH MOVE THROUGH THE STATE LATE SATURDAY NIGHT AND PROVIDE ADDITION THUNDERSTORM CHANCES INTO SUNDAY. SLIGHTLY COOLER SUNDAY INTO MONDAY. && .AVIATION...13/18Z ISSUED AT 1246 PM CDT MON JUL 13 2015 ALL TERMINALS WILL REMAIN VFR NEXT 24 HOURS. WIND SHIFT TO NW WINDS AFTER 00Z IS ONLY CHANGES TO ONGOING CONDITIONS. && .DMX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ADAIR-ADAMS- AUDUBON-BOONE-CARROLL-CASS-CRAWFORD-DALLAS-GREENE-GUTHRIE-JASPER- MADISON-MARSHALL-POLK-POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION. EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR APPANOOSE- CLARKE-DAVIS-DECATUR-LUCAS-MAHASKA-MARION-MONROE-WAPELLO-WARREN- WAYNE. && $$ SHORT TERM...HARDING LONG TERM...PODRAZIK AVIATION...HARDING  FXUS63 KDMX 132014 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 314 PM CDT THU AUG 13 2015 .SHORT TERM /TONIGHT/... ISSUED AT 312 PM CDT THU AUG 13 2015 RELATIVELY QUIET WX EXPECTED FOR MOST OF THE CWA DURING THE SHORT TERM PERIOD...WITH ONLY CHANCES FOR SHRA/TSRA BEING ACROSS THE FAR NORTH. WEATHER PATTERN WILL REMAIN RELATIVELY UNCHANGED...WITH THE AMPLIFIED UPPER-LEVEL RIDGE REMAINING TO OUR WEST. A SURFACE TROF WILL REMAIN JUST TO OUR WEST...FROM THE CENTRAL AND EASTERN DAKOTA AREA INTO CENTRAL NEBRASKA. SURFACE HIGH PRESSURE WILL REMAIN TO OUR EAST. AREA OF SCT SHRA FROM EASTERN SOUTH DAKOTA INTO SOUTHERN MINNESOTA HAS PERSISTED TODAY...IN AN AREA OF RELATIVELY WEAK FORCING COUPLED WITH ELEVATED MOISTURE LEVELS. MOISTURE LEVELS AND FORCING BOTH DECREASE TOWARD THE SOUTH...WHICH HAS KEPT THE PCPN TO THE NORTH OF THE MINNESOTA BORDER. TO THE NORTHEAST...ISOLATED TSRA HAVE DEVELOPED ACROSS FAR SOUTHEASTERN MINNESOTA INTO WESTERN WISCONSIN...IN AN AREA THAT HAS BEEN MORE CLOUD-FREE TODAY AND THUS HAS DESTABILIZED FURTHER THAN LOCATIONS TO THE WEST. HAVE CONTINUED SLIGHT CHANCE POPS ACROSS THE FAR NORTH THIS EVENING INTO TONIGHT AS THE BEST FORCING AND INSTABILITY...RELATIVELY SPEAKING...ALONG WITH HIGHER MOISTURE LEVELS...DROP A LITTLE FARTHER SOUTH. THE FORCING IS PROGGED TO CONTINUE ITS SOUTHWARD TRAJECTORY OVERNIGHT TOWARD FRIDAY MORNING...HOWEVER NEITHER MOISTURE NOR INSTABILITY WILL BE SUFFICIENT ENOUGH TO WARRANT POPS. THIS SOLUTION IS FAVORED BY MODEL GUIDANCE AND CAMS. THE AFOREMENTIONED CONVECTION ACROSS FAR SOUTHEASTERN MINNESOTA INTO WESTERN WISCONSIN IS NOT EXPECTED TO IMPACT THE CWA. INSTABILITY AND SHEAR PARAMETERS DECREASE TOWARD THE SOUTHWEST. CAMS ALSO KEEP THE CONVECTION TO OUR NORTHEAST. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 312 PM CDT THU AUG 13 2015 THROUGH EARLY FRIDAY UPPER LEVEL SHORT WAVE AND WEAKENING BOUNDARY MAY PROVIDE ENOUGH SUPPORT FOR A FEW ISO SHOWERS EARLY IN THE PERIOD. COVERAGE LOOKS RATHER SLIM AT THIS TIME SO HAVE LEFT OUT MENTION FOR NOW. BY MID AFTERNOON A WEAK RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE FORECAST AREA WITH LIGHT WINDS AND WEAK MIXING. THOUGH H850 TEMPS WILL RECOVER TO 18 TO 20C BY AFTERNOON ALONG WITH INCREASING DEW POINTS SOME LINGERING MID TO HIGH CLOUDS SHOULD HOLD TEMPERATURES IN THE UPPER 80S CENTRAL AND WEST. BY SATURDAY THE RIDGE WILL HAVE PASSED TO THE EAST WITH SOUTHWEST FLOW BECOMING MORE PREDOMINANT AT THE SFC AND ALOFT. THIS WILL PUSH AFTERNOON HIGHS TO NEAR 90 OR SLIGHTLY HIGHER CENTRAL AND WEST AND THE MID TO UPPER 80S EAST WHERE LESS MIXING IS EXPECTED. HEAT INDICES WILL REACH THE MID 90S BY AFTERNOON MAKING FOR A RATHER WARM AFTERNOON OVER THE SOUTH. WITH THE APPROACHING COLD FRONT SUNDAY AND INCREASING INSTABILITY...MODELS ARE NOW IN BETTER AGREEMENT FOR SHOWERS/STORMS FAR NORTHWEST BETWEEN 21-00Z. THOUGH WIND SHEAR IS RATHER UNIMPRESSIVE THE INSTABILITY MAY PROMOTE SOME ISO SEVERE STORMS EARLY IN THE EVENING OVER THE NORTH/NORTHWEST BEFORE THE ACTIVITY WEAKENS SLIGHTLY OVERNIGHT AND TRENDS MORE TOWARD POTENTIAL FOR LOCALLY HEAVY RAINFALL. THE BOUNDARY IS STILL FORECAST TO MOVE SLOWLY SOUTHEAST REMAINING NORTHWEST OF A KAIO-KAMW-KALO LINE BY 12Z. LOWS WILL REMAIN MILD IN THE MID 60S TO LOWER 70S SOUTH WITH LOWER 60S NORTHWEST. GFS PWATS ARE PROGGED TO 1.75 TO 2 INCHES ALONG THE BOUNDARY OVERNIGHT SUNDAY NIGHT INTO MONDAY AS THE FRONT SAGS SOUTH. WARM CLOUD DEPTHS ALONG THE BOUNDARY WILL NEAR OR EXCEED 10KFT WITH EFFICIENT RAINFALL POSSIBLE. THOUGH SOME UNCERTAINTY REMAINS AT THIS POINT...WILL NEED TO WATCH FOR SOME HEAVY RAIN POTENTIAL AS THE FRONT DRIFTS SOUTH OVERNIGHT SUNDAY NIGHT. THOUGH THERE HAS BEEN LITTLE DAY TO DAY CONSISTENCY BETWEEN MODELS THE EURO/GFS HAVE NOW COME INTO AGREEMENT WITH A SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS BY MONDAY NIGHT AS THE FRONT SAGS SOUTH INTO MISSOURI. BEYOND MONDAY THERE ARE STILL MANY UNCERTAINTIES AS TO HOW THE NEXT TWO SYSTEMS WILL EVOLVE THOUGH SOME GENERAL TRENDS ARE EVIDENT IN THE OUTPUT. THE FIRST H500 WAVE WILL HELP LIFT THE MISSOURI BOUNDARY BACK NORTH WITH SOME THUNDERSTORMS TUESDAY INTO TUESDAY NIGHT WHILE THE GFS/EURO DIVERGE WITH THE SUBSEQUENT WAVE EVOLUTION. THE EURO IS FASTER WITH THE EASTWARD PROGRESSION OF THE SYSTEM WHILE THE GFS TAKES LONGER AND AMPLIFIES THE PATTERN IN THE PROCESS. GIVEN THE VAST DIFFERENCES IN OUTPUT...HAVE NOT STRAYED MUCH FROM GUIDANCE PACKAGE BEYOND DAY5. FOR MOST OF THIS SUMMER...THE MORE SOUTHERN SOLUTIONS HAVE PREVAILED BUT WILL NEED A FEW MORE DAYS TO BETTER RESOLVE THE DIFFERENCES. OVERALL TEMPERATURES WILL REMAIN VERY WARM INTO THE WEEKEND...COOL BY MONDAY AND COULD MAKE SOME RECOVERY INTO MID TO LATE NEXT WEEK IF THE PATTERN AMPLIFIES. && .AVIATION...13/18Z ISSUED AT 1233 PM CDT THU AUG 13 2015 MAINLY HIGH CLOUDS ARE EXPECTED DURING THE VALID TAF PERIOD. SOME MID-LEVEL CLOUDS ARE POSSIBLE ESPECIALLY AT THE KMCW...KFOD AND KALO TERMINALS THIS EVENING AND OVERNIGHT. ALTHOUGH ISOLD-SCT SHRA/TSRA ARE EXPECTED TONIGHT IN SOUTHERN MINNESOTA AND POSSIBLY FAR NORTHERN IOWA...THE ACTIVITY IS EXPECTED TO REMAIN NORTH OF ALL TERMINALS INCLUDING THE NORTHERNMOST ONE...KMCW. SFC WINDS DURING THE VALID TIME PERIOD WILL BE SSW TO SW AS A SFC PRESSURE TROF REMAINS JUST TO THE W OF IOWA...EXTENDING FROM SW MN INTO SD AND EASTERN NE. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ZOGG LONG TERM...REV AVIATION...ZOGG  FXUS63 KDMX 132332 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 632 PM CDT MON JUL 13 2015 .SHORT TERM /TONIGHT/... ISSUED AT 307 PM CDT MON JUL 13 2015 WEAK BOUNDARY HAS MOVED MOSTLY THROUGH THE FORECAST AREA BRINGING SIGNIFICANTLY LOWER DEWPOINTS. CURRENT HEAT ADVISORY AND WARNING EXPIRE THIS AFTERNOON AND MOST STATIONS WILL BE WELL BELOW CRITERIA BY THEN. KEPT PRECIP CHANCES OUT OF THE FORECAST FOR TONIGHT. NONE OF THE CONVECTIVE ALLOWING MODELS SHOW ANY PRECIP NOR DO THE NAM OR GFS OR EVEN THE SREF PLUMES FROM SPC. LOOKS AGAIN LIKE EVERYTHING WILL STAY EAST OF THIS FORECAST AREA OVERNIGHT. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 307 PM CDT MON JUL 13 2015 MAIN FORECAST CONCERN WAS FOCUSED ON PRECIPITATION CHANCES WEDNESDAY INTO THURSDAY AND ANOTHER ROUND OF HOT AND HUMID CONDITIONS LATE IN THE PERIOD. LEANED TOWARD A NAM12/ECMWF/SREF BLEND FOR TUESDAY AND WEDNESDAY...THEN A LITTLE MORE WEIGHT TO THE ECMWF THROUGH THE REST OF THE WEEKEND. TUESDAY INTO THURSDAY...MUCH LESS HUMIDITY IS ANTICIPATED ON TUESDAY BUT TEMPERATURES STILL LOOK TO RISE INTO THE UPPER 80S AND LOWER 90S. A FEW SPOTS MAY REACH HEAT INDEX READINGS TO AROUND 100 BUT NOTHING CLOSE TO ADVISORY LEVEL. WEDNESDAY WILL SEE INCREASING CLOUD COVER WHICH WILL HOLD TEMPERATURES IN THE 80S. DECENT SHORTWAVE TRACKS EAST-NORTHEAST ALONG THE UPPER LEVEL RIDGE BUILDING INTO THE CENTRAL U.S. WEDNESDAY NIGHT INTO THURSDAY. TIMING HAS SLOWED SLIGHTLY AND THUS DELAYED ONSET OF POPS TO WESTERN IOWA AFTER 18Z WEDNESDAY AND ACROSS THE ENTIRE FORECAST AREA AFTER 00Z THURSDAY. ECMWF/NAM ARE SLIGHTLY FURTHER SOUTH WITH THE SHORTWAVE TRACK AND WITH THE HEAVIEST RAIN THAN THE GFS. ECMWF HAS BEEN A LITTLE MORE CONSISTENT BETWEEN MODEL RUNS AND LIKENED THE SOLUTION WHICH RESULTED IN INCREASING POPS OVERNIGHT WEDNESDAY NIGHT INTO THURSDAY. HEAVY RAIN LOOKS TO BE THE MAIN THREAT AS PRECIPITABLE WATER VALUES IN THE RANGE OF 1.5 TO 2.0 INCHES WITH STRONG MOISTURE TRANSPORT AND THETA-E ADVECTION INTO THE STATE PAST 06Z THURSDAY. WARM LAYER CLOUD DEPTHS RANGE FROM 13KFT TO 14KT FEET INTO THURSDAY MORNING SO CERTAINLY SOME EFFICIENT RAIN PRODUCERS CAN BE EXPECTED. INCREASED QPF AMOUNTS BETWEEN 00-12Z THURSDAY. SEVERE POTENTIAL IS LOW WITH MINIMAL INSTABILITY AND SHEAR AVAILABLE WEDNESDAY NIGHT INTO THURSDAY. FRIDAY INTO MONDAY...UPPER LEVEL RIDGE PERSISTS THROUGH THE WEEKEND WITH SOUTHWEST FLOW RETURNING TO THE STATE BY SATURDAY. TRENDED WARMER FOR MAX TEMPS ON SATURDAY WITH DECENT MIXING AND 850MB TEMPS TO +22C TO +23C. DEW POINTS LOOKS TO RISE BACK INTO THE MIDDLE 70S AND MAY HAVE ANOTHER HOT AND HUMID DAY SATURDAY. COLD FRONT/TROUGH MOVE THROUGH THE STATE LATE SATURDAY NIGHT AND PROVIDE ADDITION THUNDERSTORM CHANCES INTO SUNDAY. SLIGHTLY COOLER SUNDAY INTO MONDAY. && .AVIATION...14/00Z ISSUED AT 631 PM CDT MON JUL 13 2015 VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD...NORTHWEST WINDS WILL DIMINISH BELOW 10 KTS OVERNIGHT AND MAY BECOME BREEZY BY TUESDAY AFTERNOON. && .DMX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ADAIR-ADAMS-DALLAS- JASPER-MADISON-MARSHALL-POLK-POWESHIEK-RINGGOLD-TAMA-TAYLOR- UNION. EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR APPANOOSE- CLARKE-DAVIS-DECATUR-LUCAS-MAHASKA-MARION-MONROE-WAPELLO-WARREN- WAYNE. && $$ SHORT TERM...HARDING LONG TERM...PODRAZIK AVIATION...DONAVON  FXUS63 KDMX 132353 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 653 PM CDT THU AUG 13 2015 .SHORT TERM /TONIGHT/... ISSUED AT 312 PM CDT THU AUG 13 2015 RELATIVELY QUIET WX EXPECTED FOR MOST OF THE CWA DURING THE SHORT TERM PERIOD...WITH ONLY CHANCES FOR SHRA/TSRA BEING ACROSS THE FAR NORTH. WEATHER PATTERN WILL REMAIN RELATIVELY UNCHANGED...WITH THE AMPLIFIED UPPER-LEVEL RIDGE REMAINING TO OUR WEST. A SURFACE TROF WILL REMAIN JUST TO OUR WEST...FROM THE CENTRAL AND EASTERN DAKOTA AREA INTO CENTRAL NEBRASKA. SURFACE HIGH PRESSURE WILL REMAIN TO OUR EAST. AREA OF SCT SHRA FROM EASTERN SOUTH DAKOTA INTO SOUTHERN MINNESOTA HAS PERSISTED TODAY...IN AN AREA OF RELATIVELY WEAK FORCING COUPLED WITH ELEVATED MOISTURE LEVELS. MOISTURE LEVELS AND FORCING BOTH DECREASE TOWARD THE SOUTH...WHICH HAS KEPT THE PCPN TO THE NORTH OF THE MINNESOTA BORDER. TO THE NORTHEAST...ISOLATED TSRA HAVE DEVELOPED ACROSS FAR SOUTHEASTERN MINNESOTA INTO WESTERN WISCONSIN...IN AN AREA THAT HAS BEEN MORE CLOUD-FREE TODAY AND THUS HAS DESTABILIZED FURTHER THAN LOCATIONS TO THE WEST. HAVE CONTINUED SLIGHT CHANCE POPS ACROSS THE FAR NORTH THIS EVENING INTO TONIGHT AS THE BEST FORCING AND INSTABILITY...RELATIVELY SPEAKING...ALONG WITH HIGHER MOISTURE LEVELS...DROP A LITTLE FARTHER SOUTH. THE FORCING IS PROGGED TO CONTINUE ITS SOUTHWARD TRAJECTORY OVERNIGHT TOWARD FRIDAY MORNING...HOWEVER NEITHER MOISTURE NOR INSTABILITY WILL BE SUFFICIENT ENOUGH TO WARRANT POPS. THIS SOLUTION IS FAVORED BY MODEL GUIDANCE AND CAMS. THE AFOREMENTIONED CONVECTION ACROSS FAR SOUTHEASTERN MINNESOTA INTO WESTERN WISCONSIN IS NOT EXPECTED TO IMPACT THE CWA. INSTABILITY AND SHEAR PARAMETERS DECREASE TOWARD THE SOUTHWEST. CAMS ALSO KEEP THE CONVECTION TO OUR NORTHEAST. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 312 PM CDT THU AUG 13 2015 THROUGH EARLY FRIDAY UPPER LEVEL SHORT WAVE AND WEAKENING BOUNDARY MAY PROVIDE ENOUGH SUPPORT FOR A FEW ISO SHOWERS EARLY IN THE PERIOD. COVERAGE LOOKS RATHER SLIM AT THIS TIME SO HAVE LEFT OUT MENTION FOR NOW. BY MID AFTERNOON A WEAK RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE FORECAST AREA WITH LIGHT WINDS AND WEAK MIXING. THOUGH H850 TEMPS WILL RECOVER TO 18 TO 20C BY AFTERNOON ALONG WITH INCREASING DEW POINTS SOME LINGERING MID TO HIGH CLOUDS SHOULD HOLD TEMPERATURES IN THE UPPER 80S CENTRAL AND WEST. BY SATURDAY THE RIDGE WILL HAVE PASSED TO THE EAST WITH SOUTHWEST FLOW BECOMING MORE PREDOMINANT AT THE SFC AND ALOFT. THIS WILL PUSH AFTERNOON HIGHS TO NEAR 90 OR SLIGHTLY HIGHER CENTRAL AND WEST AND THE MID TO UPPER 80S EAST WHERE LESS MIXING IS EXPECTED. HEAT INDICES WILL REACH THE MID 90S BY AFTERNOON MAKING FOR A RATHER WARM AFTERNOON OVER THE SOUTH. WITH THE APPROACHING COLD FRONT SUNDAY AND INCREASING INSTABILITY...MODELS ARE NOW IN BETTER AGREEMENT FOR SHOWERS/STORMS FAR NORTHWEST BETWEEN 21-00Z. THOUGH WIND SHEAR IS RATHER UNIMPRESSIVE THE INSTABILITY MAY PROMOTE SOME ISO SEVERE STORMS EARLY IN THE EVENING OVER THE NORTH/NORTHWEST BEFORE THE ACTIVITY WEAKENS SLIGHTLY OVERNIGHT AND TRENDS MORE TOWARD POTENTIAL FOR LOCALLY HEAVY RAINFALL. THE BOUNDARY IS STILL FORECAST TO MOVE SLOWLY SOUTHEAST REMAINING NORTHWEST OF A KAIO-KAMW-KALO LINE BY 12Z. LOWS WILL REMAIN MILD IN THE MID 60S TO LOWER 70S SOUTH WITH LOWER 60S NORTHWEST. GFS PWATS ARE PROGGED TO 1.75 TO 2 INCHES ALONG THE BOUNDARY OVERNIGHT SUNDAY NIGHT INTO MONDAY AS THE FRONT SAGS SOUTH. WARM CLOUD DEPTHS ALONG THE BOUNDARY WILL NEAR OR EXCEED 10KFT WITH EFFICIENT RAINFALL POSSIBLE. THOUGH SOME UNCERTAINTY REMAINS AT THIS POINT...WILL NEED TO WATCH FOR SOME HEAVY RAIN POTENTIAL AS THE FRONT DRIFTS SOUTH OVERNIGHT SUNDAY NIGHT. THOUGH THERE HAS BEEN LITTLE DAY TO DAY CONSISTENCY BETWEEN MODELS THE EURO/GFS HAVE NOW COME INTO AGREEMENT WITH A SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS BY MONDAY NIGHT AS THE FRONT SAGS SOUTH INTO MISSOURI. BEYOND MONDAY THERE ARE STILL MANY UNCERTAINTIES AS TO HOW THE NEXT TWO SYSTEMS WILL EVOLVE THOUGH SOME GENERAL TRENDS ARE EVIDENT IN THE OUTPUT. THE FIRST H500 WAVE WILL HELP LIFT THE MISSOURI BOUNDARY BACK NORTH WITH SOME THUNDERSTORMS TUESDAY INTO TUESDAY NIGHT WHILE THE GFS/EURO DIVERGE WITH THE SUBSEQUENT WAVE EVOLUTION. THE EURO IS FASTER WITH THE EASTWARD PROGRESSION OF THE SYSTEM WHILE THE GFS TAKES LONGER AND AMPLIFIES THE PATTERN IN THE PROCESS. GIVEN THE VAST DIFFERENCES IN OUTPUT...HAVE NOT STRAYED MUCH FROM GUIDANCE PACKAGE BEYOND DAY5. FOR MOST OF THIS SUMMER...THE MORE SOUTHERN SOLUTIONS HAVE PREVAILED BUT WILL NEED A FEW MORE DAYS TO BETTER RESOLVE THE DIFFERENCES. OVERALL TEMPERATURES WILL REMAIN VERY WARM INTO THE WEEKEND...COOL BY MONDAY AND COULD MAKE SOME RECOVERY INTO MID TO LATE NEXT WEEK IF THE PATTERN AMPLIFIES. && .AVIATION...14/00Z ISSUED AT 652 PM CDT THU AUG 13 2015 HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE PERIOD WITH BKN MID TO HIGH CLOUD CIGS TRANSITIONING INTO FEW/SCT DIURNAL CU FRI. SOME ISOLATED SHOWERS ARE MOVING THROUGH IA THIS EVENING...BUT NEARLY ALL OF THIS SHOULD REMAIN ALOFT WITH POSSIBLE EXCEPTION OF NEAR MASON CITY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...ZOGG LONG TERM...REV AVIATION...SMALL  FXUS63 KDMX 140429 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1129 PM CDT MON JUL 13 2015 .SHORT TERM /TONIGHT/... ISSUED AT 307 PM CDT MON JUL 13 2015 WEAK BOUNDARY HAS MOVED MOSTLY THROUGH THE FORECAST AREA BRINGING SIGNIFICANTLY LOWER DEWPOINTS. CURRENT HEAT ADVISORY AND WARNING EXPIRE THIS AFTERNOON AND MOST STATIONS WILL BE WELL BELOW CRITERIA BY THEN. KEPT PRECIP CHANCES OUT OF THE FORECAST FOR TONIGHT. NONE OF THE CONVECTIVE ALLOWING MODELS SHOW ANY PRECIP NOR DO THE NAM OR GFS OR EVEN THE SREF PLUMES FROM SPC. LOOKS AGAIN LIKE EVERYTHING WILL STAY EAST OF THIS FORECAST AREA OVERNIGHT. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 307 PM CDT MON JUL 13 2015 MAIN FORECAST CONCERN WAS FOCUSED ON PRECIPITATION CHANCES WEDNESDAY INTO THURSDAY AND ANOTHER ROUND OF HOT AND HUMID CONDITIONS LATE IN THE PERIOD. LEANED TOWARD A NAM12/ECMWF/SREF BLEND FOR TUESDAY AND WEDNESDAY...THEN A LITTLE MORE WEIGHT TO THE ECMWF THROUGH THE REST OF THE WEEKEND. TUESDAY INTO THURSDAY...MUCH LESS HUMIDITY IS ANTICIPATED ON TUESDAY BUT TEMPERATURES STILL LOOK TO RISE INTO THE UPPER 80S AND LOWER 90S. A FEW SPOTS MAY REACH HEAT INDEX READINGS TO AROUND 100 BUT NOTHING CLOSE TO ADVISORY LEVEL. WEDNESDAY WILL SEE INCREASING CLOUD COVER WHICH WILL HOLD TEMPERATURES IN THE 80S. DECENT SHORTWAVE TRACKS EAST-NORTHEAST ALONG THE UPPER LEVEL RIDGE BUILDING INTO THE CENTRAL U.S. WEDNESDAY NIGHT INTO THURSDAY. TIMING HAS SLOWED SLIGHTLY AND THUS DELAYED ONSET OF POPS TO WESTERN IOWA AFTER 18Z WEDNESDAY AND ACROSS THE ENTIRE FORECAST AREA AFTER 00Z THURSDAY. ECMWF/NAM ARE SLIGHTLY FURTHER SOUTH WITH THE SHORTWAVE TRACK AND WITH THE HEAVIEST RAIN THAN THE GFS. ECMWF HAS BEEN A LITTLE MORE CONSISTENT BETWEEN MODEL RUNS AND LIKENED THE SOLUTION WHICH RESULTED IN INCREASING POPS OVERNIGHT WEDNESDAY NIGHT INTO THURSDAY. HEAVY RAIN LOOKS TO BE THE MAIN THREAT AS PRECIPITABLE WATER VALUES IN THE RANGE OF 1.5 TO 2.0 INCHES WITH STRONG MOISTURE TRANSPORT AND THETA-E ADVECTION INTO THE STATE PAST 06Z THURSDAY. WARM LAYER CLOUD DEPTHS RANGE FROM 13KFT TO 14KT FEET INTO THURSDAY MORNING SO CERTAINLY SOME EFFICIENT RAIN PRODUCERS CAN BE EXPECTED. INCREASED QPF AMOUNTS BETWEEN 00-12Z THURSDAY. SEVERE POTENTIAL IS LOW WITH MINIMAL INSTABILITY AND SHEAR AVAILABLE WEDNESDAY NIGHT INTO THURSDAY. FRIDAY INTO MONDAY...UPPER LEVEL RIDGE PERSISTS THROUGH THE WEEKEND WITH SOUTHWEST FLOW RETURNING TO THE STATE BY SATURDAY. TRENDED WARMER FOR MAX TEMPS ON SATURDAY WITH DECENT MIXING AND 850MB TEMPS TO +22C TO +23C. DEW POINTS LOOKS TO RISE BACK INTO THE MIDDLE 70S AND MAY HAVE ANOTHER HOT AND HUMID DAY SATURDAY. COLD FRONT/TROUGH MOVE THROUGH THE STATE LATE SATURDAY NIGHT AND PROVIDE ADDITION THUNDERSTORM CHANCES INTO SUNDAY. SLIGHTLY COOLER SUNDAY INTO MONDAY. && .AVIATION...14/06Z ISSUED AT 1129 PM CDT MON JUL 13 2015 VFR CONDITIONS THROUGH THE PERIOD WITH LIGHT WEST TO NORTHWEST WINDS OVERNIGHT INCREASING TO 10 TO 15 KTS DURING THE DAY TUESDAY. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...HARDING LONG TERM...PODRAZIK AVIATION...DONAVON  FXUS63 KDMX 140509 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1209 AM CDT FRI AUG 14 2015 .SHORT TERM /TONIGHT/... ISSUED AT 312 PM CDT THU AUG 13 2015 RELATIVELY QUIET WX EXPECTED FOR MOST OF THE CWA DURING THE SHORT TERM PERIOD...WITH ONLY CHANCES FOR SHRA/TSRA BEING ACROSS THE FAR NORTH. WEATHER PATTERN WILL REMAIN RELATIVELY UNCHANGED...WITH THE AMPLIFIED UPPER-LEVEL RIDGE REMAINING TO OUR WEST. A SURFACE TROF WILL REMAIN JUST TO OUR WEST...FROM THE CENTRAL AND EASTERN DAKOTA AREA INTO CENTRAL NEBRASKA. SURFACE HIGH PRESSURE WILL REMAIN TO OUR EAST. AREA OF SCT SHRA FROM EASTERN SOUTH DAKOTA INTO SOUTHERN MINNESOTA HAS PERSISTED TODAY...IN AN AREA OF RELATIVELY WEAK FORCING COUPLED WITH ELEVATED MOISTURE LEVELS. MOISTURE LEVELS AND FORCING BOTH DECREASE TOWARD THE SOUTH...WHICH HAS KEPT THE PCPN TO THE NORTH OF THE MINNESOTA BORDER. TO THE NORTHEAST...ISOLATED TSRA HAVE DEVELOPED ACROSS FAR SOUTHEASTERN MINNESOTA INTO WESTERN WISCONSIN...IN AN AREA THAT HAS BEEN MORE CLOUD-FREE TODAY AND THUS HAS DESTABILIZED FURTHER THAN LOCATIONS TO THE WEST. HAVE CONTINUED SLIGHT CHANCE POPS ACROSS THE FAR NORTH THIS EVENING INTO TONIGHT AS THE BEST FORCING AND INSTABILITY...RELATIVELY SPEAKING...ALONG WITH HIGHER MOISTURE LEVELS...DROP A LITTLE FARTHER SOUTH. THE FORCING IS PROGGED TO CONTINUE ITS SOUTHWARD TRAJECTORY OVERNIGHT TOWARD FRIDAY MORNING...HOWEVER NEITHER MOISTURE NOR INSTABILITY WILL BE SUFFICIENT ENOUGH TO WARRANT POPS. THIS SOLUTION IS FAVORED BY MODEL GUIDANCE AND CAMS. THE AFOREMENTIONED CONVECTION ACROSS FAR SOUTHEASTERN MINNESOTA INTO WESTERN WISCONSIN IS NOT EXPECTED TO IMPACT THE CWA. INSTABILITY AND SHEAR PARAMETERS DECREASE TOWARD THE SOUTHWEST. CAMS ALSO KEEP THE CONVECTION TO OUR NORTHEAST. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 312 PM CDT THU AUG 13 2015 THROUGH EARLY FRIDAY UPPER LEVEL SHORT WAVE AND WEAKENING BOUNDARY MAY PROVIDE ENOUGH SUPPORT FOR A FEW ISO SHOWERS EARLY IN THE PERIOD. COVERAGE LOOKS RATHER SLIM AT THIS TIME SO HAVE LEFT OUT MENTION FOR NOW. BY MID AFTERNOON A WEAK RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE FORECAST AREA WITH LIGHT WINDS AND WEAK MIXING. THOUGH H850 TEMPS WILL RECOVER TO 18 TO 20C BY AFTERNOON ALONG WITH INCREASING DEW POINTS SOME LINGERING MID TO HIGH CLOUDS SHOULD HOLD TEMPERATURES IN THE UPPER 80S CENTRAL AND WEST. BY SATURDAY THE RIDGE WILL HAVE PASSED TO THE EAST WITH SOUTHWEST FLOW BECOMING MORE PREDOMINANT AT THE SFC AND ALOFT. THIS WILL PUSH AFTERNOON HIGHS TO NEAR 90 OR SLIGHTLY HIGHER CENTRAL AND WEST AND THE MID TO UPPER 80S EAST WHERE LESS MIXING IS EXPECTED. HEAT INDICES WILL REACH THE MID 90S BY AFTERNOON MAKING FOR A RATHER WARM AFTERNOON OVER THE SOUTH. WITH THE APPROACHING COLD FRONT SUNDAY AND INCREASING INSTABILITY...MODELS ARE NOW IN BETTER AGREEMENT FOR SHOWERS/STORMS FAR NORTHWEST BETWEEN 21-00Z. THOUGH WIND SHEAR IS RATHER UNIMPRESSIVE THE INSTABILITY MAY PROMOTE SOME ISO SEVERE STORMS EARLY IN THE EVENING OVER THE NORTH/NORTHWEST BEFORE THE ACTIVITY WEAKENS SLIGHTLY OVERNIGHT AND TRENDS MORE TOWARD POTENTIAL FOR LOCALLY HEAVY RAINFALL. THE BOUNDARY IS STILL FORECAST TO MOVE SLOWLY SOUTHEAST REMAINING NORTHWEST OF A KAIO-KAMW-KALO LINE BY 12Z. LOWS WILL REMAIN MILD IN THE MID 60S TO LOWER 70S SOUTH WITH LOWER 60S NORTHWEST. GFS PWATS ARE PROGGED TO 1.75 TO 2 INCHES ALONG THE BOUNDARY OVERNIGHT SUNDAY NIGHT INTO MONDAY AS THE FRONT SAGS SOUTH. WARM CLOUD DEPTHS ALONG THE BOUNDARY WILL NEAR OR EXCEED 10KFT WITH EFFICIENT RAINFALL POSSIBLE. THOUGH SOME UNCERTAINTY REMAINS AT THIS POINT...WILL NEED TO WATCH FOR SOME HEAVY RAIN POTENTIAL AS THE FRONT DRIFTS SOUTH OVERNIGHT SUNDAY NIGHT. THOUGH THERE HAS BEEN LITTLE DAY TO DAY CONSISTENCY BETWEEN MODELS THE EURO/GFS HAVE NOW COME INTO AGREEMENT WITH A SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS BY MONDAY NIGHT AS THE FRONT SAGS SOUTH INTO MISSOURI. BEYOND MONDAY THERE ARE STILL MANY UNCERTAINTIES AS TO HOW THE NEXT TWO SYSTEMS WILL EVOLVE THOUGH SOME GENERAL TRENDS ARE EVIDENT IN THE OUTPUT. THE FIRST H500 WAVE WILL HELP LIFT THE MISSOURI BOUNDARY BACK NORTH WITH SOME THUNDERSTORMS TUESDAY INTO TUESDAY NIGHT WHILE THE GFS/EURO DIVERGE WITH THE SUBSEQUENT WAVE EVOLUTION. THE EURO IS FASTER WITH THE EASTWARD PROGRESSION OF THE SYSTEM WHILE THE GFS TAKES LONGER AND AMPLIFIES THE PATTERN IN THE PROCESS. GIVEN THE VAST DIFFERENCES IN OUTPUT...HAVE NOT STRAYED MUCH FROM GUIDANCE PACKAGE BEYOND DAY5. FOR MOST OF THIS SUMMER...THE MORE SOUTHERN SOLUTIONS HAVE PREVAILED BUT WILL NEED A FEW MORE DAYS TO BETTER RESOLVE THE DIFFERENCES. OVERALL TEMPERATURES WILL REMAIN VERY WARM INTO THE WEEKEND...COOL BY MONDAY AND COULD MAKE SOME RECOVERY INTO MID TO LATE NEXT WEEK IF THE PATTERN AMPLIFIES. && .AVIATION...14/06Z ISSUED AT 1204 AM CDT FRI AUG 14 2015 LITTLE CHANGE FROM PREVIOUS FORECAST. HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE PERIOD WITH BKN MID TO HIGH CLOUD CIGS TRANSITIONING INTO FEW/SCT DIURNAL CU FRI. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...ZOGG LONG TERM...REV AVIATION...SMALL  FXUS63 KDMX 140846 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 346 AM CDT FRI AUG 14 2015 .SHORT TERM /TODAY/... ISSUED AT 324 AM CDT FRI AUG 14 2015 WEAK WAVE CURRENTLY PASSING THROUGH THE STATE WITH A FEW SCATTERED SHOWERS ACROSS THE NORTHEAST. THE INFLUENCE OF THIS WAVE WILL WANE DURING THE MORNING AS IT PROGRESSES TO THE SOUTHEAST. AS SUBSIDENCE INCREASES ON THE BACKSIDE OF THE SYSTEM...WILL SEE CLEARING SKIES ACROSS CENTRAL IOWA ALONG WITH WEAK WARM ADVECTION. TEMPERATURES MAY INITIALLY BE SLOW TO CLIMB THIS MORNING...ESPECIALLY WHERE CLOUDS ARE THICKER IN THE EAST...HOWEVER READING SHOULD RISE NICELY BY THIS AFTERNOON WITH MORE SUNSHINE AS READINGS CLIMB INTO THE MID TO UPPER 80S IN MOST LOCATIONS. WITH DEWPOINT POINTS NEAR 70...APPARENT TEMPERATURES WILL BE FROM 90 TO 95 BY MID AFTERNOON. THE WIND WILL BE OF LITTLE RELIEF WITH ONLY LIGHT SOUTHWEST WINDS EXPECTED...ALTHOUGH SLIGHTLY HIGHER INT HE NORTH AND NORTHEAST WHERE GRADIENT IS A BIT TIGHTER. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 324 AM CDT FRI AUG 14 2015 FORECAST REMAINS CONSISTENT AND HAVE MADE FEW CHANGES TO THE EXTENDED. MAIN CONCERNS WILL BE TEMPERATURES FOR BEGINNING OF PERIOD...THEN PRECIPITATION TRENDS LATE IN THE WEEKEND FOLLOWED BY A RETURN TO AN ACTIVE WEATHER PATTERN. HAVE KEPT TEMPERATURES NEAR GOING AND GENERALLY IN LINE WITH GUIDANCE FOR THE BEGINNING OF THE PERIOD AS RIDGE REMAINS OVER IOWA. SOUTHERLY FLOW AND WAA WILL HELP TO KEEP TEMPERATURES UP THROUGH SATURDAY AHEAD OF BOUNDARY. FRONT WILL BEGIN TO PUSH SOUTH INTO NORTHWESTERN IOWA SUNDAY. MODELS REMAIN CONSISTENT WITH HANDLING OF THIS SYSTEM...AND ARE IN BETTER AGREEMENT WITH TIMING AND PLACEMENT. PLACEMENT IS CONSISTENT WITH PREVIOUS RUNS...AND WILL HAVE A LARGE IMPACT ON TEMPERATURES...WITH GOOD WARMING SOUTHEAST OF THE BOUNDARY AND COOLER TEMPERATURES NORTH. AGAIN...HAVE KEPT TEMPS NEAR GOING...THOUGH HAVE PUSHED HIGHER TEMPERATURES FURTHER TO THE NORTHWEST WITH A BIT SLOWER PROGRESSION OF BOUNDARY. WITH SLIGHTLY SLOWER PROGRESSION HAVE ALSO CUT BACK ON POPS SLIGHTLY FOR SUNDAY. INSTABILITY EXPECTED TO BUILD INTO NORTHERN IOWA NEAR BOUNDARY SUNDAY AFTERNOON. NAM IS MUCH MORE AGGRESSIVE WITH GFS MUCH LESS SO. SHEAR REMAINS MUCH LESS LIMITED AND WILL LIKELY BE LIMITING FACTOR FOR SEVERE POTENTIAL. HOWEVER...CANNOT RULE OUT SEVERE THUNDERSTORMS AND FEEL SPC MARGINAL RISK IS WELL PLACED. EXPECT BEST CHANCES FOR PRECIPITATION TO COME OVERNIGHT SUNDAY NIGHT. MOISTURE INCREASES WITH PWAT VALUES NEARING 2 INCHES INDICATED ON SOUNDINGS WITH GOOD WARM CLOUD DEPTHS. WILL THEREFORE NEED TO KEEP MONITORING FOR HEAVY RAIN POTENTIAL. SYSTEM BECOMES MORE ACTIVE THROUGH THE END OF THE PERIOD...THOUGH MODELS CONTINUE TO NOT BE IN GOOD AGREEMENT WITH HANDLING OF SYSTEM...ESPECIALLY WITH RUN TO RUN CONSISTENCY. BOUNDARY IS EXPECTED TO SLOWLY PUSH SOUTH THROUGHOUT THE DAY MONDAY...WITH GFS STALLING BOUNDARY ACROSS CENTRAL IOWA BEFORE ANOTHER LOW PRESSURE SYSTEM PUSHES EAST LATE TUESDAY. LOW WILL KEEP CHANCES FOR THUNDERSTORMS ACROSS THE REGION THROUGH THE END OF THE PERIOD. HOWEVER...STILL MUCH UNCERTAINTY ON TIMING AND EVOLUTION OF SYSTEM. GFS HAS BEEN FAIRLY CONSISTENT WITH SOLUTION...AND ECMWF HAS BEGUN TO COME MORE IN LINE. THEREFORE...HAVE CONTINUED TO TREND TOWARDS GFS. TEMPERATURES WILL BE MUCH COOLER BEHIND BOUNDARY...AND WILL REMAIN COOL THROUGH THE END OF THE PERIOD WITH PRECIPITATION AND CLOUDS HELPING TO KEEP TEMPERATURES DOWN...THOUGH READINGS WILL STILL BE NEAR NORMAL FOR TIME OF YEAR. && .AVIATION...14/06Z ISSUED AT 1204 AM CDT FRI AUG 14 2015 LITTLE CHANGE FROM PREVIOUS FORECAST. HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE PERIOD WITH BKN MID TO HIGH CLOUD CIGS TRANSITIONING INTO FEW/SCT DIURNAL CU FRI. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...COGIL LONG TERM...AWB AVIATION...SMALL  FXUS63 KDMX 141123 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 623 AM CDT TUE JUL 14 2015 .SHORT TERM /TODAY/... ISSUED AT 345 AM CDT TUE JUL 14 2015 LITTLE OF CONCERN TODAY WITH NO PRECIP AND A RETURN TO SEASONAL TEMPS AND DEWPOINTS. EXPANSIVE SUBSIDENCE HAS FOLLOWED DEPARTING GREAT LAKES SHORT WAVE WITH CENTRAL PLAINS RIDGE GRADUALLY WORKING ITS WAY EASTWARD THROUGH THE PERIOD. WEAK SHORT WAVES/PV ANOMALIES OVER SD AND MN ARE DROPPING INTO AFOREMENTIONED SHORT WAVE TROUGH...AND HAVE TRIGGERED ISOLATED SHOWERS AND WEAK STORMS OVERNIGHT NE...BUT ANY FORCING WITH THESE FEATURES SHOULD BE EAST OF THE AREA SHORTLY. RELATIVELY LOW END MLCAPES WILL BE UNCAPPED DURING PEAK HEATING BUT WITH LITTLE CONVERGENCE AND WINDS VEERING TO NELY LATE AS SURFACE HIGH REACHES WRN GREAT LAKES. FORECAST SOUNDINGS AND MOS AND IN GOOD AGREEMENT WITH HIGHS MID 80S TO LOWER 90S. IT WILL STILL FEEL QUITE WARM WITH HEAT INDICES REACHING THE MID 90S CENTRAL AND SOUTH...BUT STILL FEEL SOMEWHAT BETTER WITH 10 DEGREE REDUCTION FROM YESTERDAY. NO HEAT HEADLINES NEEDED. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 345 AM CDT TUE JUL 14 2015 THE START OF THE PERIOD WILL FEATURE A SURFACE RIDGE AXIS CENTERED JUST EAST OF THE CWA...BRINGING THE REGION QUIET WEATHER AND SHIFTING EAST DURING THE NIGHT. A SURFACE CYCLONE DEVELOPING OVER THE OKLAHOMA PANHANDLE TUESDAY NIGHT LIFTS NORTHEASTWARD WITH A 500 MB SHORTWAVE/VORT MAX OVER THE COURSE OF THE DAY ON WEDNESDAY. NUDGED WEDNESDAY HIGHS DOWN A DEGREE OR SO DUE TO THE COMBINATION OF NEUTRAL/SLIGHTLY COOL TEMPERATURE ADVECTION AND INCREASING MID TO HIGH LEVEL CLOUDS AHEAD OF THE LOW. MODELS DIFFER SOMEWHAT ON THE TRACK OF THE SYSTEM AS IT REACHES IOWA...WITH THE GFS/NAM CLUSTERED IN A NORTHERN SOLUTION IN CONTRAST TO A SOUTHERN EC. MADE LITTLE CHANGE TO THE ONGOING POP FORECAST...TAKING A BLEND OF THE GFS/EC AND PAINTING A SWATH OF HIGHER POPS OVER THE NORTHERN TWO THIRDS OF THE CWA. MULTIPLE SIGNALS POINT TO A HEAVY RAIN EVENT WITH LOW CHANCES FOR OTHER MODES OF SEVERE WEATHER GIVEN THE WEAK SHEAR AND INSTABILITY PROFILES. ELEVATED CONVECTION IS FORECAST TO INITIATE ON THE 850 MB WARM FRONT LIFTING AHEAD OF THE LOW WEDNESDAY AFTERNOON AND EVENING. MIDLEVEL SOUTHWEST US MONSOONAL MOISTURE COUPLED WITH STRONG LOW LEVEL MOISTURE TRANSPORT OFF THE GULF WILL LEAD TO DEEPLY SATURATED SOUNDINGS WITH PWATS EXCEEDING 2 INCHES AND WARM CLOUD DEPTHS OVER 13 KFT. A STRENGTHENING LLJ WILL FUEL THE STORMS THROUGH THE OVERNIGHT HOURS WITH WEAK 600-300 MB STEERING FLOW FURTHER AIDING IN THE HEAVY RAIN THREAT. MULTIPLE ROUNDS OF STORMS ARE POSSIBLE THROUGH THE NIGHT AND INTO THURSDAY MORNING. HAVE RAISED STORM TOTAL QPF AMOUNTS TO AROUND 1 INCH IN THE WESTERN CWA (AGAIN A COMPROMISE IN MODEL TRACKS)...BUT WOULD NOT BE SURPRISED TO SEE 2+ INCHES IN MANY AREAS IN THE HEAVIEST RAIN SWATH. THE WARM FRONT LIFTS NORTH THURSDAY AND WILL ALLOW A WARM AND HUMID AIR BACK INTO THE STATE TO END THE WEEK. TEMPERATURES WILL RETURN TO THE LOW 90S WITH DEWPOINTS IN THE 70S. THE SURFACE TROUGH WILL LINGER OUT OVER NEBRASKA INTO THE WEEKEND...KEEPING IOWA IN THE WARM SECTOR THROUGH SUNDAY BEFORE THE TROUGH SAGS BACK SOUTH. && .AVIATION...14/12Z ISSUED AT 623 AM CDT TUE JUL 14 2015 LITTLE OF CONCERN THROUGH THE PERIOD WITH VFR CONDITIONS FROM CLEAR TO NOTHING MORE THAN SCT MAINLY DIURNAL CU. SURFACE HIGH PRESSURE WILL EVENTUALLY MOVE THROUGH THE WRN GREAT LAKES WITH WINDS VEERING FROM NWLY TO SELY LATE. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SMALL LONG TERM...SKOW AVIATION...SMALL  FXUS63 KDMX 141138 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 638 AM CDT FRI AUG 14 2015 .SHORT TERM /TODAY/... ISSUED AT 324 AM CDT FRI AUG 14 2015 WEAK WAVE CURRENTLY PASSING THROUGH THE STATE WITH A FEW SCATTERED SHOWERS ACROSS THE NORTHEAST. THE INFLUENCE OF THIS WAVE WILL WANE DURING THE MORNING AS IT PROGRESSES TO THE SOUTHEAST. AS SUBSIDENCE INCREASES ON THE BACKSIDE OF THE SYSTEM...WILL SEE CLEARING SKIES ACROSS CENTRAL IOWA ALONG WITH WEAK WARM ADVECTION. TEMPERATURES MAY INITIALLY BE SLOW TO CLIMB THIS MORNING...ESPECIALLY WHERE CLOUDS ARE THICKER IN THE EAST...HOWEVER READING SHOULD RISE NICELY BY THIS AFTERNOON WITH MORE SUNSHINE AS READINGS CLIMB INTO THE MID TO UPPER 80S IN MOST LOCATIONS. WITH DEWPOINT POINTS NEAR 70...APPARENT TEMPERATURES WILL BE FROM 90 TO 95 BY MID AFTERNOON. THE WIND WILL BE OF LITTLE RELIEF WITH ONLY LIGHT SOUTHWEST WINDS EXPECTED...ALTHOUGH SLIGHTLY HIGHER INT HE NORTH AND NORTHEAST WHERE GRADIENT IS A BIT TIGHTER. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 324 AM CDT FRI AUG 14 2015 FORECAST REMAINS CONSISTENT AND HAVE MADE FEW CHANGES TO THE EXTENDED. MAIN CONCERNS WILL BE TEMPERATURES FOR BEGINNING OF PERIOD...THEN PRECIPITATION TRENDS LATE IN THE WEEKEND FOLLOWED BY A RETURN TO AN ACTIVE WEATHER PATTERN. HAVE KEPT TEMPERATURES NEAR GOING AND GENERALLY IN LINE WITH GUIDANCE FOR THE BEGINNING OF THE PERIOD AS RIDGE REMAINS OVER IOWA. SOUTHERLY FLOW AND WAA WILL HELP TO KEEP TEMPERATURES UP THROUGH SATURDAY AHEAD OF BOUNDARY. FRONT WILL BEGIN TO PUSH SOUTH INTO NORTHWESTERN IOWA SUNDAY. MODELS REMAIN CONSISTENT WITH HANDLING OF THIS SYSTEM...AND ARE IN BETTER AGREEMENT WITH TIMING AND PLACEMENT. PLACEMENT IS CONSISTENT WITH PREVIOUS RUNS...AND WILL HAVE A LARGE IMPACT ON TEMPERATURES...WITH GOOD WARMING SOUTHEAST OF THE BOUNDARY AND COOLER TEMPERATURES NORTH. AGAIN...HAVE KEPT TEMPS NEAR GOING...THOUGH HAVE PUSHED HIGHER TEMPERATURES FURTHER TO THE NORTHWEST WITH A BIT SLOWER PROGRESSION OF BOUNDARY. WITH SLIGHTLY SLOWER PROGRESSION HAVE ALSO CUT BACK ON POPS SLIGHTLY FOR SUNDAY. INSTABILITY EXPECTED TO BUILD INTO NORTHERN IOWA NEAR BOUNDARY SUNDAY AFTERNOON. NAM IS MUCH MORE AGGRESSIVE WITH GFS MUCH LESS SO. SHEAR REMAINS MUCH LESS LIMITED AND WILL LIKELY BE LIMITING FACTOR FOR SEVERE POTENTIAL. HOWEVER...CANNOT RULE OUT SEVERE THUNDERSTORMS AND FEEL SPC MARGINAL RISK IS WELL PLACED. EXPECT BEST CHANCES FOR PRECIPITATION TO COME OVERNIGHT SUNDAY NIGHT. MOISTURE INCREASES WITH PWAT VALUES NEARING 2 INCHES INDICATED ON SOUNDINGS WITH GOOD WARM CLOUD DEPTHS. WILL THEREFORE NEED TO KEEP MONITORING FOR HEAVY RAIN POTENTIAL. SYSTEM BECOMES MORE ACTIVE THROUGH THE END OF THE PERIOD...THOUGH MODELS CONTINUE TO NOT BE IN GOOD AGREEMENT WITH HANDLING OF SYSTEM...ESPECIALLY WITH RUN TO RUN CONSISTENCY. BOUNDARY IS EXPECTED TO SLOWLY PUSH SOUTH THROUGHOUT THE DAY MONDAY...WITH GFS STALLING BOUNDARY ACROSS CENTRAL IOWA BEFORE ANOTHER LOW PRESSURE SYSTEM PUSHES EAST LATE TUESDAY. LOW WILL KEEP CHANCES FOR THUNDERSTORMS ACROSS THE REGION THROUGH THE END OF THE PERIOD. HOWEVER...STILL MUCH UNCERTAINTY ON TIMING AND EVOLUTION OF SYSTEM. GFS HAS BEEN FAIRLY CONSISTENT WITH SOLUTION...AND ECMWF HAS BEGUN TO COME MORE IN LINE. THEREFORE...HAVE CONTINUED TO TREND TOWARDS GFS. TEMPERATURES WILL BE MUCH COOLER BEHIND BOUNDARY...AND WILL REMAIN COOL THROUGH THE END OF THE PERIOD WITH PRECIPITATION AND CLOUDS HELPING TO KEEP TEMPERATURES DOWN...THOUGH READINGS WILL STILL BE NEAR NORMAL FOR TIME OF YEAR. && .AVIATION...14/12Z ISSUED AT 636 AM CDT FRI AUG 14 2015 VFR CEILINGS WILL EXIT TO THE SOUTHEAST TODAY WITH WIDESPREAD VFR CONDITIONS TODAY INTO MUCH OF TONIGHT. ONLY CONCERN LATE TONIGHT WILL BE WITH THE LIGHT WINDS AND POSSIBLE FOG DEVELOPMENT THAT MAY LEAD TO MVFR/IFR CONDITIONS AT TERMINAL LOCATIONS. WINDS WILL BE SOUTH TO SOUTHWEST TODAY AND BECOME QUIET LIGHT BY TONIGHT WITH WEAK PRESSURE GRADIENT ACROSS THE STATE. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...COGIL LONG TERM...AWB AVIATION...COGIL  FXUS63 KDMX 141715 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1215 PM CDT TUE JUL 14 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TODAY/... ISSUED AT 345 AM CDT TUE JUL 14 2015 LITTLE OF CONCERN TODAY WITH NO PRECIP AND A RETURN TO SEASONAL TEMPS AND DEWPOINTS. EXPANSIVE SUBSIDENCE HAS FOLLOWED DEPARTING GREAT LAKES SHORT WAVE WITH CENTRAL PLAINS RIDGE GRADUALLY WORKING ITS WAY EASTWARD THROUGH THE PERIOD. WEAK SHORT WAVES/PV ANOMALIES OVER SD AND MN ARE DROPPING INTO AFOREMENTIONED SHORT WAVE TROUGH...AND HAVE TRIGGERED ISOLATED SHOWERS AND WEAK STORMS OVERNIGHT NE...BUT ANY FORCING WITH THESE FEATURES SHOULD BE EAST OF THE AREA SHORTLY. RELATIVELY LOW END MLCAPES WILL BE UNCAPPED DURING PEAK HEATING BUT WITH LITTLE CONVERGENCE AND WINDS VEERING TO NELY LATE AS SURFACE HIGH REACHES WRN GREAT LAKES. FORECAST SOUNDINGS AND MOS AND IN GOOD AGREEMENT WITH HIGHS MID 80S TO LOWER 90S. IT WILL STILL FEEL QUITE WARM WITH HEAT INDICES REACHING THE MID 90S CENTRAL AND SOUTH...BUT STILL FEEL SOMEWHAT BETTER WITH 10 DEGREE REDUCTION FROM YESTERDAY. NO HEAT HEADLINES NEEDED. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 345 AM CDT TUE JUL 14 2015 THE START OF THE PERIOD WILL FEATURE A SURFACE RIDGE AXIS CENTERED JUST EAST OF THE CWA...BRINGING THE REGION QUIET WEATHER AND SHIFTING EAST DURING THE NIGHT. A SURFACE CYCLONE DEVELOPING OVER THE OKLAHOMA PANHANDLE TUESDAY NIGHT LIFTS NORTHEASTWARD WITH A 500 MB SHORTWAVE/VORT MAX OVER THE COURSE OF THE DAY ON WEDNESDAY. NUDGED WEDNESDAY HIGHS DOWN A DEGREE OR SO DUE TO THE COMBINATION OF NEUTRAL/SLIGHTLY COOL TEMPERATURE ADVECTION AND INCREASING MID TO HIGH LEVEL CLOUDS AHEAD OF THE LOW. MODELS DIFFER SOMEWHAT ON THE TRACK OF THE SYSTEM AS IT REACHES IOWA...WITH THE GFS/NAM CLUSTERED IN A NORTHERN SOLUTION IN CONTRAST TO A SOUTHERN EC. MADE LITTLE CHANGE TO THE ONGOING POP FORECAST...TAKING A BLEND OF THE GFS/EC AND PAINTING A SWATH OF HIGHER POPS OVER THE NORTHERN TWO THIRDS OF THE CWA. MULTIPLE SIGNALS POINT TO A HEAVY RAIN EVENT WITH LOW CHANCES FOR OTHER MODES OF SEVERE WEATHER GIVEN THE WEAK SHEAR AND INSTABILITY PROFILES. ELEVATED CONVECTION IS FORECAST TO INITIATE ON THE 850 MB WARM FRONT LIFTING AHEAD OF THE LOW WEDNESDAY AFTERNOON AND EVENING. MIDLEVEL SOUTHWEST US MONSOONAL MOISTURE COUPLED WITH STRONG LOW LEVEL MOISTURE TRANSPORT OFF THE GULF WILL LEAD TO DEEPLY SATURATED SOUNDINGS WITH PWATS EXCEEDING 2 INCHES AND WARM CLOUD DEPTHS OVER 13 KFT. A STRENGTHENING LLJ WILL FUEL THE STORMS THROUGH THE OVERNIGHT HOURS WITH WEAK 600-300 MB STEERING FLOW FURTHER AIDING IN THE HEAVY RAIN THREAT. MULTIPLE ROUNDS OF STORMS ARE POSSIBLE THROUGH THE NIGHT AND INTO THURSDAY MORNING. HAVE RAISED STORM TOTAL QPF AMOUNTS TO AROUND 1 INCH IN THE WESTERN CWA (AGAIN A COMPROMISE IN MODEL TRACKS)...BUT WOULD NOT BE SURPRISED TO SEE 2+ INCHES IN MANY AREAS IN THE HEAVIEST RAIN SWATH. THE WARM FRONT LIFTS NORTH THURSDAY AND WILL ALLOW A WARM AND HUMID AIR BACK INTO THE STATE TO END THE WEEK. TEMPERATURES WILL RETURN TO THE LOW 90S WITH DEWPOINTS IN THE 70S. THE SURFACE TROUGH WILL LINGER OUT OVER NEBRASKA INTO THE WEEKEND...KEEPING IOWA IN THE WARM SECTOR THROUGH SUNDAY BEFORE THE TROUGH SAGS BACK SOUTH. && .AVIATION...14/18Z ISSUED AT 1214 PM CDT TUE JUL 14 2015 VFR CONDITIONS WILL PREVAIL THROUGHOUT THE ENTIRE TAF PERIOD. WINDS ARE EXPECTED TO BE NORTH TO NORTHEAST THROUGH THE AFTERNOON BEFORE SHIFTING EAST TONIGHT INTO WEDNESDAY MORNING. SOUTHERLY FLOW RETURNS BY MID-MORNING WEDNESDAY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SMALL LONG TERM...SKOW AVIATION...PODRAZIK  FXUS63 KDMX 141721 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1218 PM CDT FRI AUG 14 2015 ...UPDATED FOR 14/18Z AVIATION DISCUSSION... .SHORT TERM /TODAY/... ISSUED AT 324 AM CDT FRI AUG 14 2015 WEAK WAVE CURRENTLY PASSING THROUGH THE STATE WITH A FEW SCATTERED SHOWERS ACROSS THE NORTHEAST. THE INFLUENCE OF THIS WAVE WILL WANE DURING THE MORNING AS IT PROGRESSES TO THE SOUTHEAST. AS SUBSIDENCE INCREASES ON THE BACKSIDE OF THE SYSTEM...WILL SEE CLEARING SKIES ACROSS CENTRAL IOWA ALONG WITH WEAK WARM ADVECTION. TEMPERATURES MAY INITIALLY BE SLOW TO CLIMB THIS MORNING...ESPECIALLY WHERE CLOUDS ARE THICKER IN THE EAST...HOWEVER READING SHOULD RISE NICELY BY THIS AFTERNOON WITH MORE SUNSHINE AS READINGS CLIMB INTO THE MID TO UPPER 80S IN MOST LOCATIONS. WITH DEWPOINT POINTS NEAR 70...APPARENT TEMPERATURES WILL BE FROM 90 TO 95 BY MID AFTERNOON. THE WIND WILL BE OF LITTLE RELIEF WITH ONLY LIGHT SOUTHWEST WINDS EXPECTED...ALTHOUGH SLIGHTLY HIGHER INT HE NORTH AND NORTHEAST WHERE GRADIENT IS A BIT TIGHTER. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 324 AM CDT FRI AUG 14 2015 FORECAST REMAINS CONSISTENT AND HAVE MADE FEW CHANGES TO THE EXTENDED. MAIN CONCERNS WILL BE TEMPERATURES FOR BEGINNING OF PERIOD...THEN PRECIPITATION TRENDS LATE IN THE WEEKEND FOLLOWED BY A RETURN TO AN ACTIVE WEATHER PATTERN. HAVE KEPT TEMPERATURES NEAR GOING AND GENERALLY IN LINE WITH GUIDANCE FOR THE BEGINNING OF THE PERIOD AS RIDGE REMAINS OVER IOWA. SOUTHERLY FLOW AND WAA WILL HELP TO KEEP TEMPERATURES UP THROUGH SATURDAY AHEAD OF BOUNDARY. FRONT WILL BEGIN TO PUSH SOUTH INTO NORTHWESTERN IOWA SUNDAY. MODELS REMAIN CONSISTENT WITH HANDLING OF THIS SYSTEM...AND ARE IN BETTER AGREEMENT WITH TIMING AND PLACEMENT. PLACEMENT IS CONSISTENT WITH PREVIOUS RUNS...AND WILL HAVE A LARGE IMPACT ON TEMPERATURES...WITH GOOD WARMING SOUTHEAST OF THE BOUNDARY AND COOLER TEMPERATURES NORTH. AGAIN...HAVE KEPT TEMPS NEAR GOING...THOUGH HAVE PUSHED HIGHER TEMPERATURES FURTHER TO THE NORTHWEST WITH A BIT SLOWER PROGRESSION OF BOUNDARY. WITH SLIGHTLY SLOWER PROGRESSION HAVE ALSO CUT BACK ON POPS SLIGHTLY FOR SUNDAY. INSTABILITY EXPECTED TO BUILD INTO NORTHERN IOWA NEAR BOUNDARY SUNDAY AFTERNOON. NAM IS MUCH MORE AGGRESSIVE WITH GFS MUCH LESS SO. SHEAR REMAINS MUCH LESS LIMITED AND WILL LIKELY BE LIMITING FACTOR FOR SEVERE POTENTIAL. HOWEVER...CANNOT RULE OUT SEVERE THUNDERSTORMS AND FEEL SPC MARGINAL RISK IS WELL PLACED. EXPECT BEST CHANCES FOR PRECIPITATION TO COME OVERNIGHT SUNDAY NIGHT. MOISTURE INCREASES WITH PWAT VALUES NEARING 2 INCHES INDICATED ON SOUNDINGS WITH GOOD WARM CLOUD DEPTHS. WILL THEREFORE NEED TO KEEP MONITORING FOR HEAVY RAIN POTENTIAL. SYSTEM BECOMES MORE ACTIVE THROUGH THE END OF THE PERIOD...THOUGH MODELS CONTINUE TO NOT BE IN GOOD AGREEMENT WITH HANDLING OF SYSTEM...ESPECIALLY WITH RUN TO RUN CONSISTENCY. BOUNDARY IS EXPECTED TO SLOWLY PUSH SOUTH THROUGHOUT THE DAY MONDAY...WITH GFS STALLING BOUNDARY ACROSS CENTRAL IOWA BEFORE ANOTHER LOW PRESSURE SYSTEM PUSHES EAST LATE TUESDAY. LOW WILL KEEP CHANCES FOR THUNDERSTORMS ACROSS THE REGION THROUGH THE END OF THE PERIOD. HOWEVER...STILL MUCH UNCERTAINTY ON TIMING AND EVOLUTION OF SYSTEM. GFS HAS BEEN FAIRLY CONSISTENT WITH SOLUTION...AND ECMWF HAS BEGUN TO COME MORE IN LINE. THEREFORE...HAVE CONTINUED TO TREND TOWARDS GFS. TEMPERATURES WILL BE MUCH COOLER BEHIND BOUNDARY...AND WILL REMAIN COOL THROUGH THE END OF THE PERIOD WITH PRECIPITATION AND CLOUDS HELPING TO KEEP TEMPERATURES DOWN...THOUGH READINGS WILL STILL BE NEAR NORMAL FOR TIME OF YEAR. && .AVIATION...14/18Z ISSUED AT 1218 PM CDT FRI AUG 14 2015 MAINLY VFR CONDITIONS ARE EXPECTED DURING THE VALID TAF PERIOD. ONLY CONCERN IS FOG POTENTIAL LATE TONIGHT...DUE TO LIGHT WINDS. HAVE INTRODUCED MVFR VSBYS IN FOG AT THE KOTM TERMINAL LATE TONIGHT...BUT HAVE HELD OFF ON MENTION AT OTHER TERMINALS SINCE CONFIDENCE IS NOT HIGH ENOUGH ATTM. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...COGIL LONG TERM...AWB AVIATION...ZOGG  FXUS63 KDMX 150900 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 400 AM CDT WED JUL 15 2015 .SHORT TERM /TODAY/... ISSUED AT 400 AM CDT WED JUL 15 2015 CONVECTIVE TRENDS WILL BE THE MAIN FOCUS TODAY BUT UNFORTUNATELY CONFIDENCE IS LOW. KS/NE MCSS ARE REMNANTS OF PEAK HEATING CONVECTION DRIVEN BY WEAK NE BOUNDARY AND SUBTLE SHORT WAVES LIFTING THROUGH NM AND CO. WOULD HAVE EXPECTED MORE OF A DIMINISHING TREND BY NOW WITH CONVECTION ENTERING HIGH MUCAPE AREA BUT ALSO HIGH MUCINHS. DIFFICULT TO FIND MUCH SUPPORT IN SOUNDING PARCEL TRACES DOWNSTREAM. THERE IS SOME WEAK WARM ADVECTION NOTED H85/H7...ESPECIALLY LOWER TOWARD H85...BUT COMPLEXES SEEM QUITE ELEVATED AND ARE LIKELY DRIVEN MORE BY WEAK SHORT WAVES EMBEDDED IN MOIST FLOW ATOP THE SRN PLAINS RIDGE. THERE IS SOME 0-2KM MOISTURE CONVERGENCE AHEAD OF THE CLUSTERS...BUT CONVECTION WOULD SEEM TO BE ROOTED ABOVE THAT. THE POSITIVE TO NEGATIVE CG RATE ACROSS KS IS QUITE HIGH SUGGESTION A VERY ELEVATED NATURE. RAP DOES NOT APPEAR TO BE HANDLING CURRENT SITUATION WELL WITH LITTLE IN THE WAY OF A PV COUPLET SHOWING UP ASSOCIATED WITH POTENT KS MCS. THERE IS LITTLE SUPPORT THERMODYNAMICALLY INTO IA...BUT NERN NE MCS IS SHOWING NO SIGNS UP DISSIPATING EITHER SO HAVE BROUGHT CHANCE POPS INTO WRN IA THIS MORNING AND SLOWLY PUSHING EASTWARD INTO THE AFTERNOON. ECMWF AND GFS MID LEVEL FORCING...CURRENTLY OVER KS/NE...TAKES ITS TIME GETTING EASTWARD ONLY REACHING FAR ERN FORECAST AREA BY 00Z. ITS DIFFICULT TO HAVE TOO MUCH CONFIDENCE HOWEVER AS RADAR TRENDS ARE BUCKING WHAT MODELS AND SUBJECTIVE ANALYSIS WOULD SUGGEST. HAVE KEPT TEMPS AT OR BELOW THE LOW END OF GUIDANCE WITH CONVECTIVE DEBRIS AND EASTERLY WINDS GETTING NO BETTER THAN SELY INTO THE AFTERNOON...AND OF COURSE THE POTENTIAL FOR PRECIP GETTING FARTHER EAST THAN ANTICIPATED. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 400 AM CDT WED JUL 15 2015 MAIN FORECAST CHALLENGE FOR THE PERIOD CONTINUES TO BE THE PLACEMENT OF RAINFALL FOR TONIGHT AND THURSDAY MORNING. WEAK SURFACE CYCLONE IS STILL PROGGED TO EJECT FROM THE QUASI- STATIONARY HIGH PLAINS TROUGH DURING THE DAY AS A SUBTLE 500 MB SHORTWAVE/VORT MAX CRESTS THE SOUTHERN PLAINS HIGH. THESE FEATURES WILL TRACK OVER THE REGION THROUGHOUT THE COURSE OF THE NIGHT AND INTO THURSDAY. 00Z MODEL SOLUTIONS ARE STRUGGLING IN THIS WEAK FLOW PATTERN TO LATCH ON TO A CONSENSUS SOLUTION WITH THE TRACK OF THE CYCLONE AND ITS ASSOCIATED PRECIPITATION. GFS/NAM/GEM REMAIN FOCUSED ON A NORTHERN TRACK THAT WOULD TAKE THE HEAVIEST PRECIPITATION ACROSS NORTHERN IOWA AND SOUTHERN MINNESOTA. MEANWHILE...THE EC AND RECENT RUNS OF THE NMM/ARW DEVELOP ELEVATED CONVECTION FURTHER SOUTH ALONG THE LIFTING WARM FRONT AND TAKE IT ACROSS MUCH OF IOWA. IN EITHER CASE...THE SETUP REMAINS CONDUCIVE FOR A HEAVY RAIN EVENT WITH SATURATED SOUNDING PROFILES/PWATS OVER 2 INCHES...STRONG MOISTURE TRANSPORT TIED TO A 40 TO 50 KT LLJ...AND WARM CLOUD DEPTHS OVER 13 KFT. IN GENERAL USED A COMBINATION OF WPC GUIDANCE AND THE GFS FOR PLACEMENT OF THE NORTHERN POPS/QPF...WITH A SWATHS OF HIGHER POPS EXTENDING SOUTHWARD ALONG THE 925-50MB THETA-E BOUNDARY TO ACCOUNT FOR THIS SOUTHERN CONVECTION POSSIBILITY. ALSO CANNOT RULE OUT A STRONG STORM EARLY ON IN THIS SOUTHERN BAND OWING TO HIGHER MUCAPE VALUES OF OVER 1000-1300 J/KG AT 06Z. RAINFALL AMOUNTS IN EXCESS OF 2 INCHES ARE POSSIBLE IN THE HEAVIEST BANDS OF PRECIP. THIS SYSTEM SHOULD PUSH EAST OF THE CWA SHORTLY AFTER 12Z THURSDAY...IF NOT SOONER...AS AN 850 MB THERMAL RIDGE BUILDS IN. AFTERNOON CONVECTION WILL STILL BE POSSIBLE ACROSS THE NORTHEASTERN CWA CLOSER TO THE DEPARTING SURFACE LOW WERE THE WARM NOSE WILL BE LESS PRONOUNCED AND GREATER LIFT WILL EXIST WITH THE LOW. CLEAR SKIES ACROSS THE NORTH FRIDAY MORNING WILL PROMOTE FOG DEVELOPMENT IN AREAS THAT SAW HEAVY RAINFALL...BUT DID NOT MENTION FOG IN THE SOUTH WERE MID LEVEL CLOUDS AND STRONGER WINDS WILL LIMIT FOG POTENTIAL. THE STORY FOR THE REST OF FRIDAY AND THE WEEKEND WILL BE A RETURN OF WARM AND MUGGY AIR WITH THE AFOREMENTIONED SURFACE HIGH PLAINS TROUGH GRADUALLY MIGRATING OVER NEBRASKA THROUGH SATURDAY...PROMOTING SOUTHERLY FLOW OFF THE GULF. MULTIPLE ROUNDS OF SHOWERS AND STORMS ARE POSSIBLE FRIDAY NIGHT INTO SATURDAY AS A SERIES OF UPPER LEVEL WAVES INTERACT WITH THE BOUNDARY. THE BETTER THREAT FOR STORMS WILL COME SUNDAY AS AN AMPLIFYING PATTERN WILL USHER THE BOUNDARY EASTWARD ACROSS IOWA. THIS WILL BRING COOLER AND DRY WEATHER TO START NEXT WEEK. && .AVIATION...15/06Z ISSUED AT 1151 PM CDT TUE JUL 14 2015 VFR CONDITIONS WILL CONTINUE TO BE WIDESPREAD DURING THE OVERNIGHT AND INTO WEDNESDAY. HIGH CLOUDS FROM CONVECTION TO THE WEST WILL REMAIN OVER THE STATE DURING THIS TIME FRAME WITH LIGHT NORTHEAST TO EAST SURFACE WINDS BECOMING SOUTHEAST ON WEDNESDAY. WITH INCREASING WARM ADVECTION...MOISTURE TRANSPORT AND DECENT QG FORCING ARRIVING LATER ON WEDNESDAY...ANTICIPATE CONVECTION INCREASING IN WESTERN IOWA AND SPREADING EASTWARD INTO PORTIONS OF THE AREA BY THE END OF THE PERIOD. THESE STORMS WILL BRING AN INCREASING THREAT OF MVFR TO IFR CONDITIONS IN AND AROUND THE STORMS. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMALL LONG TERM...SKOW AVIATION...COGIL  FXUS63 KDMX 152028 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 328 PM CDT WED JUL 15 2015 .SHORT TERM /TONIGHT/... ISSUED AT 327 PM CDT WED JUL 15 2015 CHALLENGING FORECAST FOR THE OVERNIGHT. TWO DISTINCT VORTICITY MAXIMUM OVER THE REGION THIS AFTERNOON...ONE ASSOCIATED WITH THE H500 SHORTWAVE IN EASTERN NEBRASKA AND THE OTHER FARTHER SOUTH OVER NORTHWEST MISSOURI. TO COMPLICATE MATTERS A WEAK SFC LOW AND TROUGH EXTEND FROM SOUTH CENTRAL NEBRASKA TO NORTHEAST IOWA. SYNOPTIC SCALE MODELS HAVE BEEN FAIRLY CONSISTENT WITH FORCING INCREASING OVER WEST CENTRAL TO NORTHEAST IOWA BY 12Z...FOCUSING AN EXPANDING AREA OF MODERATE TO HEAVY RAINFALL IN THIS LOCATION. OF THESE THE EURO HAS TRENDED SLIGHTLY FARTHER SOUTH WITH WIDESPREAD COVERAGE OF RAINFALL. THE HRRR IS CONCENTRATING THE LIONS SHARE OF FORCING OVER SOUTHERN IOWA TONIGHT...RIGHT ON THE NORTHERN EDGE OF MORE ROBUST INSTABILITY. WITH BOTH VORT MAXES PLAYING A ROLE IN THE OVERNIGHT FORECAST...IT LOOKS LIKE AN AREA OF MODERATE TO POTENTIALLY LOCALLY HEAVY RAINFALL WILL OCCUR FROM WEST CENTRAL TOWARD NORTHEAST WITH A SECONDARY MAXIMUM OVER THE SOUTHERN SECTIONS SOUTH OF INTERSTATE 80...EAST TO ABOUT I35 AGAIN THIS AREA COULD SEE LOCALLY HEAVY RAINFALL. WITH THE MAXIMUM INSTABILITY SOUTH OF IOWA NOW...THE SOUTHERN AREAS SHOULD FILL IN LATER THIS EVENING AS THE H850 LOW LEVEL JET OF 30 TO 40KT INCREASES AFTER 03-04Z. PRECIPITABLE WATER VALUES ARE EXPECTED TO INCREASE TO NEARLY 2 INCHES BY 06Z OVER MUCH OF THE REGION WITH WARM CLOUD DEPTHS IN EXCESS OF 13KFT...PROMOTING EFFICIENT RAINFALL PROCESSES. THE DAY1 CONVECTIVE OUTLOOK HAS BEEN INCREASED FOR A SLIGHT RISK ACROSS THE SOUTH WITH SOME POTENTIAL FOR SEVERE STORMS SOUTHWEST/WEST THROUGH THE EVENING HOURS...THOUGH MAIN CONCERNS REMAIN POTENTIAL FOR LOCALLY HEAVY RAINFALL. WITH FLASH FLOOD GUIDANCE BETWEEN 2 TO 3 INCHES PER 3 HOURS OVER THE WEST/SOUTHWEST...WE MAY SEE SOME LOCALIZED FLASH FLOODING OVER PORTIONS OF WESTERN/SOUTHWEST SECTIONS TONIGHT. FOR NOW HAVE HELD OFF ON HEADLINES DUE TO SOME UNCERTAINTIES IN THE DEVELOPMENT OF CONVECTION AND EVENTUAL EVOLUTION. LOWS WILL HOLD IN THE UPPER 60S TO LOWER 70S WITH UNCOMFORTABLE DEW POINTS NEAR THE SAME VALUES. WINDS WILL INCREASE A BIT FROM THE SOUTH DURING THE OVERNIGHT HOURS. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 327 PM CDT WED JUL 15 2015 THE STORM SYSTEM SET TO AFFECT THE AREA TONIGHT...AS DISCUSSED AT LENGTH IN THE SHORT TERM SECTION ABOVE...WILL CLEAR OUT TO THE EAST ON THURSDAY MORNING. LARGE SCALE MODELS ARE A BIT SLOWER WITH THIS CLEARING...WHILE THE HIGH RESOLUTION MODELS ARE SOMEWHAT FASTER WHICH IS MORE CONSISTENT WITH CLIMATOLOGY IN THIS SYNOPTIC SET UP. FURTHERMORE THERE ARE INDICATIONS THAT A WEAK UPPER IMPULSE MOVING IN BEHIND THE INITIAL WAVE...COMBINED WITH AFTERNOON DESTABILIZATION AND LINGERING OUTFLOW BOUNDARIES FROM MORNING CONVECTION...MAY LEAD TO SOME ISOLATED STORM REDEVELOPMENT LATE IN THE DAY OR THURSDAY EVENING. AS A RESULT OF ALL OF THESE FACTORS...MAINTAINED A FAIRLY RAPID CLEARING OF HIGHER POPS TO THE EAST ON THURSDAY MORNING BUT HELD SOME LOWER POPS BACK IN THE SOUTH AND WEST AT TIMES MAINLY THURSDAY EVENING. ALSO MAINTAINED SOME FOG MENTION LATE THURSDAY NIGHT/EARLY FRIDAY MORNING GIVEN THE LIGHT AND VARIABLE WINDS EXPECTED ALONG WITH CLEARING SKIES AND WET GROUND/HIGH DEWPOINTS. BY FRIDAY SOUTHERLY SURFACE WINDS WILL RETURN TO THE AREA...WITH 500 MB FLOW TURNING TO WEST SOUTHWEST AND A FRONTAL BOUNDARY DEVELOPING WELL TO OUR NORTHWEST ACROSS SOUTH DAKOTA AND MINNESOTA. THIS BOUNDARY WILL LIKELY PROVIDE THE IMPETUS FOR THUNDERSTORM DEVELOPMENT FRIDAY EVENING AND FRIDAY NIGHT...BUT THIS SHOULD LARGELY STAY NORTH OF OUR FORECAST AREA. ALSO...THERE MAY BE SOME PEAK HEATING STORM DEVELOPMENT ACROSS OUR AREA IN THE WARM SECTOR FRIDAY AFTERNOON AND EVENING...HOWEVER A GENERAL LACK OF FORCING OR FOCUS MECHANISM PROHIBIT INTRODUCING POPS AT THIS TIME. FRIDAY WILL ALSO SEE A RETURN OF MORE HEAT AND HUMIDITY...AS LOW LEVEL WARM AIR AND MOISTURE ADVECTION BENEATH INCREASING TEMPERATURES ALOFT PROMOTE HIGH TEMPERATURES IN THE LOWER 90S WITH HEAT INDEX VALUES APPROACHING 100 LATE IN THE DAY. SATURDAY WILL BE QUITE SIMILAR...WITH HOT AND HUMID CONDITIONS AND A LOW CHANCE OF WARM SECTOR THUNDERSTORMS THAT WOULD BE ISOLATED IF THEY DEVELOP. FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT THE FORECAST WILL BE DOMINATED BY THE APPROACH AND PASSAGE OF THE AFOREMENTIONED FRONTAL BOUNDARY FROM NORTHWEST TO SOUTHEAST. A WARM AND VERY UNSTABLE AIRMASS AHEAD OF THE FRONT WILL PROMOTE VIGOROUS THUNDERSTORM DEVELOPMENT PARTICULARLY SUNDAY AFTERNOON AND EVENING...WITH BULK SHEAR FORECASTS CERTAINLY SUPPORTING SOME SEVERE WEATHER THREAT WITH THE ADVANCING FRONTAL ZONE. HOWEVER...SIGNIFICANT DIFFERENCES IN THE TIMING OF THIS PASSAGE REMAIN AMONG THE VARIOUS MODELS. THE ECMWF HAS BEEN STICKING TO ITS GUNS FOR THE LAST THREE RUNS WITH A MUCH FASTER PASSAGE AND THE GFS HAS BEEN SLOWLY COMING AROUND IN THAT DIRECTION. IF THIS OCCURS...IT WOULD RESULT IN SOMEWHAT COOLER HIGHS SUNDAY AND SHIFT ANY SEVERE WEATHER POTENTIAL MORE ACROSS SOUTHERN AND EASTERN IOWA RATHER THAN FURTHER NORTHWEST. FOR NOW THE UNCERTAINTY IN THIS EVOLUTION RESULTS IN SEVERAL PERIODS OF CHANCE POPS WITH NO LIKELIES INTRODUCED AS OF YET...BUT ONCE THE DETAILS OF TIMING BECOME CLEARER THEN HIGHER POPS WILL NEED TO BE INTRODUCED IN ONE OR MORE OF THE PERIODS FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT...AND SUNDAY HIGH TEMPERATURES MAY NEED TO BE ADJUSTED FURTHER AS WELL. AS ROUGHLY ZONAL STEERING FLOW PERSISTS INTO EARLY NEXT WEEK TEMPERATURES BEHIND THE SUNDAY COOL FRONT WILL SLOWLY MODERATE AND LOW RAIN CHANCES WILL PERSIST. GIVEN THE DIFFICULTY IN PREDICTING ANY SUBTLE IMPULSES TYPICALLY MOVING THROUGH SUCH FLOW AT THIS TIME RANGE...HAVE MAINTAINED ONLY LOW POPS AT TIMES IN THE LATTER PART OF THE EXTENDED FORECAST PERIOD. && .AVIATION...15/18Z ISSUED AT 1247 PM CDT WED JUL 15 2015 REMNANT MODERATE SHOWERS MOVING ACROSS THE AREA FROM THE SOUTHWEST AS MCV CONTINUES TO GENERATE MORE SHOWERS WEST. ACROSS THE EAST CIGS REMAIN MVFR NEAR KALO AND KOTM...WITH SOME IMPROVEMENT AFT 19Z. MCV EXPECTED TO EXPAND PRECIP SHIELD TONIGHT WITH IFR/MVFR CIGS AND POTENTIAL FOR +SHRA AND TSRA THROUGH 13Z ACROSS THE REGION. FAVORED AREAS REMAIN NORTH SITES...HOWEVER MESO MODELS OFFERING DIFFERING SOLNS EVEN NOW WHICH MAY RESULT IN SOME SOUTHWARD SHIFT OF HEAVY RAIN/LOWER CONDITIONS AXIS IN THE NEXT TAF PACKAGE./REV && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...LEE AVIATION...REV  FXUS63 KDMX 160857 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 357 AM CDT THU JUL 16 2015 .SHORT TERM /TODAY/... ISSUED AT 355 AM CDT THU JUL 16 2015 WIDESPREAD SHOWERS AND THUNDERSTORMS ONGOING ACROSS MUCH OF CENTRAL AND SOUTHWEST IOWA EARLY THIS MORNING AS STRONG MOISTURE TRANSPORT AND THETA-E ADVECTION LIFT INTO THE THE STATE THANKS TO A 45+ KT LOW LEVEL JET FOCUSED INTO THE AREA. PWAT VALUES IN EXCESS OF 2 INCHES ARE NOW IN PLACE OVER THE AREA AIDED BY FLOW GENERATED BY A SUB- TROPICAL HIGH OVER THE SOUTHERN CONUS AND HURRICANE DOLORES. THE THETA-E ADVECTION AND MOISTURE TRANSPORT WILL BEGIN TO SHIFT EAST/NORTHEAST ALONG WITH A PASSING SHORT WAVE TOWARD 12Z. THE PRIMARY THUNDERSTORMS ACTIVITY WILL FOLLOW. ADDITIONAL SCATTERED THUNDERSTORMS WILL REMAIN POSSIBLE OVER CENTRAL AND SOUTHWEST IOWA INTO THE AFTERNOON THOUGH AS THE AREA REMAINS CONVECTIVELY UNSTABLE. THE SEVERE WEATHER THREAT WITH THIS ACTIVITY THROUGH THE MORNING HOURS WILL BE LOW. THE PRIMARY THREAT REMAINS AREAS OF HEAVY RAINFALL AS THE ATMOSPHERE REMAINS CONDUCIVE TO EFFICIENT RAIN PRODUCING STORMS. PWAT VALUES REMAIN AT OR ABOVE 2 INCHES THROUGH THE DAY WITH WARM CLOUD DEPTHS ABOVE 13500 FT. BEST POTENTIAL FOR HEAVY RAINFALL REMAINS ALONG AND SOUTH OF INTERSTATE 80 THOUGH THE SMALL CELL OVER SOUTHERN SAC COUNTY IS AN EXAMPLE OF HOW EFFICIENT THESE STORMS ARE. WILL LEAVE CURRENT FLASH FLOOD WATCH AS IS AND THROUGH 15Z. A BOUNDARY WILL ARRIVE BY THIS AFTERNOON AND WILL BRING THE POTENTIAL FOR ADDITIONAL THUNDERSTORMS...MAINLY TO THE SOUTHERN HALF OF THE STATE. .LONG TERM /TONIGHT THROUGH WEDNESDAY/... ISSUED AT 355 AM CDT THU JUL 16 2015 THE BEGINNING OF THE EXTENDED WILL BE CHARACTERIZED BY SEASONABLY HOT AND HUMID CONDITIONS DUE TO CONTINUED S TO SW FLOW OUT AHEAD OF A NEARLY STATIONARY GREAT PLAINS SURFACE TROUGH. FOR THURSDAY NIGHT INTO FRIDAY MORNING...A SUBTLE 500 MB WAVE SHOOTS THROUGH THE MEAN WESTERLY FLOW WITH WEAK MID-LEVEL ASCENT ASSOCIATED WITH ITS PASSAGE. CONVECTION LOOKS TO INITIATE ALONG THE SURFACE TROUGH OVER NORTHEASTERN NEBRASKA AND GROW UPSCALE. MOST CAMS AND THE EC/NAM DROP THE SYSTEM SOUTHWARD WITH THE MEAN CORFIDI VECTORS AND DISSIPATE IT SHORTLY AFTER 06Z. THE 16.00Z GFS IS THE ONE NOTABLE OUTLIER ATTM AND TAKES THE STORM EAST ACROSS IOWA. HOWEVER...WENT WITH THE CONSENSUS APPROACH FOR THIS PRECIP GIVEN THE HEIGHT RISES OVER CENTRAL IOWA DURING THIS TIME BEHIND TODAY'S DEPARTING TROUGH. THIS RESULTED IN ADDING 15-20 POPS ALONG THE WEST CENTRAL CWA BORDER BETWEEN 00 AND 06Z. WAA TAKING PLACE THROUGHOUT THE DAY ON FRIDAY WILL RAISE 850 MB TEMPS TO +23 TO +27C OVER CENTRAL IOWA BY 00Z SATURDAY AND WILL PERSIST THROUGH THE DAY ON SATURDAY. HIGHS ON BOTH FRIDAY AND SATURDAY LOOK TO REACH THE UPPER 80S TO LOW 90S. GOOD MOISTURE TRANSPORT WILL ENABLE DEWPOINTS TO REACH THE LOW TO EVEN MID 70S AT TIMES...PRODUCING HEAT INDICES OVER 100 DEGREES DURING THE HOTTEST PARTS OF THE DAY IN SOUTHERN IOWA. ANOTHER ROUND OF CONVECTION SHOULD INITIATE FRIDAY AFTERNOON OVER SOUTH DAKOTA AND TRACK EASTWARD ALONG THE INSTABILITY GRADIENT/THETA-E BOUNDARY ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA. BOTH THE EC/GFS INITIATE SATURDAY'S ROUND OF STORMS OVER SOUTHEAST MINNESOTA...POSSIBLY ON THE OUTFLOW OF THE EARLIER CONVECTION...AND GROW THE SYSTEM INTO A BACKBUILDING MCS THAT DROPS SOUTH TO SOUTHWEST ACROSS EASTERN IOWA. TIMING DIFFERENCES DO EXIST BETWEEN THE MODELS WITH THE EC EARLIER IN THE AFTERNOON WHILE THE MCS DOESN'T ARRIVE IN IOWA UNTIL LATE EVENING IN THE GFS. ELEVATED INSTABILITY OF 2500 TO 3000+ J/KG BUT MARGINAL DEEP SHEAR OF 10-20 KTS WOULD SUPPORT THIS STORM MODE. SHOULD THIS SOLUTION COME TO FRUITION...HEAVY RAIN WOULD ONCE AGAIN BE A CONCERN WITH WEAK STEERING FLOW...STRONG LOW LEVEL MOISTURE TRANSPORT...PWATS OVER 2 INCHES...AND WARM CLOUD DEPTHS OVER 14 KFT. THE AFOREMENTIONED WESTERN SURFACE TROUGH FINALLY SWINGS SOUTHEASTWARD ACROSS IOWA SUNDAY MORNING AS THE UPSTREAM PATTERN AMPLIFIES AHEAD OF A DIGGING WESTERN CANADA TROUGH. THIS WILL USHER IN COOLER AND DRIER WEATHER TO START THE WEEK AS HIGH PRESSURE MOVES THROUGH. MODEL CONFIDENCE LESSENS BEYOND THIS TIMEFRAME WITH THE UPPER LEVEL TROUGH WEAKENING WHILE INTERACTING WITH THE SOUTHERN US RIDGE...PLACING IOWA IN BROAD WEST TO NORTHWEST ZONAL FLOW FOR THE MIDDLE PART OF THE WEEK WITH ADDITIONAL WEAK DISTURBANCES MOVING THROUGH. && .AVIATION...16/06Z ISSUED AT 1237 AM CDT THU JUL 16 2015 STRONG THETA-E ADVECTION ONGOING THROUGH THE EARLY MORNING HOURS WITH LLJ POINTED INTO IOWA. ANTICIPATE WIDESPREAD CONVECTION THROUGH DAYBREAK ON THURSDAY WITH PRECIPITATION ENDING FROM WEST TO EAST DURING THE MORNING. EXPECTED VFR CONDITIONS TO DETERIORATE OVERNIGHT WITH MVFR TO IFR CONDITIONS BECOMING WIDESPREAD DURING THE EARLY MORNING HOURS WITH NUMEROUS SHOWERS AND THUNDERSTORMS. THESE CONDITIONS WILL PERSIST INTO THE MORNING BEFORE GRADUALLY LIFTING CEILINGS BY AFTERNOON WILL ALLOW FOR VFR CONDITIONS ONCE MORE. SURFACE WINDS WILL INCREASE FROM THE EAST SOUTHEAST OVERNIGHT AND CONTINUE INTO THURSDAY BEFORE SWITCHING TO THE SOUTH AND SOUTHWEST AS A FRONT LIFT NORTH INTO THE STATE. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR ADAIR-ADAMS- APPANOOSE-AUDUBON-CASS-CLARKE-DALLAS-DAVIS-DECATUR-GUTHRIE- JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE-POLK-POWESHIEK- RINGGOLD-TAYLOR-UNION-WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...DONAVON LONG TERM...SKOW AVIATION...COGIL  FXUS63 KDMX 162029 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 329 PM CDT SUN AUG 16 2015 .SHORT TERM /TONIGHT/... ISSUED AT 329 PM CDT SUN AUG 16 2015 SFC COLD FRONT IS SINKING SLOWLY THROUGH SOUTHEAST SOUTH DAKOTA AND SOUTHWEST MINNESOTA THIS AFTERNOON. A WEAK UPPER RIDGE REMAINS STRETCHED THROUGH CENTRAL IOWA AND IS SEPARATING THE MUCH DRIER AIR TO THE SOUTHEAST FROM THE DEEPER MOISTURE TO THE WEST AND NORTHWEST OF THE SYSTEM. THE RIDGE WILL SHIFT SOUTHEAST AND WEAKEN FURTHER OVERNIGHT ALLOWING THE SFC BOUNDARY TO ENTER NORTHERN IOWA. THE OVERALL FORCING AND INSTABILITY OVERNIGHT IS LIMITED AND DESPITE A RELATIVELY WEAK LOW LEVEL JET...THE MOISTURE TRANSPORT LIFTING INTO THE BOUNDARY IS GOOD AND WILL HELP PUSH PWATS TO NEAR 2 INCHES OVER NORTHERN IOWA. WARM CLOUD DEPTHS AROUND 13 KFT ARE SUPPORTIVE OF AN EFFICIENT RAIN PRODUCING ENVIRONMENT AND MEAN STORM MOTIONS ARE CLOSE TO PARALLEL TO THE SFC BOUNDARY LEADING TO THE POTENTIAL FOR TRAINING STORMS. GIVEN ALL OF THE ABOVE...DO EXPECT SOME AREAS WITH HEAVY RAINFALL POSSIBLY EXCEEDING 3 INCHES. PLANNING TO HOLD OFF ON A FLASH FLOOD WATCH AT THIS TIME FOR A VARIETY OF REASONS. MUCH OF NORTHERN IOWA NORTH OF HIGHWAY 20 HAVE HAD ONE HALF INCH OR LESS OF PRECIPITATION FOR AUGUST. THE CROPS ARE NEARING FULL MATURATION AND LIMIT RUNOFF RATES AND THE AREA WITH THE GREATEST THREAT FOR HEAVY RAIN OVER THE FAR NORTHWEST ARE CLIMATOLOGICALLY DIFFICULT TO FLASH FLOOD DUE TO THE LANDSCAPE. WILL MENTION LOCALIZED FLASH FLOODING POSSIBLE IN THE HWO. SHOULD THE THREAT FOR HIGHER QPF ARISE...THEN HEADLINES MAY BE REQUIRED. THE SEVERE WEATHER THREAT IS LOW...GIVEN THE DEEPER WARM CLOUD DEPTHS AND SATURATED PROFILES...THE HAIL THREAT WILL BE LOW LEAVING AN ISOLATED DAMAGING WIND GUST AS THE PRIMARY SEVERE THREAT. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 329 PM CDT SUN AUG 16 2015 CURRENTLY HAVE AN AREA OF LOW PRESSURE CENTERED ACROSS SRN MANITOBA AND SASKATCHEWAN...THIS WILL PUSH INTO SOUTHERN ONTARIO SUNDAY EVENING WITH THE ASSOCIATED COLD FRONT TO PUSH INTO NORTHWESTERN IOWA AND THE NORTHWESTERN CWA BY LATE SUNDAY. THE FRONTAL BOUNDARY WILL CONTINUE TO PUSH SOUTHWARD ACROSS THE CWA...STALLING OUT ACROSS THE AREA BY LATER MONDAY INTO TUESDAY. THIS WILL ALLOW FOR AN EXTENDED PERIOD OF RAIN CHANCES BEGINNING MAINLY LATE SUNDAY AFTERNOON NORTHWEST AND SPREADING ACROSS THE CWA SUNDAY NIGHT INTO MONDAY. THETA-E ADVECTION BETTER ACROSS THE NORTH INTO THE EVENING...WITH MOISTURE CONVERGENCE INCREASING ALONG THE FRONT INTO THE LATE NIGHT HOURS. WITH THE GRADUAL MOVEMENT IN THE FRONT...AND MID LEVEL FLOW PARALLEL TO THE BOUNDARY...TRAINING OF STORMS IS POSSIBLE. PWATS ALSO HIGH IN THE 1.9 TO 2 INCH RANGE...FURTHERING HEAVY RAIN CHANCES. HOWEVER THIS AREA HAS BEEN DRIER AND FFG IS HOVERING AROUND 3 INCHES OR JUST BELOW FOR 3 HOURS...THEREFORE THE FLASH FLOOD THREAT IS MINIMIZED SOME. AN UPPER LEVEL TROUGH WILL DIG INTO THE WESTERN US WITH A WEST TO SOUTHWEST FLOW PATTERN SETTING UP TOWARD MID WEEK. A STRONGER AREA OF LOW PRESSURE IS EXPECTED TO LIFT OUT OF THE SOUTHERN HIGH PLAINS THROUGH IOWA AND INTO THE GREAT LAKES TUESDAY INTO WEDNESDAY. THIS SYSTEM WILL EJECT ENERGY INTERACTING WITH THE LINGERING BOUNDARY BRINGING THE NEXT WIDESPREAD CHANCES FOR PRECIPITATION TO MUCH OF THE STATE. SHEAR PARAMETERS ALSO INCREASE WITH THE APPROACHING AREA OF LOW PRESSURE ALLOWING FOR SEVERE WEATHER CHANCES AS WELL. WRAP- AROUND PRECIP POSSIBLE INTO WEDNESDAY/WEDNESDAY NIGHT WITH HIGH PRESSURE TO BUILD INTO THE AREA BY THURSDAY/FRIDAY. THIS SHOULD ALLOW THE AREA TO DRY OUT BY THE END OF THE WEEK BEFORE PRECIP CHANCES RETURN FOR THE WEEKEND WITH ANOTHER UPPER LEVEL TROUGH PUSHING EAST FROM THE ROCKIES AND THROUGH THE NORTHERN PLAINS. MODELS IN DISAGREEMENT OVER HOW FAR NORTH THIS SYSTEM WILL TRACK...WITH THE EC MORE BULLISH KEEPING IT FURTHER SOUTH WHICH WOULD BE MORE OF AN IMPACT TO THE CWA VERSUS THE GFS WHICH KEEPS THE MAIN TROUGH ACROSS SOUTHERN CANADA. TEMPERATURES EXPECTED TO BE HOT AND HUMID SUNDAY AS DEWPOINTS INCREASE AHEAD OF THE COLD FRONT AND H85 TEMPS PUSH INTO THE LOW 20S CELSIUS IN SOUTHERLY TO SOUTHWESTERLY FLOW. TEMPS TO DROP INTO THE MID TEENS CELSIUS AS THE FRONT SAGS SOUTH...WITH COOLER TEMPS FOR MUCH OF THE WEEK. TEMPS EXPECTED TO RETURN TO THE 80S AS SOUTHERLY FLOW WARMS THINGS BACK UP AGAIN FRIDAY INTO SATURDAY AHEAD OF THE UPPER LEVEL TROUGH. && .AVIATION...16/18Z ISSUED AT 1245 PM CDT SUN AUG 16 2015 VFR CONDITIONS THROUGH THE AFTERNOON AND INTO THE EVENING. CHANCES FOR THUNDERSTORMS AND LOWERING CIGS INCREASE FROM NORTHWEST TO SOUTHEAST AFTER 06Z AND INTO MONDAY MORNING. CIGS WILL LOWER TO MVFR AT TIMES. BREEZY SOUTHERLY WINDS DIMINISHING THIS EVENING. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...DONAVON LONG TERM...BEERENDS AVIATION...DONAVON  FXUS63 KDMX 170233 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 933 PM CDT SUN AUG 16 2015 .UPDATE... ISSUED AT 928 PM CDT SUN AUG 16 2015 CONCERN THIS EVENING REMAINS FLASH FLOOD POTENTIAL. RADAR ESTIMATES AND OBSERVATIONS INDICATE PORTIONS OF ABOUT FOUR NW/N CENTRAL COUNTIES HAVE SEEN TWO TO THREE INCHES OF RAINFALL ALREADY. PWATS AND WARM CLOUD DEPTHS ARE ALL QUITE FAVORABLE FOR VERY EFFICIENT RAINS BUT WEAKENING INSTABILITY WITH LOSS OF HEATING WILL MAKE IT DIFFICULT TO REALIZE THESE CONDITIONS ON A WIDESPREAD BASIS. WITH ONE HOUR FLASH FLOOD GUIDANCE PUSHING 2.50 INCHES...MOST LOCATIONS CAN TAKE ONE EVENT WITH 2-3 EVENTS NEEDED TO GET TO FLASH FLOOD CRITERIA. RAP 305K ISENT MOISTURE CONVERGENCE SUGGESTS RECENT POST FRONTAL CONVECTIVE DEVELOPMENT OVER NW IA WILL CONTINUE THROUGH MIDNIGHT...BUT HAVE OPTED FOR TARGETED SPS ISSUANCES RATHER THAN MORE WIDESPREAD FLASH FLOOD WATCH FOR REASONS ALSO NOTED IN SHORT TERM SECTIONS BELOW. && .SHORT TERM /TONIGHT/... ISSUED AT 329 PM CDT SUN AUG 16 2015 SFC COLD FRONT IS SINKING SLOWLY THROUGH SOUTHEAST SOUTH DAKOTA AND SOUTHWEST MINNESOTA THIS AFTERNOON. A WEAK UPPER RIDGE REMAINS STRETCHED THROUGH CENTRAL IOWA AND IS SEPARATING THE MUCH DRIER AIR TO THE SOUTHEAST FROM THE DEEPER MOISTURE TO THE WEST AND NORTHWEST OF THE SYSTEM. THE RIDGE WILL SHIFT SOUTHEAST AND WEAKEN FURTHER OVERNIGHT ALLOWING THE SFC BOUNDARY TO ENTER NORTHERN IOWA. THE OVERALL FORCING AND INSTABILITY OVERNIGHT IS LIMITED AND DESPITE A RELATIVELY WEAK LOW LEVEL JET...THE MOISTURE TRANSPORT LIFTING INTO THE BOUNDARY IS GOOD AND WILL HELP PUSH PWATS TO NEAR 2 INCHES OVER NORTHERN IOWA. WARM CLOUD DEPTHS AROUND 13 KFT ARE SUPPORTIVE OF AN EFFICIENT RAIN PRODUCING ENVIRONMENT AND MEAN STORM MOTIONS ARE CLOSE TO PARALLEL TO THE SFC BOUNDARY LEADING TO THE POTENTIAL FOR TRAINING STORMS. GIVEN ALL OF THE ABOVE...DO EXPECT SOME AREAS WITH HEAVY RAINFALL POSSIBLY EXCEEDING 3 INCHES. PLANNING TO HOLD OFF ON A FLASH FLOOD WATCH AT THIS TIME FOR A VARIETY OF REASONS. MUCH OF NORTHERN IOWA NORTH OF HIGHWAY 20 HAVE HAD ONE HALF INCH OR LESS OF PRECIPITATION FOR AUGUST. THE CROPS ARE NEARING FULL MATURATION AND LIMIT RUNOFF RATES AND THE AREA WITH THE GREATEST THREAT FOR HEAVY RAIN OVER THE FAR NORTHWEST ARE CLIMATOLOGICALLY DIFFICULT TO FLASH FLOOD DUE TO THE LANDSCAPE. WILL MENTION LOCALIZED FLASH FLOODING POSSIBLE IN THE HWO. SHOULD THE THREAT FOR HIGHER QPF ARISE...THEN HEADLINES MAY BE REQUIRED. THE SEVERE WEATHER THREAT IS LOW...GIVEN THE DEEPER WARM CLOUD DEPTHS AND SATURATED PROFILES...THE HAIL THREAT WILL BE LOW LEAVING AN ISOLATED DAMAGING WIND GUST AS THE PRIMARY SEVERE THREAT. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 329 PM CDT SUN AUG 16 2015 CURRENTLY HAVE AN AREA OF LOW PRESSURE CENTERED ACROSS SRN MANITOBA AND SASKATCHEWAN...THIS WILL PUSH INTO SOUTHERN ONTARIO SUNDAY EVENING WITH THE ASSOCIATED COLD FRONT TO PUSH INTO NORTHWESTERN IOWA AND THE NORTHWESTERN CWA BY LATE SUNDAY. THE FRONTAL BOUNDARY WILL CONTINUE TO PUSH SOUTHWARD ACROSS THE CWA...STALLING OUT ACROSS THE AREA BY LATER MONDAY INTO TUESDAY. THIS WILL ALLOW FOR AN EXTENDED PERIOD OF RAIN CHANCES BEGINNING MAINLY LATE SUNDAY AFTERNOON NORTHWEST AND SPREADING ACROSS THE CWA SUNDAY NIGHT INTO MONDAY. THETA-E ADVECTION BETTER ACROSS THE NORTH INTO THE EVENING...WITH MOISTURE CONVERGENCE INCREASING ALONG THE FRONT INTO THE LATE NIGHT HOURS. WITH THE GRADUAL MOVEMENT IN THE FRONT...AND MID LEVEL FLOW PARALLEL TO THE BOUNDARY...TRAINING OF STORMS IS POSSIBLE. PWATS ALSO HIGH IN THE 1.9 TO 2 INCH RANGE...FURTHERING HEAVY RAIN CHANCES. HOWEVER THIS AREA HAS BEEN DRIER AND FFG IS HOVERING AROUND 3 INCHES OR JUST BELOW FOR 3 HOURS...THEREFORE THE FLASH FLOOD THREAT IS MINIMIZED SOME. AN UPPER LEVEL TROUGH WILL DIG INTO THE WESTERN US WITH A WEST TO SOUTHWEST FLOW PATTERN SETTING UP TOWARD MID WEEK. A STRONGER AREA OF LOW PRESSURE IS EXPECTED TO LIFT OUT OF THE SOUTHERN HIGH PLAINS THROUGH IOWA AND INTO THE GREAT LAKES TUESDAY INTO WEDNESDAY. THIS SYSTEM WILL EJECT ENERGY INTERACTING WITH THE LINGERING BOUNDARY BRINGING THE NEXT WIDESPREAD CHANCES FOR PRECIPITATION TO MUCH OF THE STATE. SHEAR PARAMETERS ALSO INCREASE WITH THE APPROACHING AREA OF LOW PRESSURE ALLOWING FOR SEVERE WEATHER CHANCES AS WELL. WRAP- AROUND PRECIP POSSIBLE INTO WEDNESDAY/WEDNESDAY NIGHT WITH HIGH PRESSURE TO BUILD INTO THE AREA BY THURSDAY/FRIDAY. THIS SHOULD ALLOW THE AREA TO DRY OUT BY THE END OF THE WEEK BEFORE PRECIP CHANCES RETURN FOR THE WEEKEND WITH ANOTHER UPPER LEVEL TROUGH PUSHING EAST FROM THE ROCKIES AND THROUGH THE NORTHERN PLAINS. MODELS IN DISAGREEMENT OVER HOW FAR NORTH THIS SYSTEM WILL TRACK...WITH THE EC MORE BULLISH KEEPING IT FURTHER SOUTH WHICH WOULD BE MORE OF AN IMPACT TO THE CWA VERSUS THE GFS WHICH KEEPS THE MAIN TROUGH ACROSS SOUTHERN CANADA. TEMPERATURES EXPECTED TO BE HOT AND HUMID SUNDAY AS DEWPOINTS INCREASE AHEAD OF THE COLD FRONT AND H85 TEMPS PUSH INTO THE LOW 20S CELSIUS IN SOUTHERLY TO SOUTHWESTERLY FLOW. TEMPS TO DROP INTO THE MID TEENS CELSIUS AS THE FRONT SAGS SOUTH...WITH COOLER TEMPS FOR MUCH OF THE WEEK. TEMPS EXPECTED TO RETURN TO THE 80S AS SOUTHERLY FLOW WARMS THINGS BACK UP AGAIN FRIDAY INTO SATURDAY AHEAD OF THE UPPER LEVEL TROUGH. && .AVIATION...17/00Z ISSUED AT 714 PM CDT SUN AUG 16 2015 PRIMARY CONCERN THROUGH THE PERIOD WILL BE CONVECTIVE TRENDS AND ASSOCIATED CATEGORY DEGRADATIONS...FOLLOWED BY POTENTIAL STRATUS LATE IN THE PERIOD. HAVE PLAYED THUNDER AND CATEGORY RESTRICTIONS SOMEWHAT CONSERVATIVE DEPENDING ON NEAR TERM TRENDS WITH A FAIRLY WIDE VARIABILITY DEPENDING ON STORMS. WILL LEAVE BROADER VICINITY WORDING UNTIL CONFIDENCE INCREASES ON THE ORDER OF HOURS WITH PRECIP POTENTIAL RIGHT ON INTO MON. MODELS SUGGEST LOWERING CIGS WITH SAGGING FRONT AND OUTFLOW BOUNDARIES...ALONG WITH PROLONGED PERIOD OF SCATTERED PRECIP. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SMALL SHORT TERM...DONAVON LONG TERM...BEERENDS AVIATION...SMALL  FXUS63 KDMX 170934 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 434 AM CDT MON AUG 17 2015 .SHORT TERM /TODAY/... ISSUED AT 427 AM CDT MON AUG 17 2015 SEVERAL CONCERNS FOR TODAY AS FRONTAL BOUNDARY SLIDES ACROSS THE STATE. CURRENTLY...WEAK CONVECTION HAS CONTINUED ACROSS THE NORTHWEST THIRD OF THE FORECAST AREA WITH GENERALLY MODERATE TO BRIEF HEAVY RAINFALL OVERNIGHT. THE CONVECTION HAS BEEN ROOTED IN NARROW INSTABILITY/MOISTURE AXIS THAT RESIDES ACROSS NORTHWEST IOWA WITH A SHARP GRADIENT TO THE SOUTHEAST. THIS GRADIENT WILL SINK GRADUALLY SOUTHWARD DURING THE DAY WITH THE FRONT/OUTFLOW AS SYNOPTIC FORCING DECREASES ACROSS THE STATE. ANTICIPATE THE CONVECTION TO DIMINISH SOMEWHAT THIS MORNING IN COVERAGE AND INTENSITY AS LOW LEVEL INFLOW WEAKENS. QUESTION WILL BE REDEVELOPMENT THIS AFTERNOON AS INSTABILITY INCREASES WITH DAYTIME HEATING. NAM SUGGEST REDEVELOPMENT ALONG SURFACE BOUNDARY IN THE FAR SOUTH AND IS GENERALLY THE ODD MODEL OUT AS THE OTHER SOLUTIONS KEEPING REDEVELOPMENT FARTHER NORTH ALONG 850MB FRONT WHERE LOWER LEVEL CONVERGENCE IS A BIT BETTER AND INSTABILITY IS MAXIMIZED WITH THE DEEPER MOISTURE. SHEAR REMAINS RATHER PALTRY AND THE OVERALL SEVERE WEATHER THREAT WILL BE LIMITED. HEAVY RAINS WILL CONTINUE TO BE THE PRIMARY CONCERN AND WITH GOOD SATURATION FROM THE CURRENT RAINS...MAY HAVE SOME LIMITED FLASH FLOOD THREAT BY THIS EVENING OR OVERNIGHT AND WILL LET DAYSHIFT DETERMINE ANY WATER HEADLINE FOR THAT TIMEFRAME. TEMPERATURES WILL BE MUCH COOLER ACROSS THE NORTHWEST TODAY WITH CLOUDINESS AND THE SCATTERED RAINFALL. THE FAR SOUTHEAST WILL LIKELY SEE SOME SUNSHINE THIS MORNING BEFORE FRONT ARRIVES AND CLOUDS INCREASE LATER TODAY AND THIS SHOULD ALLOW READINGS TO CLIMB TO NEAR NORMAL. .LONG TERM /TONIGHT THROUGH SUNDAY/... ISSUED AT 427 AM CDT MON AUG 17 2015 THE FIRST 36 OR SO HOURS OF THE LONG TERM FCST LOOK TO BE ACTIVE WITH HEAVY RAINFALL AND SEVERE WX CONSIDERATIONS. COOLER AIR WILL THEN COME RUSHING IN...DROPPING TEMPERATURES ABOUT 20 TO 25 DEGREES COOLER THAN WHAT THEY WERE FOR THIS PAST WEEKEND. ONGOING THUNDERSTORMS PSBL TO START THE FCST PERIOD MONDAY NIGHT. KICKER SHORTWAVE FROM PVS AM DISCUSSION TO BE EXITING OVER EASTERN IA WITH DIVERGENCE NOTED AT 250MB. MODEL CONSENSUS GOOD WITH HANDLING TRAILING BAROCLINIC ZONE/AXIS OF SFC MOISTURE CONV LOOKS TO EXTEND FROM NE IA THROUGH SW IA. PWATS SHOULD BE AROUND 1.75 INCHES ...SOUNDINGS LOOK VERY SATURATED ALOFT AND WARM CLOUD DEPTHS NEAR 13000FT. THUS AM HOLDING WIDESPREAD PRECIP OVERNIGHT. MUCAPE VALUES NEAR 500 J/KG OR LESS...SO AM NOT EXPECTING MASSIVE CONVECTION/DOWNPOURS TUESDAY AM. THE MORE SIGNIFICANT ACTIVITY COMES TUESDAY AFTERNOON/EVE INTO WEDNESDAY MORNING. RUN TO RUN CONSISTENCY REMAINS EXCELLENT WITH MODELS FEATURING A -2 TO -3 STD DEV NEGATIVELY TILTED TROUGH PUSHING THROUGH THE CENTRAL PLAINS WITH THE PARENT SFC LOW MAKING IT INTO IA. INTERESTING AND SIGNIFICANT THAT THE 00Z SUN PACKAGE SLOWED THE ARRIVAL OF THE SFC LOW...PUTTING IT NEAR THE IA/NE BORDER AT 18Z TUE. WORTH NOTING IF 12Z MODELS HOLD THIS SOLUTION...AS THE DMX CWA WOULD BE IN THE HOT ZONE DURING PEAK DAYTIME HEATING. ADDITIONAL SYNOPTIC SETUP FEATURES A STRONG SW MID-LEVEL JET PUSHING INTO IA. S TO SE WARM...MOIST...FLOW WILL BE UNDERRUNNING COLD AIR ALOFT. A HUGE SLUG OF FORCING WILL ALSO ARRIVE FROM THE SOUTH WITH A 35 KT LLJ. DRY AIR ADVECTION PRESENT AROUND THE BASE OF THE LOW. BIG NEGATIVE IS CLOUDS/PRECIP EXPECTED MUCH OF THE MORNING WHICH WOULD HINDER DAYTIME HEATING DESTABILIZATION OF ATMOS. 0 TO 6 KM MU CAPES PEAK OUT IN THE 1500 TO 2000 J/KG RANGE WHICH ISN/T THE MOST IMPRESSIVE. IN ALL...THIS SETUP CAN DEFINITELY LEAD TO HAIL PRODUCTION. 00Z MODELS SHOW A BOUNDARY PROPAGATING EASTWARD THROUGH IA...LOCATED NEAR INTERSTATE 35 AROUND 00Z-03Z. 0 TO 3 KM HELICITY APPROACHING 200 M2/S2 WITH THIS BOUNDARY. WITH LOW LCL HEIGHTS ALSO SUGGESTED...TOR THREAT WORTH A MENTION. LASTLY...TIMING BEING FROM THE 00Z TO THE 06Z FRAME FAVORS BOWING POSSIBLE AND TRANSITION TO DAMAGING WIND THREAT EAST OF I-35 AFTER SUNSET. AGAIN...TIMING/PLACEMENT OF LOW AT PEAK DAYTIME HEATING IMPORTANT SO 12Z RUNS WORTH A CLOSE LOOK FOR CONSISTENCY SAKE. FOR WEDNESDAY...WELL BELOW NORMAL TEMPERATURES AND STRONG WINDS BECOME THE MAIN HIGHLIGHTS. MODELS HAVE BEEN TRENDING AGGRESSIVELY DOWNWARD AS EACH PACKAGE HAS COME IN COLDER THAN THE PVS ONE. GOOD NEWS FOR FORECASTING PURPOSES IS BOTTOM FINALLY APPEARS TO BE IN SIGHT. WITH VERY STRONG CAA...MODELS BRINGING IN 850MB TEMPS IN THE UPPER SINGLE DIGITS TO IA BEHIND THE TUESDAY/S TROUGH. FCST SOUNDINGS SHOW 40 KTS AT THE TOP OF THE MIXED LAYER WITH FAIRLY UNIDIRECTIONAL FLOW TO THE SFC...LIKELY BRINGING STRONG WINDS TO IA WEDNESDAY AFTERNOON. RECORD LOW MAX TEMP FOR KDSM IS 63 (1950). DOES NOT APPEAR WE WILL GET THAT COOL...BUT COULD BE WITHIN 5 DEGREES. AS LOW TREKS INTO THE NORTHWOODS OF WI...WRAP AROUND -RA POSSIBLE WED PM...ESPECIALLY NORTH OF HIGHWAY 30. IF THIS CURRENT TEMPERATURE SETUP HOLDS...WILL ONLY NEED TO LOWER TEMPS A FEW DEGREES IN NEXT UPDATE WITH BOTTOM FOUND. TO ROUND OUT THE WORK-WEEK...SFC HIGH PRESSURE WILL PASS FROM THE OZARKS INTO THE OHIO VALLEY REGION. THIS HIGH WILL BE STRONG ENOUGH TO INFLUENCE IA WEATHER...KEEPING US DRY THU AND FRI. SINCE LAST FRI...MODELS HAVE BEEN PLACING IA IN RETURN FLOW BY THE WEEKEND. 00Z MON PACKAGE HAS THE GULF WIDE OPEN WITH A 35 KT LLJ PRIMED TO TRANSPORT GULF MOISTURE INTO IOWA. THIS SETUP WILL INCREASE TEMPS BACK INTO THE 80S AND BRING A RETURN OF POPS FOR THE WEEKEND. && .AVIATION...17/06Z ISSUED AT 1231 AM CDT MON AUG 17 2015 CONFIDENCE IS LOW THROUGH THE PERIOD WITH SHOWERS AND STORMS POSSIBLE THE ENTIRE TIME...AND AN INCREASED POTENTIAL FOR STRATUS NORTH LATE. HAVE PLAYED THUNDER AND CATEGORY RESTRICTIONS SOMEWHAT CONSERVATIVE DEPENDING ON NEAR TERM TRENDS. WILL LEAVE BROADER VICINITY WORDING UNTIL CONFIDENCE INCREASES ON THE ORDER OF HOURS. MODELS SUGGEST LOWERING CIGS WITH SAGGING FRONT AND OUTFLOW BOUNDARIES...ALONG WITH PROLONGED PERIOD OF SCATTERED PRECIP. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...COGIL LONG TERM...KOTENBERG AVIATION...SMALL  FXUS63 KDMX 172033 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 333 PM CDT MON AUG 17 2015 .SHORT TERM /TONIGHT/... ISSUED AT 333 PM CDT MON AUG 17 2015 A VIGOROUS PV ANOMALY THAT HAS BEEN MOVING ACROSS SOUTHEAST NEBRASKA TODAY HAS WEAKENED A BIT AND SHIFTED SLIGHTLY SOUTH. THE PRECIPITATION ACROSS NORTHERN IOWA HAS BEEN SLOWLY DIMINISHING THROUGHOUT THE DAY WITH THE FOCUS MORE OVER SOUTHEAST IOWA WHERE THE REGION OF GREATER INSTABILITY EXISTS AND AHEAD OF AN OUTFLOW BOUNDARY FROM THE OVERNIGHT CONVECTION. THERE IS THE POTENTIAL FOR AN ISOLATED SEVERE STORM ACROSS THE SOUTHEAST THROUGH EARLY EVENING AND THE POTENTIAL FOR A FEW LANDSPOUT FUNNELS DOES EXIST GIVEN THE STAGNANT BOUNDARY AND GOOD LOW LEVEL CAPES. THE OTHER AREA OF PRECIPITATION IS FOCUSED OVER SOUTHWEST IA AHEAD OF THE PV ANOMALY. THIS AREA HAS BEEN HAVING DIFFICULTY SUSTAINING THIS AFTERNOON AS THE UPPER DYNAMICS DECREASE. HAVE TRENDED DRIER ACROSS THE NORTH FOR THROUGH THE EVENING WITH THE FOCUS REMAINING OVER SOUTHERN IOWA. THE NEXT STRONG SHORTWAVE WILL BE MOVING INTO SOUTH DAKOTA AND NEBRASKA AND SPREADING QG FORCING INTO WESTERN IOWA LATE. MUCH OF THE NIGHT WILL BE DEVOID OF A LOW LEVEL JET OR MOISTURE ADVECTION UNTIL LATE. THE LOW LEVEL JET WILL INCREASE LATE AS THE UPPER SYSTEM APPROACHES AND THIS WILL BRING ANOTHER PUSH OF GOOD MOISTURE ADVECTION LIFTING INTO WESTERN IOWA BY 12Z. THIS WILL BRING INCREASING SHOWER AND THUNDERSTORMS CHANCES MAINLY OVER WESTERN IOWA. NO SEVERE WEATHER OR HEAVY RAIN FALL IS EXPECTED WITH THIS ACTIVITY. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 333 PM CDT MON AUG 17 2015 UPPER LEVEL WAVE CURRENTLY DIGGING INTO THE NORTHERN ROCKIES TO CONTINUE TO DEEPEN AS IT PUSHES SOUTHEAST INTO SC SD BY MID-DAY TUESDAY. AN ASSOCIATED SURFACE LOW BEGINNING TO DEVELOP IN ERN CO WILL LIFT ENE TONIGHT INTO TUESDAY...AND BE CENTERED ACROSS NW IOWA BY LATE TUESDAY AFTERNOON BEFORE LIFTING INTO MN TUESDAY NIGHT. STRONG THETA-E ADVECTION WITH A WEAK WARM FRONT LIFTING NORTH THROUGH THE STATE...SHOULD ALLOW FOR CONVECTION TO BE ONGOING/OVERSPREAD MUCH OF THE NORTHERN CWA TUESDAY MORNING. STRONGER VORT MAX ALOFT TO ROTATE AROUND THE UPPER LOW AND THROUGH THE CWA LATER TUESDAY TO KICK OFF ANOTHER ROUND OF STORMS IN THE AFTERNOON ACROSS THE WESTERN CWA TUESDAY AFTERNOON WITH A LINE OF STORMS EXPECTED TO MOVE EASTWARD ACROSS THE CWA LATE TUESDAY AFTERNOON INTO EARLY EVENING. ADDITIONAL DEVELOPMENT POSSIBLE INTO THE TUESDAY EVENING AS THE COLD FRONT FINALLY MAKES ITS WAY THROUGH THE CWA AS WELL...WITH LOW STRATUS EXPECTED TO FILL IN BEHIND THE FRONT. AMOUNT OF SURFACE HEATING IS QUESTIONABLE GIVEN THE CLOUD COVER AND PRECIP POSSIBLE THROUGH THE DAY...HOWEVER STILL EXPECTING MUCAPE OF AROUND 1500-2000 J/KG BY TUESDAY AFTERNOON WITH DECENT SHEAR. DEEP LAYER SHEAR MARGINAL FOR SUPERCELLS...SO EXPECTING MORE OF A MULTICELLULAR EVENT. STORM MOTIONS MAY BE PROGRESSIVE ENOUGH TO WARRANT HEAVY RAIN ISSUES...HOWEVER WITH A FEW ROUNDS OF STORMS POSSIBLE AND PWAT VALUES IN THE 1.5 TO 2 INCH RANGE AND HIGHER WARM CLOUD DEPTHS HEAVY RAIN STILL A THREAT. THIS IS ESPECIALLY TRUE WITH SOME OF THE HEAVIER RAINFALL POSSIBLE OVER THE SAME AREA THAT HAS ALREADY HAD 5+ INCHES OF RAIN OVER THE PAST 24 HOURS. THEREFORE AN ISOLATED FLASH FLOOD THREAT WILL BE POSSIBLE WITH SOME SATURATED SOILS AND HIGH RAINFALL RATES EXPECTED. MUCH OF THE GUIDANCE ACROSS THE CWA IS STILL IN THE 2.5 TO 3.5 INCH RANGE FOR 3 HOUR FLASH FLOOD GUIDANCE OTHER THAN THE ISOLATED AREA THAT RECEIVED THE HEAVY RAIN PREVIOUSLY. THEREFORE WILL REFRAIN FROM ISSUING A HYDRO WATCH AT THIS TIME...BUT WILL NEED TO MONITOR FOR A POSSIBLE HYDRO WATCH WITH SUBSEQUENT SHIFTS. OTHERWISE STRONG COLD FRONT TO MOVE THROUGH WITH THE SYSTEM TUESDAY NIGHT...WITH MUCH COOLER AIR IN PLACE FOR WEDNESDAY WITH H85 TEMPS DROPPING TO AROUND +5C BEHIND THE FRONT. CLOUD COVER POSSIBLE INTO WEDNESDAY ESPECIALLY A CU FIELD INTO THE AFTERNOON HOURS WITH DEF ZONE MOISTURE AND WEAK LOW LEVEL INSTABILITY SHOWERS POSSIBLE WEDNESDAY ACROSS THE NORTH. THEREFORE WITH CAA...PRECIP AND CLOUD COVER TEMPS WILL HAVE TROUBLE WARMING TOO MUCH. THEREFORE HAVE HIGHS ONLY IN THE LOW 60S NORTH...WITH AREAS THAT COULD SEE A FEW MORE PEEKS OF SUN WARMING TO AROUND 70 ACROSS THE SOUTH. HIGH PRESSURE TO BUILD INTO THE AREA FOR THURSDAY WITH DRY CONDITIONS...AND FAIRLY DECENT RECOVERY IN TEMPS INTO FRIDAY AND SATURDAY AS SOUTHERLY FLOW INCREASES AHEAD OF THE NEXT UPPER WAVE TO DIG INTO THE CENTRAL US THIS WEEKEND. THIS WILL BRING CHANCES FOR PRECIPITATION MAINLY SATURDAY INTO SATURDAY NIGHT...WITH A LARGE AREA OF HIGH PRESSURE EXPECTED TO BUILD INTO THE WESTERN AND CENTRAL US BENEATH A LARGE WESTERN US RIDGE FOR EARLY NEXT WEEK. TEMPERATURES LOOK MORE SEASONAL FOR THE WEEKEND INTO NEXT WEEK. && .AVIATION...17/18Z ISSUED AT 122 PM CDT MON AUG 17 2015 AREAS OF IFR TO MVFR IN PLACE ACROSS NORTHWEST IOWA WITH LOCAL IMPACT THROUGH THE AFTERNOON. PRECIPITATION CHANCES WILL CONTINUE THROUGH MUCH OF THE AFTERNOON MOVING FROM WEST TO EAST. SHOULD HAVE A LULL OVERNIGHT THEN LOWERING CIGS AND INCREASING POPS AGAIN LATE TONIGHT THROUGH TUESDAY MORNING. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...DONAVON LONG TERM...BEERENDS AVIATION...DONAVON  FXUS63 KDMX 172152 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 352 PM CST TUE NOV 17 2015 .SHORT TERM /TONIGHT/... ISSUED AT 351 PM CST TUE NOV 17 2015 A LARGE STORM SYSTEM WILL APPROACH OUR AREA FROM THE SOUTHWEST TONIGHT...WITH A SURFACE LOW TRACKING FROM SOUTH TO NORTH ACROSS WESTERN IOWA...WHILE THE MID/UPPER LOW CENTER MOVES ACROSS KANSAS AND TOWARD SOUTHWESTERN IOWA BY SUNRISE. REGIONAL RADAR IMAGERY DEPICTS A LARGE SWATH OF LIGHT TO MODERATE RAIN ALONG THE EASTERN FLANK OF THIS SYSTEM...GRADUALLY TRANSLATING UP ACROSS ABOUT THE EASTERN HALF OF IOWA LATE THIS AFTERNOON AND EVENING...AND WILL MAINTAIN CATEGORICAL POPS IN ASSOCIATION WITH THIS FEATURE. OTHERWISE...THE AREA WILL REMAIN LARGELY DRY THROUGH THE EVENING BUT WITH LIGHT RAIN/DRIZZLE LIKELY FILLING IN AFTER SUNSET AS THE SURFACE LOW MOVES THROUGH AND FORECAST SOUNDINGS INDICATE INCREASING NEAR SURFACE CLOUD DEPTHS. HAVE THUS MAINTAINED MAINLY CHANCE POPS IN THESE AREAS...BUT WITH VERY LOW QPF. THERE MAY BE SOME RELATIVE CLEARING WITHIN THIS DRY SLOT...BUT THE VERY LOW LEVEL MOISTURE DOES NOT APPEAR LIKELY TO GO AWAY SO WE MAY STILL SEE MOSTLY CLOUDY SKIES AND DRIZZLE EVEN THOUGH THE CLOUDS WOULD BE VERY SHALLOW. FINALLY...THE MID/UPPER LEVEL LOW CORE WILL BE ACCOMPANIED BY MORE LIGHT SHOWERS AND THICKER CLOUDS...REACHING OUR SOUTHWESTERN COUNTIES BY 12Z BUT HAVING MORE WIDESPREAD IMPACTS LATER INTO TOMORROW AS DISCUSSED IN THE LONG TERM SECTION BELOW. TEMPERATURES WILL REMAIN UNSEASONABLY WARM OVERNIGHT AS WELL...WITH MOSTLY TO COMPLETELY CLOUDY SKIES AND MODEST BUT PERSISTENT WINDS...AND HAVE INCREASED THE LOW TEMP FORECAST ACCORDINGLY. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 351 PM CST TUE NOV 17 2015 ACTIVE WEATHER IS ANTICIPATED THROUGH THE WEEK WITH MULTIPLE SENSIBLE WEATHER CONCERNS. CURRENT OK/KS UPPER LEVEL SYSTEM WILL CONTINUE LIFTING NNEWD REACHING FAR ERN NE AT ONSET. CURRENT LOBE OF FORCING AND WEAK CONVECTION SHOULD HAVE EXITED THE FOREACTIVE WEATHER IS ANTICIPATED THROUGH THE WEEK WITH MULTIPLE SENSIBLE WEATHER CONCERNS. CURRENT OK/KS UPPER LEVEL SYSTEM WILL CONTINUE LIFTING NNEWD REACHING FAR ERN NE AT ONSET. CURRENT LOBE OF FORCING AND WEAK CONVECTION SHOULD HAVE EXITED THE FORECAST AREA BY 12Z IN TANDEM WITH SHARP LOBE OF H85/H7 FORCING WITH DRY SLOT AND COLD FRONT ALOFT. HOWEVER PATCHY MID LEVEL FORCING ASSOCIATED WITH THE CORE OF THE SYSTEM WILL STILL COMBINE WITH LOW LEVEL INSTABILITY TO PRODUCE SCATTERED SHOWERS INTO THE AFTERNOON. THIS LOW LEVEL MIXING AND INSTABILITY MAY ALSO PRODUCE WIND GUSTS TO 30KTS PLUS...ESPECIALLY TOWARD ERN SECTIONS. THE SYSTEM WILL EXIT INTO WED NIGHT WITH DEEP SUBSIDENCE...DRYING AND COOLER TEMPERATURES INTO THU. MSLP GRADIENT CONTRIBUTION WILL NOT BE EXTREME WITH ISALLOBARIC MAX PAST US BY 12Z BUT SHOULD STILL BE SUFFICIENT FOR ADVISORY CRITERIA SUSTAINED WINDS /26KTS/ IN MANY CENTRAL AND NRN LOCATIONS. MIXING COMPONENT LOOKS A BIT MORE EXTREME HOWEVER WITH DEPTHS UP TO 750MB OR MORE. EXAMINATION OF BUFR SOUNDINGS...AND AVERAGING SPEEDS AT THE TOP OF THE MIXED LAYER WITH LAYER MEAN SUGGESTS WIND GUSTS MAY REACH 45KTS DURING THE AFTERNOON. NO HEADLINES AS OF YET...BUT FULLY EXPECT AT LEAST AN ADVISORY FOR THU AFTERNOON AS THE EVENT NEARS. THERE SHOULD ONLY BE A MINIMAL TEMP REBOUND THU WITH HIGHS NO BETTER THAN THE UPPER 30S OR 40S. ATTENTION WILL THEN TURN TO WHAT IS SHAPING UP TO THE FIRST ACCUMULATING SNOWFALL OF THE SEASON. CONFIDENCE IN SNOW OCCURRING IS FAIRLY HIGH...HOWEVER CONFIDENCE IN THE DETAILS WITH REGARDS TO TIMING AND SNOW AMOUNTS ARE STILL ON THE LOW SIDE. THE SYSTEM IS CURRENTLY STILL WELL OFF INTO THE PACIFIC SO MODELS WILL LIKELY STILL CHANGE SOMEWHAT MOVING FORWARD...HOWEVER THE ECMWF AND GFS ARE GRADUALLY TRYING TO CONVERGE ON A CONSENSUS SOLUTION. BOTH SCENARIOS INCLUDE STRONG MID LEVEL FORCING EXPANDING INTO IA WITH AN INITIAL LACK OF LOW LEVEL MOISTURE. THE GFS SATURATES FASTER THAN THEN ECMWF WITH A MORE PROLONGED PHASING OF FORCING AND ADEQUATE MOISTURE SO GFS AMOUNTS ARE SLIGHTLY HIGHER. CONFIDENCE IS REDUCED BY THIS AND ALSO WITH REGARD TO TIMING AS THE GFS IS AROUND SIX HOURS FASTER. THERMODYNAMIC CONCERNS RAISE QUESTIONS AS WELL WITH RAIN/SNOW LINE TRANSITION...DEGREE OF EVAPORATIVE COOLING AND MELTING ALL CAUSING PROBLEMS WITH FORECAST SNOW AMOUNTS. HAVE ADDED AN INCH OR TWO ACCUMS WEST CENTRAL SECTIONS THROUGH 00Z SAT...BUT ADDITIONAL SNOW IS ANTICIPATED INTO FRI NIGHT WHICH MAY INCREASE AMOUNTS SOMEWHAT. THE WEEKEND WILL BE COLD BUT DRY. TEMPERATURES WILL BE BELOW NORMAL WITH BRISK NORTHWEST WINDS DROPPING WIND CHILLS INTO THE SINGLE DIGITS AT TIMES NORTH EARLY SATURDAY. GFS AND ECMWF BOTH DROP A SHORT WAVE INTO THE MO VALLEY EARLY SUNDAY IN NW FLOW ALOFT. THE ECMWF IS WEAKER AND DOES NOT GENERATE MUCH IN THE WAY OF PRECIPITATION...UNLIKE THE MORE AGGRESSIVE GFS. HAVE OPTED TO LEAN TOWARD THE ECMWF AND STAY DRY UNTIL RUN TO RUN TRENDS SAY OTHERWISE. ONCE THIS WAVE EXITS THE LARGE CENTRAL CONUS MEAN TROUGH WEAKENS SOMEWHAT WITH RETREATING WESTERLIES. THIS WILL KEEP US DRY INTO THE EXTENDED WITH SEASONALLY COOL TEMPERATURES. CAST AREA BY 12Z IN TANDEM WITH SHARP LOBE OF H85/H7 FORCING WITH DRY SLOT AND COLD FRONT ALOFT. HOWEVER PATCHY MID LEVEL FORCING ASSOCIATED WITH THE CORE OF THE SYSTEM WILL STILL COMBINE WITH LOW LEVEL INSTABILITY TO PRODUCE SCATTERED SHOWERS INTO THE AFTERNOON. THIS LOW LEVEL MIXING AND INSTABILITY MAY ALSO PRODUCE WIND GUSTS TO 30KTS PLUS...ESPECIALLY TOWARD ERN SECTIONS. THE SYSTEM WILL EXIT INTO WED NIGHT WITH DEEP SUBSIDENCE...DRYING AND COOLER TEMPERATURES INTO THU. MSLP GRADIENT CONTRIBUTION WILL NOT BE EXTREME WITH ISALLOBARIC MAX PAST US BY 12Z...BUT SHOULD STILL BE SUFFICIENT FOR ADVISORY CRITERIA SUSTAINED WINDS /26KTS/ IN MANY CENTRAL AND NRN LOCATIONS. MIXING COMPONENT LOOKS A BIT MORE EXTREME HOWEVER WITH DEPTHS UP TO 750MB OR MORE. EXAMINATION OF BUFR SOUNDINGS...AND AVERAGING SPEEDS AT THE TOP OF THE MIXED LAYER WITH LAYER MEAN...SUGGESTS WIND GUSTS MAY REACH 45KTS DURING THE AFTERNOON NORTH. NO HEADLINES AS OF YET...BUT FULLY EXPECT AT LEAST AN ADVISORY FOR THU AFTERNOON AS THE EVENT NEARS. THERE SHOULD ONLY BE A MINIMAL TEMP REBOUND THU WITH HIGHS NO BETTER THAN THE UPPER 30S OR 40S. ATTENTION WILL THEN TURN TO WHAT IS SHAPING UP TO THE FIRST ACCUMULATING SNOWFALL OF THE SEASON. CONFIDENCE IN SNOW OCCURRING IS FAIRLY HIGH...HOWEVER CONFIDENCE IN THE DETAILS WITH REGARDS TO TIMING AND AMOUNTS ARE STILL ON THE LOW SIDE. THE SYSTEM IS CURRENTLY STILL WELL OFF INTO THE PACIFIC SO MODELS WILL LIKELY STILL CHANGE SOMEWHAT MOVING FORWARD...HOWEVER THE ECMWF AND GFS ARE GRADUALLY TRYING TO CONVERGE ON A CONSENSUS SOLUTION. BOTH SCENARIOS INCLUDE STRONG MID LEVEL FORCING EXPANDING INTO IA WITH AN INITIAL LACK OF LOW LEVEL MOISTURE. THE GFS SATURATES FASTER THAN THE ECMWF WITH A MORE PROLONGED PHASING OF FORCING AND ADEQUATE MOISTURE SO GFS AMOUNTS ARE SLIGHTLY HIGHER. CONFIDENCE IS REDUCED BY THIS AND ALSO WITH REGARD TO TIMING AS THE GFS IS AROUND SIX HOURS FASTER. THERMODYNAMIC CONCERNS RAISE QUESTIONS AS WELL WITH RAIN/SNOW LINE TRANSITION THROUGH FORECAST AREA...ONSET OF PRECIP AND ASSOCIATED EVAPORATIVE COOLING AND MELTING ALL CAUSING PROBLEMS WITH FORECAST SNOW AMOUNTS. HAVE ADDED AN INCH OR TWO ACCUMS WEST CENTRAL SECTIONS THROUGH 00Z SAT...BUT ADDITIONAL SNOW IS ANTICIPATED INTO FRI NIGHT WHICH MAY INCREASE AMOUNTS SOMEWHAT. BOTTOM LINE IS THAT TIMING...AMOUNTS...AND HOW MUCH WILL MELT ON PAVEMENT VS VEGETATION ARE STILL ALL IN QUESTION. WHATEVER MATERIALIZES WILL LIKELY OCCUR AROUND THE FRI EVENING COMMUTE AND BEING THE FIRST SNOW OF THE YEAR MAY IMPACT TRAVEL REGARDLESS OF AMOUNTS. THE WEEKEND WILL BE COLD BUT DRY. TEMPERATURES WILL BE BELOW NORMAL WITH BRISK NORTHWEST WINDS DROPPING WIND CHILLS INTO THE SINGLE DIGITS AT TIMES NORTH EARLY SATURDAY. GFS AND ECMWF BOTH DROP A SHORT WAVE INTO THE MO VALLEY EARLY SUNDAY IN NW FLOW ALOFT. THE ECMWF IS WEAKER AND DOES NOT GENERATE MUCH IN THE WAY OF PRECIPITATION...UNLIKE THE MORE AGGRESSIVE GFS. HAVE OPTED TO LEAN TOWARD THE ECMWF AND STAY DRY UNTIL RUN TO RUN TRENDS SAY OTHERWISE. ONCE THIS WAVE EXITS THE LARGE CENTRAL CONUS MEAN TROUGH WEAKENS SOMEWHAT WITH RETREATING WESTERLIES. THIS WILL KEEP US DRY INTO THE EXTENDED WITH SOME WARMING...BUT STILL SEASONALLY COOL TEMPERATURES. && .AVIATION...17/18Z ISSUED AT 1138 AM CST TUE NOV 17 2015 IFR AND LOWER CONDITIONS WILL BE PREVALENT THROUGH THE TAF PERIOD WITH -SHRA AT TIMES. THERE MAY BE A BRIEF IMPROVEMENT IN CIGS TO MVFR OR EVEN VFR AT DSM/OTM THIS AFTERNOON PER UPSTREAM OBS...HOWEVER CONFIDENCE IS LOW AS SHRA DEVELOPING UPSTREAM MAY INDICATE A RESURGENCE OF LOW LEVEL MOISTURE AND RENEWED LOWER CIGS AS INDICATED BY FORECAST SOUNDINGS. OTHERWISE...THE LOW CIGS WILL CONTINUE WELL INTO TONIGHT BEFORE SLOWLY IMPROVING ON WED MORNING. EVEN THEN...MVFR CIGS ARE STILL LIKELY WITH MORE -SHRA MOVING IN AFTER SUNRISE. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...LEE LONG TERM...SMALL AVIATION...LEE  FXUS63 KDMX 172343 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 643 PM CDT MON AUG 17 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TONIGHT/... ISSUED AT 333 PM CDT MON AUG 17 2015 A VIGOROUS PV ANOMALY THAT HAS BEEN MOVING ACROSS SOUTHEAST NEBRASKA TODAY HAS WEAKENED A BIT AND SHIFTED SLIGHTLY SOUTH. THE PRECIPITATION ACROSS NORTHERN IOWA HAS BEEN SLOWLY DIMINISHING THROUGHOUT THE DAY WITH THE FOCUS MORE OVER SOUTHEAST IOWA WHERE THE REGION OF GREATER INSTABILITY EXISTS AND AHEAD OF AN OUTFLOW BOUNDARY FROM THE OVERNIGHT CONVECTION. THERE IS THE POTENTIAL FOR AN ISOLATED SEVERE STORM ACROSS THE SOUTHEAST THROUGH EARLY EVENING AND THE POTENTIAL FOR A FEW LANDSPOUT FUNNELS DOES EXIST GIVEN THE STAGNANT BOUNDARY AND GOOD LOW LEVEL CAPES. THE OTHER AREA OF PRECIPITATION IS FOCUSED OVER SOUTHWEST IA AHEAD OF THE PV ANOMALY. THIS AREA HAS BEEN HAVING DIFFICULTY SUSTAINING THIS AFTERNOON AS THE UPPER DYNAMICS DECREASE. HAVE TRENDED DRIER ACROSS THE NORTH FOR THROUGH THE EVENING WITH THE FOCUS REMAINING OVER SOUTHERN IOWA. THE NEXT STRONG SHORTWAVE WILL BE MOVING INTO SOUTH DAKOTA AND NEBRASKA AND SPREADING QG FORCING INTO WESTERN IOWA LATE. MUCH OF THE NIGHT WILL BE DEVOID OF A LOW LEVEL JET OR MOISTURE ADVECTION UNTIL LATE. THE LOW LEVEL JET WILL INCREASE LATE AS THE UPPER SYSTEM APPROACHES AND THIS WILL BRING ANOTHER PUSH OF GOOD MOISTURE ADVECTION LIFTING INTO WESTERN IOWA BY 12Z. THIS WILL BRING INCREASING SHOWER AND THUNDERSTORMS CHANCES MAINLY OVER WESTERN IOWA. NO SEVERE WEATHER OR HEAVY RAIN FALL IS EXPECTED WITH THIS ACTIVITY. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 333 PM CDT MON AUG 17 2015 UPPER LEVEL WAVE CURRENTLY DIGGING INTO THE NORTHERN ROCKIES TO CONTINUE TO DEEPEN AS IT PUSHES SOUTHEAST INTO SC SD BY MID-DAY TUESDAY. AN ASSOCIATED SURFACE LOW BEGINNING TO DEVELOP IN ERN CO WILL LIFT ENE TONIGHT INTO TUESDAY...AND BE CENTERED ACROSS NW IOWA BY LATE TUESDAY AFTERNOON BEFORE LIFTING INTO MN TUESDAY NIGHT. STRONG THETA-E ADVECTION WITH A WEAK WARM FRONT LIFTING NORTH THROUGH THE STATE...SHOULD ALLOW FOR CONVECTION TO BE ONGOING/OVERSPREAD MUCH OF THE NORTHERN CWA TUESDAY MORNING. STRONGER VORT MAX ALOFT TO ROTATE AROUND THE UPPER LOW AND THROUGH THE CWA LATER TUESDAY TO KICK OFF ANOTHER ROUND OF STORMS IN THE AFTERNOON ACROSS THE WESTERN CWA TUESDAY AFTERNOON WITH A LINE OF STORMS EXPECTED TO MOVE EASTWARD ACROSS THE CWA LATE TUESDAY AFTERNOON INTO EARLY EVENING. ADDITIONAL DEVELOPMENT POSSIBLE INTO THE TUESDAY EVENING AS THE COLD FRONT FINALLY MAKES ITS WAY THROUGH THE CWA AS WELL...WITH LOW STRATUS EXPECTED TO FILL IN BEHIND THE FRONT. AMOUNT OF SURFACE HEATING IS QUESTIONABLE GIVEN THE CLOUD COVER AND PRECIP POSSIBLE THROUGH THE DAY...HOWEVER STILL EXPECTING MUCAPE OF AROUND 1500-2000 J/KG BY TUESDAY AFTERNOON WITH DECENT SHEAR. DEEP LAYER SHEAR MARGINAL FOR SUPERCELLS...SO EXPECTING MORE OF A MULTICELLULAR EVENT. STORM MOTIONS MAY BE PROGRESSIVE ENOUGH TO WARRANT HEAVY RAIN ISSUES...HOWEVER WITH A FEW ROUNDS OF STORMS POSSIBLE AND PWAT VALUES IN THE 1.5 TO 2 INCH RANGE AND HIGHER WARM CLOUD DEPTHS HEAVY RAIN STILL A THREAT. THIS IS ESPECIALLY TRUE WITH SOME OF THE HEAVIER RAINFALL POSSIBLE OVER THE SAME AREA THAT HAS ALREADY HAD 5+ INCHES OF RAIN OVER THE PAST 24 HOURS. THEREFORE AN ISOLATED FLASH FLOOD THREAT WILL BE POSSIBLE WITH SOME SATURATED SOILS AND HIGH RAINFALL RATES EXPECTED. MUCH OF THE GUIDANCE ACROSS THE CWA IS STILL IN THE 2.5 TO 3.5 INCH RANGE FOR 3 HOUR FLASH FLOOD GUIDANCE OTHER THAN THE ISOLATED AREA THAT RECEIVED THE HEAVY RAIN PREVIOUSLY. THEREFORE WILL REFRAIN FROM ISSUING A HYDRO WATCH AT THIS TIME...BUT WILL NEED TO MONITOR FOR A POSSIBLE HYDRO WATCH WITH SUBSEQUENT SHIFTS. OTHERWISE STRONG COLD FRONT TO MOVE THROUGH WITH THE SYSTEM TUESDAY NIGHT...WITH MUCH COOLER AIR IN PLACE FOR WEDNESDAY WITH H85 TEMPS DROPPING TO AROUND +5C BEHIND THE FRONT. CLOUD COVER POSSIBLE INTO WEDNESDAY ESPECIALLY A CU FIELD INTO THE AFTERNOON HOURS WITH DEF ZONE MOISTURE AND WEAK LOW LEVEL INSTABILITY SHOWERS POSSIBLE WEDNESDAY ACROSS THE NORTH. THEREFORE WITH CAA...PRECIP AND CLOUD COVER TEMPS WILL HAVE TROUBLE WARMING TOO MUCH. THEREFORE HAVE HIGHS ONLY IN THE LOW 60S NORTH...WITH AREAS THAT COULD SEE A FEW MORE PEEKS OF SUN WARMING TO AROUND 70 ACROSS THE SOUTH. HIGH PRESSURE TO BUILD INTO THE AREA FOR THURSDAY WITH DRY CONDITIONS...AND FAIRLY DECENT RECOVERY IN TEMPS INTO FRIDAY AND SATURDAY AS SOUTHERLY FLOW INCREASES AHEAD OF THE NEXT UPPER WAVE TO DIG INTO THE CENTRAL US THIS WEEKEND. THIS WILL BRING CHANCES FOR PRECIPITATION MAINLY SATURDAY INTO SATURDAY NIGHT...WITH A LARGE AREA OF HIGH PRESSURE EXPECTED TO BUILD INTO THE WESTERN AND CENTRAL US BENEATH A LARGE WESTERN US RIDGE FOR EARLY NEXT WEEK. TEMPERATURES LOOK MORE SEASONAL FOR THE WEEKEND INTO NEXT WEEK. && .AVIATION...18/00Z ISSUED AT 632 PM CDT MON AUG 17 2015 NORTHERN TAF SITES (FOD/MCW) WILL SEE SOME GUSTY WINDS AND MVFR TO IFR CIGS WITH LINE OF SHOWERS THROUGH 03Z TONIGHT. EXPECTING MVFR AND POTENTIALLY IFR CIGS TO PERSIST INTO TOMORROW MORNING. LOW CONFIDENCE IN DURATION OF IFR CIGS AND LEFT OUT MENTION FOR MOST TAF SITES EXCEPT FOD ATTM. WITH THE COLD FROPA ADVANCING ACROSS THE STATE TOMORROW AFTERNOON...MENTIONED TS AND GUSTY WINDS AND LIKELY WILL SEE IFR/MVFR CIGS LATE IN THE PERIOD WITH THE HEAVY RAIN POTENTIAL. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...DONAVON LONG TERM...BEERENDS AVIATION...PODRAZIK  FXUS63 KDMX 180329 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 929 PM CST TUE NOV 17 2015 .UPDATE... ISSUED AT 929 PM CST TUE NOV 17 2015 SCATTERED SHOWERS AND DRIZZLE MOVING INTO THE FAR SOUTH AT THIS TIME WITH AREAS DENSE FOG FORMING OVER THE FAR NORTHWEST. FOR NOW WILL COVER WITH AN SPS FOR THE AREA. RAIN SHOWERS WILL HELP DISPERSE FOG AFT 06Z. TEMPS REMAIN MILD OVERNIGHT UNTIL LOW ROTATES NORTHEAST AND COOLER AIR FOLLOWS THE OCCLUDED FRONT. && .SHORT TERM /TONIGHT/... ISSUED AT 351 PM CST TUE NOV 17 2015 A LARGE STORM SYSTEM WILL APPROACH OUR AREA FROM THE SOUTHWEST TONIGHT...WITH A SURFACE LOW TRACKING FROM SOUTH TO NORTH ACROSS WESTERN IOWA...WHILE THE MID/UPPER LOW CENTER MOVES ACROSS KANSAS AND TOWARD SOUTHWESTERN IOWA BY SUNRISE. REGIONAL RADAR IMAGERY DEPICTS A LARGE SWATH OF LIGHT TO MODERATE RAIN ALONG THE EASTERN FLANK OF THIS SYSTEM...GRADUALLY TRANSLATING UP ACROSS ABOUT THE EASTERN HALF OF IOWA LATE THIS AFTERNOON AND EVENING...AND WILL MAINTAIN CATEGORICAL POPS IN ASSOCIATION WITH THIS FEATURE. OTHERWISE...THE AREA WILL REMAIN LARGELY DRY THROUGH THE EVENING BUT WITH LIGHT RAIN/DRIZZLE LIKELY FILLING IN AFTER SUNSET AS THE SURFACE LOW MOVES THROUGH AND FORECAST SOUNDINGS INDICATE INCREASING NEAR SURFACE CLOUD DEPTHS. HAVE THUS MAINTAINED MAINLY CHANCE POPS IN THESE AREAS...BUT WITH VERY LOW QPF. THERE MAY BE SOME RELATIVE CLEARING WITHIN THIS DRY SLOT...BUT THE VERY LOW LEVEL MOISTURE DOES NOT APPEAR LIKELY TO GO AWAY SO WE MAY STILL SEE MOSTLY CLOUDY SKIES AND DRIZZLE EVEN THOUGH THE CLOUDS WOULD BE VERY SHALLOW. FINALLY...THE MID/UPPER LEVEL LOW CORE WILL BE ACCOMPANIED BY MORE LIGHT SHOWERS AND THICKER CLOUDS...REACHING OUR SOUTHWESTERN COUNTIES BY 12Z BUT HAVING MORE WIDESPREAD IMPACTS LATER INTO TOMORROW AS DISCUSSED IN THE LONG TERM SECTION BELOW. TEMPERATURES WILL REMAIN UNSEASONABLY WARM OVERNIGHT AS WELL...WITH MOSTLY TO COMPLETELY CLOUDY SKIES AND MODEST BUT PERSISTENT WINDS...AND HAVE INCREASED THE LOW TEMP FORECAST ACCORDINGLY. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 351 PM CST TUE NOV 17 2015 ACTIVE WEATHER IS ANTICIPATED THROUGH THE WEEK WITH MULTIPLE SENSIBLE WEATHER CONCERNS. CURRENT OK/KS UPPER LEVEL SYSTEM WILL CONTINUE LIFTING NNEWD REACHING FAR ERN NE AT ONSET. CURRENT LOBE OF FORCING AND WEAK CONVECTION SHOULD HAVE EXITED THE FORECAST AREA BY 12Z IN TANDEM WITH SHARP LOBE OF H85/H7 FORCING WITH DRY SLOT AND COLD FRONT ALOFT. HOWEVER PATCHY MID LEVEL FORCING ASSOCIATED WITH THE CORE OF THE SYSTEM WILL STILL COMBINE WITH LOW LEVEL INSTABILITY TO PRODUCE SCATTERED SHOWERS INTO THE AFTERNOON. THIS LOW LEVEL MIXING AND INSTABILITY MAY ALSO PRODUCE WIND GUSTS TO 30KTS PLUS...ESPECIALLY TOWARD ERN SECTIONS. THE SYSTEM WILL EXIT INTO WED NIGHT WITH DEEP SUBSIDENCE...DRYING AND COOLER TEMPERATURES INTO THU. MSLP GRADIENT CONTRIBUTION WILL NOT BE EXTREME WITH ISALLOBARIC MAX PAST US BY 12Z BUT SHOULD STILL BE SUFFICIENT FOR ADVISORY CRITERIA SUSTAINED WINDS /26KTS/ IN MANY CENTRAL AND NRN LOCATIONS. MIXING COMPONENT LOOKS A BIT MORE EXTREME HOWEVER WITH DEPTHS UP TO 750MB OR MORE. EXAMINATION OF BUFR SOUNDINGS...AND AVERAGING SPEEDS AT THE TOP OF THE MIXED LAYER WITH LAYER MEAN SUGGESTS WIND GUSTS MAY REACH 45KTS DURING THE AFTERNOON. NO HEADLINES AS OF YET...BUT FULLY EXPECT AT LEAST AN ADVISORY FOR THU AFTERNOON AS THE EVENT NEARS. THERE SHOULD ONLY BE A MINIMAL TEMP REBOUND THU WITH HIGHS NO BETTER THAN THE UPPER 30S OR 40S. ATTENTION WILL THEN TURN TO WHAT IS SHAPING UP TO THE FIRST ACCUMULATING SNOWFALL OF THE SEASON. CONFIDENCE IN SNOW OCCURRING IS FAIRLY HIGH...HOWEVER CONFIDENCE IN THE DETAILS WITH REGARDS TO TIMING AND SNOW AMOUNTS ARE STILL ON THE LOW SIDE. THE SYSTEM IS CURRENTLY STILL WELL OFF INTO THE PACIFIC SO MODELS WILL LIKELY STILL CHANGE SOMEWHAT MOVING FORWARD...HOWEVER THE ECMWF AND GFS ARE GRADUALLY TRYING TO CONVERGE ON A CONSENSUS SOLUTION. BOTH SCENARIOS INCLUDE STRONG MID LEVEL FORCING EXPANDING INTO IA WITH AN INITIAL LACK OF LOW LEVEL MOISTURE. THE GFS SATURATES FASTER THAN THEN ECMWF WITH A MORE PROLONGED PHASING OF FORCING AND ADEQUATE MOISTURE SO GFS AMOUNTS ARE SLIGHTLY HIGHER. CONFIDENCE IS REDUCED BY THIS AND ALSO WITH REGARD TO TIMING AS THE GFS IS AROUND SIX HOURS FASTER. THERMODYNAMIC CONCERNS RAISE QUESTIONS AS WELL WITH RAIN/SNOW LINE TRANSITION...DEGREE OF EVAPORATIVE COOLING AND MELTING ALL CAUSING PROBLEMS WITH FORECAST SNOW AMOUNTS. HAVE ADDED AN INCH OR TWO ACCUMS WEST CENTRAL SECTIONS THROUGH 00Z SAT...BUT ADDITIONAL SNOW IS ANTICIPATED INTO FRI NIGHT WHICH MAY INCREASE AMOUNTS SOMEWHAT. THE WEEKEND WILL BE COLD BUT DRY. TEMPERATURES WILL BE BELOW NORMAL WITH BRISK NORTHWEST WINDS DROPPING WIND CHILLS INTO THE SINGLE DIGITS AT TIMES NORTH EARLY SATURDAY. GFS AND ECMWF BOTH DROP A SHORT WAVE INTO THE MO VALLEY EARLY SUNDAY IN NW FLOW ALOFT. THE ECMWF IS WEAKER AND DOES NOT GENERATE MUCH IN THE WAY OF PRECIPITATION...UNLIKE THE MORE AGGRESSIVE GFS. HAVE OPTED TO LEAN TOWARD THE ECMWF AND STAY DRY UNTIL RUN TO RUN TRENDS SAY OTHERWISE. ONCE THIS WAVE EXITS THE LARGE CENTRAL CONUS MEAN TROUGH WEAKENS SOMEWHAT WITH RETREATING WESTERLIES. THIS WILL KEEP US DRY INTO THE EXTENDED WITH SEASONALLY COOL TEMPERATURES. && .AVIATION...18/00Z ISSUED AT 539 PM CST TUE NOV 17 2015 MAIN CHALLENGES REMAIN CIGS/VSBY AND RAINFALL. LARGE UPPER LOW EXPECTED TO ROTATE NORTHEAST THROUGH PERIOD WITH DRY SLOT AND MVFR/POSSIBLE VFR CIGS WORKING NORTH OVERNIGHT IF MOISTURE DOESNT OVERTAKE THE SLOT. SOME UNCERTAINTY ABOUT EXTEND OF DRYING...SO HAVE KEPT TRENDS LOWER FOR NOW. OTHERWISE WIND AND RETURN OF SHOWERS WILL BE MAIN CONCERN AFT 15Z WED WHEN UPPER LOW CREATES -SHRA AND GUSTY WINDS FROM SW/W THROUGH 00Z. /REV && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...REV SHORT TERM...LEE LONG TERM...SMALL AVIATION...REV  FXUS63 KDMX 180448 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1148 PM CDT MON AUG 17 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TONIGHT/... ISSUED AT 333 PM CDT MON AUG 17 2015 A VIGOROUS PV ANOMALY THAT HAS BEEN MOVING ACROSS SOUTHEAST NEBRASKA TODAY HAS WEAKENED A BIT AND SHIFTED SLIGHTLY SOUTH. THE PRECIPITATION ACROSS NORTHERN IOWA HAS BEEN SLOWLY DIMINISHING THROUGHOUT THE DAY WITH THE FOCUS MORE OVER SOUTHEAST IOWA WHERE THE REGION OF GREATER INSTABILITY EXISTS AND AHEAD OF AN OUTFLOW BOUNDARY FROM THE OVERNIGHT CONVECTION. THERE IS THE POTENTIAL FOR AN ISOLATED SEVERE STORM ACROSS THE SOUTHEAST THROUGH EARLY EVENING AND THE POTENTIAL FOR A FEW LANDSPOUT FUNNELS DOES EXIST GIVEN THE STAGNANT BOUNDARY AND GOOD LOW LEVEL CAPES. THE OTHER AREA OF PRECIPITATION IS FOCUSED OVER SOUTHWEST IA AHEAD OF THE PV ANOMALY. THIS AREA HAS BEEN HAVING DIFFICULTY SUSTAINING THIS AFTERNOON AS THE UPPER DYNAMICS DECREASE. HAVE TRENDED DRIER ACROSS THE NORTH FOR THROUGH THE EVENING WITH THE FOCUS REMAINING OVER SOUTHERN IOWA. THE NEXT STRONG SHORTWAVE WILL BE MOVING INTO SOUTH DAKOTA AND NEBRASKA AND SPREADING QG FORCING INTO WESTERN IOWA LATE. MUCH OF THE NIGHT WILL BE DEVOID OF A LOW LEVEL JET OR MOISTURE ADVECTION UNTIL LATE. THE LOW LEVEL JET WILL INCREASE LATE AS THE UPPER SYSTEM APPROACHES AND THIS WILL BRING ANOTHER PUSH OF GOOD MOISTURE ADVECTION LIFTING INTO WESTERN IOWA BY 12Z. THIS WILL BRING INCREASING SHOWER AND THUNDERSTORMS CHANCES MAINLY OVER WESTERN IOWA. NO SEVERE WEATHER OR HEAVY RAIN FALL IS EXPECTED WITH THIS ACTIVITY. .LONG TERM /TUESDAY THROUGH MONDAY/... ISSUED AT 333 PM CDT MON AUG 17 2015 UPPER LEVEL WAVE CURRENTLY DIGGING INTO THE NORTHERN ROCKIES TO CONTINUE TO DEEPEN AS IT PUSHES SOUTHEAST INTO SC SD BY MID-DAY TUESDAY. AN ASSOCIATED SURFACE LOW BEGINNING TO DEVELOP IN ERN CO WILL LIFT ENE TONIGHT INTO TUESDAY...AND BE CENTERED ACROSS NW IOWA BY LATE TUESDAY AFTERNOON BEFORE LIFTING INTO MN TUESDAY NIGHT. STRONG THETA-E ADVECTION WITH A WEAK WARM FRONT LIFTING NORTH THROUGH THE STATE...SHOULD ALLOW FOR CONVECTION TO BE ONGOING/OVERSPREAD MUCH OF THE NORTHERN CWA TUESDAY MORNING. STRONGER VORT MAX ALOFT TO ROTATE AROUND THE UPPER LOW AND THROUGH THE CWA LATER TUESDAY TO KICK OFF ANOTHER ROUND OF STORMS IN THE AFTERNOON ACROSS THE WESTERN CWA TUESDAY AFTERNOON WITH A LINE OF STORMS EXPECTED TO MOVE EASTWARD ACROSS THE CWA LATE TUESDAY AFTERNOON INTO EARLY EVENING. ADDITIONAL DEVELOPMENT POSSIBLE INTO THE TUESDAY EVENING AS THE COLD FRONT FINALLY MAKES ITS WAY THROUGH THE CWA AS WELL...WITH LOW STRATUS EXPECTED TO FILL IN BEHIND THE FRONT. AMOUNT OF SURFACE HEATING IS QUESTIONABLE GIVEN THE CLOUD COVER AND PRECIP POSSIBLE THROUGH THE DAY...HOWEVER STILL EXPECTING MUCAPE OF AROUND 1500-2000 J/KG BY TUESDAY AFTERNOON WITH DECENT SHEAR. DEEP LAYER SHEAR MARGINAL FOR SUPERCELLS...SO EXPECTING MORE OF A MULTICELLULAR EVENT. STORM MOTIONS MAY BE PROGRESSIVE ENOUGH TO WARRANT HEAVY RAIN ISSUES...HOWEVER WITH A FEW ROUNDS OF STORMS POSSIBLE AND PWAT VALUES IN THE 1.5 TO 2 INCH RANGE AND HIGHER WARM CLOUD DEPTHS HEAVY RAIN STILL A THREAT. THIS IS ESPECIALLY TRUE WITH SOME OF THE HEAVIER RAINFALL POSSIBLE OVER THE SAME AREA THAT HAS ALREADY HAD 5+ INCHES OF RAIN OVER THE PAST 24 HOURS. THEREFORE AN ISOLATED FLASH FLOOD THREAT WILL BE POSSIBLE WITH SOME SATURATED SOILS AND HIGH RAINFALL RATES EXPECTED. MUCH OF THE GUIDANCE ACROSS THE CWA IS STILL IN THE 2.5 TO 3.5 INCH RANGE FOR 3 HOUR FLASH FLOOD GUIDANCE OTHER THAN THE ISOLATED AREA THAT RECEIVED THE HEAVY RAIN PREVIOUSLY. THEREFORE WILL REFRAIN FROM ISSUING A HYDRO WATCH AT THIS TIME...BUT WILL NEED TO MONITOR FOR A POSSIBLE HYDRO WATCH WITH SUBSEQUENT SHIFTS. OTHERWISE STRONG COLD FRONT TO MOVE THROUGH WITH THE SYSTEM TUESDAY NIGHT...WITH MUCH COOLER AIR IN PLACE FOR WEDNESDAY WITH H85 TEMPS DROPPING TO AROUND +5C BEHIND THE FRONT. CLOUD COVER POSSIBLE INTO WEDNESDAY ESPECIALLY A CU FIELD INTO THE AFTERNOON HOURS WITH DEF ZONE MOISTURE AND WEAK LOW LEVEL INSTABILITY SHOWERS POSSIBLE WEDNESDAY ACROSS THE NORTH. THEREFORE WITH CAA...PRECIP AND CLOUD COVER TEMPS WILL HAVE TROUBLE WARMING TOO MUCH. THEREFORE HAVE HIGHS ONLY IN THE LOW 60S NORTH...WITH AREAS THAT COULD SEE A FEW MORE PEEKS OF SUN WARMING TO AROUND 70 ACROSS THE SOUTH. HIGH PRESSURE TO BUILD INTO THE AREA FOR THURSDAY WITH DRY CONDITIONS...AND FAIRLY DECENT RECOVERY IN TEMPS INTO FRIDAY AND SATURDAY AS SOUTHERLY FLOW INCREASES AHEAD OF THE NEXT UPPER WAVE TO DIG INTO THE CENTRAL US THIS WEEKEND. THIS WILL BRING CHANCES FOR PRECIPITATION MAINLY SATURDAY INTO SATURDAY NIGHT...WITH A LARGE AREA OF HIGH PRESSURE EXPECTED TO BUILD INTO THE WESTERN AND CENTRAL US BENEATH A LARGE WESTERN US RIDGE FOR EARLY NEXT WEEK. TEMPERATURES LOOK MORE SEASONAL FOR THE WEEKEND INTO NEXT WEEK. && .AVIATION...18/06Z ISSUED AT 1147 PM CDT MON AUG 17 2015 SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER WEST- CENTRAL IOWA DURING THE OVERNIGHT HOURS AND SPREAD EAST-NORTHEAST LIKELY AFFECTING FOD/MCW/DSM PRIOR TO NEXT TAF UPDATE. CIGS WILL CONTINUE TO BOUNCE FROM IFR TO MVFR TO VFR DEPENDING ON IF SITE RECEIVES RAIN...BUT HIGHER CONFIDENCE IN EXTENDED TIME FRAME OF MVFR CIGS/VIS AND KEPT MENTION AS RAIN LOOKS TO SPREAD OVER MUCH OF CENTRAL IOWA TOWARDS 12Z-14Z TUESDAY. THE MORE WIDESPREAD AND HEAVIER RAIN BY MIDDAY INTO THE AFTERNOON WILL BRING THE BEST POTENTIAL FOR IFR VIS AND CIGS. WINDS INCREASE AND SHIFT WEST- NORTHWEST TUESDAY EVENING BEHIND THE COLD FRONT. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...DONAVON LONG TERM...BEERENDS AVIATION...PODRAZIK  FXUS63 KDMX 180538 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1138 PM CST TUE NOV 17 2015 .UPDATE... ISSUED AT 929 PM CST TUE NOV 17 2015 SCATTERED SHOWERS AND DRIZZLE MOVING INTO THE FAR SOUTH AT THIS TIME WITH AREAS DENSE FOG FORMING OVER THE FAR NORTHWEST. FOR NOW WILL COVER WITH AN SPS FOR THE AREA. RAIN SHOWERS WILL HELP DISPERSE FOG AFT 06Z. TEMPS REMAIN MILD OVERNIGHT UNTIL LOW ROTATES NORTHEAST AND COOLER AIR FOLLOWS THE OCCLUDED FRONT. && .SHORT TERM /TONIGHT/... ISSUED AT 351 PM CST TUE NOV 17 2015 A LARGE STORM SYSTEM WILL APPROACH OUR AREA FROM THE SOUTHWEST TONIGHT...WITH A SURFACE LOW TRACKING FROM SOUTH TO NORTH ACROSS WESTERN IOWA...WHILE THE MID/UPPER LOW CENTER MOVES ACROSS KANSAS AND TOWARD SOUTHWESTERN IOWA BY SUNRISE. REGIONAL RADAR IMAGERY DEPICTS A LARGE SWATH OF LIGHT TO MODERATE RAIN ALONG THE EASTERN FLANK OF THIS SYSTEM...GRADUALLY TRANSLATING UP ACROSS ABOUT THE EASTERN HALF OF IOWA LATE THIS AFTERNOON AND EVENING...AND WILL MAINTAIN CATEGORICAL POPS IN ASSOCIATION WITH THIS FEATURE. OTHERWISE...THE AREA WILL REMAIN LARGELY DRY THROUGH THE EVENING BUT WITH LIGHT RAIN/DRIZZLE LIKELY FILLING IN AFTER SUNSET AS THE SURFACE LOW MOVES THROUGH AND FORECAST SOUNDINGS INDICATE INCREASING NEAR SURFACE CLOUD DEPTHS. HAVE THUS MAINTAINED MAINLY CHANCE POPS IN THESE AREAS...BUT WITH VERY LOW QPF. THERE MAY BE SOME RELATIVE CLEARING WITHIN THIS DRY SLOT...BUT THE VERY LOW LEVEL MOISTURE DOES NOT APPEAR LIKELY TO GO AWAY SO WE MAY STILL SEE MOSTLY CLOUDY SKIES AND DRIZZLE EVEN THOUGH THE CLOUDS WOULD BE VERY SHALLOW. FINALLY...THE MID/UPPER LEVEL LOW CORE WILL BE ACCOMPANIED BY MORE LIGHT SHOWERS AND THICKER CLOUDS...REACHING OUR SOUTHWESTERN COUNTIES BY 12Z BUT HAVING MORE WIDESPREAD IMPACTS LATER INTO TOMORROW AS DISCUSSED IN THE LONG TERM SECTION BELOW. TEMPERATURES WILL REMAIN UNSEASONABLY WARM OVERNIGHT AS WELL...WITH MOSTLY TO COMPLETELY CLOUDY SKIES AND MODEST BUT PERSISTENT WINDS...AND HAVE INCREASED THE LOW TEMP FORECAST ACCORDINGLY. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 351 PM CST TUE NOV 17 2015 ACTIVE WEATHER IS ANTICIPATED THROUGH THE WEEK WITH MULTIPLE SENSIBLE WEATHER CONCERNS. CURRENT OK/KS UPPER LEVEL SYSTEM WILL CONTINUE LIFTING NNEWD REACHING FAR ERN NE AT ONSET. CURRENT LOBE OF FORCING AND WEAK CONVECTION SHOULD HAVE EXITED THE FORECAST AREA BY 12Z IN TANDEM WITH SHARP LOBE OF H85/H7 FORCING WITH DRY SLOT AND COLD FRONT ALOFT. HOWEVER PATCHY MID LEVEL FORCING ASSOCIATED WITH THE CORE OF THE SYSTEM WILL STILL COMBINE WITH LOW LEVEL INSTABILITY TO PRODUCE SCATTERED SHOWERS INTO THE AFTERNOON. THIS LOW LEVEL MIXING AND INSTABILITY MAY ALSO PRODUCE WIND GUSTS TO 30KTS PLUS...ESPECIALLY TOWARD ERN SECTIONS. THE SYSTEM WILL EXIT INTO WED NIGHT WITH DEEP SUBSIDENCE...DRYING AND COOLER TEMPERATURES INTO THU. MSLP GRADIENT CONTRIBUTION WILL NOT BE EXTREME WITH ISALLOBARIC MAX PAST US BY 12Z BUT SHOULD STILL BE SUFFICIENT FOR ADVISORY CRITERIA SUSTAINED WINDS /26KTS/ IN MANY CENTRAL AND NRN LOCATIONS. MIXING COMPONENT LOOKS A BIT MORE EXTREME HOWEVER WITH DEPTHS UP TO 750MB OR MORE. EXAMINATION OF BUFR SOUNDINGS...AND AVERAGING SPEEDS AT THE TOP OF THE MIXED LAYER WITH LAYER MEAN SUGGESTS WIND GUSTS MAY REACH 45KTS DURING THE AFTERNOON. NO HEADLINES AS OF YET...BUT FULLY EXPECT AT LEAST AN ADVISORY FOR THU AFTERNOON AS THE EVENT NEARS. THERE SHOULD ONLY BE A MINIMAL TEMP REBOUND THU WITH HIGHS NO BETTER THAN THE UPPER 30S OR 40S. ATTENTION WILL THEN TURN TO WHAT IS SHAPING UP TO THE FIRST ACCUMULATING SNOWFALL OF THE SEASON. CONFIDENCE IN SNOW OCCURRING IS FAIRLY HIGH...HOWEVER CONFIDENCE IN THE DETAILS WITH REGARDS TO TIMING AND SNOW AMOUNTS ARE STILL ON THE LOW SIDE. THE SYSTEM IS CURRENTLY STILL WELL OFF INTO THE PACIFIC SO MODELS WILL LIKELY STILL CHANGE SOMEWHAT MOVING FORWARD...HOWEVER THE ECMWF AND GFS ARE GRADUALLY TRYING TO CONVERGE ON A CONSENSUS SOLUTION. BOTH SCENARIOS INCLUDE STRONG MID LEVEL FORCING EXPANDING INTO IA WITH AN INITIAL LACK OF LOW LEVEL MOISTURE. THE GFS SATURATES FASTER THAN THEN ECMWF WITH A MORE PROLONGED PHASING OF FORCING AND ADEQUATE MOISTURE SO GFS AMOUNTS ARE SLIGHTLY HIGHER. CONFIDENCE IS REDUCED BY THIS AND ALSO WITH REGARD TO TIMING AS THE GFS IS AROUND SIX HOURS FASTER. THERMODYNAMIC CONCERNS RAISE QUESTIONS AS WELL WITH RAIN/SNOW LINE TRANSITION...DEGREE OF EVAPORATIVE COOLING AND MELTING ALL CAUSING PROBLEMS WITH FORECAST SNOW AMOUNTS. HAVE ADDED AN INCH OR TWO ACCUMS WEST CENTRAL SECTIONS THROUGH 00Z SAT...BUT ADDITIONAL SNOW IS ANTICIPATED INTO FRI NIGHT WHICH MAY INCREASE AMOUNTS SOMEWHAT. THE WEEKEND WILL BE COLD BUT DRY. TEMPERATURES WILL BE BELOW NORMAL WITH BRISK NORTHWEST WINDS DROPPING WIND CHILLS INTO THE SINGLE DIGITS AT TIMES NORTH EARLY SATURDAY. GFS AND ECMWF BOTH DROP A SHORT WAVE INTO THE MO VALLEY EARLY SUNDAY IN NW FLOW ALOFT. THE ECMWF IS WEAKER AND DOES NOT GENERATE MUCH IN THE WAY OF PRECIPITATION...UNLIKE THE MORE AGGRESSIVE GFS. HAVE OPTED TO LEAN TOWARD THE ECMWF AND STAY DRY UNTIL RUN TO RUN TRENDS SAY OTHERWISE. ONCE THIS WAVE EXITS THE LARGE CENTRAL CONUS MEAN TROUGH WEAKENS SOMEWHAT WITH RETREATING WESTERLIES. THIS WILL KEEP US DRY INTO THE EXTENDED WITH SEASONALLY COOL TEMPERATURES. && .AVIATION...18/06Z ISSUED AT 1138 PM CST TUE NOV 17 2015 -SHRA MOVING ACROSS THE AREA NOW...WITH CIGS/WINDS EXPECTED TO BE QUITE DYNAMIC OVERNIGHT AS THE OCCLUDED FRONT LIFTS NORTH. AS THE UPPER LEVEL LOW MOVES INTO THE REGION WED...EXPECTING ANOTHER ROUND OF SHOWERS AND MVFR CIGS. WINDS WILL BE STRENGTHENING BEHIND THE DEPARTING LOW BY 00Z WITH GUSTS INCREASING BETWEEN 18-00Z. /REV && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...REV SHORT TERM...LEE LONG TERM...SMALL AVIATION...REV  FXUS63 KDMX 220844 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 344 AM CDT SAT AUG 22 2015 .SHORT TERM /TODAY/... ISSUED AT 327 AM CDT SAT AUG 22 2015 A VERY POTENT 500MB TROUGH WILL CONTINUE TO DEEPEN THROUGHOUT THE DAY AS EJECTS OUT OF THE NORTHERN ROCKIES INTO THE DAKOTAS THIS AFTERNOON. THE SURFACE LOW LOOKS TO DEVELOP AND STRENGTHEN OVER THE EASTERN PORTIONS OF THE DAKOTAS WITH A SHARP COLD FRONT EXTENDING SOUTHWARD INTO NEBRASKA BY MIDDAY TODAY AND THEN TRANSITION SOUTHEAST INTO NORTHWEST IOWA LATE IN THE PERIOD. TROUGH BECOMES NEGATIVELY TILTED BY AROUND 00Z SUNDAY. THERE IS A LOW POTENTIAL FOR SOME ELEVATED STORMS TO TRY AND DEVELOP OVER WESTERN TO NORTHWEST PORTIONS OF IOWA AHEAD OF THE COLD FRONT...BUT WITH A VERY STRONG CAP IN PLACE...HAVE LOW CONFIDENCE WITH ANYTHING WIDESPREAD AND THUS ANY SEVERE WX PRIOR TO THE FROPA AND LEFT FORECAST DRY UNTIL 21Z. THE HIRES 22.00Z ARW/NMM...22.00Z NSSL-WRF...22.05Z HRRR AND COUPLE MEMBERS OF THE 22.03Z HOPWRF ALL SUGGEST CONVECTIVE INITIATION B/T 21-23Z OVER FAR NORTHWEST IOWA. ACROSS THE WEST TO NORTHWEST SECTIONS OF THE FORECAST AREA...DEEP LAYER SHEAR INCREASES TO 40-45 KNOTS PAST 21Z WITH 0-1KM AND 0-3KM SHEAR BOTH IN THE 20-30 KNOT RANGE. STRONG SURFACE BASE CAPE INCREASES TO 3000-3800 J/KG WITH STEEP LAPSE RATES IN THE 7.5-8 C/KM RANGE. LCL HEIGHTS AROUND 600M IN THE WARM SECTOR AND EXPECTING DISCRETE SUPERCELLS WITH INITIATION THIS AFTERNOON. HOWEVER...THE MOST LIKELY SCENARIO IS STORMS LOOK TO QUICKLY EVOLVE INTO QLCS SQUALL LINE BY TIME THEY MOVE INTO THE FORECAST AREA. THERE IS A POTENTIAL FOR SUPERCELLS TO CREEP INTO THE FAR WESTERN TO NORTHWESTERN EDGES OF THE FORECAST AREA (DENISON TO ESTHERVILLE LINE) PRIOR TO THE SQUALL LINE EVOLUTION...AND HAVE POPS INTRODUCED BY 21Z. ALL MODES OF SEVERE WEATHER POSSIBLE LATE THIS AFTERNOON...WITH TORNADIC AND LARGE HAIL POTENTIAL UPON INITIATION AND THEN MORE LIKELY DAMAGING WINDS WITH THE SUPERCELLS EVOLVING INTO QLCS. CERTAINLY CANNOT RULE TORNADIC POTENTIAL WITHIN THE QLCS LATE IN THE PERIOD. REGARDLESS...HAVE SEVERE MENTIONED PAST 21Z IN THE FAR NORTHWEST TO COINCIDE WITH SPC ENHANCED RISK AREA. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 327 AM CDT SAT AUG 22 2015 ONGOING SEVERE WEATHER AND HEAVY RAINFALL EXPECTED EARLY IN THE FIRST PERIOD. SEVERAL FACTORS POINT TO A ROBUST LINE OF CONVECTION THIS EVENING. A STRONG COLD FRONT WITH IMPRESSIVE SFC CONVERGENCE ...STRONG INSTABILITY/HIGH PRECIPITABLE WATER AND APPROACHING H500 WAVE WILL COMBINE TO ENHANCE CONVECTION THROUGH AT LEAST 06Z. MAIN CONCERNS AFTER 02Z WILL BE THREAT FOR WIND/HAIL AND HEAVY RAINFALL. GFS BUFR SOUNDINGS AT 00Z SHOW 0-3KM SRH ABOUT 200-300 J/KG AT KDSM AS THE LINE REACHES CENTRAL IA AT THAT TIME WITH STORM RELATIVE HELICITY WEAKENING TOWARD 06Z IN THE SOUTHEAST. SBCAPE IS PROGGED TO BE 2750 WITH LCL OF NEAR 692M/2000FT. INITIALLY THE THREAT THROUGH ABOUT I35 WILL STILL INCLUDE THE RISK OF A TORNADO THOUGH ANY DISCRETE SUPERCELLS IN THE LATE AFTERNOON SHOULD BE EVOLVING INTO A MORE LINEAR AND ACCELERATING LINE OF STORMS AS IT MOVES MORE RAPIDLY SOUTHEAST WITH TIME. THROUGH THE EVENING HOURS THE THREAT FOR SEVERE WEATHER WILL GRADUALLY WEAKEN AS BOTH CAPE AND HELICITY BEGIN TO LESSEN WITH TIME. THE OTHER CONCERN WITH THIS EVENT WILL BE BRIEF BUT VERY HEAVY RAINFALL. SUBJECTIVE 00Z SATURDAY H850 ANALYSIS THIS EVENING SHOWS A +15C PLUME OF MOISTURE FROM THE TEXAS COAST UP INTO CENTRAL/WESTERN NEBRASKA. THE GFS IS FORECASTING PRECIPITABLE WATER OF UP TO 1.7 INCHES ALONG THE BOUNDARY IN WESTERN IA AT 18Z...AND A MORE BROAD AREA OF 1.75 TO AROUND 2 INCHES FROM CENTRAL THROUGH SOUTHEAST IA FROM 00-06Z TONIGHT. THIS COMBINED WITH AN EXPECTED WARM CLOUD DEPTH OF 3600-3800M (>12KFT) OVER WESTERN IOWA...INCREASING TO OVER 4000M (>13KFT) FROM TAMA TO DECATUR COUNTY BY 06Z WILL PROMOTE INCREASINGLY EFFICIENT RAINFALL AS THE LINE BECOMES MORE ORGANIZED AND 0-6KM BULK SHEAR 50-60KTS BEHIND THE BOUNDARY CATCHES UP TO THE LINE FROM 03-06Z. NMM MOISTURE CONVERGENCE AND MOISTURE TRANSPORT VECTORS ARE BOTH MAXIMIZED AT THIS TIME OVER CENTRAL/SOUTHERN IOWA. FOR NOW AM ANTICIPATING AT LEAST A PERIOD OF 1-2 HOURS OF 1-2 INCH RAINFALL/HOUR MAINLY FROM 03-06Z FROM NEAR AMES SOUTHWEST TO CRESTON/LAMONI OR GENERALLY SOUTH OF HIGHWAY 30 AND ALONG AND WEST OF I35. CURRENT 1HR GRIDDED FLASH FLOOD GUIDANCE IS RUNNING ABOUT 1.75 TO NEARLY 2 INCHES OVER MOST OF THIS REGION AND HIGH ENOUGH TO AVOID A HEADLINE FOR FLASH FLOODING. HOWEVER...THE TIMING OF THE RAINFALL AND LIKELIHOOD THAT IT WILL FALL DURING THE LATE EVENING HOURS ON A WEEKEND EVENING OVER URBAN AREAS IS A CONCERN. PONDING OF WATER AND SOME STREET FLOODING COULD BE A PROBLEM ACROSS MOSTLY URBAN AREAS. EVENTUALLY THE LINE WILL BE NEARLY OUT OF THE AREA BY 10-13Z AS THE FORWARD MOTION TAKES IT INTO NORTHERN MO AND SOUTHEAST IA BY 13Z. THE REMAINDER OF THE FORECAST IS FAIRLY BENIGN. ONCE THE VIGOROUS H500 TROUGH MOVE EAST INTO THE GREAT LAKES SUNDAY INTO MONDAY MUCH COOLER AND DRIER WEATHER WILL BE EXPECTED FROM SUNDAY THROUGH TUESDAY. A GRADUAL WARMING TREND IS EXPECTED FROM WEDNESDAY THROUGH FRIDAY WITH A WEAK WAVE IMPACTING THE REGION ON THURSDAY. HIGHS WILL WARM FROM THE LOWER TO MID 70S EARLY IN THE PERIOD TO THE MID 70S TO LOWER 80S LATE IN THE PERIOD. LOWS RECOVER FROM THE 40S/50S TO THE 50S/60S LATER IN THE PERIOD. && .AVIATION...22/06Z ISSUED AT 1158 PM CDT FRI AUG 21 2015 LOW VFR OR MVFR CEILINGS MAY ENTER WESTERN SITES NEAR 12Z...THOUGH HAVE NOT INCLUDED MENTION ATTM DUE TO UNCERTAINTIES. WINDS WILL REMAIN SOUTHERLY AND WILL BE GUSTY DURING THE DAY SATURDAY WITH GUSTS UP TO 30KTS POSSIBLE. BOUNDARY WILL BEGIN TO IMPACT SITES NEAR 00Z...BRINGING CHANCES FOR TSRA TO SITES. TSRA MAY BRING MVFR OR LOWER CEILINGS AND VISIBILITIES FOR END OF PERIOD...WITH WINDS BECOMING WESTERLY BEHIND BOUNDARY. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...AWB  FXUS63 KDMX 220959 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 459 AM CDT TUE SEP 22 2015 .SHORT TERM /TODAY/... ISSUED AT 457 AM CDT TUE SEP 22 2015 PRIMARY QUESTION TODAY WILL BE ONSET OF PRECIP...IF ANY. STRONG ONTARIO SHORT WAVE/PV ANOMALY CONTINUES TO PUSH COLD FRONT THROUGH MN WITH ISALLOBARIC MAX TOWARD THE CANADIAN BORDER. MODELS SUGGEST THE FRONT WILL BRIEFLY DRIFT INTO NRN IA BEFORE WAVE DEPARTS AND HEIGHT RISES EVENTUALLY DIFFUSE IT AND PUSH WHAT IS LEFT OF THE BOUNDARY NWD AGAIN. LOW LEVEL MOISTURE CONVERGENCE IS CURRENTLY STRONG BUT SOUNDINGS SHOW LITTLE HOPE OF ANY SURFACE BASED DEVELOPMENT DUE TO INVERSION. LOW LEVELS EVENTUALLY MIX BY AFTERNOON...BUT WARM LAYER AROUND 2KM SHOULD KEEP ANYTHING MORE THAN CU FROM FORMING WITH CONVERGENCE WEAKENING SIMULTANEOUSLY. ELEVATED POTENTIAL LOOKS MINIMAL INITIALLY AS WELL WITH MOISTURE LACKING. SOUNDINGS QUITE DRY ABOVE 2KM. H7/H85 MOISTURE...THETA-E ADVECTION AND FRONTOGENETICAL FORCING DO INCREASE SOMEWHAT INTO WRN IA BY AFTERNOON HOWEVER. THUS FORECAST IS ESSENTIALLY DRY OUTSIDE OF SLIGHT CHANCES STARTING IN W CENTRAL IA BY LATE AFTERNOON. MODELS SUGGEST STRATUS WILL MAINTAIN OR POSSIBLY EXPAND INTO THE MORNING BEFORE MIXING OUT SOMEWHAT SOUTH. STRATUS MAY LINGER LONGER NORTH IN THE VICINITY OF THE BOUNDARY HOWEVER SO HAVE HIT CLOUD WORDING STRONGER THERE. GENERAL LOW LEVEL WARM ADVECTION REGIME WILL CONTINUE BUT LOW CLOUDS WILL MAKE THE DEGREE OF ADDITIONAL WARMING ABOVE PERSISTENCE PROBLEMATIC. THUS HAVE AT OR JUST BELOW PERSISTENCE NORTH AND SEVERAL DEGREES WARMER SOUTH. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 457 AM CDT TUE SEP 22 2015 RELATIVELY QUIET WEATHER FOR THE LONG TERM CONTINUES. WEDNESDAY INTO THURSDAY LOOKS LIKE THE ONLY "ACTIVE" PERIOD IN THIS FCST. WEDNESDAY AND THURSDAY... 06Z TUE WATER VAPOR IMAGERY PICKING UP ON MOISTURE FROM THE REMNANTS OF DECAYING TROPICAL DEPRESSION 16-E ADVANCING OVER THE SW CONUS. UPSTREAM IS A MID-LEVEL CUT-OFF LOW WHICH IS PHASING IN ENERGY WITH THE TROPICAL SYSTEM. THIS SYSTEM BECOMES POSITIVELY TILTED AS IT PROPAGATES NEWARD TOWARDS THE MIDWEST. THROUGHOUT THIS SEASON...MODELS HAVE GENERALLY UNDERDONE QPF WITH SYSTEMS THAT TAP INTO ENERGY/MOISTURE BEING ADVECTED ACROSS THE SW CONUS INTO IOWA. DIFFERENCE IN THIS EVENT IS THAT THERE WILL BE A NOTABLE LACK OF REINFORCING MOISTURE TRANSPORT FROM THE GULF OF MEXICO AS EASTERLY FLOW WILL BE PRESENT ACROSS THE SOUTHEASTERN CONUS. 00Z TUE MODEL RUNS IN GOOD AGREEMENT WITH SQUEEZING OUT PWATS IN THE 1.5 TO 1.75 INCH RANGE...OR +1 TO +2 STD DEV. WITH THE EXCEPTION OF DAYTIME HEATING WEDNESDAY...CAPE NOT THE STRONGEST. DURING DAYTIME HEATING HOURS...WESTERN IOWA HAS CAPE VALUES IN THE 1500 TO 2000 J/KG RANGE. WHILE INSTABILITY PRESENT...LACK OF STRONG FORCING MECHANISM PLUS 0-6KM BULK SHEAR VALUES LESS THAN 30 KTS WILL EFFECTIVELY NULLIFY SVR WX CHANCES AS STORMS WILL STRUGGLE TO ORGANIZE ENOUGH TO BECOME SVR. FOR EXCESSIVE RAINFALL POTENTIAL IN DMX CWA...WARM CLOUD DEPTHS IN THE 10 TO 12KFT RANGE...PLUS AFOREMENTIONED PWATS...WITH MARGINAL CAPE VALUES SUGGEST LOWER CHANCES FOR EXCESSIVE RAINFALL. BY LATE THURSDAY...THIS SYSTEM ESSENTIALLY LOSES ITS ENERGY AND HIGH PRESSURE TAKES OVER FROM THE EAST. FRIDAY THROUGH MONDAY... HIGH PRESSURE WILL KEEP US DRY. MSLP IS IN THE +1 TO +2 STD DEV RANGE. 850MB TEMPS NEAR 0 STD DEV INITIALLY SUGGEST NEAR NORMAL TEMPERATURES DURING THIS TIME PERIOD. FURTHER EXAMINATION HOLDS PERSISTENT 850MB TEMPS IN THE 13 TO 16C RANGE. THUS HAVE GONE IN THE MID 70S TO LOW 80S. MONDAY AND BEYOND...THE GFS AND EURO VARY WILDLY. THE EURO BRINGS A HIGH THROUGH SOUTHERN SASKATCHEWAN/MANITOBA INTO THE CONUS...WHICH WOULD BRING BIG TIME CAA TO IOWA. THE GFS HAS THE COMPLETE OPPOSITE AND WAA INTO IOWA. WILL STICK WITH PERSISTENCE UNTIL PROVEN OTHERWISE. && .AVIATION...22/06Z ISSUED AT 1154 PM CDT MON SEP 21 2015 STRATUS DECK EXPANDING OVER CENTRAL IOWA THIS EVENING WITH A MIX OF MVFR AND VFR CIGS. LOW LEVEL MOISTURE ADVECTION OVERNIGHT SUGGESTS CIGS SHOULD LOWER TO POSSIBLY IFR OVER THE NORTH. GUIDANCE STILL ROBUST ON LOWERING VSBYS DUE TO FOG OVERNIGHT. HAVE LOWERED VSBYS BUT NOT TO THE EXTENT OF GUIDANCE. CIGS WILL GRADUALLY SCATTER ON TUESDAY. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMALL LONG TERM...KOTENBERG AVIATION...DONAVON  FXUS63 KDMX 221139 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 639 AM CDT SAT AUG 22 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TODAY/... ISSUED AT 327 AM CDT SAT AUG 22 2015 A VERY POTENT 500MB TROUGH WILL CONTINUE TO DEEPEN THROUGHOUT THE DAY AS EJECTS OUT OF THE NORTHERN ROCKIES INTO THE DAKOTAS THIS AFTERNOON. THE SURFACE LOW LOOKS TO DEVELOP AND STRENGTHEN OVER THE EASTERN PORTIONS OF THE DAKOTAS WITH A SHARP COLD FRONT EXTENDING SOUTHWARD INTO NEBRASKA BY MIDDAY TODAY AND THEN TRANSITION SOUTHEAST INTO NORTHWEST IOWA LATE IN THE PERIOD. TROUGH BECOMES NEGATIVELY TILTED BY AROUND 00Z SUNDAY. THERE IS A LOW POTENTIAL FOR SOME ELEVATED STORMS TO TRY AND DEVELOP OVER WESTERN TO NORTHWEST PORTIONS OF IOWA AHEAD OF THE COLD FRONT...BUT WITH A VERY STRONG CAP IN PLACE...HAVE LOW CONFIDENCE WITH ANYTHING WIDESPREAD AND THUS ANY SEVERE WX PRIOR TO THE FROPA AND LEFT FORECAST DRY UNTIL 21Z. THE HIRES 22.00Z ARW/NMM...22.00Z NSSL-WRF...22.05Z HRRR AND COUPLE MEMBERS OF THE 22.03Z HOPWRF ALL SUGGEST CONVECTIVE INITIATION B/T 21-23Z OVER FAR NORTHWEST IOWA. ACROSS THE WEST TO NORTHWEST SECTIONS OF THE FORECAST AREA...DEEP LAYER SHEAR INCREASES TO 40-45 KNOTS PAST 21Z WITH 0-1KM AND 0-3KM SHEAR BOTH IN THE 20-30 KNOT RANGE. STRONG SURFACE BASE CAPE INCREASES TO 3000-3800 J/KG WITH STEEP LAPSE RATES IN THE 7.5-8 C/KM RANGE. LCL HEIGHTS AROUND 600M IN THE WARM SECTOR AND EXPECTING DISCRETE SUPERCELLS WITH INITIATION THIS AFTERNOON. HOWEVER...THE MOST LIKELY SCENARIO IS STORMS LOOK TO QUICKLY EVOLVE INTO QLCS SQUALL LINE BY TIME THEY MOVE INTO THE FORECAST AREA. THERE IS A POTENTIAL FOR SUPERCELLS TO CREEP INTO THE FAR WESTERN TO NORTHWESTERN EDGES OF THE FORECAST AREA (DENISON TO ESTHERVILLE LINE) PRIOR TO THE SQUALL LINE EVOLUTION...AND HAVE POPS INTRODUCED BY 21Z. ALL MODES OF SEVERE WEATHER POSSIBLE LATE THIS AFTERNOON...WITH TORNADIC AND LARGE HAIL POTENTIAL UPON INITIATION AND THEN MORE LIKELY DAMAGING WINDS WITH THE SUPERCELLS EVOLVING INTO QLCS. CERTAINLY CANNOT RULE TORNADIC POTENTIAL WITHIN THE QLCS LATE IN THE PERIOD. REGARDLESS...HAVE SEVERE MENTIONED PAST 21Z IN THE FAR NORTHWEST TO COINCIDE WITH SPC ENHANCED RISK AREA. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 327 AM CDT SAT AUG 22 2015 ONGOING SEVERE WEATHER AND HEAVY RAINFALL EXPECTED EARLY IN THE FIRST PERIOD. SEVERAL FACTORS POINT TO A ROBUST LINE OF CONVECTION THIS EVENING. A STRONG COLD FRONT WITH IMPRESSIVE SFC CONVERGENCE ...STRONG INSTABILITY/HIGH PRECIPITABLE WATER AND APPROACHING H500 WAVE WILL COMBINE TO ENHANCE CONVECTION THROUGH AT LEAST 06Z. MAIN CONCERNS AFTER 02Z WILL BE THREAT FOR WIND/HAIL AND HEAVY RAINFALL. GFS BUFR SOUNDINGS AT 00Z SHOW 0-3KM SRH ABOUT 200-300 J/KG AT KDSM AS THE LINE REACHES CENTRAL IA AT THAT TIME WITH STORM RELATIVE HELICITY WEAKENING TOWARD 06Z IN THE SOUTHEAST. SBCAPE IS PROGGED TO BE 2750 WITH LCL OF NEAR 692M/2000FT. INITIALLY THE THREAT THROUGH ABOUT I35 WILL STILL INCLUDE THE RISK OF A TORNADO THOUGH ANY DISCRETE SUPERCELLS IN THE LATE AFTERNOON SHOULD BE EVOLVING INTO A MORE LINEAR AND ACCELERATING LINE OF STORMS AS IT MOVES MORE RAPIDLY SOUTHEAST WITH TIME. THROUGH THE EVENING HOURS THE THREAT FOR SEVERE WEATHER WILL GRADUALLY WEAKEN AS BOTH CAPE AND HELICITY BEGIN TO LESSEN WITH TIME. THE OTHER CONCERN WITH THIS EVENT WILL BE BRIEF BUT VERY HEAVY RAINFALL. SUBJECTIVE 00Z SATURDAY H850 ANALYSIS THIS EVENING SHOWS A +15C PLUME OF MOISTURE FROM THE TEXAS COAST UP INTO CENTRAL/WESTERN NEBRASKA. THE GFS IS FORECASTING PRECIPITABLE WATER OF UP TO 1.7 INCHES ALONG THE BOUNDARY IN WESTERN IA AT 18Z...AND A MORE BROAD AREA OF 1.75 TO AROUND 2 INCHES FROM CENTRAL THROUGH SOUTHEAST IA FROM 00-06Z TONIGHT. THIS COMBINED WITH AN EXPECTED WARM CLOUD DEPTH OF 3600-3800M (>12KFT) OVER WESTERN IOWA...INCREASING TO OVER 4000M (>13KFT) FROM TAMA TO DECATUR COUNTY BY 06Z WILL PROMOTE INCREASINGLY EFFICIENT RAINFALL AS THE LINE BECOMES MORE ORGANIZED AND 0-6KM BULK SHEAR 50-60KTS BEHIND THE BOUNDARY CATCHES UP TO THE LINE FROM 03-06Z. NMM MOISTURE CONVERGENCE AND MOISTURE TRANSPORT VECTORS ARE BOTH MAXIMIZED AT THIS TIME OVER CENTRAL/SOUTHERN IOWA. FOR NOW AM ANTICIPATING AT LEAST A PERIOD OF 1-2 HOURS OF 1-2 INCH RAINFALL/HOUR MAINLY FROM 03-06Z FROM NEAR AMES SOUTHWEST TO CRESTON/LAMONI OR GENERALLY SOUTH OF HIGHWAY 30 AND ALONG AND WEST OF I35. CURRENT 1HR GRIDDED FLASH FLOOD GUIDANCE IS RUNNING ABOUT 1.75 TO NEARLY 2 INCHES OVER MOST OF THIS REGION AND HIGH ENOUGH TO AVOID A HEADLINE FOR FLASH FLOODING. HOWEVER...THE TIMING OF THE RAINFALL AND LIKELIHOOD THAT IT WILL FALL DURING THE LATE EVENING HOURS ON A WEEKEND EVENING OVER URBAN AREAS IS A CONCERN. PONDING OF WATER AND SOME STREET FLOODING COULD BE A PROBLEM ACROSS MOSTLY URBAN AREAS. EVENTUALLY THE LINE WILL BE NEARLY OUT OF THE AREA BY 10-13Z AS THE FORWARD MOTION TAKES IT INTO NORTHERN MO AND SOUTHEAST IA BY 13Z. THE REMAINDER OF THE FORECAST IS FAIRLY BENIGN. ONCE THE VIGOROUS H500 TROUGH MOVE EAST INTO THE GREAT LAKES SUNDAY INTO MONDAY MUCH COOLER AND DRIER WEATHER WILL BE EXPECTED FROM SUNDAY THROUGH TUESDAY. A GRADUAL WARMING TREND IS EXPECTED FROM WEDNESDAY THROUGH FRIDAY WITH A WEAK WAVE IMPACTING THE REGION ON THURSDAY. HIGHS WILL WARM FROM THE LOWER TO MID 70S EARLY IN THE PERIOD TO THE MID 70S TO LOWER 80S LATE IN THE PERIOD. LOWS RECOVER FROM THE 40S/50S TO THE 50S/60S LATER IN THE PERIOD. && .AVIATION...22/12Z ISSUED AT 636 AM CDT SAT AUG 22 2015 WINDY CONDITIONS EXPECTED LATER THIS MORNING INTO THE AFTERNOON HOURS AS GOOD MIXING AND STRONG PRESSURE GRADIENT DEVELOP. INCREASED SUSTAINED AND GUSTS ACROSS ALL TAF SITES. INTRODUCED IFR VIS AND LOWER MVFR CIGS FOR LATE THIS AFTERNOON INTO THE EVENING FOR TIMING OF STORMS. NO SEVERE WINDS MENTIONED ATTM BUT CERTAINLY THE BEST POTENTIAL IS AT MCW/FOD/DSM. WEST TO NORTHWEST WINDS DEVELOP BEHIND THE COLD FRONT LATE TONIGHT. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...PODRAZIK  FXUS63 KDMX 221154 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 654 AM CDT TUE SEP 22 2015 .SHORT TERM /TODAY/... ISSUED AT 457 AM CDT TUE SEP 22 2015 PRIMARY QUESTION TODAY WILL BE ONSET OF PRECIP...IF ANY. STRONG ONTARIO SHORT WAVE/PV ANOMALY CONTINUES TO PUSH COLD FRONT THROUGH MN WITH ISALLOBARIC MAX TOWARD THE CANADIAN BORDER. MODELS SUGGEST THE FRONT WILL BRIEFLY DRIFT INTO NRN IA BEFORE WAVE DEPARTS AND HEIGHT RISES EVENTUALLY DIFFUSE IT AND PUSH WHAT IS LEFT OF THE BOUNDARY NWD AGAIN. LOW LEVEL MOISTURE CONVERGENCE IS CURRENTLY STRONG BUT SOUNDINGS SHOW LITTLE HOPE OF ANY SURFACE BASED DEVELOPMENT DUE TO INVERSION. LOW LEVELS EVENTUALLY MIX BY AFTERNOON...BUT WARM LAYER AROUND 2KM SHOULD KEEP ANYTHING MORE THAN CU FROM FORMING WITH CONVERGENCE WEAKENING SIMULTANEOUSLY. ELEVATED POTENTIAL LOOKS MINIMAL INITIALLY AS WELL WITH MOISTURE LACKING. SOUNDINGS QUITE DRY ABOVE 2KM. H7/H85 MOISTURE...THETA-E ADVECTION AND FRONTOGENETICAL FORCING DO INCREASE SOMEWHAT INTO WRN IA BY AFTERNOON HOWEVER. THUS FORECAST IS ESSENTIALLY DRY OUTSIDE OF SLIGHT CHANCES STARTING IN W CENTRAL IA BY LATE AFTERNOON. MODELS SUGGEST STRATUS WILL MAINTAIN OR POSSIBLY EXPAND INTO THE MORNING BEFORE MIXING OUT SOMEWHAT SOUTH. STRATUS MAY LINGER LONGER NORTH IN THE VICINITY OF THE BOUNDARY HOWEVER SO HAVE HIT CLOUD WORDING STRONGER THERE. GENERAL LOW LEVEL WARM ADVECTION REGIME WILL CONTINUE BUT LOW CLOUDS WILL MAKE THE DEGREE OF ADDITIONAL WARMING ABOVE PERSISTENCE PROBLEMATIC. THUS HAVE AT OR JUST BELOW PERSISTENCE NORTH AND SEVERAL DEGREES WARMER SOUTH. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 457 AM CDT TUE SEP 22 2015 RELATIVELY QUIET WEATHER FOR THE LONG TERM CONTINUES. WEDNESDAY INTO THURSDAY LOOKS LIKE THE ONLY "ACTIVE" PERIOD IN THIS FCST. WEDNESDAY AND THURSDAY... 06Z TUE WATER VAPOR IMAGERY PICKING UP ON MOISTURE FROM THE REMNANTS OF DECAYING TROPICAL DEPRESSION 16-E ADVANCING OVER THE SW CONUS. UPSTREAM IS A MID-LEVEL CUT-OFF LOW WHICH IS PHASING IN ENERGY WITH THE TROPICAL SYSTEM. THIS SYSTEM BECOMES POSITIVELY TILTED AS IT PROPAGATES NEWARD TOWARDS THE MIDWEST. THROUGHOUT THIS SEASON...MODELS HAVE GENERALLY UNDERDONE QPF WITH SYSTEMS THAT TAP INTO ENERGY/MOISTURE BEING ADVECTED ACROSS THE SW CONUS INTO IOWA. DIFFERENCE IN THIS EVENT IS THAT THERE WILL BE A NOTABLE LACK OF REINFORCING MOISTURE TRANSPORT FROM THE GULF OF MEXICO AS EASTERLY FLOW WILL BE PRESENT ACROSS THE SOUTHEASTERN CONUS. 00Z TUE MODEL RUNS IN GOOD AGREEMENT WITH SQUEEZING OUT PWATS IN THE 1.5 TO 1.75 INCH RANGE...OR +1 TO +2 STD DEV. WITH THE EXCEPTION OF DAYTIME HEATING WEDNESDAY...CAPE NOT THE STRONGEST. DURING DAYTIME HEATING HOURS...WESTERN IOWA HAS CAPE VALUES IN THE 1500 TO 2000 J/KG RANGE. WHILE INSTABILITY PRESENT...LACK OF STRONG FORCING MECHANISM PLUS 0-6KM BULK SHEAR VALUES LESS THAN 30 KTS WILL EFFECTIVELY NULLIFY SVR WX CHANCES AS STORMS WILL STRUGGLE TO ORGANIZE ENOUGH TO BECOME SVR. FOR EXCESSIVE RAINFALL POTENTIAL IN DMX CWA...WARM CLOUD DEPTHS IN THE 10 TO 12KFT RANGE...PLUS AFOREMENTIONED PWATS...WITH MARGINAL CAPE VALUES SUGGEST LOWER CHANCES FOR EXCESSIVE RAINFALL. BY LATE THURSDAY...THIS SYSTEM ESSENTIALLY LOSES ITS ENERGY AND HIGH PRESSURE TAKES OVER FROM THE EAST. FRIDAY THROUGH MONDAY... HIGH PRESSURE WILL KEEP US DRY. MSLP IS IN THE +1 TO +2 STD DEV RANGE. 850MB TEMPS NEAR 0 STD DEV INITIALLY SUGGEST NEAR NORMAL TEMPERATURES DURING THIS TIME PERIOD. FURTHER EXAMINATION HOLDS PERSISTENT 850MB TEMPS IN THE 13 TO 16C RANGE. THUS HAVE GONE IN THE MID 70S TO LOW 80S. MONDAY AND BEYOND...THE GFS AND EURO VARY WILDLY. THE EURO BRINGS A HIGH THROUGH SOUTHERN SASKATCHEWAN/MANITOBA INTO THE CONUS...WHICH WOULD BRING BIG TIME CAA TO IOWA. THE GFS HAS THE COMPLETE OPPOSITE AND WAA INTO IOWA. WILL STICK WITH PERSISTENCE UNTIL PROVEN OTHERWISE. && .AVIATION...22/12Z ISSUED AT 654 AM CDT TUE SEP 22 2015 PRIMARY CONCERN WILL BE STRATUS TRENDS THROUGH THE PERIOD AND PROGRESSION OF CURRENT SUB MVFR CONDITIONS OVER WRN IA IN PARTICULAR. EXPECT THESE TO IMPROVE GRADUALLY THROUGH THE MORNING WITH LITTLE CHANGE IN VFR CIGS FARTHER EAST OVER TAF SITES. CONFIDENCE IS NOT HIGH...BUT EXPECT VFR CIGS TO CONTINUE AT MOST SITES INTO THE NIGHT. KFOD WOULD BE THE MOST SUSCEPTIBLE TO DEGRADED CONDITIONS...BUT CONFIDENCE IS NOT THERE TO INCLUDE AS OF YET. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SMALL LONG TERM...KOTENBERG AVIATION...SMALL  FXUS63 KDMX 221810 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 110 PM CDT SAT AUG 22 2015 .UPDATE... ISSUED AT 108 PM CDT SAT AUG 22 2015 SEVERE WEATHER POTENTIAL REMAINS ON TRACK FOR LATER TODAY AND TONIGHT. SFC COLD FRONT IS MOVING THROUGH THE EASTERN DAKOTAS AND NEBRASKA EARLY THIS AFTERNOON. LATEST VISIBLE SATELLITE IMAGERY SHOWS SOME AGITATE CUMULUS ALONG AND AHEAD OF THE BOUNDARY HOWEVER THE AIRMASS REMAINS CAPPED THROUGH THE AREA. A VIGOROUS SHORT WAVE IS TRAILING OVER TO THE WEST AND SHOULD CATCH UP TO THE BOUNDARY BY MID TO LATE AFTERNOON. THIS SYSTEM HAS AN ASSOCIATED 90 KT UPPER LEVEL JET AND COMBINED...WILL BRING STRONG QG FORCING AND UPPER LEVEL DIVERGENCE ALONG WITH COOLING MID LEVELS THAT WILL ERODE THE CAP AND FORCE ASCENT. IN ADDITION...INCREASING LOW TO UPPER LEVEL SHEAR WILL OCCUR DURING THIS TIME SUPPORTING STRONG ORGANIZED UPDRAFTS SUPPORTIVE OF SUPERCELLS INITIALLY AND BRING AN INCREASING TORNADO THREAT. THE STORMS SHOULD EVOLVE INTO QLCS LINEAR SYSTEM AS IT MOVES INTO CENTRAL IOWA. THE SYSTEM SHOULD MAINTAIN AN ATTENDANT TORNADO THREAT WITH ESRH VALUES AT 200-300 M2/S2 AND 0-3 KM LINE NORMAL SHEAR NEAR 30KTS. DAMAGING WINDS TO 70 MPH WILL ALSO BE POSSIBLE ALONG WITH LARGE HAIL. TIMING WISE...EXPECT THUNDERSTORMS TO DEVELOP OVER WESTERN IOWA ROUGHLY 4-5 PM THEN SPREAD EASTWARD THROUGH THE EVENING AND REACHING DSM METRO IN THE 7-9 PM TIME WINDOW THEN TOWARDS THE EAST 9 PM- MIDNIGHT. && .SHORT TERM /TODAY/... ISSUED AT 327 AM CDT SAT AUG 22 2015 A VERY POTENT 500MB TROUGH WILL CONTINUE TO DEEPEN THROUGHOUT THE DAY AS EJECTS OUT OF THE NORTHERN ROCKIES INTO THE DAKOTAS THIS AFTERNOON. THE SURFACE LOW LOOKS TO DEVELOP AND STRENGTHEN OVER THE EASTERN PORTIONS OF THE DAKOTAS WITH A SHARP COLD FRONT EXTENDING SOUTHWARD INTO NEBRASKA BY MIDDAY TODAY AND THEN TRANSITION SOUTHEAST INTO NORTHWEST IOWA LATE IN THE PERIOD. TROUGH BECOMES NEGATIVELY TILTED BY AROUND 00Z SUNDAY. THERE IS A LOW POTENTIAL FOR SOME ELEVATED STORMS TO TRY AND DEVELOP OVER WESTERN TO NORTHWEST PORTIONS OF IOWA AHEAD OF THE COLD FRONT...BUT WITH A VERY STRONG CAP IN PLACE...HAVE LOW CONFIDENCE WITH ANYTHING WIDESPREAD AND THUS ANY SEVERE WX PRIOR TO THE FROPA AND LEFT FORECAST DRY UNTIL 21Z. THE HIRES 22.00Z ARW/NMM...22.00Z NSSL-WRF...22.05Z HRRR AND COUPLE MEMBERS OF THE 22.03Z HOPWRF ALL SUGGEST CONVECTIVE INITIATION B/T 21-23Z OVER FAR NORTHWEST IOWA. ACROSS THE WEST TO NORTHWEST SECTIONS OF THE FORECAST AREA...DEEP LAYER SHEAR INCREASES TO 40-45 KNOTS PAST 21Z WITH 0-1KM AND 0-3KM SHEAR BOTH IN THE 20-30 KNOT RANGE. STRONG SURFACE BASE CAPE INCREASES TO 3000-3800 J/KG WITH STEEP LAPSE RATES IN THE 7.5-8 C/KM RANGE. LCL HEIGHTS AROUND 600M IN THE WARM SECTOR AND EXPECTING DISCRETE SUPERCELLS WITH INITIATION THIS AFTERNOON. HOWEVER...THE MOST LIKELY SCENARIO IS STORMS LOOK TO QUICKLY EVOLVE INTO QLCS SQUALL LINE BY TIME THEY MOVE INTO THE FORECAST AREA. THERE IS A POTENTIAL FOR SUPERCELLS TO CREEP INTO THE FAR WESTERN TO NORTHWESTERN EDGES OF THE FORECAST AREA (DENISON TO ESTHERVILLE LINE) PRIOR TO THE SQUALL LINE EVOLUTION...AND HAVE POPS INTRODUCED BY 21Z. ALL MODES OF SEVERE WEATHER POSSIBLE LATE THIS AFTERNOON...WITH TORNADIC AND LARGE HAIL POTENTIAL UPON INITIATION AND THEN MORE LIKELY DAMAGING WINDS WITH THE SUPERCELLS EVOLVING INTO QLCS. CERTAINLY CANNOT RULE TORNADIC POTENTIAL WITHIN THE QLCS LATE IN THE PERIOD. REGARDLESS...HAVE SEVERE MENTIONED PAST 21Z IN THE FAR NORTHWEST TO COINCIDE WITH SPC ENHANCED RISK AREA. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 327 AM CDT SAT AUG 22 2015 ONGOING SEVERE WEATHER AND HEAVY RAINFALL EXPECTED EARLY IN THE FIRST PERIOD. SEVERAL FACTORS POINT TO A ROBUST LINE OF CONVECTION THIS EVENING. A STRONG COLD FRONT WITH IMPRESSIVE SFC CONVERGENCE ...STRONG INSTABILITY/HIGH PRECIPITABLE WATER AND APPROACHING H500 WAVE WILL COMBINE TO ENHANCE CONVECTION THROUGH AT LEAST 06Z. MAIN CONCERNS AFTER 02Z WILL BE THREAT FOR WIND/HAIL AND HEAVY RAINFALL. GFS BUFR SOUNDINGS AT 00Z SHOW 0-3KM SRH ABOUT 200-300 J/KG AT KDSM AS THE LINE REACHES CENTRAL IA AT THAT TIME WITH STORM RELATIVE HELICITY WEAKENING TOWARD 06Z IN THE SOUTHEAST. SBCAPE IS PROGGED TO BE 2750 WITH LCL OF NEAR 692M/2000FT. INITIALLY THE THREAT THROUGH ABOUT I35 WILL STILL INCLUDE THE RISK OF A TORNADO THOUGH ANY DISCRETE SUPERCELLS IN THE LATE AFTERNOON SHOULD BE EVOLVING INTO A MORE LINEAR AND ACCELERATING LINE OF STORMS AS IT MOVES MORE RAPIDLY SOUTHEAST WITH TIME. THROUGH THE EVENING HOURS THE THREAT FOR SEVERE WEATHER WILL GRADUALLY WEAKEN AS BOTH CAPE AND HELICITY BEGIN TO LESSEN WITH TIME. THE OTHER CONCERN WITH THIS EVENT WILL BE BRIEF BUT VERY HEAVY RAINFALL. SUBJECTIVE 00Z SATURDAY H850 ANALYSIS THIS EVENING SHOWS A +15C PLUME OF MOISTURE FROM THE TEXAS COAST UP INTO CENTRAL/WESTERN NEBRASKA. THE GFS IS FORECASTING PRECIPITABLE WATER OF UP TO 1.7 INCHES ALONG THE BOUNDARY IN WESTERN IA AT 18Z...AND A MORE BROAD AREA OF 1.75 TO AROUND 2 INCHES FROM CENTRAL THROUGH SOUTHEAST IA FROM 00-06Z TONIGHT. THIS COMBINED WITH AN EXPECTED WARM CLOUD DEPTH OF 3600-3800M (>12KFT) OVER WESTERN IOWA...INCREASING TO OVER 4000M (>13KFT) FROM TAMA TO DECATUR COUNTY BY 06Z WILL PROMOTE INCREASINGLY EFFICIENT RAINFALL AS THE LINE BECOMES MORE ORGANIZED AND 0-6KM BULK SHEAR 50-60KTS BEHIND THE BOUNDARY CATCHES UP TO THE LINE FROM 03-06Z. NMM MOISTURE CONVERGENCE AND MOISTURE TRANSPORT VECTORS ARE BOTH MAXIMIZED AT THIS TIME OVER CENTRAL/SOUTHERN IOWA. FOR NOW AM ANTICIPATING AT LEAST A PERIOD OF 1-2 HOURS OF 1-2 INCH RAINFALL/HOUR MAINLY FROM 03-06Z FROM NEAR AMES SOUTHWEST TO CRESTON/LAMONI OR GENERALLY SOUTH OF HIGHWAY 30 AND ALONG AND WEST OF I35. CURRENT 1HR GRIDDED FLASH FLOOD GUIDANCE IS RUNNING ABOUT 1.75 TO NEARLY 2 INCHES OVER MOST OF THIS REGION AND HIGH ENOUGH TO AVOID A HEADLINE FOR FLASH FLOODING. HOWEVER...THE TIMING OF THE RAINFALL AND LIKELIHOOD THAT IT WILL FALL DURING THE LATE EVENING HOURS ON A WEEKEND EVENING OVER URBAN AREAS IS A CONCERN. PONDING OF WATER AND SOME STREET FLOODING COULD BE A PROBLEM ACROSS MOSTLY URBAN AREAS. EVENTUALLY THE LINE WILL BE NEARLY OUT OF THE AREA BY 10-13Z AS THE FORWARD MOTION TAKES IT INTO NORTHERN MO AND SOUTHEAST IA BY 13Z. THE REMAINDER OF THE FORECAST IS FAIRLY BENIGN. ONCE THE VIGOROUS H500 TROUGH MOVE EAST INTO THE GREAT LAKES SUNDAY INTO MONDAY MUCH COOLER AND DRIER WEATHER WILL BE EXPECTED FROM SUNDAY THROUGH TUESDAY. A GRADUAL WARMING TREND IS EXPECTED FROM WEDNESDAY THROUGH FRIDAY WITH A WEAK WAVE IMPACTING THE REGION ON THURSDAY. HIGHS WILL WARM FROM THE LOWER TO MID 70S EARLY IN THE PERIOD TO THE MID 70S TO LOWER 80S LATE IN THE PERIOD. LOWS RECOVER FROM THE 40S/50S TO THE 50S/60S LATER IN THE PERIOD. && .AVIATION...22/18Z ISSUED AT 108 PM CDT SAT AUG 22 2015 AVIATION CONCERNS WILL REVOLVE AROUND THUNDERSTORM CHANCES THROUGH THE EVENING THEN GUSTY WINDS ON SUNDAY. LOCAL MVFR THROUGH THE AFTERNOON THEN EXPECT THUNDERSTORMS TO DEVELOP OVER WRN IA AFT 21Z. STRONG THUNDERSTORM WIND GUSTS FROM THE WEST APPROACHING 50 KTS MAY OCCUR. EXPECT MVFR CIGS WITH THUNDERSTORMS POSSIBLE DROPPING TO IFR IN LOCATIONS. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...DONAVON SHORT TERM...PODRAZIK LONG TERM...REV AVIATION...DONAVON  FXUS63 KDMX 230935 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 435 AM CDT WED SEP 23 2015 .SHORT TERM /TODAY/... ISSUED AT 401 AM CDT WED SEP 23 2015 OBVIOUS CONCERN TODAY WILL BE PRECIP TRENDS. CURRENT SITUATION HAS SRN END OF SIOUXLAND MCS SEEMINGLY ANCHORED IN PLACE WITH LOW LEVEL MOISTURE TRANSPORT BALANCING MEAN WIND. THIS RESULTS IN NEGLIGIBLE CORFIDI VECTORS AND SLOW CELL MOVEMENT. HOWEVER MORE WIDESPREAD AND ELEVATED WARM/THETA-E ADVECTION IS ALSO PUSHING NORTHWARD AND RESULTING IN EXPANSION ACROSS SD...BUT NOT FARTHER INTO NW IA AS OF YET. FEEL THIS WILL HAPPEN SOON HOWEVER SO HAVE POPS TO LIKELY DURING THE MORNING. LOOKING FARTHER UPSTREAM MOISTURE AND FAIRLY DEEP FORCING ASSOCIATED WITH TD REMNANTS BUILDS INTO WRN IA BY AFTERNOON. ALTHOUGH CLIMATOLOGICAL PERCENTILE EXTREMES ARE FARTHER WEST OF FORECAST AREA...STILL FEEL WARM CLOUD DEPTHS OVER 3.5KM AND PWATS PUSHING 1.75 WITHIN A ZONE OF STEADY MOISTURE TRANSPORT ARE MORE THAN SUFFICIENT FOR EFFICIENT RAINS. CONCERN IS THAT LEFT OVER CONVERGENCE FROM SIOUXLAND MCS WILL INTERACT WITH THIS APPROACHING FORCING AND MOISTURE TO PRODUCE HEAVY RAINS. HI RES HOPWRF AND NCAR ENSEMBLE NEIGHBORHOOD PROBABILITIES OF A FEW INCHES OF RAIN ARE QUITE HIGH INTO IA LATER TODAY SO HAVE ADDED HEAVY RAIN WORDING. THIS MAKES SENSE CONSIDERING THE ENVIRONMENT WITH MOISTURE TRANSPORT AND FAIRLY WEAK MEAN WIND PARALLEL THROUGH THE DAY. OUR NW COUNTIES ARE NOT TOPOGRAPHICALLY FAVORABLE FOR FLASH FLOODING AND HAVE DECENT TILING...BUT THREE HOUR FLASH FLOOD GUIDANCE VALUES ARE GENERALLY IN THE 2.5 TO 2.75 INCH RANGE. A FLASH FLOOD WATCH MAY NEED TO BE CONSIDERED IF CONFIDENCE IN THE EASTERN EXTENT OF HEAVY RAIN INCREASES. TEMP CONFIDENCE IS NOT THE GREATEST DUE TO PRECIP POTENTIAL. THERE MAY BE QUITE A GRADIENT NW-SE. KEPT NW IA IN THE MID 70S WITH SERN SECTIONS JUST A TAD BELOW PERSISTENCE. .LONG TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 401 AM CDT WED SEP 23 2015 THURSDAY INTO EARLY FRIDAY WILL BE THE HIGHLIGHT OF WHAT SHOULD BE A QUIET LONG TERM FCST PERIOD. PRECIP...AS HIGHLIGHTED IN THE SHORT TERM DISCUSSION...WILL LIKELY BE ONGOING IN OUR W/NW TO START THIS LONG TERM PERIOD. MODELS BEGINNING TO SHOW CONSISTENCY WITH HANDLING EVOLUTION OF THIS SYSTEM. GFS ON AN ISLAND OF ITS OWN WITH TRANSPORTING MOISTURE EAST AND NORTH INTO EASTERN IOWA SO HAVE LEANED AWAY FROM IT. EURO...UKMET...AND THE NAM HAVE BEEN STRONGLY ADVOCATING A MORE SOUTHERLY TRACK FOR THE SFC LOW. WITH THE GULF CLOSED...THIS SYSTEM IS LOSES ITS MOISTURE REINFORCEMENT AND GRADUALLY WEAKENS AFTER 12Z THU. PWAT VALUES WILL BE GRADUALLY DECREASING THROUGHOUT THURSDAY...BUT AFTER STARTING OFF ALMOST IN THE +2 TO +3 STD DEV RANGE EARLY ON...THERE WILL STILL BE ENOUGH MOISTURE PRESENT TO KICK OUT AT LEAST A QUARTER TO HALF AN INCH OF RAIN IN OUR WEST AS PRECIP EFFICIENCY SHOULD REMAIN DECENT. CAPE VALUES ALSO EFFECTIVELY DECREASE THROUGHOUT THURSDAY...SUGGESTING WEAKENING OF THIS SYSTEM. BULK SHEAR VALUES REMAIN UNDER 30 KTS...WHICH...WHEN COUPLED WITH DWINDLING INSTABILITY...NULLIFY SVR WX CHANCES FOR THURSDAY. FOR FRIDAY INTO THE WEEKEND...AN UPPER LEVEL RIDGE WILL MOVE ACROSS THE SOUTHWESTERN CONUS TOWARDS THE MIDWEST. SFC HIGH PRESSURE WILL BE LOCATED OVER THE GREAT LAKES AND WILL SERVE AS A PRECIP SHIELD FOR OUR CWA AS SUBSIDENCE SHOULD BE IN PLACE FOR A FEW DAYS. 850MB TEMPERATURES NEAR 15C LOOK TO BE AROUND 1 STD DEV ABOVE NORMAL AND SHOULD TRANSLATE TO DAYTIME HIGHS IN THE MID 70S TO LOW 80S. PERSISTENCE WILL PROVIDE A GOOD FCST STARTING POINT. BEYOND THIS WEEKEND...EURO AND GFS ACTUALLY COME INTO AGREEMENT WITH BRINGING A COLD FRONT THROUGH THE REGION SOMETIME LATE MONDAY INTO TUESDAY. THE GFS IS SIGNALING PWATS IN THE 1.5 INCH RANGE SO THIS APPEARS TO BE OUR NEXT BEST PRECIP CHANCE AFTER EARLY FRIDAY. BEHIND THE BOUNDARY...MUCH COOLER AIR BE ADVECTED INTO IOWA AS A SIZABLE AREA OF HIGH PRESSURE IS PROGGD TO SLIDE ACROSS THE NORTHERN GREAT PLAINS. 850MB TEMPS MAY REACH DOWN INTO THE SINGLE DIGITS...WHICH WOULD PUT LOWS IN THE UPPER 30S TO MID 40S AND HIGHS IN THE 60S. && .AVIATION...23/06Z ISSUED AT 1142 PM CDT TUE SEP 22 2015 MAIN CONCERN WILL BE PROGRESSION OF CONVECTION OVER NEBRASKA OVERNIGHT. WARM FRONT OVER NEBRASKA IS INITIATION AREA AND MOST OF THE CONVECTION WILL DROP SOUTHEAST OVERNIGHT. HIGH RES HRRR AND 00Z NAM BOTH SUGGEST THAT CONVECTION WILL GENERALLY HOLD OFF UNTIL 13-15Z OVER THE WEST AND SLOWLY BUILD NORTH WITH TIME. CIGS TO MAINLY REMAIN VFR. PATCHY BR WILL BE POSSIBLE BETWEEN 11-14Z. FOR MOST OF THE PERIOD CONVECTION WILL REMAIN WEST OF I35. SOUTHEAST WINDS INCREASE TO NEAR 12KTS WITH POTENTIAL FOR GUSTS 15-17KTS AFT 18Z. /REV && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMALL LONG TERM...KOTENBERG AVIATION...REV  FXUS63 KDMX 232042 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 342 PM CDT FRI OCT 23 2015 .SHORT TERM /TONIGHT/... ISSUED AT 342 PM CDT FRI OCT 23 2015 BROAD TROUGH TO CONTINUE ITS EASTWARD PROPAGATION ACROSS THE UPPER MIDWEST OVERNIGHT...EVENTUALLY MAKING IT E/NE OF THE DMX CWA TOWARDS THE END OF THE SHORT TERM FCST PERIOD. WITH SUFFICIENT SFC MOISTURE PROVIDED FROM MORNING PRECIP...WIDESPREAD FOG HAS ENVELOPED THE CWA...DROPPING VSBYS DOWN TO AROUND 1 TO 2 SM IN MANY PLACES. SEE NO REASON FOR FOG TO LIFT THIS EVENING AS SFC TEMPS WILL BEGIN TO COOL WITH SUNSET PLUS MOISTURE ADVECTION WITH APPROACHING LOW. PRECIP CHANCES...WILL BE ON THE INCREASE AFTER 00Z SAT AS THE ATTENDANT COLD FRONT PUSHES THROUGH IA. MODELS CONVERGING ON SOLN OF PUSHING FRONT EAST OF CWA BY AROUND 09Z SAT. PER USUAL...THE NAM MOST EXCITED FOR THUNDERSTORM CHANCES. REGARDLESS OF MODEL CHOICE...APPEARS TO BE ENOUGH INSTABILITY PRESENT FOR ISOLATED THUNDER WITH THIS FROPA. SFC MOISTURE CONV NOT THE BEST. PWATS AROUND 1.25 INCHES. CLOUD THICKNESS BTX 5KFT AND 7KFT. BASED UPON WIND/THERMO PROFILES...OVERRUNNING CONVECTION WILL NOT BE AN ISSUE TONIGHT. IN ALL...SLIGHTLY LESS IMPRESSIVE OF A SETUP THAN THIS MORNING/S WHICH YIELDED A WIDESPREAD QUARTER OF AN INCH...WITH SOME PLACES APPROACHING HALF AN INCH. AMOUNT-WISE ONE TENTH TO THE OCCASIONAL QUARTER OR SO OF AN INCH OF RAIN SEEMS REASONABLE FOR TONIGHT. WINDS BEHIND THE BOUNDARY WILL BE TOUCHED UPON IN THE LONG TERM...BUT WORTH MENTIONING THAT IT WILL BE GUSTY BEHIND THIS FRONT. BY 12Z SAT...WINDS COULD ALREADY BE GUSTING IN EXCESS OF 20KTS IN MUCH OF THE DMX CWA. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 342 PM CDT FRI OCT 23 2015 AFTER THE PASSAGE OF THE SYSTEM TONIGHT...FEW CONCERNS FOR THE NEXT SEVERAL DAYS. SUBJECTIVE ANALYSES THIS MORNING SHOW SFC LOW NEAR VALENTINE NEBRASKA AT 13Z WITH UPPER LEVEL LOW/TROUGH FROM THE NORTHERN PLAINS SOUTH TO THE GULF COAST. A RIDGE OF HIGH PRESSURE EXTENDS FROM HUDSON BAY CANADA SOUTH TO THE SOUTHEAST. THIS BLOCKING HIGH AS KEPT THE CENTRAL PLAINS LOW FROM MOVING MORE EAST...INSTEAD MOVING NORTHEAST/NORTH THROUGH SATURDAY MORNING. MODELS HAVE SLOWED THE SYSTEM DOWN BY ABOUT 6 HOURS. THIS MAY KEEP A SMALL CHANCE FOR SOME LIGHT SHOWER ACTIVITY IN NORTHEAST SECTIONS OF THE FORECAST AREA THROUGH ABOUT 15Z SATURDAY. AFTER THAT...HIGH PRESSURE BUILDS EAST AND WILL ALLOW FOR A RATHER TRANQUIL PERIOD OF WEATHER FROM SATURDAY THROUGH EARLY TUESDAY. THE MAIN BUT SUBTLE CHANGE OVER THE WEEKEND WILL BE A GRADUAL LOWERING OF HEIGHTS AS A LARGE ANCHOR LOW OVER EASTERN CANADA DEEPENS IN RESPONSE TO THE DEPARTING SYSTEM EARLY TOMORROW. WITH THE ANCHOR LOW IN PLACE...A WEAK SHORT WAVE TRACKING NEAR THE US CAN BORDER WILL SPREAD SLIGHTLY COOLER AIR INTO THE REGION BY MONDAY. GENERALLY TEMPERATURES WILL STILL BE ABOVE NORMAL THIS WEEKEND WITH HIGHS/LOWS ABOUT 2-3 DEGREES ABOVE NORMAL. THE BIGGER CHALLENGE THROUGH THE EXTENDED REMAINS NEXT WEEK. THERE REMAIN DIFFERENCES BETWEEN THE THREE SYNOPTIC SCALE MODELS... GFS/EURO/GEM WITH REGARD TO THE EVOLUTION OF THE PATTERN NEXT WEEK. CONFIDENCE STILL REMAINS LOWER FOR NOW. ITS QUITE RARE TO POTENTIALLY SEE REMNANTS OF A STRONG HURRICANE/EXTRA TROPICAL SYSTEM EVENTUALLY PHASING WITH BOTH THE NORTHERN/SOUTHERN NORTHERN HEMISPHERIC STREAMS. THIS IS THE REASON FOR THE WIDE VARIETY OF SOLUTIONS OVER THE PAST FEW DAYS. AS PATRICIA GOES EXTRA TROPICAL ACROSS THE MEXICO AS IT CROSSES THE SIERRA MADRE RANGE...IT IS EXPECTED TO REORGANIZE AS AN EXTRATROPICAL SYSTEM NEAR CORPUS CHRISTI/HOUSTON TEXAS AND REMAIN ALONG THE GULF COAST UNTIL MON/TUE. MEANWHILE TWO DISTINCT WAVES WILL BEGIN TO AFFECT THE WESTERN CONUS...ONE ENTERING THE PACNW THEN DIGGING SOUTHEAST TOWARD THE ROCKIES BY 12Z TUES AND ANOTHER STRONGER WAVE DROPPING SOUTH INTO THE NORTHERN ROCKIES ABOUT THE SAME TIME. MUCH OF NEXT WEEKS FORECAST DEPENDS ON WHEN/WHERE/IF THESE THREE FEATURES BEGIN TO PHASE. TODAY...THERE IS A HINT THAT OLD PATRICIA MAY DRIFT FARTHER NORTHEAST PRIOR TO PHASING. THIS WOULD RESULT IN A SLIGHTLY WEAKER AND FARTHER EAST PHASING OF THE THREE WAVES. REGARDLESS...A PERIOD OF ACTIVE WEATHER WITH PLENTY OF MOISTURE WILL AFFECT ABOUT THE EASTERN HALF OF THE NATION AS THIS PROCESS PASSES EAST OF IOWA. INDIVIDUALLY...THE 00Z EURO NOW HOLDS THE ARRIVAL OF THE FIRST ROUND OF FORCING UNTIL TUESDAY EVENING WHILE THE GFS ARRIVES ABOUT 6 TO 12 HOURS EARLIER AND THE CURRENT 12Z RUN SHOWING EVEN LESS PHASING DURING THE ENTIRE EVENT. THE 12Z EURO CONTINUES TO HOLD ONTO THE REMNANTS OF PATRICIA/EXTRA TROPICAL SYSTEM LONGER IN THE GULF THAN THE GFS AND THERE IS LITTLE NORTHEAST DRIFT IN THIS MORNINGS PACKAGE. THIS LEADS TO A SIMILAR SOLUTION AS YESTERDAYS 12Z RUN WITH A GENERAL PHASING OF THE 3 WAVES ACROSS THE MID MISSISSIPPI RIVER VALLEY BY 12Z THURSDAY BEFORE A MORE COMPLETE CYCLOGENISIS TAKES PLACE EAST OF THE REGION. FOR NOW HOLD ONTO A BLEND WITH SOME EMPHASIS ON THE EURO SINCE IT REMAINS MORE CONSISTENT FROM RUN TO RUN. STILL PLENTY OF PACKAGES AHEAD PRIOR TO ITS ARRIVAL. TIMING ASIDE A PERIOD OF RAIN AND BLUSTERY CONDITIONS IS EXPECTED FROM TUESDAY NIGHT THROUGH EARLY THURSDAY AS THE ENTIRE SYSTEM SLOWS DOWN WHILE PHASING. INITIALLY MILD AIR AT H850 ON TUESDAY MAY ALLOW FOR HIGHS TO REACH THE 50S TO LOWER 60S IF THE RAIN HOLDS OFF THROUGH EVENING. BY WEDNESDAY INTO THURSDAY HOWEVER...HIGHS MAY STRUGGLE TO REACH 50 OVER THE FORECAST AREA WITH LITTLE SUNSHINE AND ONLY A SMALL DIURNAL RANGE IN TEMPERATURE. FORTUNATELY BOTH THICKNESS AND H850 TEMPERATURES SUPPORT ALL LIQUID AT THIS TIME. WITH ANOTHER WAVE QUICKLY DROPPING SOUTHEAST FROM SASKATCHEWAN BY FRIDAY...THIS KICKER WAVE WILL HELP MAINTAIN A PROGRESSIVE FLOW WITH FRIDAY SEEING A DECENT CHANCE OF SUNSHINE WITH HIGHS IN THE 50S. && .AVIATION...23/18Z ISSUED AT 1240 PM CDT FRI OCT 23 2015 CHALLENGING TAF FCST AS CLOUD BASES AND VSBYS MEANDER BTX FLIGHT CATEGORIES. BY 18Z FRI...THE FIRST BAND OF PRECIP IS CLEARING NE OF OUR TAF SITES. SATELLITE IMAGERY SHOWING EXTENSIVE CLOUD COVER TO KEEP SKIES OVC. ROUND TWO OF PRECIP SHOULD BEGIN TO ARRIVE IN THE WEST AFTER 01Z...EXITING BY AROUND 09Z TO OUR EAST. CLOUD BASES GENERALLY HOVER BTX 500FT AND 1000FT AND VSBYS BTX 3SM AND 5SM DURING THIS TIME...WILL LIKELY NEED TO BE FINE TUNED AS PRECIP NEARS. TRIED TO CAPTURE EVENTUAL CLEARING EXPECTED SAT PM BY KICKING ALL TAF SITES TO VFR CONDITIONS BY THE END OF THE FCST PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KOTENBERG LONG TERM...REV AVIATION...KOTENBERG  FXUS63 KDMX 232115 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 415 PM CDT WED SEP 23 2015 .SHORT TERM /TONIGHT/... ISSUED AT 342 PM CDT WED SEP 23 2015 WIDESPREAD AND SLOW MOVING MORNING CONVECTION HAS WANED DURING THE COURSE OF THE LATE MORNING AND EARLY AFTERNOON HOURS...BUT NOT BEFORE DROPPING SWATHS OF AN ESTIMATED 3 TO 4 INCHES OF RAIN ACROSS PORTIONS OF TAYLOR...AUDUBON...AND CASS COUNTIES. WHILE THE BULK OF THE THERMODYNAMIC AND KINEMATIC FORCING WILL BE FOCUSED ACROSS NORTHWEST IOWA AND SOUTHEAST SOUTH DAKOTA TONIGHT WITH THE APPROACH OF THE MID LEVEL TROUGH...THERE IS STILL ENOUGH OF A CHANCE FOR RENEWED THUNDERSTORM DEVELOPMENT ALONG THE EASTERN FLANK OF THE LLJ TO WARRANT THE CONTINUATION OF THE FLASH FLOOD WATCH. DEEP TROPICAL MOISTURE REMAINS IN PLACE WITH PWATS IN THE 1.5 TO 1.7 INCH RANGE AND WARM CLOUD DEPTHS CLOSE TO 10 KFT. SLOW STORM MOTION CAN ALSO BE EXPECTED WITH CORFIDI VECTORS OF AROUND 5 KTS OR LESS. WHILE CONFIDENCE IN POPS IS LOW (AS REFLECTED IN THE GOING POP/QPF GRIDS)...THE THREAT STILL EXISTS AND WILL NEED TO BE MONITORED. SHOULD PRECIP FAIL TO MATERIALIZE THIS EVENING...THE WATCH CAN LIKELY BE CANCELLED EARLY. AS MENTIONED EARLIER...THE BEST CONCENTRATION OF STORMS AND HEAVY RAIN SHOULD FALL JUST TO THE NORTH AND WEST OF THE CWA TONIGHT THE 500MB WAVE/VORT MAX APPROACHES. STRONGEST FG FORCING JUST CLIPS THE NORTHWESTERN CWA DURING THE OVERNIGHT PERIOD AND HAVE THUS FOCUSED THE HIGHER POPS/QPF IN THIS LOCATION. DRY AIR BEING ADVECTED IN FROM THE EAST COMBINED WITH THE MID TO HIGH LEVEL CLOUDS WILL RESULT IN A RATHER LARGE SPREAD IN MIN TEMPERATURES TONIGHT IN EASTERN IOWA. DEWPOINTS IN THE LOW TO MID 50S HAVE BEEN SLOWLY WORKING INTO EASTERN IOWA AND SHOULD CONTINUE TO MIX ACROSS THE FAR EASTERN CWA. HOWEVER...WITH 500MB FLOW DIRECTED FROM THE CONVECTION TO THE NORTHWEST...THERE IS A STRONG LIKELIHOOD OF CIRRUS LIMITING THE RADIATIONAL COOLING. THE QUESTION BECOMES WHERE THIS CUTOFF WILL OCCUR. HAVE TRENDED DOWN TEMPS SLIGHTLY IN THE FAR EAST TO REFLECT THIS UNCERTAINTY. .LONG TERM /THURSDAY THROUGH WEDNESDAY/... ISSUED AT 342 PM CDT WED SEP 23 2015 THURSDAY INTO THURSDAY NIGHT QG FORCING REMAIN IMPRESSIVE OVER WESTERN IOWA THROUGH THE MORNING BEFORE BEGINNING TO WANE IN THE LATE AFTERNOON AND EVENING. MUCH LIKE TODAY...SHOWERS AND ISOLATED THUNDERSTORMS WILL MOVE ACROSS THE AREA WITH THE POTENTIAL FOR HEAVY RAINFALL. THE BEST POTENTIAL WILL REMAIN TO THE NORTHWEST BUT THE HEAVIEST SHOWERS OR STRONGEST STORMS WILL STILL HAVE THE POTENTIAL TO DROP A COUPLE OF INCHES AND IF THEY FALL OVER AN AREA THAT RECEIVES HEAVY RAINFALL FROM WEDNESDAY NIGHT THEN A POTENTIAL FOR SOME FLASH FLOODING EXISTS. AT THIS TIME OUR NW CWA DODGED MUCH OF THE RAINFALL SO IT APPEARS THEY CAN TAKE SOME RAINFALL BUT OVERNIGHT WILL TELL A BETTER STORY AS TO WHERE THE HEAVIEST RAINFALL WILL OCCUR FOR POSSIBLE EXPANSION OF THE FLASH FLOOD WATCH IN OUR AREA NORTHWARD AND IN TIME FOR THURSDAY MORNING AS WELL. ONCE THE SHORTWAVE LIFTS TO THE NORTHEAST LATER IN THE MORNING OUR HEAVY PRECIP POTENTIAL SHOULD LIFT NORTHEAST WITH IT. FOR FRIDAY INTO THE WEEKEND RIDGING BUILDS INT OTHER REGION. THE MODELS CONTINUE TO SHOW A SHORTWAVE DROPPING SOUTH TO THE WEST OF THE FORECAST AREA WHICH MAY AGAIN BRING A GLANCING SHOT OF PRECIP TO WESTERN PORTIONS OF THE FORECAST AREA FRIDAY MORNING. AFTER THAT A BEAUTIFUL WEEKEND IS IN STORE WITH DRY AND MILD CONDITIONS EXPECTED FOR CENTRAL IOWA. BEYOND THE WEEKEND...THE FORECAST BECOMES MORE UNCERTAIN AS MODELS DIFFER IN HOW THEY HANDLE THE PASSAGE OF A FRONTAL BOUNDARY. THE GFS DROPS THE FRONT FURTHER SOUTH AND STALLS IT SOMEWHERE OVER CENTRAL IOWA FINALLY PUSHING IT THROUGH ON WEDNESDAY. THE EURO BRINGS THE FRONT THROUGH A LITTLE FASTER ON TUESDAY WITH A SHORTWAVE DROPPING DOWN THE FLOW IN WEDNESDAY. TEMPS WILL BE A CHALLENGE DUE TO FRONTAL POSITION BUT PRECIP CHANCES WILL REMAIN ACROSS THE AREA FOR DIFFERENT REASONS. TEMPS WISE I WENT WITH A BLEND BETWEEN THE COOLER EURO AND THE WARMER GFS FOR TUESDAY THEN COOLER FOR WEDNESDAY. I WENT COOLER THAN THE GFS PRIMARILY DUE TO CLOUDS ON PRECIP. MY CONFIDENCE IS LOW HOWEVER ON THE FRONTAL POSITION SO I DID NOT GO AS COOL AS SOME MODELS WERE SUGGESTING. BY WEDNESDAY COOLER AIR WILL DEFINITELY BE IN PLACE WITH CLOUD COVER HAMPERING TEMPS SOMEWHAT. PRECIP WISE WE'LL EITHER BE IN THE VICINITY OF THE FRONT OR HAVE A SHORTWAVE DROPPING ACROSS THE NORTH AND EAST SO I KEPT WITH THE BLENDED MODEL POPS TUESDAY THROUGH WEDNESDAY. && .AVIATION...23/18Z ISSUED AT 1247 PM CDT WED SEP 23 2015 WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED ACROSS THE WESTERN HALF OF IOWA THIS AFTERNOON AND ACROSS NORTHWEST IOWA TONIGHT. MVFR CIGS/VSBYS ARE POSSIBLE WITHIN THE POCKETS OF HEAVIER RAIN. OTHERWISE...CONDITIONS SHOULD REMAIN VFR OUTSIDE OF THE RAIN AT MOST TAF SITES WITH A SOUTH TO SOUTHEAST WIND OF 5 TO 10 KTS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR ADAIR-ADAMS- AUDUBON-CARROLL-CASS-CRAWFORD-GUTHRIE-TAYLOR. && $$ SHORT TERM...SKOW LONG TERM...FAB AVIATION...SKOW  FXUS63 KDMX 232349 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 649 PM CDT FRI OCT 23 2015 .SHORT TERM /TONIGHT/... ISSUED AT 342 PM CDT FRI OCT 23 2015 BROAD TROUGH TO CONTINUE ITS EASTWARD PROPAGATION ACROSS THE UPPER MIDWEST OVERNIGHT...EVENTUALLY MAKING IT E/NE OF THE DMX CWA TOWARDS THE END OF THE SHORT TERM FCST PERIOD. WITH SUFFICIENT SFC MOISTURE PROVIDED FROM MORNING PRECIP...WIDESPREAD FOG HAS ENVELOPED THE CWA...DROPPING VSBYS DOWN TO AROUND 1 TO 2 SM IN MANY PLACES. SEE NO REASON FOR FOG TO LIFT THIS EVENING AS SFC TEMPS WILL BEGIN TO COOL WITH SUNSET PLUS MOISTURE ADVECTION WITH APPROACHING LOW. PRECIP CHANCES...WILL BE ON THE INCREASE AFTER 00Z SAT AS THE ATTENDANT COLD FRONT PUSHES THROUGH IA. MODELS CONVERGING ON SOLN OF PUSHING FRONT EAST OF CWA BY AROUND 09Z SAT. PER USUAL...THE NAM MOST EXCITED FOR THUNDERSTORM CHANCES. REGARDLESS OF MODEL CHOICE...APPEARS TO BE ENOUGH INSTABILITY PRESENT FOR ISOLATED THUNDER WITH THIS FROPA. SFC MOISTURE CONV NOT THE BEST. PWATS AROUND 1.25 INCHES. CLOUD THICKNESS BTX 5KFT AND 7KFT. BASED UPON WIND/THERMO PROFILES...OVERRUNNING CONVECTION WILL NOT BE AN ISSUE TONIGHT. IN ALL...SLIGHTLY LESS IMPRESSIVE OF A SETUP THAN THIS MORNING/S WHICH YIELDED A WIDESPREAD QUARTER OF AN INCH...WITH SOME PLACES APPROACHING HALF AN INCH. AMOUNT-WISE ONE TENTH TO THE OCCASIONAL QUARTER OR SO OF AN INCH OF RAIN SEEMS REASONABLE FOR TONIGHT. WINDS BEHIND THE BOUNDARY WILL BE TOUCHED UPON IN THE LONG TERM...BUT WORTH MENTIONING THAT IT WILL BE GUSTY BEHIND THIS FRONT. BY 12Z SAT...WINDS COULD ALREADY BE GUSTING IN EXCESS OF 20KTS IN MUCH OF THE DMX CWA. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 342 PM CDT FRI OCT 23 2015 AFTER THE PASSAGE OF THE SYSTEM TONIGHT...FEW CONCERNS FOR THE NEXT SEVERAL DAYS. SUBJECTIVE ANALYSES THIS MORNING SHOW SFC LOW NEAR VALENTINE NEBRASKA AT 13Z WITH UPPER LEVEL LOW/TROUGH FROM THE NORTHERN PLAINS SOUTH TO THE GULF COAST. A RIDGE OF HIGH PRESSURE EXTENDS FROM HUDSON BAY CANADA SOUTH TO THE SOUTHEAST. THIS BLOCKING HIGH AS KEPT THE CENTRAL PLAINS LOW FROM MOVING MORE EAST...INSTEAD MOVING NORTHEAST/NORTH THROUGH SATURDAY MORNING. MODELS HAVE SLOWED THE SYSTEM DOWN BY ABOUT 6 HOURS. THIS MAY KEEP A SMALL CHANCE FOR SOME LIGHT SHOWER ACTIVITY IN NORTHEAST SECTIONS OF THE FORECAST AREA THROUGH ABOUT 15Z SATURDAY. AFTER THAT...HIGH PRESSURE BUILDS EAST AND WILL ALLOW FOR A RATHER TRANQUIL PERIOD OF WEATHER FROM SATURDAY THROUGH EARLY TUESDAY. THE MAIN BUT SUBTLE CHANGE OVER THE WEEKEND WILL BE A GRADUAL LOWERING OF HEIGHTS AS A LARGE ANCHOR LOW OVER EASTERN CANADA DEEPENS IN RESPONSE TO THE DEPARTING SYSTEM EARLY TOMORROW. WITH THE ANCHOR LOW IN PLACE...A WEAK SHORT WAVE TRACKING NEAR THE US CAN BORDER WILL SPREAD SLIGHTLY COOLER AIR INTO THE REGION BY MONDAY. GENERALLY TEMPERATURES WILL STILL BE ABOVE NORMAL THIS WEEKEND WITH HIGHS/LOWS ABOUT 2-3 DEGREES ABOVE NORMAL. THE BIGGER CHALLENGE THROUGH THE EXTENDED REMAINS NEXT WEEK. THERE REMAIN DIFFERENCES BETWEEN THE THREE SYNOPTIC SCALE MODELS... GFS/EURO/GEM WITH REGARD TO THE EVOLUTION OF THE PATTERN NEXT WEEK. CONFIDENCE STILL REMAINS LOWER FOR NOW. ITS QUITE RARE TO POTENTIALLY SEE REMNANTS OF A STRONG HURRICANE/EXTRA TROPICAL SYSTEM EVENTUALLY PHASING WITH BOTH THE NORTHERN/SOUTHERN NORTHERN HEMISPHERIC STREAMS. THIS IS THE REASON FOR THE WIDE VARIETY OF SOLUTIONS OVER THE PAST FEW DAYS. AS PATRICIA GOES EXTRA TROPICAL ACROSS THE MEXICO AS IT CROSSES THE SIERRA MADRE RANGE...IT IS EXPECTED TO REORGANIZE AS AN EXTRATROPICAL SYSTEM NEAR CORPUS CHRISTI/HOUSTON TEXAS AND REMAIN ALONG THE GULF COAST UNTIL MON/TUE. MEANWHILE TWO DISTINCT WAVES WILL BEGIN TO AFFECT THE WESTERN CONUS...ONE ENTERING THE PACNW THEN DIGGING SOUTHEAST TOWARD THE ROCKIES BY 12Z TUES AND ANOTHER STRONGER WAVE DROPPING SOUTH INTO THE NORTHERN ROCKIES ABOUT THE SAME TIME. MUCH OF NEXT WEEKS FORECAST DEPENDS ON WHEN/WHERE/IF THESE THREE FEATURES BEGIN TO PHASE. TODAY...THERE IS A HINT THAT OLD PATRICIA MAY DRIFT FARTHER NORTHEAST PRIOR TO PHASING. THIS WOULD RESULT IN A SLIGHTLY WEAKER AND FARTHER EAST PHASING OF THE THREE WAVES. REGARDLESS...A PERIOD OF ACTIVE WEATHER WITH PLENTY OF MOISTURE WILL AFFECT ABOUT THE EASTERN HALF OF THE NATION AS THIS PROCESS PASSES EAST OF IOWA. INDIVIDUALLY...THE 00Z EURO NOW HOLDS THE ARRIVAL OF THE FIRST ROUND OF FORCING UNTIL TUESDAY EVENING WHILE THE GFS ARRIVES ABOUT 6 TO 12 HOURS EARLIER AND THE CURRENT 12Z RUN SHOWING EVEN LESS PHASING DURING THE ENTIRE EVENT. THE 12Z EURO CONTINUES TO HOLD ONTO THE REMNANTS OF PATRICIA/EXTRA TROPICAL SYSTEM LONGER IN THE GULF THAN THE GFS AND THERE IS LITTLE NORTHEAST DRIFT IN THIS MORNINGS PACKAGE. THIS LEADS TO A SIMILAR SOLUTION AS YESTERDAYS 12Z RUN WITH A GENERAL PHASING OF THE 3 WAVES ACROSS THE MID MISSISSIPPI RIVER VALLEY BY 12Z THURSDAY BEFORE A MORE COMPLETE CYCLOGENESIS TAKES PLACE EAST OF THE REGION. FOR NOW HOLD ONTO A BLEND WITH SOME EMPHASIS ON THE EURO SINCE IT REMAINS MORE CONSISTENT FROM RUN TO RUN. STILL PLENTY OF PACKAGES AHEAD PRIOR TO ITS ARRIVAL. TIMING ASIDE A PERIOD OF RAIN AND BLUSTERY CONDITIONS IS EXPECTED FROM TUESDAY NIGHT THROUGH EARLY THURSDAY AS THE ENTIRE SYSTEM SLOWS DOWN WHILE PHASING. INITIALLY MILD AIR AT H850 ON TUESDAY MAY ALLOW FOR HIGHS TO REACH THE 50S TO LOWER 60S IF THE RAIN HOLDS OFF THROUGH EVENING. BY WEDNESDAY INTO THURSDAY HOWEVER...HIGHS MAY STRUGGLE TO REACH 50 OVER THE FORECAST AREA WITH LITTLE SUNSHINE AND ONLY A SMALL DIURNAL RANGE IN TEMPERATURE. FORTUNATELY BOTH THICKNESS AND H850 TEMPERATURES SUPPORT ALL LIQUID AT THIS TIME. WITH ANOTHER WAVE QUICKLY DROPPING SOUTHEAST FROM SASKATCHEWAN BY FRIDAY...THIS KICKER WAVE WILL HELP MAINTAIN A PROGRESSIVE FLOW WITH FRIDAY SEEING A DECENT CHANCE OF SUNSHINE WITH HIGHS IN THE 50S. && .AVIATION...24/00Z ISSUED AT 648 PM CDT FRI OCT 23 2015 CONDITIONS WILL BE QUITE VARIABLE EARLY IN THE PERIOD. LOW PRESSURE JUST NORTH OF KFSD AT 00Z WILL TRACK EASTWARD JUST NORTH OF THE IA/MN BORDER. ATTENDANT WARM FRONT ACROSS NRN IA INTO NRN IL WILL CONTINUE TO DRIFT SLOWLY NWD AHEAD OF ITS TRACK. LIFR CONDITIONS CAN BE EXPECTED NORTH OF THE WARM FRONT. FARTHER SOUTH EXPECT VFR CONDITIONS WITH A BRIEF PERIOD OF WEAK CONVECTION...POSSIBLY WITH SOME GUSTY WINDS. BY IN THE EARLY MORNING HOURS SAT THE COLD FRONT ASSOCIATED WITH THE LOW...JUST ENTERING WRN IA AT 00Z...WILL PASS THROUGH IA WITH SUB 2KFT MVFR CIGS BEHIND FOR AROUND 8 HOURS. EXPECT MODERATE NWLY WIND GUSTS DURING MUCH OF THE DAY AS WELL. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...KOTENBERG LONG TERM...REV AVIATION...SMALL  FXUS63 KDMX 242042 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 342 PM CDT FRI JUL 24 2015 .SHORT TERM /TONIGHT/... ISSUED AT 341 PM CDT FRI JUL 24 2015 WITH MORNING CONVECTION SOUTH OF THE DMX CWA BY EARLY AFTERNOON...FCST FOCUS WILL SHIFT TO EVENING CONVECTION AND OVERNIGHT PRECIP CHANCES. A BOUNDARY ORIENTED FROM NE TO SW WILL BE PROPAGATING SOUTHEASTWARD INTO NORTHERN AND CENTRAL IOWA. 12Z GFS TIMING IS HORRIBLE WITH THIS BOUNDARY AS IT IS TOO FAST...BUT REST OF THE SHORT TERM MODELS/NAM/EURO GENERALLY INITIALIZE AND HANDLE BOUNDARY PROGRESSION BETTER...SO HAVE GONE WITH A BLEND THERE. BOUNDARY SHOULD BE SLIGHTLY WEST OF KMCW AND OUR NORTHERN TIER OF COUNTIES BY AROUND 00Z. SPC MESO ANALYSIS SHOWS ENVIRONMENT DESTABILIZING IN THIS LOCATION WITH MOSTLY CLEAR SKIES. SBCAPE VALUES AT THIS TIME PROJECTED TO BE AROUND 1500 TO 2000 J/KG...WHICH IS NOT GREAT. KMCW FCST SOUNDING ALSO LOOKS VERY ELEVATED IN TERMS OF ANY CONVECTION THAT WOULD GENERATE. MAIN THREAT WITH ANY STORMS THAT DEVELOP WOULD BE STRONG WINDS AS DCAPE IS OVER 1500 J/KG. BULK SHEAR AROUND 40 KTS WHICH IS MINIMAL FOR SUSTAINING STORMS. IN ALL...TIMING WILL VERY LIKELY INHIBIT ANY STORMS THAT MAY DEVELOP FROM REACHING SEVERE LEVELS. CONVECTION WILL DIE OFF WITH SUNSET. THE OVERNIGHT PERIOD LOOKS FAR MORE ACTIVE ACROSS SOUTHERN IOWA. THE RIDGE OF THE THETA-E AXIS WILL BE AROUND INDIANOLA. MODELS SHOW SOME DECENTLY DEEP MOISTURE CONVERGENCE EXPECTED AROUND HIGHWAY 34 AND SOUTH ALONG THE AFOREMENTIONED BOUNDARY WHICH WILL KEEP MOVING SOUTHEAST. SIGNAL FOR MODERATE TO HEAVY PRECIP THERE AS PWATS AROUND 2 TO 2.2 INCHES APPEAR LIKELY. 0-6KM MIXING RATIOS ABOVE 8G/KG AND 0- 6KM MUCAPES AROUND 500 TO 1000 J/KG WILL SUPPORT UPWARD MOISTURE FLUX. FCST SOUNDINGS PICK UP ON SOME DRY AIR ALOFT TO CONTEND PLUS WARM CLOUD DEPTHS AROUND 12KFT...SO SYSTEM WON/T BE COMPLETELY EFFICIENT IN PRODUCING PRECIP...BUT CERTAINLY ENOUGH SUPPORT FOR AT LEAST HALF AN INCH OF RAIN. WITH SOME PLACES FURTHER SOUTH REACHING AN INCH OR MORE. WITH HIGH PRESSURE AND SUBSIDENCE NORTH...NORTHERN TIER OF DMX CWA SHOULD BE DRY OVERNIGHT. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 341 PM CDT FRI JUL 24 2015 IA WILL BE ON THE FRINGE OF THE WESTERLIES AND VARIED INFLUENCE OF THE S CENTRAL CONUS RIDGE INTO EARLY NEXT WEEK. AT ONSET ATTENTION WILL BEGIN UPSTREAM WITH WEAK RIPPLES TOPPING RIDGE ALONG AZ/CO/NE MOISTURE RIBBON NOTED IN WATER VAPOR IMAGERY. REMNANTS MAY TRACK ALONG CURRENT SIOUXLAND FRONTAL BOUNDARY SAGGING SOUTHEASTWARD TOWARD MO BORDER BY DAYBREAK...OR WHAT IS LEFT OF CURRENT SWRN IA OUTFLOW FROM ERN IA CONVECTION TODAY. THIS TOGETHER WILL LIKELY BE SUFFICIENT FOR MCS OF SOME FORM TO SUSTAIN IN WEAK WARM ADVECTION REGIME SAT...MAINLY OVER CENTRAL SRN SECTIONS. WEAK WARM/THETA-E ADVECTION WILL THEN PERSIST INTO SAT NIGHT WITH AFOREMENTIONED FRONTAL ZONE BEGINNING TO LIFT NORTHWARD BACK THROUGH IA. THUS HAVE PUSH POPS WELL THROUGH THE CHANCE CATEGORY SW-NE BY EARLY SUN MORNING. ANY REMNANTS SHOULD EXIT DURING THE DAY SUN LEADING TO ANOTHER INCREASE IN HEAT AND HUMIDITY. TEMPS AND DEWPOINTS SHOULD BE SEVERAL DEGREES WARMER THAN SAT WITH HEAT INDICES TOPPING 100F IN SPOTS. ALTHOUGH THERE IS NOT MUCH TO FOCUS ON...HAVE KEPT SLIGHT CHANCES GOING INTO SUN NIGHT AND CONTINUED WEAK WARM ADVECTION. FORECAST MONDAY IS MORE PROBLEMATIC. NAM AND ECMWF SUGGEST LITTLE WILL HAPPEN HOWEVER THE 12Z GFS DEPICTS SIGNIFICANT CO/KS/NE PEAK HEATING CONVECTION SUSTAINING ITSELF OVERNIGHT IN THE WARM ADVECTION AND CROSSING IA DURING THE DAY. HAVE GONE DRY FOR NOW...BLENDING IN ADJACENT OFFICE CONSENSUS...HOWEVER THIS WILL BE A PERIOD TO WATCH FOR ADDITION OF POPS IN THE COMING DAYS. PATTERN WILL BEGIN TO CHANGE GOING FURTHER IN THE NEXT WORK WEEK. WAVE CURRENTLY OFF THE BC COAST WILL MIGRATE EASTWARD AS POTENT SHORT WAVE DRAGGING FRONT AND ASSOCIATED DEEP FORCING THROUGH IA. TIMING APPEARS TO BE THE ONLY QUESTION. MOST LIKELY SCENARIO NOW HAS SIOUXLAND PEAK HEATING SURFACE BASED DEVELOPMENT MOVING THROUGH REMAINDER OF IA INTO TUE NIGHT AND POSSIBLY SE IA WED. THE REST OF THE EXTENDED LOOKS DRY WITH TEMPS AND DEWPOINTS NO WORSE THAN SEASONAL LEVELS. && .AVIATION...24/18Z ISSUED AT 1251 PM CDT FRI JUL 24 2015 AT 18Z...LINE OF TSRA PASSING SOUTHWARD THROUGH KOTM. AS SYSTEM PROPAGATES SOUTHWARD...CLOUDS BREAKING UP OVER KFOD...KMCW...AND KALO. SPOTTY THUNDERSTORMS MAY DEVELOP LATE THIS EVENING NEAR KMCW AND MOVE SOUTHEASTWARD. MAY NEED TO ADD TS TO KALO TAF AROUND 02Z TO 05Z SAT TIMEFRAME. INCREASING CONFIDENCE WITH OVERNIGHT STORMS IMPACTING KDSM AND KOTM. MAY NEED TO LOWER CIGS AND VSBYS IF MOD TO HEAVY PRECIP PANS OUT. && .DMX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ADAIR-ADAMS- AUDUBON-CARROLL-CASS-CRAWFORD-GUTHRIE-RINGGOLD-SAC-TAYLOR-UNION. && $$ SHORT TERM...KOTENBERG LONG TERM...SMALL AVIATION...KOTENBERG  FXUS63 KDMX 280830 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 330 AM CDT FRI AUG 28 2015 .SHORT TERM /TODAY/... ISSUED AT 330 AM CDT FRI AUG 28 2015 PRECIP TRENDS WILL BE THE STRAIGHT FORWARD FORECAST ISSUE TODAY WITH SOME TEMP REBOUND CONCERNS AS WELL. UPPER LEVEL FLOW WILL CONTINUE TO AMPLIFY TODAY WITH PASSAGE OF MID LEVEL WAVE THROUGH THE MO VALLEY. BOTH KINEMATIC AND THERMODYNAMIC FORCING ARE STRONGLY NOTED WITH SOME RIGHT ENTRANCE REGION SUPPORT FROM WI/MI SPEED MAX AND DPVA AHEAD OF ERN NE SHORT WAVE MECHANICALLY. FAIRLY DECENT BAROCLINIC ZONE IS ALSO NOTED ON 305K ISENT SURFACE WITH NAM DEPICTING OVER 100 MB OF LIFT ACROSS IA BY 12Z WITH 40-50KTS OF FLOW. THIS RESULTS IN VERY STRONG MOISTURE TRANSPORT AND ASSOCIATED CONVERGENCE ZONES...WHICH MOVE SLOWLY ACROSS IA REACHING NERN SECTIONS BY EARLY AFTERNOON. ALTHOUGH THE FORCING IS STRONG WITH PWATS AND WARM CLOUD DEPTHS SEASONALLY HIGH SUGGESTING HIGH RAINFALL EFFICIENCY...THE LACK OF INSTABILITY WILL HOLD THINGS BACK SOMEWHAT WITH CONVECTION ONLY EMBEDDED WITHIN LARGER STRATIFORM AREA. RAINFALL AMOUNTS WILL STILL EXCEED AN INCH IN MANY LOCATIONS HOWEVER WITH POSSIBLY OVER TWO INCHES IN THE CENTRAL AND ERN I80 TO HIGHWAY 20 ZONES. AGREE WITH WPC QPF ASSESSMENT FAVORING THIS FARTHER SOUTH MAX AXIS. DO NOT FEEL RAINFALL RATES WILL BE SUFFICIENT TO JUSTIFY ANY HEADLINES AT THIS POINT HOWEVER. TEMP REBOUND WILL BE SOMEWHAT OF A MINOR CONCERN. SOUNDINGS SUGGEST THERE MAY BE A LITTLE MIXING BOOST IN THE WARM SECTOR FOR S CENTRAL AND SERN SECTIONS BY AFTERNOON BEHIND THE MAIN PRECIP SHIELD...WHICH MAY ALSO REDEVELOP SOME SHOWERS OR ISOLD STORMS...BUT CLOUDS AND PRECIP SHOULD OFFSET TOO MUCH OF A REBOUND SO STAYED CLOSER TO WARMER MOS RATHER THAN WHAT SOME RAW TEMPS SUGGEST. ACROSS THE NORTH...CLOUDS PRECIP AND AN UNFAVORABLE MORE ELY WIND SHOULD KEEP ANY REBOUND TO A MINIMUM. HOWEVER SHEAR MOISTURE ADDITION FROM PRECIP AND TRANSPORT SHOULD NUDGE THINGS UP SEVERAL DEGREES DURING THE HEATING OF THE DAY. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 330 AM CDT FRI AUG 28 2015 FOCUS IS MAINLY ON TEMPERATURES THROUGHOUT THE PERIOD...AND POPS TONIGHT. SFC LOW ASSOCIATED WITH THE STRONG SHORTWAVE TROUGH DROPPING THROUGH THE REGION TODAY INTO TONIGHT...WILL BE CENTERED NEAR DES MOINES BY 00Z THIS EVENING. MUCH OF THE PRECIP EXPECTED TO BE ON THE WARM SIDE OF THE LOW AND THUS AS THE SFC TROUGH AXIS SHOVES EASTWARD THROUGH THE CWA TONIGHT...EXPECT PRECIP CHANCES TO DIMINISH. HIGHER LOW LEVEL MOISTURE NOTED WITH THE MODELS SO DO EXPECT AN AREA OF LINGERING LOW STRATUS ACROSS MUCH OF THE CWA INTO EARLY SATURDAY WITH THE CLOUD DECK SLOWLY ERODING/PUSHING ESE THROUGH THE DAY. WITH ALL THE RESIDUAL MOISTURE AROUND AFTER THE RAIN...SOME CLEARING POSSIBLE ACROSS THE FAR WEST TONIGHT...AND LIGHTER WINDS SETTING IN COULD SEE SOME FOG DEVELOPMENT. PREVIOUS GRIDS HAD IT MENTIONED ACROSS THE WESTERN THIRD OF THE CWA...SO STUCK WITH THAT AREAL COVERAGE BUT DID EXTEND THE MENTION INTO SATURDAY MORNING. OTHERWISE LARGE UPPER RIDGE ACROSS THE CENTRAL US TO AMPLIFY INTO BUILD EASTWARD INTO NEXT WEEK. THIS WILL BRING WARMING AS THE THERMAL RIDGE BUILDS INTO THE AREA AND MAINLY DRY CONDITIONS. MODELS TRY TO BRING A FEW IMPULSES MOVING THROUGH THE RIDGE TUESDAY NIGHT AND AGAIN WEDNESDAY NIGHT...AND MAY SEE AN ISOLATED SHOWER/THUNDERSTORM. BETTER CHANCES TO THE NORTH AND WEST. THEREFORE DID KEEP MUCH OF THE PERIOD DRY WITH JUST SOME SLIGHT CHANCE POPS ACROSS THE FAR NORTHWEST TUESDAY NIGHT. H85 TEMPS COOLER TO BEGIN THE PERIOD IN THE TEENS CELSIUS WITH LINGERING CLOUD COVER INTO SATURDAY ESPECIALLY ACROSS THE EAST. THEREFORE KEPT TEMPS A BIT COOLER IN THE MID TO UPPER 70S. AS THE WARMER AIRMASS BUILDS INTO THE REGION AND H85 TEMPS EXPECTED TO PUSH INTO THE LOW TO MID 20S CELSIUS TOWARD MID/LATE WEEK HAVE HIGHS WARMING INTO THE MID TO UPPER 80S AND LOWS IN THE 60S. DEWPOINTS ALSO EXPECTED TO INCREASE BACK INTO THE MID TO UPPER 60S TOWARD NEXT WEEK MAKING THINGS FEEL A BIT MORE HUMID. && .AVIATION...28/06Z ISSUED AT 1209 AM CDT FRI AUG 28 2015 RAIN MOVING INTO NW IA AND CONDITIONS WILL DETERIORATE OVER THE NEXT COUPLE OF HOURS. MVFR CONDITIONS WITH LOCAL IFR CONDITIONS EXPECTED THROUGH MUCH OF AT LEAST FRIDAY MORNING AS UPPER LEVEL SHORTWAVE AND ATTENDANT SURFACE LOW LIFT ACROSS IOWA. SFC FLOW WILL BE S TO SE AT 10-15KTS AHEAD OF THE LOW THEN SWITCH AROUND TO THE TO THE NORTH OR NW ACROSS WESTERN TAF LOCATIONS VERY LATE IN THE FCST PD. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SMALL LONG TERM...BEERENDS AVIATION...FAB  FXUS63 KDMX 280858 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 358 AM CDT TUE JUL 28 2015 .SHORT TERM /TODAY/... ISSUED AT 358 AM CDT TUE JUL 28 2015 A VERY COMPLEX FORECAST FOR TODAY WITH MANY CONSIDERATIONS. FIRST AND FOREMOST...OUR MESSY CONVECTIVE PATTERN CONTINUES AS WE REMAIN WITHIN THE SAME SOUPY AIRMASS THAT HAS PERSISTED THIS WEEKEND. REGIONAL RADAR CURRENTLY DEPICTS A LONG SQUALL LINE STRETCHING DOWN THE EASTERN DAKOTAS AND INTO NORTHEASTERN NEBRASKA...MOVING STEADILY EASTWARD TOWARD NORTHWESTERN IOWA. AHEAD OF THIS LINE...SCATTERED THUNDERSTORMS ARE DEVELOPING ACROSS ABOUT THE NORTHERN HALF OF IOWA WITHIN A BROAD WARM AIR ADVECTION REGIME. RADAR TRENDS AND HIGH RESOLUTION MODEL FORECASTS SUPPORT A CONTINUATION OF THESE SCATTERED STORMS UNTIL THE SQUALL LINE MOVES ACROSS OUR NORTHERN COUNTIES LATER THIS MORNING. THERE IS LOWER CONFIDENCE IN THE SOUTHERN HALF OR SO OF THE FORECAST AREA BEING AFFECTED. IF THE STORMS DIVE DOWN THE INSTABILITY GRADIENT DEPICTED BY MESOANALYSIS THEN THEY MAY REACH SOUTHERN IOWA...HOWEVER WARMER AIR ALOFT IS WORKING IN FROM THE SOUTHWEST AND SATELLITE IMAGERY SHOWS A DISTINCT LACK OF CONVECTIVE CLOUD DEVELOPMENT IN THAT AREA. IT IS MORE LIKELY THAT THE SQUALL LINE WILL AFFECT NORTHERN IOWA...LEAVING IN ITS WAKE SOME DEBRIS CLOUDS AND REMNANT OUTFLOW BOUNDARIES AS WELL AS A GRADUALLY MODIFYING COLD POOL BY AROUND MIDDAY. IN THE SOUTH AND SOUTHEAST...IF CONVECTION REALLY DOES REMAIN CONFINED TO OUR NORTH...TEMPERATURES WILL WARM INTO THE LOWER 90S BY THIS AFTERNOON WITH DEWPOINTS IN THE MID 70S OR SO. THIS WILL PRODUCE HEAT INDEX VALUES NEAR 105 DEGREES...AND JUSTIFIES THE ISSUANCE OF A SMALL HEAT ADVISORY AGAINST THOSE ALREADY ISSUED BY NEIGHBORING OFFICES AGAINST OUR SOUTHEASTERN CORNER. HOWEVER...IF THE MORNING STORMS MAKE IT FURTHER SOUTH THAN EXPECTED THE ADVISORY MAY NOT PAN OUT...AND CONVERSELY IF MORNING CONVECTIVE DEBRIS REMAINS CONFINED TO NORTH OF HIGHWAY 30 THEN THE ADVISORY MAY NEED TO BE EXPANDED NORTHWARD A BIT DURING THE DAY. BY LATE THIS AFTERNOON AND EARLY EVENING AS WE REACH PEAK DIURNAL HEATING TIME THE AFOREMENTIONED RESIDUAL OUTFLOW BOUNDARIES SHOULD PROVIDE FOCI FOR ADDITIONAL THUNDERSTORM DEVELOPMENT WITHIN THE VERY UNSTABLE AIRMASS PRECEDING OUR WELL ADVERTISED COOL FRONT APPROACHING FROM SOUTH DAKOTA AS DISCUSSED IN THE LONG TERM SECTION BELOW. THERE IS SOME UNCERTAINTY REGARDING LOCATION OF THIS REDEVELOPMENT CONTINGENT ON THE PATH MORNING STORMS TAKE...BUT ANY STORMS THAT DO DEVELOP LATE IN THE DAY WILL CERTAINLY BE WITHIN A FAVORABLE SEVERE WEATHER ENVIRONMENT AS OUTLINED BY SPC PRODUCTS. HAVE MAINTAINED LIKELY POPS AFTER ABOUT 22Z TO ACCOUNT FOR THIS. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 358 AM CDT TUE JUL 28 2015 MAIN FORECAST CONCERN WAS FOCUSED ON COLD FRONT TO SWEEP ACROSS THE STATE TONIGHT AND THE CONVECTION IT WILL BRING TO THE FORECAST AREA. MODELS ARE IN OKAY AGREEMENT WITH THE TIMING OF THE COLD FRONT TONIGHT WITH THE 28.00Z NAM THE SLOWEST MODEL AND NOT INITIALIZING WELL THIS MORNING...THUS KEPT IT AS THE OUTLIER TONIGHT INTO TOMORROW AND LEANED TOWARD THE GFS/ECMWF. TONIGHT THROUGH WEDNESDAY...CONVECTION WILL BE ONGOING THIS EVENING WITH THE PROGRESSION OF THE COLD FRONT ENTERING THE WESTERN TO NORTHWESTERN PORTION OF THE CWA. DEEP LAYER SHEAR AHEAD OF THE FRONT IS MAINLY UNIDIRECTIONAL BUT STRONG ENOUGH TO SUSTAIN A COLD POOL. INSTABILITY IS PLENTIFUL WITH MUCAPE VALUES RANGING FROM 1500-3500J/KG PER GFS/ECMWF. MCS MAINTENANCE PROBABILITY VIA THE ECMWF/GFS ARE OVER 40 PERCENT WITH GFS AS HIGH AS 90 THIS EVENING. CONFIDENCE STORMS WILL BE MOVING ACROSS CENTRAL DURING MUCH OF THE EVENING BEFORE CLEARING THE FORECAST AREA B/T 06-09Z WEDNESDAY. LOWER CONFIDENCE IS WIDESPREAD SEVERE WEATHER...BUT STILL CANNOT RULE OUT A FEW STORMS PRODUCING STRONG WINDS/LARGE HAIL EARLY IN THE EVENING WITH THE SHEAR AND INSTABILITY AVAILABLE. THE OTHER THREAT IS HEAVY RAIN WITH STRONG MOISTURE TRANSPORT VECTORS AND THETA-E ADVECTION INTO THE STATE AHEAD OF THE FRONT COMBINED WITH THE DEEP WARM LAYER CLOUD DEPTHS AND PRECIPITABLE WATER VALUES FROM 2 TO 2.4 INCHES. ISOLATED AREAS OF FLASH FLOODING COULD POSE AN ISSUE TONIGHT IF ANY TRAINING OCCURS ON TOP OF THE AREAS THAT WERE HIT WITH HEAVY RAIN MONDAY AND OVER THE WEEKEND. COLD FRONT WILL BRING SOME MUCH NEEDED COOLER AND DRIER AIR INTO THE STATE OVERNIGHT TONIGHT THROUGHOUT THE DAY WEDNESDAY. WEDNESDAY LOOKS TO BE A LITTLE BREEZY...ESPECIALLY ACROSS THE NORTH WHERE PRESSURE GRADIENT AND SLIGHTLY DEEPER MIXING IS ANTICIPATED. HOWEVER...SUB-ADVISORY ATTM. THURSDAY THROUGH MONDAY...SURFACE HIGH PRESSURE AND A LARGE UPPER RIDGE BUILD INTO THE REGION THROUGH THE END OF THE WORK WEEK. SOME MODERATING TEMPERATURES IN THE 80S TO LOWER 90S BEGIN ON FRIDAY AND CONTINUE THROUGH THE WEEKEND. WEAK SHORTWAVE CUTS ACROSS THE STATE FRIDAY BUT WITH LIMITED MOISTURE AND FORCING...KEPT FORECAST DRY FOR NOW. LATE IN THE WEEKEND...THE GFS AND ECMWF HINTING ON A DECENT COLD FRONT AND UPPER LEVEL SHORTWAVE TO MOVE ACROSS THE REGION LATE SATURDAY NIGHT INTO SUNDAY...THEN ANOTHER SHORTWAVE THROUGH THE FORECAST AREA BY EARLY MONDAY. && .AVIATION...28/06Z ISSUED AT 1133 PM CDT MON JUL 27 2015 WARM FRONT ALOFT/SFC JUST TO WEST OF AREA THIS EVENING. MCS OVER THE DAKOTAS/NEBRASKA WILL BEGIN TO EXPAND EAST/SOUTHEAST BETWEEN 09-13Z WITH AREA OF LIFT ACROSS NORTH CENTRAL IOWA BY 09-10Z AND A GRADUAL EXPANSION FROM WEST CENTRAL/NORTH CENTRAL BY 10-12Z. HAVE DELAYED ARRIVAL IN TAFS WITH UPDATED HRRR MODEL RUNS...SOUTHERN SITES AT KDSM/KOTM SHOULD SEE LESS DURATION OF THUNDER BETWEEN 11-15Z THAN NORTH. AS MAIN COLD FRONT MOVES INTO THE AREA... ANOTHER ROUND OF STORMS IS EXPECTED FROM 20-00Z LINGERING AFT 29/00Z OVER THE EAST. CONFIDENCE ON TIMING IS STILL MODEST...SO HAVE KEPT VICINITY WORDING FOR NOW./REV && .DMX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR APPANOOSE-DAVIS-MAHASKA-MONROE-WAPELLO-WAYNE. && $$ SHORT TERM...LEE LONG TERM...PODRAZIK AVIATION...REV  FXUS63 KDMX 281154 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 654 AM CDT FRI AUG 28 2015 .SHORT TERM /TODAY/... ISSUED AT 330 AM CDT FRI AUG 28 2015 PRECIP TRENDS WILL BE THE STRAIGHT FORWARD FORECAST ISSUE TODAY WITH SOME TEMP REBOUND CONCERNS AS WELL. UPPER LEVEL FLOW WILL CONTINUE TO AMPLIFY TODAY WITH PASSAGE OF MID LEVEL WAVE THROUGH THE MO VALLEY. BOTH KINEMATIC AND THERMODYNAMIC FORCING ARE STRONGLY NOTED WITH SOME RIGHT ENTRANCE REGION SUPPORT FROM WI/MI SPEED MAX AND DPVA AHEAD OF ERN NE SHORT WAVE MECHANICALLY. FAIRLY DECENT BAROCLINIC ZONE IS ALSO NOTED ON 305K ISENT SURFACE WITH NAM DEPICTING OVER 100 MB OF LIFT ACROSS IA BY 12Z WITH 40-50KTS OF FLOW. THIS RESULTS IN VERY STRONG MOISTURE TRANSPORT AND ASSOCIATED CONVERGENCE ZONES...WHICH MOVE SLOWLY ACROSS IA REACHING NERN SECTIONS BY EARLY AFTERNOON. ALTHOUGH THE FORCING IS STRONG WITH PWATS AND WARM CLOUD DEPTHS SEASONALLY HIGH SUGGESTING HIGH RAINFALL EFFICIENCY...THE LACK OF INSTABILITY WILL HOLD THINGS BACK SOMEWHAT WITH CONVECTION ONLY EMBEDDED WITHIN LARGER STRATIFORM AREA. RAINFALL AMOUNTS WILL STILL EXCEED AN INCH IN MANY LOCATIONS HOWEVER WITH POSSIBLY OVER TWO INCHES IN THE CENTRAL AND ERN I80 TO HIGHWAY 20 ZONES. AGREE WITH WPC QPF ASSESSMENT FAVORING THIS FARTHER SOUTH MAX AXIS. DO NOT FEEL RAINFALL RATES WILL BE SUFFICIENT TO JUSTIFY ANY HEADLINES AT THIS POINT HOWEVER. TEMP REBOUND WILL BE SOMEWHAT OF A MINOR CONCERN. SOUNDINGS SUGGEST THERE MAY BE A LITTLE MIXING BOOST IN THE WARM SECTOR FOR S CENTRAL AND SERN SECTIONS BY AFTERNOON BEHIND THE MAIN PRECIP SHIELD...WHICH MAY ALSO REDEVELOP SOME SHOWERS OR ISOLD STORMS...BUT CLOUDS AND PRECIP SHOULD OFFSET TOO MUCH OF A REBOUND SO STAYED CLOSER TO WARMER MOS RATHER THAN WHAT SOME RAW TEMPS SUGGEST. ACROSS THE NORTH...CLOUDS PRECIP AND AN UNFAVORABLE MORE ELY WIND SHOULD KEEP ANY REBOUND TO A MINIMUM. HOWEVER SHEAR MOISTURE ADDITION FROM PRECIP AND TRANSPORT SHOULD NUDGE THINGS UP SEVERAL DEGREES DURING THE HEATING OF THE DAY. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 330 AM CDT FRI AUG 28 2015 FOCUS IS MAINLY ON TEMPERATURES THROUGHOUT THE PERIOD...AND POPS TONIGHT. SFC LOW ASSOCIATED WITH THE STRONG SHORTWAVE TROUGH DROPPING THROUGH THE REGION TODAY INTO TONIGHT...WILL BE CENTERED NEAR DES MOINES BY 00Z THIS EVENING. MUCH OF THE PRECIP EXPECTED TO BE ON THE WARM SIDE OF THE LOW AND THUS AS THE SFC TROUGH AXIS SHOVES EASTWARD THROUGH THE CWA TONIGHT...EXPECT PRECIP CHANCES TO DIMINISH. HIGHER LOW LEVEL MOISTURE NOTED WITH THE MODELS SO DO EXPECT AN AREA OF LINGERING LOW STRATUS ACROSS MUCH OF THE CWA INTO EARLY SATURDAY WITH THE CLOUD DECK SLOWLY ERODING/PUSHING ESE THROUGH THE DAY. WITH ALL THE RESIDUAL MOISTURE AROUND AFTER THE RAIN...SOME CLEARING POSSIBLE ACROSS THE FAR WEST TONIGHT...AND LIGHTER WINDS SETTING IN COULD SEE SOME FOG DEVELOPMENT. PREVIOUS GRIDS HAD IT MENTIONED ACROSS THE WESTERN THIRD OF THE CWA...SO STUCK WITH THAT AREAL COVERAGE BUT DID EXTEND THE MENTION INTO SATURDAY MORNING. OTHERWISE LARGE UPPER RIDGE ACROSS THE CENTRAL US TO AMPLIFY INTO BUILD EASTWARD INTO NEXT WEEK. THIS WILL BRING WARMING AS THE THERMAL RIDGE BUILDS INTO THE AREA AND MAINLY DRY CONDITIONS. MODELS TRY TO BRING A FEW IMPULSES MOVING THROUGH THE RIDGE TUESDAY NIGHT AND AGAIN WEDNESDAY NIGHT...AND MAY SEE AN ISOLATED SHOWER/THUNDERSTORM. BETTER CHANCES TO THE NORTH AND WEST. THEREFORE DID KEEP MUCH OF THE PERIOD DRY WITH JUST SOME SLIGHT CHANCE POPS ACROSS THE FAR NORTHWEST TUESDAY NIGHT. H85 TEMPS COOLER TO BEGIN THE PERIOD IN THE TEENS CELSIUS WITH LINGERING CLOUD COVER INTO SATURDAY ESPECIALLY ACROSS THE EAST. THEREFORE KEPT TEMPS A BIT COOLER IN THE MID TO UPPER 70S. AS THE WARMER AIRMASS BUILDS INTO THE REGION AND H85 TEMPS EXPECTED TO PUSH INTO THE LOW TO MID 20S CELSIUS TOWARD MID/LATE WEEK HAVE HIGHS WARMING INTO THE MID TO UPPER 80S AND LOWS IN THE 60S. DEWPOINTS ALSO EXPECTED TO INCREASE BACK INTO THE MID TO UPPER 60S TOWARD NEXT WEEK MAKING THINGS FEEL A BIT MORE HUMID. && .AVIATION...28/12Z ISSUED AT 654 AM CDT FRI AUG 28 2015 SHOWERS WILL AFFECT TAF SITES TO VARIED DEGREES THROUGH THE MORNING WITH MOST DEGRADED CONDITIONS OVER NRN IA /KFOD/KMCW/KALO/. THERE MAY BE A FEW PERIODS OF THUNDER...BUT ONLY MENTION WILL BE NEAR KFOD FOR THE TIME BEING UNTIL TRENDS AND CONFIDENCE BECOME MORE CLEAR. PRECIP POTENTIAL WILL BE MORE SCATTERED BY AFTERNOON WITH MAIN CONCERN TURNING TO CIGS/VSBYS. HAVE DROPPED NRN SITES TO IFR AS LOW LEVEL MOISTURE LINGERS AND WINDS DECREASE. HAVE SIMILAR TRENDS SOUTH BUT HOLDING OFF UNTIL LATE IN THE PERIOD. CONFIDENCE IN DETAILS THAT FAR OUT IS LOW HOWEVER. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SMALL LONG TERM...BEERENDS AVIATION...SMALL  FXUS63 KDMX 281738 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1238 PM CDT TUE JUL 28 2015 .SHORT TERM /TODAY/... ISSUED AT 358 AM CDT TUE JUL 28 2015 A VERY COMPLEX FORECAST FOR TODAY WITH MANY CONSIDERATIONS. FIRST AND FOREMOST...OUR MESSY CONVECTIVE PATTERN CONTINUES AS WE REMAIN WITHIN THE SAME SOUPY AIRMASS THAT HAS PERSISTED THIS WEEKEND. REGIONAL RADAR CURRENTLY DEPICTS A LONG SQUALL LINE STRETCHING DOWN THE EASTERN DAKOTAS AND INTO NORTHEASTERN NEBRASKA...MOVING STEADILY EASTWARD TOWARD NORTHWESTERN IOWA. AHEAD OF THIS LINE...SCATTERED THUNDERSTORMS ARE DEVELOPING ACROSS ABOUT THE NORTHERN HALF OF IOWA WITHIN A BROAD WARM AIR ADVECTION REGIME. RADAR TRENDS AND HIGH RESOLUTION MODEL FORECASTS SUPPORT A CONTINUATION OF THESE SCATTERED STORMS UNTIL THE SQUALL LINE MOVES ACROSS OUR NORTHERN COUNTIES LATER THIS MORNING. THERE IS LOWER CONFIDENCE IN THE SOUTHERN HALF OR SO OF THE FORECAST AREA BEING AFFECTED. IF THE STORMS DIVE DOWN THE INSTABILITY GRADIENT DEPICTED BY MESOANALYSIS THEN THEY MAY REACH SOUTHERN IOWA...HOWEVER WARMER AIR ALOFT IS WORKING IN FROM THE SOUTHWEST AND SATELLITE IMAGERY SHOWS A DISTINCT LACK OF CONVECTIVE CLOUD DEVELOPMENT IN THAT AREA. IT IS MORE LIKELY THAT THE SQUALL LINE WILL AFFECT NORTHERN IOWA...LEAVING IN ITS WAKE SOME DEBRIS CLOUDS AND REMNANT OUTFLOW BOUNDARIES AS WELL AS A GRADUALLY MODIFYING COLD POOL BY AROUND MIDDAY. IN THE SOUTH AND SOUTHEAST...IF CONVECTION REALLY DOES REMAIN CONFINED TO OUR NORTH...TEMPERATURES WILL WARM INTO THE LOWER 90S BY THIS AFTERNOON WITH DEWPOINTS IN THE MID 70S OR SO. THIS WILL PRODUCE HEAT INDEX VALUES NEAR 105 DEGREES...AND JUSTIFIES THE ISSUANCE OF A SMALL HEAT ADVISORY AGAINST THOSE ALREADY ISSUED BY NEIGHBORING OFFICES AGAINST OUR SOUTHEASTERN CORNER. HOWEVER...IF THE MORNING STORMS MAKE IT FURTHER SOUTH THAN EXPECTED THE ADVISORY MAY NOT PAN OUT...AND CONVERSELY IF MORNING CONVECTIVE DEBRIS REMAINS CONFINED TO NORTH OF HIGHWAY 30 THEN THE ADVISORY MAY NEED TO BE EXPANDED NORTHWARD A BIT DURING THE DAY. BY LATE THIS AFTERNOON AND EARLY EVENING AS WE REACH PEAK DIURNAL HEATING TIME THE AFOREMENTIONED RESIDUAL OUTFLOW BOUNDARIES SHOULD PROVIDE FOCI FOR ADDITIONAL THUNDERSTORM DEVELOPMENT WITHIN THE VERY UNSTABLE AIRMASS PRECEDING OUR WELL ADVERTISED COOL FRONT APPROACHING FROM SOUTH DAKOTA AS DISCUSSED IN THE LONG TERM SECTION BELOW. THERE IS SOME UNCERTAINTY REGARDING LOCATION OF THIS REDEVELOPMENT CONTINGENT ON THE PATH MORNING STORMS TAKE...BUT ANY STORMS THAT DO DEVELOP LATE IN THE DAY WILL CERTAINLY BE WITHIN A FAVORABLE SEVERE WEATHER ENVIRONMENT AS OUTLINED BY SPC PRODUCTS. HAVE MAINTAINED LIKELY POPS AFTER ABOUT 22Z TO ACCOUNT FOR THIS. .LONG TERM /TONIGHT THROUGH MONDAY/... ISSUED AT 358 AM CDT TUE JUL 28 2015 MAIN FORECAST CONCERN WAS FOCUSED ON COLD FRONT TO SWEEP ACROSS THE STATE TONIGHT AND THE CONVECTION IT WILL BRING TO THE FORECAST AREA. MODELS ARE IN OKAY AGREEMENT WITH THE TIMING OF THE COLD FRONT TONIGHT WITH THE 28.00Z NAM THE SLOWEST MODEL AND NOT INITIALIZING WELL THIS MORNING...THUS KEPT IT AS THE OUTLIER TONIGHT INTO TOMORROW AND LEANED TOWARD THE GFS/ECMWF. TONIGHT THROUGH WEDNESDAY...CONVECTION WILL BE ONGOING THIS EVENING WITH THE PROGRESSION OF THE COLD FRONT ENTERING THE WESTERN TO NORTHWESTERN PORTION OF THE CWA. DEEP LAYER SHEAR AHEAD OF THE FRONT IS MAINLY UNIDIRECTIONAL BUT STRONG ENOUGH TO SUSTAIN A COLD POOL. INSTABILITY IS PLENTIFUL WITH MUCAPE VALUES RANGING FROM 1500-3500J/KG PER GFS/ECMWF. MCS MAINTENANCE PROBABILITY VIA THE ECMWF/GFS ARE OVER 40 PERCENT WITH GFS AS HIGH AS 90 THIS EVENING. CONFIDENCE STORMS WILL BE MOVING ACROSS CENTRAL DURING MUCH OF THE EVENING BEFORE CLEARING THE FORECAST AREA B/T 06-09Z WEDNESDAY. LOWER CONFIDENCE IS WIDESPREAD SEVERE WEATHER...BUT STILL CANNOT RULE OUT A FEW STORMS PRODUCING STRONG WINDS/LARGE HAIL EARLY IN THE EVENING WITH THE SHEAR AND INSTABILITY AVAILABLE. THE OTHER THREAT IS HEAVY RAIN WITH STRONG MOISTURE TRANSPORT VECTORS AND THETA-E ADVECTION INTO THE STATE AHEAD OF THE FRONT COMBINED WITH THE DEEP WARM LAYER CLOUD DEPTHS AND PRECIPITABLE WATER VALUES FROM 2 TO 2.4 INCHES. ISOLATED AREAS OF FLASH FLOODING COULD POSE AN ISSUE TONIGHT IF ANY TRAINING OCCURS ON TOP OF THE AREAS THAT WERE HIT WITH HEAVY RAIN MONDAY AND OVER THE WEEKEND. COLD FRONT WILL BRING SOME MUCH NEEDED COOLER AND DRIER AIR INTO THE STATE OVERNIGHT TONIGHT THROUGHOUT THE DAY WEDNESDAY. WEDNESDAY LOOKS TO BE A LITTLE BREEZY...ESPECIALLY ACROSS THE NORTH WHERE PRESSURE GRADIENT AND SLIGHTLY DEEPER MIXING IS ANTICIPATED. HOWEVER...SUB-ADVISORY ATTM. THURSDAY THROUGH MONDAY...SURFACE HIGH PRESSURE AND A LARGE UPPER RIDGE BUILD INTO THE REGION THROUGH THE END OF THE WORK WEEK. SOME MODERATING TEMPERATURES IN THE 80S TO LOWER 90S BEGIN ON FRIDAY AND CONTINUE THROUGH THE WEEKEND. WEAK SHORTWAVE CUTS ACROSS THE STATE FRIDAY BUT WITH LIMITED MOISTURE AND FORCING...KEPT FORECAST DRY FOR NOW. LATE IN THE WEEKEND...THE GFS AND ECMWF HINTING ON A DECENT COLD FRONT AND UPPER LEVEL SHORTWAVE TO MOVE ACROSS THE REGION LATE SATURDAY NIGHT INTO SUNDAY...THEN ANOTHER SHORTWAVE THROUGH THE FORECAST AREA BY EARLY MONDAY. && .AVIATION...28/18Z ISSUED AT 1234 PM CDT TUE JUL 28 2015 WEAK BOUNDARY WITH ONGOING TSRA MAY AFFECT KFOD AND KDSM EARLY IN THE PERIOD. APPROACHING FRONT WILL BRING BEST CHANCES FOR TSRA IN LATER AFTERNOON AND NEAR 00Z TO SITES. HAVE INCLUDED VCTS MENTION FOR NOW WITH UNCERTAINTIES IN TIMING AND LOCATION OF TSRA. TSRA AT SITES MAY CAUSE MVFR OR LOWER CEILINGS AND VISIBILITIES...ALONG WITH STRONG WINDS. BEHIND BOUNDARY WINDS WILL SHIFT TO THE NORTH...AND WILL INCREASE BEYOND 12Z. && .DMX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR APPANOOSE-DAVIS- MAHASKA-MONROE-WAPELLO-WAYNE. && $$ SHORT TERM...LEE LONG TERM...PODRAZIK AVIATION...AWB  FXUS63 KDMX 281807 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 107 PM CDT FRI AUG 28 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TODAY/... ISSUED AT 330 AM CDT FRI AUG 28 2015 PRECIP TRENDS WILL BE THE STRAIGHT FORWARD FORECAST ISSUE TODAY WITH SOME TEMP REBOUND CONCERNS AS WELL. UPPER LEVEL FLOW WILL CONTINUE TO AMPLIFY TODAY WITH PASSAGE OF MID LEVEL WAVE THROUGH THE MO VALLEY. BOTH KINEMATIC AND THERMODYNAMIC FORCING ARE STRONGLY NOTED WITH SOME RIGHT ENTRANCE REGION SUPPORT FROM WI/MI SPEED MAX AND DPVA AHEAD OF ERN NE SHORT WAVE MECHANICALLY. FAIRLY DECENT BAROCLINIC ZONE IS ALSO NOTED ON 305K ISENT SURFACE WITH NAM DEPICTING OVER 100 MB OF LIFT ACROSS IA BY 12Z WITH 40-50KTS OF FLOW. THIS RESULTS IN VERY STRONG MOISTURE TRANSPORT AND ASSOCIATED CONVERGENCE ZONES...WHICH MOVE SLOWLY ACROSS IA REACHING NERN SECTIONS BY EARLY AFTERNOON. ALTHOUGH THE FORCING IS STRONG WITH PWATS AND WARM CLOUD DEPTHS SEASONALLY HIGH SUGGESTING HIGH RAINFALL EFFICIENCY...THE LACK OF INSTABILITY WILL HOLD THINGS BACK SOMEWHAT WITH CONVECTION ONLY EMBEDDED WITHIN LARGER STRATIFORM AREA. RAINFALL AMOUNTS WILL STILL EXCEED AN INCH IN MANY LOCATIONS HOWEVER WITH POSSIBLY OVER TWO INCHES IN THE CENTRAL AND ERN I80 TO HIGHWAY 20 ZONES. AGREE WITH WPC QPF ASSESSMENT FAVORING THIS FARTHER SOUTH MAX AXIS. DO NOT FEEL RAINFALL RATES WILL BE SUFFICIENT TO JUSTIFY ANY HEADLINES AT THIS POINT HOWEVER. TEMP REBOUND WILL BE SOMEWHAT OF A MINOR CONCERN. SOUNDINGS SUGGEST THERE MAY BE A LITTLE MIXING BOOST IN THE WARM SECTOR FOR S CENTRAL AND SERN SECTIONS BY AFTERNOON BEHIND THE MAIN PRECIP SHIELD...WHICH MAY ALSO REDEVELOP SOME SHOWERS OR ISOLD STORMS...BUT CLOUDS AND PRECIP SHOULD OFFSET TOO MUCH OF A REBOUND SO STAYED CLOSER TO WARMER MOS RATHER THAN WHAT SOME RAW TEMPS SUGGEST. ACROSS THE NORTH...CLOUDS PRECIP AND AN UNFAVORABLE MORE ELY WIND SHOULD KEEP ANY REBOUND TO A MINIMUM. HOWEVER SHEAR MOISTURE ADDITION FROM PRECIP AND TRANSPORT SHOULD NUDGE THINGS UP SEVERAL DEGREES DURING THE HEATING OF THE DAY. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 330 AM CDT FRI AUG 28 2015 FOCUS IS MAINLY ON TEMPERATURES THROUGHOUT THE PERIOD...AND POPS TONIGHT. SFC LOW ASSOCIATED WITH THE STRONG SHORTWAVE TROUGH DROPPING THROUGH THE REGION TODAY INTO TONIGHT...WILL BE CENTERED NEAR DES MOINES BY 00Z THIS EVENING. MUCH OF THE PRECIP EXPECTED TO BE ON THE WARM SIDE OF THE LOW AND THUS AS THE SFC TROUGH AXIS SHOVES EASTWARD THROUGH THE CWA TONIGHT...EXPECT PRECIP CHANCES TO DIMINISH. HIGHER LOW LEVEL MOISTURE NOTED WITH THE MODELS SO DO EXPECT AN AREA OF LINGERING LOW STRATUS ACROSS MUCH OF THE CWA INTO EARLY SATURDAY WITH THE CLOUD DECK SLOWLY ERODING/PUSHING ESE THROUGH THE DAY. WITH ALL THE RESIDUAL MOISTURE AROUND AFTER THE RAIN...SOME CLEARING POSSIBLE ACROSS THE FAR WEST TONIGHT...AND LIGHTER WINDS SETTING IN COULD SEE SOME FOG DEVELOPMENT. PREVIOUS GRIDS HAD IT MENTIONED ACROSS THE WESTERN THIRD OF THE CWA...SO STUCK WITH THAT AREAL COVERAGE BUT DID EXTEND THE MENTION INTO SATURDAY MORNING. OTHERWISE LARGE UPPER RIDGE ACROSS THE CENTRAL US TO AMPLIFY INTO BUILD EASTWARD INTO NEXT WEEK. THIS WILL BRING WARMING AS THE THERMAL RIDGE BUILDS INTO THE AREA AND MAINLY DRY CONDITIONS. MODELS TRY TO BRING A FEW IMPULSES MOVING THROUGH THE RIDGE TUESDAY NIGHT AND AGAIN WEDNESDAY NIGHT...AND MAY SEE AN ISOLATED SHOWER/THUNDERSTORM. BETTER CHANCES TO THE NORTH AND WEST. THEREFORE DID KEEP MUCH OF THE PERIOD DRY WITH JUST SOME SLIGHT CHANCE POPS ACROSS THE FAR NORTHWEST TUESDAY NIGHT. H85 TEMPS COOLER TO BEGIN THE PERIOD IN THE TEENS CELSIUS WITH LINGERING CLOUD COVER INTO SATURDAY ESPECIALLY ACROSS THE EAST. THEREFORE KEPT TEMPS A BIT COOLER IN THE MID TO UPPER 70S. AS THE WARMER AIRMASS BUILDS INTO THE REGION AND H85 TEMPS EXPECTED TO PUSH INTO THE LOW TO MID 20S CELSIUS TOWARD MID/LATE WEEK HAVE HIGHS WARMING INTO THE MID TO UPPER 80S AND LOWS IN THE 60S. DEWPOINTS ALSO EXPECTED TO INCREASE BACK INTO THE MID TO UPPER 60S TOWARD NEXT WEEK MAKING THINGS FEEL A BIT MORE HUMID. && .AVIATION...28/18Z ISSUED AT 105 PM CDT FRI AUG 28 2015 IFR TO MVFR STRATUS WILL PERSIST THROUGH THE AFTERNOON AND INTO THE OVERNIGHT HOURS. MCW/ALO HAVE THE BEST SHOT OF IFR VIS WRT TO HEAVY RAIN THIS AFTERNOON. OTHERWISE...EXPECTING FOG/STRATUS TO CONTINUE OVERNIGHT INTO SATURDAY MORNING AND HAVE MENTION OF IFR CONDITIONS PAST 06Z SATURDAY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SMALL LONG TERM...BEERENDS AVIATION...PODRAZIK  FXUS63 KDMX 282052 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 352 PM CDT TUE JUL 28 2015 .SHORT TERM /TONIGHT/... ISSUED AT 351 PM CDT TUE JUL 28 2015 CONCERN FOR PERIOD CONTINUES TO BE PRECIPITATION TRENDS. REMNANT PRECIPITATION WILL PERSIST AHEAD OF 700MB WARM NOSE...WITH INCREASING CHANCES AS BOUNDARY BEGINS TO PUSH SOUTHEAST INTO IOWA. CONCERN WILL BE IF MORE ROBUST CONVECTION CAN DEVELOP GENERALLY SOUTH OF THIS ONGOING PRECIPITATION. SPC MESO ANALYSIS INDICATES GOOD INSTABILITY BUT GIVEN CLOUD COVER AND LACK OF DEVELOPMENT...CONVECTIVE THREAT WILL BE TOWARDS LATE AFTERNOON HOURS. STORMS WHICH DEVELOP WILL HAVE SUFFICIENT INSTABILITY AND STRONG SHEAR TO ALLOW FOR PERSISTENCE AND HAIL AND STRONG WINDS WILL BE THE MAIN THREAT...THOUGH CANNOT RULE OUT TORNADIC THREAT. MAIN CONCERN WILL BE WITH HEAVY RAIN POTENTIAL ACROSS THE AREA. EXPECT PRECIPITATION TO EXPAND AS FRONTAL BOUNDARY PUSHES INTO AREA. HAVE GENERALLY FAVORED HIGH RES MODEL TIMING AND PLACEMENT...GENERALLY BEFORE 06Z AND PUSHING SOUTHEAST. EXPECT SYSTEM TO BE FAIRLY PROGRESSIVE AS BOUNDARY PUSHES THROUGH. HOWEVER...EXPECT STORMS TO BE EFFICIENT RAINFALL PRODUCERS...WITH PWAT VALUES VERY NEAR 2 INCHES AND GOOD WARM CLOUD DEPTH. GIVEN PREVIOUS DAYS HEAVY RAINFALL AND CURRENT RAINFALL TRENDS ACROSS CENTRAL IOWA...HAVE ISSUED FLASH FLOOD WATCH FOR PORTIONS OF CENTRAL AND SOUTHERN CWA. HAVE ISSUED THROUGH 12Z...THOUGH EXPECT EARLY CANCELLATION BEHIND FRONT. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 351 PM CDT TUE JUL 28 2015 WEDNESDAY 12Z THROUGH SATURDAY 12Z...SHAPES UP TO BE A VERY QUIET PERIOD WITH SURFACE HIGH PRESSURE AND NORTHWEST FLOW ALOFT SETTING IN WEDNESDAY AND DOMINATING THROUGH THE END OF THE WORK WEEK AND INTO SATURDAY. TEMPERATURES WILL BE SEASONABLE...IN THE MID TO UPPER 80S AND SOME LOW 90S. THURSDAY APPEARS TO BE THE BEST CHANCE FOR A FEW LOW 90S WITH MODEL SOUNDINGS DEPICTING THE BEST MIXING...TO ABOVE 850MB...BETWEEN NOW AND THE WEEKEND. SATURDAY 12Z THROUGH TUESDAY...WHILE NORTHWEST FLOW WILL REMAIN IN PLACE THROUGH THE PERIOD...KEEPING TEMPERATURES SEASONABLE TO SEASONABLY COOL...CHANCES FOR SHOWERS AND THUNDER RETURN TO THE REGION THANKS TO A COUPLE SUCCESSIVE SHORTWAVES. GFS/ECMWF ARE GENERALLY IN GOOD AGREEMENT ON TIMING OF THE SHORTWAVES...BUT DISAGREE ON PLACEMENT. THEREFORE...HAVE KEPT WIDESPREAD LOW END POPS SATURDAY NIGHT THROUGH TUESDAY. THE STRONGEST SHORTWAVE APPEARS TO BE SUNDAY EVENING INTO MONDAY AS A COLD FRONT PUSHES THROUGH...BUT IS DEPICTED STRONGEST BY THE GFS VERSUS THE ECMWF WHICH ONLY HINTS AT THE COLD FRONT. MODELS DIGRESS FURTHER BEYOND MONDAY WITH THE GFS TRYING TO BUILD IN AN UPPER LEVEL TROUGH ACROSS THE GREAT LAKES WHILE THE ECMWF STICKS TO THE STATUS QUO WITH CONTINUED NORTHWEST FLOW AND SOME FLATTENING OF THE FLOW. && .AVIATION...28/18Z ISSUED AT 1234 PM CDT TUE JUL 28 2015 WEAK BOUNDARY WITH ONGOING TSRA MAY AFFECT KFOD AND KDSM EARLY IN THE PERIOD. APPROACHING FRONT WILL BRING BEST CHANCES FOR TSRA IN LATER AFTERNOON AND NEAR 00Z TO SITES. HAVE INCLUDED VCTS MENTION FOR NOW WITH UNCERTAINTIES IN TIMING AND LOCATION OF TSRA. TSRA AT SITES MAY CAUSE MVFR OR LOWER CEILINGS AND VISIBILITIES...ALONG WITH STRONG WINDS. BEHIND BOUNDARY WINDS WILL SHIFT TO THE NORTH...AND WILL INCREASE BEYOND 12Z. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH WEDNESDAY MORNING FOR APPANOOSE-CLARKE-DAVIS-DECATUR-JASPER-LUCAS-MADISON- MAHASKA-MARION-MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD-TAMA- TAYLOR-UNION-WAPELLO-WARREN-WAYNE. HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR APPANOOSE-DAVIS- MAHASKA-MONROE-WAPELLO-WAYNE. && $$ SHORT TERM...AWB LONG TERM...CURTIS AVIATION...AWB  FXUS63 KDMX 282058 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 358 PM CDT FRI AUG 28 2015 .SHORT TERM /TONIGHT/... ISSUED AT 358 PM CDT FRI AUG 28 2015 HEAVY RAIN WILL PERSIST ACROSS THE NORTHEAST THROUGH THE EVENING. LATEST HRRR RUN KEEPS CONVECTION GOING IN THE FAR EAST THROUGH 04-05Z TIME FRAME AND LEANED TOWARD THIS SOLUTION FOR POPS/WX. THE WARM RAIN PROCESSES CURRENTLY AFFECTING THE FLASH FLOOD WARNED AREAS ARE PRODUCING 2-4 INCH PER HOUR RAINFALL RATES. STRONG DEEP MOISTURE CONVERGENCE OVER THE WATERLOO AREA WITH ROUGHLY 1.5-2 INCH PRECIPITABLE WATER AND WARM CLOUD DEPTHS TO AROUND 4000 METERS IS ENOUGH TO CONTINUE THE HEAVY RAIN THREAT BEFORE SURFACE LOW IN WESTERN IOWA PUSHES FURTHER EAST LATER THIS EVENING. POTENTIAL FOR HEAVY RAIN TO CONTINUE IN THE EAST TO NORTHEAST SECTIONS OF THE FORECAST AREA THROUGH 03Z TONIGHT...TO COINCIDE WITH THE LATEST HRRR THINKING. OTHER CONCERN IS FOG OVERNIGHT WITH PLENTY OF MOISTURE AND VERY LITTLE FLOW AT THE SURFACE A WEAK SURFACE RIDGE BUILDS INTO WESTERN IOWA. HAVE MENTIONED PATCHY FOG PAST 09Z WEST OF I-35. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 358 PM CDT FRI AUG 28 2015 THE WEATHER WILL GENERALLY BE QUIET IN THE LONGER TERM WITH UPPER RIDGING BUILDING INTO THE CENTRAL UNITED STATES. THICKNESSES WILL INCREASE WITH TEMPERATURES CORRESPONDINGLY RESPONDING WITH HIGHS CLIMBING ABOVE NORMAL...LIKELY TOWARD 90 BY EARLY NEXT WEEK...ESPECIALLY IN THE SOUTH AND WEST. BOTH GFS AND EURO INDICATED A WEAK SYSTEM PULLING NORTHEAST ON TUESDAY INTO THE PLAINS WHICH MAY BRING THE THREAT OF ISOLATED THUNDER INTO THE NORTHWEST PORTIONS OF IOWA BY LATER IN THE DAY INTO TUESDAY NIGHT. OTHERWISE...THE RIDGE WILL REMAIN IN PLACE INTO LATE IN THE WEEK WITH THE VERY WARM TEMPERATURES AND LITTLE THREAT OF PRECIPITATION. && .AVIATION...28/18Z ISSUED AT 105 PM CDT FRI AUG 28 2015 IFR TO MVFR STRATUS WILL PERSIST THROUGH THE AFTERNOON AND INTO THE OVERNIGHT HOURS. MCW/ALO HAVE THE BEST SHOT OF IFR VIS WRT TO HEAVY RAIN THIS AFTERNOON. OTHERWISE...EXPECTING FOG/STRATUS TO CONTINUE OVERNIGHT INTO SATURDAY MORNING AND HAVE MENTION OF IFR CONDITIONS PAST 06Z SATURDAY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...COGIL AVIATION...PODRAZIK  FXUS63 KDMX 290542 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1242 AM CDT WED JUL 29 2015 .SHORT TERM /TONIGHT/... ISSUED AT 351 PM CDT TUE JUL 28 2015 CONCERN FOR PERIOD CONTINUES TO BE PRECIPITATION TRENDS. REMNANT PRECIPITATION WILL PERSIST AHEAD OF 700MB WARM NOSE...WITH INCREASING CHANCES AS BOUNDARY BEGINS TO PUSH SOUTHEAST INTO IOWA. CONCERN WILL BE IF MORE ROBUST CONVECTION CAN DEVELOP GENERALLY SOUTH OF THIS ONGOING PRECIPITATION. SPC MESO ANALYSIS INDICATES GOOD INSTABILITY BUT GIVEN CLOUD COVER AND LACK OF DEVELOPMENT...CONVECTIVE THREAT WILL BE TOWARDS LATE AFTERNOON HOURS. STORMS WHICH DEVELOP WILL HAVE SUFFICIENT INSTABILITY AND STRONG SHEAR TO ALLOW FOR PERSISTENCE AND HAIL AND STRONG WINDS WILL BE THE MAIN THREAT...THOUGH CANNOT RULE OUT TORNADIC THREAT. MAIN CONCERN WILL BE WITH HEAVY RAIN POTENTIAL ACROSS THE AREA. EXPECT PRECIPITATION TO EXPAND AS FRONTAL BOUNDARY PUSHES INTO AREA. HAVE GENERALLY FAVORED HIGH RES MODEL TIMING AND PLACEMENT...GENERALLY BEFORE 06Z AND PUSHING SOUTHEAST. EXPECT SYSTEM TO BE FAIRLY PROGRESSIVE AS BOUNDARY PUSHES THROUGH. HOWEVER...EXPECT STORMS TO BE EFFICIENT RAINFALL PRODUCERS...WITH PWAT VALUES VERY NEAR 2 INCHES AND GOOD WARM CLOUD DEPTH. GIVEN PREVIOUS DAYS HEAVY RAINFALL AND CURRENT RAINFALL TRENDS ACROSS CENTRAL IOWA...HAVE ISSUED FLASH FLOOD WATCH FOR PORTIONS OF CENTRAL AND SOUTHERN CWA. HAVE ISSUED THROUGH 12Z...THOUGH EXPECT EARLY CANCELLATION BEHIND FRONT. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ISSUED AT 351 PM CDT TUE JUL 28 2015 WEDNESDAY 12Z THROUGH SATURDAY 12Z...SHAPES UP TO BE A VERY QUIET PERIOD WITH SURFACE HIGH PRESSURE AND NORTHWEST FLOW ALOFT SETTING IN WEDNESDAY AND DOMINATING THROUGH THE END OF THE WORK WEEK AND INTO SATURDAY. TEMPERATURES WILL BE SEASONABLE...IN THE MID TO UPPER 80S AND SOME LOW 90S. THURSDAY APPEARS TO BE THE BEST CHANCE FOR A FEW LOW 90S WITH MODEL SOUNDINGS DEPICTING THE BEST MIXING...TO ABOVE 850MB...BETWEEN NOW AND THE WEEKEND. SATURDAY 12Z THROUGH TUESDAY...WHILE NORTHWEST FLOW WILL REMAIN IN PLACE THROUGH THE PERIOD...KEEPING TEMPERATURES SEASONABLE TO SEASONABLY COOL...CHANCES FOR SHOWERS AND THUNDER RETURN TO THE REGION THANKS TO A COUPLE SUCCESSIVE SHORTWAVES. GFS/ECMWF ARE GENERALLY IN GOOD AGREEMENT ON TIMING OF THE SHORTWAVES...BUT DISAGREE ON PLACEMENT. THEREFORE...HAVE KEPT WIDESPREAD LOW END POPS SATURDAY NIGHT THROUGH TUESDAY. THE STRONGEST SHORTWAVE APPEARS TO BE SUNDAY EVENING INTO MONDAY AS A COLD FRONT PUSHES THROUGH...BUT IS DEPICTED STRONGEST BY THE GFS VERSUS THE ECMWF WHICH ONLY HINTS AT THE COLD FRONT. MODELS DIGRESS FURTHER BEYOND MONDAY WITH THE GFS TRYING TO BUILD IN AN UPPER LEVEL TROUGH ACROSS THE GREAT LAKES WHILE THE ECMWF STICKS TO THE STATUS QUO WITH CONTINUED NORTHWEST FLOW AND SOME FLATTENING OF THE FLOW. && .AVIATION...29/06Z ISSUED AT 1239 AM CDT WED JUL 29 2015 HIGH CONFIDENCE IN VFR CONDITIONS AT KFOD/KMCW/KALO/KDSM. SKIES SHOULD CLEAR OVERNIGHT AT KFOD/KMCW WITH ISOLATED SHOWERS ENDING SOON AT KDSM/KALO. KOTM WILL BE IMPACTED BY MVFR FOG AND/OR SHOWER VSBY RESTRICTIONS BEFORE SEEING SIMILAR TRENDS TOWARD VFR AND CLEARING LATER THIS MORNING. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR APPANOOSE- CLARKE-DAVIS-DECATUR-JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE- POLK-POWESHIEK-RINGGOLD-TAYLOR-UNION-WAPELLO-WARREN-WAYNE. && $$ SHORT TERM...AWB LONG TERM...CURTIS AVIATION...SMALL  FXUS63 KDMX 300755 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 255 AM CDT THU JUL 30 2015 .SHORT TERM /TODAY/... ISSUED AT 255 AM CDT THU JUL 30 2015 FEW CONCERNS TODAY AS LOW DEPARTS OVER SOUTHERN CANADA AND A WEAK FRONT DROPS SOUTH AND DISSIPATES BY MID MORNING. OVERALL WEAK WARM AIR ADVECTION WILL RETURN BY LATE AFTERNOON WITH WNW WINDS AT H850 AND WARMING H850 TEMPS TO 17C EAST TO 19C WEST. THOUGH SFC DEW POINTS WILL BE LOWER TODAY...TEMPS WILL BE SIMILAR OR MODESTLY WARMER WITH MIXING IN THE AFTERNOON WITH JUST A FEW FAIR WEATHER CLOUDS AROUND 7-8KFT. HIGHS EXPECTED TO REACH THE LOWER 80S IN THE NORTHEAST TO THE UPPER 80S TO NEAR 90 FROM CENTRAL TO SOUTHWEST AREAS. WINDS WILL MIX TO 18 TO 23 MPH ACROSS THE EAST DURING THE AFTERNOON WHICH SHOULD ALSO HELP LOWER DEW POINTS AND RESULT IN A NICE DAY ACROSS THE REGION. .LONG TERM /TONIGHT THROUGH TUESDAY/... ISSUED AT 255 AM CDT THU JUL 30 2015 MAIN FORECAST CONCERN WAS FOCUSED ON SATURDAY NIGHT AND WITH TEMPERATURES THROUGH THE EXTENDED PERIOD. LEANED TOWARD GFS/ECMWF FOR PRECIP TRENDS AND TEMPERATURES THROUGH EARLY NEXT WEEK. TONIGHT INTO SUNDAY...LARGE UPPER LEVEL RIDGE REMAINS ENTRENCHED OVER THE SOUTHWEST TO SOUTH-CENTRAL UNITED STATES AND PLACES IOWA WITHIN NORTHWEST FLOW ALOFT THROUGH EARLY NEXT WEEK. SURFACE HIGH CONTINUES OVER THE STATE THROUGH SATURDAY WITH GOOD MIXING DEVELOPING FRIDAY AFTERNOON. MIXING TO AROUND 850MB SEEMS REASONABLE AND WILL PUSH TEMPS BACK CLOSE TO 90 OVER CENTRAL TO SOUTHERN IOWA AND IN THE MIDDLE 80S OVER THE NORTH. DRIER DEW POINTS WILL AID IN THE WARM UP AS THEY RANGE FROM UPPER 50S NORTH TO UPPER 60S SOUTH. BUMPED UP WIND SPEED AND GUSTS THROUGH THE AFTERNOON HOURS TOMORROW WITH THE WINDS ATOP THE MIXED LAYER AROUND 25-30 KNOTS AND MUCH OF THAT SHOULD MATERIALIZE AT THE SURFACE. SOME WEAK CONVERGENCE AND MID-LEVEL VORTICITY MAY SPAWN SOME ISOLATED SHOWERS AND THUNDERSTORMS LATE FRIDAY AFTERNOON OVER THE FAR SOUTH IN RESPONSE TO A VERY WEAK SHORTWAVE MOVING INTO NORTHERN MISSOURI. HAVE INTRODUCED SLIGHT CHANCE POPS B/T 21Z FRIDAY TO 00Z SATURDAY. HOWEVER...IF ANYTHING DOES DEVELOP IT WILL BE VERY HIGH BASED AND NOT ANTICIPATING MUCH QPF. A MORE SIGNIFICANT POTENTIAL FOR THUNDERSTORMS IS SATURDAY NIGHT INTO EARLY SUNDAY. ECMWF/GFS AND EVEN THE NAM HAVE COME INTO VERY GOOD AGREEMENT WITH TIMING AND PLACEMENT OF PRECIP AND FORCING DURING THE EVENING SATURDAY NIGHT. SEVERE THREAT REMAINS LIMITED DUE TO LACK OF STRONG SHEAR PRESENT EVEN WITH SOME MODERATE INSTABILITY AVAILABLE. PLUS...THE FORCING WITH THE SHORTWAVE IS WEAK AND SOMEWHAT DISORGANIZED. THERE IS A THREAT OF HEAVY RAIN WITH PRECIPITABLE WATER VALUES INCREASING TO 1.5-2.0 INCHES AND WARM LAYER CLOUD DEPTHS TO AROUND 3700M SATURDAY EVENING. ALBEIT NOT ANYTHING LIKE EARLIER THIS WEEK FOR HEAVY RAIN...BUT STILL A DECENT SIGNAL AND CONFIDENT ENOUGH TO AT LEAST INCREASE POPS SATURDAY EVENING. SUNDAY INTO TUESDAY...ANOTHER WEAKER SHORTWAVE CUTS ACROSS NORTHERN IOWA LATE SUNDAY NIGHT INTO MONDAY AND HAVE SOME CHANCE POPS GOING OVER THE NORTHEAST. THROUGH THE REMAINDER OF THE FORECAST...EXTENDED MODELS IN DISAGREEMENT WITH TIMING OF SHORTWAVES AND LOW CONFIDENCE WITH ANY TIMING AND LOCATION OF PRECIP AFTER SUNDAY. && .AVIATION...30/06Z ISSUED AT 1154 PM CDT WED JUL 29 2015 ALTHOUGH CONFIDENCE IS STILL HIGH IN VFR CONDITIONS ACROSS MOST SITES...HAVE ADDED A TOKEN MENTION OF MVFR VSBY FOR RADIATION FOG AT KOTM. SKIES ARE CLEAR...WITH LIGHT WIND...MOIST SOIL...AND TEMP/DEWPOINT SPREADS SHRINKING. EXPECT NOTHING MORE THAN FEW/SCT MID CLOUDS INTO THU WITH RELATIVELY LIGHT WLY-SWLY WINDS AND ONLY MINOR DIURNAL GUSTS. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...PODRAZIK AVIATION...SMALL  FXUS63 KDMX 310836 AFDDMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 336 AM CDT FRI JUL 31 2015 .SHORT TERM /TODAY/... ISSUED AT 336 AM CDT FRI JUL 31 2015 COUPLE OF CHALLENGES IN FORECAST FOR TODAY. FIRST...SUBJECTIVE SFC ANALYSIS SHOWS WEAK TROUGH FROM NORTHEAST IA TO NEAR KOMA AT 06Z WITH SECONDARY WEAK COOL FRONT STRETCHING FROM NEAR KDLH SSW TO NEAR ST CLOUD AND ABERDEEN...BOTH MOVING SOUTHEAST WITH TIME TODAY. WEAK UPPER LEVEL SUPPORT ACROSS NEBRASKA COMBINED WITH H850 MOISTURE PLUME HAS UNSETTLED AIRMASS OVER NORTHEAST NEBRASKA/FAR WESTERN IA WITH A SMALL BUT INCREASING CLUSTER OF THUNDERSTORMS AS MODEST WARM AIR ADVECTION AT H850 AND MOISTURE PLUME FROM SOUTHWEST US TOWARD EASTERN NEBRASKA INTERACT WITH H850 UPSLOPE. HRRR MODEL CONTINUES TO DEVELOP THE AREA SOUTH SOUTHEAST WITH TIME THROUGH 12Z WEAKENING IT AS IT DOES. MID TO HIGH LEVEL BLOWOFF WILL CONTINUE TO ADVECT DOWNSTREAM OVER CENTRAL/SOUTHERN IA THROUGH MID MORNING. FOR NOW...WILL KEEP TRENDS OF WEAKENING CONVECTION/-SHRA OVER FAR SOUTHWEST THROUGH 12Z...AND CLOUD DECK THROUGH MOST OF DAY BUT DRIFTING SOUTH WITH TIME. WHATS LEFT OF WEAK COOL FRONT WILL END UP NEAR THE IA MO BORDER BY 00Z WITH SOME ADDITIONAL ISO THUNDER COVERAGE OVER THE FAR SOUTH BY LATE AFTERNOON. IN REALITY...NO COOLING ALOFT DURING THE DAY SO HIGHS ONCE AGAIN PUSH INTO THE MID 80S NORTH TO THE UPPER 80S NEAR 90 FROM I80 SOUTH WITH WARMER HEAT ISLAND EFFECTS ACCOUNTING FOR THE NEAR 90 MARK TODAY. SPC HAS RAISED SVR THREAT TO MARGINAL SOUTHWEST QUARTER FROM SOUTH OF I80/WEST OF I35. PERHAPS AS FRONT SETTLES TOWARD THE BORDER THIS EVENING RETURN FLOW FROM 00-06Z MAY PROVIDE ENOUGH LIFT TO SUPPORT SOME ISO HAILERS AND WIND. WIND FIELDS ALOFT FAIRLY WEAK SO MOST OF THE SUPPORT SHOULD BE THERMAL INSTABILITY THROUGH MID EVENING. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 336 AM CDT FRI JUL 31 2015 NEXT SEVERE WEATHER AND HEAVY RAIN POTENTIAL WILL BE SATURDAY NIGHT INTO EARLY SUNDAY. THEN...AN ACTIVE WEATHER PATTERN RETURNS THROUGHOUT NEXT WEEK WITH SEVERAL SHORTWAVES RIDING THE NORTHWEST FLOW ALOFT COMBINED WITH A BOUNDARY STALLING ACROSS THE STATE. MODELS ARE IN DECENT AGREEMENT THROUGH THE WEEKEND BEFORE THE BIGGER DISCREPANCIES SHOW UP BETWEEN SOLUTIONS SUNDAY NIGHT. TONIGHT...WEAK THETA-E ADVECTION AND ISENTROPIC LIFT PROVIDE ENOUGH FORCING TO BRING A FEW ELEVATED SHOWERS AND THUNDERSTORMS ACROSS FAR SOUTHERN IOWA LATE TONIGHT INTO SATURDAY MORNING. INTRODUCED POPS PAST 06Z SATURDAY BUT KEPT QPF AMOUNTS LOW ATTM DUE TO THE ISOLATED NATURE OF THE CONVECTION. SATURDAY INTO SUNDAY...A STRONGER SHORTWAVE BRINGS THE POTENTIAL FOR SEVERE WEATHER SATURDAY LATE AFTERNOON INTO THE EVENING. DEEP LAYER SHEAR IS FAVORABLE TO SUSTAINED THUNDERSTORMS...BUT LOW LEVEL SHEAR REMAINS WEAK AND THUS LOW CONFIDENCE WITH ANY TORNADIC ACTIVITY SATURDAY NIGHT. MAIN THREAT APPEARS TO HAIL AND DAMAGING WINDS WITH DECENT INSTABILITY AND MID-LEVEL LAPSE RATES IN THE 7.5-8C/KM RANGE. HEAVY RAIN ALSO A THREAT WITH MODELS DEPICTING STRONG MOISTURE TRANSPORT INTO THE STATE AND WARM LAYER CLOUD DEPTHS RANGE FROM 3500-3800 METERS. PRECIPITABLE WATER VALUES IN THE 1.5-1.8 INCH RANGE AND CORFIDI VECTORS SOMEWHAT CONDUCIVE TO TRAINING STORMS...SO CERTAINLY CANNOT RULE OUT A FEW LOCALLY HEAVY RAIN PRODUCERS SATURDAY NIGHT. SYSTEM MOVES OUT BY SUNDAY MORNING WITH THE ECMWF SLIGHTLY SLOWER THAN THE GFS BUT LOOKS TO BE DRY ACROSS MUCH OF THE CWA BY 18Z SUNDAY AT THE LATEST. MONDAY THROUGH THURSDAY...FRONT STALLS ACROSS IOWA FROM WEST- NORTHWEST TO EAST-SOUTHEAST BY MONDAY AND REMAINS PLANTED OVER THE STATE INTO AT LEAST TUESDAY AND LIKELY INTO WEDNESDAY. DEPENDING ON WHICH MODEL...TIMING OF THE SHORTWAVES TO RIDE THE UPPER LEVEL RIDGE WILL BE PROBLEMATIC. HOWEVER...CONFIDENT ENOUGH TO INCREASE POPS MONDAY NIGHT AS BOTH ECMWF/GFS ARE AT LEAST IN SOMEWHAT AGREEMENT WITH WIDESPREAD CONVECTION DEVELOPING ALONG THE STALLED FRONT AS THE LLJ INCREASES. VERY DEEP MOISTURE...HIGH PRECIPITABLE WATER VALUES AND NEAR 4000 METERS OF WARM LAYER CLOUD DEPTHS MONDAY NIGHT SHOULD PROVIDE ANOTHER ROUND OF HEAVY RAIN. ADDITIONAL SHORTWAVES CONTINUE TO MOVE THROUGH THE REGION FROM TUESDAY NIGHT INTO THURSDAY BUT AGAIN LOW CONFIDENCE WITH TIMING AND LOCATION OF THESE SHORTWAVES AND THUS HAVE SMALL CHANCE POPS GOING DURING THIS TIME FRAME. && .AVIATION...31/06Z ISSUED AT 1126 PM CDT THU JUL 30 2015 UNLESS CONDITIONS CHANGE SOON...EXPECT VFR CONDITIONS ACROSS TAFS AND NO THUNDER WITH ERN NE CONVECTION STAYING SW OF SITES. CONVECTION SEEMS TO HAVE CYCLED DOWN AND THEN BACK OUT OF NOWHERE RECENTLY HOWEVER...SO CONFIDENCE IN THAT HAS DECREASED SOMEWHAT. OTHERWISE EXPECT NOTHING MORE THAN SCT MID CLOUDS AND GENERALLY LIGHT WINDS EVENTUALLY VEERING TO NWLY DURING FRI PEAK HEATING MIXING. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...REV LONG TERM...PODRAZIK AVIATION...SMALL  FXUS63 KDMX 271004 AFDDMX AREA FORECAST DISCUSSION National Weather Service Des Moines IA 404 AM CST Sun Nov 27 2016 .SHORT TERM.../Today through Tonight/ Issued at 404 AM CST Sun Nov 27 2016 This morning... Radiational cooling having big impacts across northern Iowa. Models incorrectly proggd mid/high level clouds to help impede fog development. However, those mid-level clouds over the Great Lakes region now and clear skies have been in place. Temperatures across northern Iowa have fallen to the mid 20s, leading to freezing fog. With no apparati to lead to notable temp increases before sunrise, expect freezing fog to remain a hazard through sunrise as temperatures to remain below freezing. This afternoon into tonight... 06Z Water vapor imagery picking up on an impulse of moisture trekking across the Great Plains towards Iowa associated with a shortwave that is expected to phase with a deep upper low located near the Rockies along the Canada/U.S. border. Models have become extremely well-converged in terms of their solutions...so have gone with an overall consensus blend for timing. Accompanying sfc low to be in Nebraska by 21z Sun and over eastern SD by around 06z Mon. With the low well to our west, we are able to tap into sufficient gulf moisture for precip via a 45kt LLJ. PWATs are over an inch, which is high for this time of year. Even a few rumbles of thunder are possible as 0-6km muCAPE values make it into the 300 j/kg range. Soundings are very well-saturated in the low levels, suggesting a very cloudy day at the very least...and cloud thicknesses deep enough for sustained precip beyond drizzle. With the expected cloud cover and precip, Sunday daytime temperatures may be slightly overdone, so will need to monitor this. As we remain in the warm/WAA sector overnight, diurnal temperature range between Sunday and monday will be very low. In fact, temperatures may increase slightly....leading to the possibility of record high min temps. .LONG TERM.../Monday through Saturday/ Issued at 404 AM CST Sun Nov 27 2016 The upper level low pressure will be centered over the eastern Dakotas on Monday. The mid level dry slot will be over Iowa Monday morning. Some uncertainty regarding how much stratus will be lingering Monday morning and how deep. If the low stratus is still intact, likely will have a few areas of drizzle. A boundary will move through central Iowa Monday afternoon with a few showers possible ahead of the front. The NAM solution is the most aggressive with weak convective instability developing ahead of the boundary and is an outlier at this time therefore will keep the mention for thunder out. The upper low will progress very slowly east across Minnesota on Tuesday and Wednesday then become more progressive Wednesday night and Thursday as it reaches the eastern Great Lakes. Conditions will be cooler and mostly dry on Tuesday. Light precipitation chances will arrive Wednesday as a more cyclonic flow develops with the upper low beginning to transition further east. Precipitation type will be a mix of rain and snow. Deep cold air will exist above 2500 ft with precipitation type and melting dependent on sfc wetbulb temperatures. With deep cold air aloft need wetbulb temperatures near 34.5 F to ensure melting and a transition to rain. This will be close on Wednesday but a reinforcing push of cold air will aid the transition further Wednesday night. Light accumulations of snow may occur over northern Iowa and cannot discount accumulations over 1 inch. The end of the forecast period will remain cool with highs in the 30s. The potential for very light snow or flurries will persist through the period as northerly flow continues and periods of stratus move through. && .AVIATION.../For the 00Z TAFS through 00Z Sunday evening/ Issued at 536 PM CST Sat Nov 26 2016 Mainly VFR conditions will prevail through mid-morning Sunday. The exception is across northern Iowa, where we may see some fog development once again overnight. An old, decayed surface trough is draped across southern Minnesota where winds have gone calm beneath clear skies. However, up toward MCW winds are still light from the southwest and it remains to be seen whether either the trough or associated fog will get as far south as MCW. By midday tomorrow an approaching storm system will result in rapidly expanding and lowering ceilings across the region, with showers and possibly a few thunderstorms bringing IFR conditions by the mid to late afternoon and evening. MVFR ceilings may arrive a few hours before the rain, but IFR ceilings will be tied to it. && .DMX WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 9 AM CST this morning for IAZ004>007- 016-017-025>028. && $$ SHORT TERM...Kotenberg LONG TERM...Donavon AVIATION...Lee  FXUS63 KDMX 200902 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 402 AM CDT Sat May 20 2017 .SHORT TERM.../Today through Tonight/ Issued at 359 AM CDT Sat May 20 2017 Large upper trough continues to impact the mid-section of the country and is currently spinning over NE with fetch of moisture pushing ahead of it into Iowa. This has resulted in a widespread showers throughout the overnight hours. Associated surface low is currently located over north central to northeast KS, with the dry slot nosing into eastern KS. Upper low set to migrate slowly ENE into central MN by early Sunday, with the surface low tracking northeastward through IA and into western WI. This will allow the dry slot to punch into much of the state through the afternoon hours and into tonight. Therefore expect bulk of the precipitation to come to an end early this morning as the waa wing of precip shoves north and east through the state. May still see some spotty showers/thunderstorms as the sfc low moves into SW IA, and with the sfc warm front lifting northward through southern/eastern IA. System to nearly occlude as it lifts through IA, with the dryline shoving ENE through central/eastern IA this afternoon. May see some additional scattered shower/storm development with that nosing through the area. Majority of precip chances tonight to be in the def zone region across northwest to northern IA as the entire system continues to lift north and east. As for temperatures cloud cover to remain across much of the CWA today into tonight, with some breaks possible in the far south/east as the warm front lifts northward. This should allow sfc temps to pops up quickly in that region, otherwise remainder of the CWA will struggle to warm much today with highs only in the upper 40s to upper 50s. Push of colder air into the state on the backside of the system tonight as H85 temps actually drop below freezing. However low clouds expected to be across the CWA so should limit the temp drop with lows mainly in the 40s tonight. .LONG TERM.../Sunday through Friday/ Issued at 359 AM CDT Sat May 20 2017 Sunday... Parent upper low described in the short term slated to trek northward, making it to the Canada/Minnesota border by 00z Mon. 00z model runs cluster well enough to where general consensus blend reliable...with less emphasis continuing to be placed on the NAM. Associated sfc low to be located over the Northwoods of Wisconsin by 00z Mon. The past few model runs have been persistent with wrap-around stratus covering Iowa most of the day. Now seeing the whites of the eyes of the clouds, must buy in to stratus...especially across northern to northeastern Iowa. As advertised in yesterday morning's AFD, have followed through on expectation to lower max temps 5 degrees vs guidance. Now have highs in the 50s down to Creston and Ottumwa. Still may have a degree or two to shave off and could probably even trim a few additional degrees more across the north/northeast given higher likelihood of denser stratus during daytime heating. Cloud thickness depths should generally not be high enough to warrant drizzle mention beyond perhaps the north/northeastern tier of counties. Monday into Tuesday... Models showing high run-to-run consistency in dropping a shortwave southeastward through Canada and towards the upper Midwest. Models also showing great run-to-run consistency in "phasing" this shortwave with the upper low from this weekend. Accompanying sfc low should be near the IA/MN border by 21z Mon...with attendant cold front dropping south/southwestward through the western portion of the DMX CWA. MLCAPE values approach 1000 J/KG ahead of the boundary...which would serve as a focusing mechanism for thunderstorm development. With dewpoints in the mid to upper 40s and sfc temps in the mid to upper 60s, sounding analysis confirms any storms should be elevated, effectively confining the threat to marginal hail chances, with a low strong wind threat. This system will propagate eastward overnight, pushing east of the DMX CWA by 09Z-12Z Tue. Wednesday and Beyond... Behind the Tuesday system, ridging/thermal ridging will have been building over the intermountain west. Long- range models showing good agreement in placing sfc high over the Midwest by 06Z Thursday...with the thermal ridge crashing down over Iowa Thursday into Friday. If this solution holds, temperatures will need to be bumped up several degrees. && .AVIATION.../For the 06Z TAFS through 06Z Saturday night/ Issued at 1145 PM CDT Fri May 19 2017 Widespread IFR to LIFR cigs will be over Iowa through much of Saturday before improving late. A couple waves of showers and a few thunderstorms through the period that may reduce vsbys at times. A boundary will move through late afternoon and into the evenings and bring a switch in wind direction. Drier air will arrive with the boundary and cigs will begin to improve. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Beerends LONG TERM...Kotenberg AVIATION...Donavon  FXUS63 KDMX 302112 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 412 PM CDT Wed Aug 30 2017 .SHORT TERM.../Tonight through Thursday/ Issued at 411 PM CDT Wed Aug 30 2017 Bottom Line up Front... Fog potential once again tonight...though at this time, it does not appear the fog will be as dense as it was this morning. A few showers are possible this evening in the northeast, but they should pose no hazardous impacts. Tonight... 20z water vapor imagery shows an upper low spinning near the Hudson Bay. Meanwhile, a 1020mb sfc high has been in place directly over Iowa today. Models are picking up on a weak impulse ejecting off the base of the longwave trough associated with the Hudson Bay low, that is propagating southward, interacting slightly with the low-level convergence created from the westerly component to the winds from the sfc high over Iowa. 20z vis sat shows this band very readily. Hi- res models now coming into good agreement with retrograding the sfc high to the northwest and breaking it down slightly, with transport winds aloft pushing the band of clouds/light precip south/SW into northern Iowa overnight. CIGs are around 1000 to 2000 ft with these clouds...which would obviously hinder radiational fog development. Cloud thicknesses may increase enough to where some low-end showers may reach the ground in northern Iowa. Ahead of the clouds, patchy to areas of fog may be possible again. For tomorrow afternoon, the overall trend for thunderstorms to fire along this band of clouds is decreasing, as it appears there will be a strong push to the west with the next sfc high being positioned over northern Wisconsin by peak heating. Have slight chance for pops in there now from central to western IA, but this may need to be removed. .LONG TERM.../Thursday night through Wednesday/ Issued at 411 PM CDT Wed Aug 30 2017 Bottom Line up Front... What perhaps may be Summer's last gasp will impact us Sunday into Monday as high temperatures may make it into the upper 80s and perhaps even low 90s in some locations. By Tuesday and the rest of the week, highs will struggle to reach 70 degrees (no typo), with low temperatures making it into the 40s...with upper 30s possible in northern Iowa. Friday through Monday... With a very broad area of high pressure located over the Four Corners region, a thermal ridge has been building over the intermountain west and pushing well into Canada. Meanwhile, a deep upper low has been spinning off the Alaska shoreline. Several impulses are expected to eject off the low between today and Monday. With the Four Corners high amplifying and drifting north, these impulses will all remain in Canada, keeping us dry through this weekend. In perhaps what will be the final show of warm weather for this summer, the thermal ridge will come crashing down over Iowa Sunday into Monday. 850mb temps should be somewhere near +20C to +25C for Sunday afternoon, which will yield temperatures well into the 80s for Sunday. Models then diverge very wildly on the curtain call for thermal ridge over Iowa. A deep, broad upper low has been well- advertised for the past several days, with the accompanying longwave trough digging all the way down to the Gulf of Mexico. At some point on Monday, the lad cold front will be passing through Iowa. The 12z GFS is much slower with the fropa and, resultingly, has another day with the thermal ridge and +25C temps over Iowa...meaning temperatures could be in the 90s. The 12z ECMWF, however, pushes the front through during the morning hours on Monday, leading to strong CAA throughout peak heating and confining temperatures in the 70s and 80s. At this point, the GFS solution seems to be the outlier, so have leaned strongly towards the ECMWF, keeping temperatures in the 80s... this is subject to change. Tuesday and beyond... Confidence continues to be high in well-below normal temperatures and dry conditions across Iowa. The trends have been slowly downward, with 850mb temps perhaps making it down to +5C by Wednesday night. For the first week in September, record daily low maximum temperatures are in the 50s, and record low minimum temperatures are in the 30s. At this time, it appears we should be 5 to 10 degrees to warm to break those records, but we will be watching closely. && .AVIATION.../For the 18Z TAFS through 18Z Thursday afternoon/ Issued at 1223 PM CDT Wed Aug 30 2017 High confidence in VFR conditions the rest of today. Will be contending with fog again across the northern sites... KFOD...and especially KMCW and KALO. Band in clouds moving from north to south across northern Wisconsin will make it into northern Iowa by tomorrow morning. CIGs with these clouds should be near 1000ft. Have kept out of IFR for now, but next update may need IFR at least for KMCW. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Kotenberg LONG TERM...Kotenberg AVIATION...Kotenberg  FXUS63 KDMX 060857 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 357 AM CDT Fri Oct 6 2017 .SHORT TERM.../Today through Tonight/ Issued at 356 AM CDT Fri Oct 6 2017 Main focus will be on several chances of precipitation across the area today into tonight. A few light showers out there currently with another round expected to move into far southern Iowa through the mid morning hours as another push of theta-e advection becomes oriented into southern Iowa in vicinity of the sfc warm front currently stretched across the area. Associated sfc low stretches back to the southwest centered over SW KS currently. The sfc low will lift ENE into SW IA by this evening, and push into eastern IA as the upper trough exits the Rockies and digs into the central US by early Saturday. Precipitation is expected to become more widespread toward mid morning into the afternoon hours as an upper level shortwave trough ejects out ahead of the main upper level trough. This shortwave currently kicking off scattered showers and storms across central and western NE. As the sfc low approaches SW IA expect an area of thunderstorms to develop in vicinity of the sfc low/sfc trough axis and move through much of central/eastern IA by late afternoon/evening. MUCAPE values increase to around 1000 J/kg or higher, with stronger deep layer shear. An isolated strong to possibly severe storm will be possible in the far SW where CAPE values and shear values better. Otherwise precipitation potential the main issue with deep warm cloud depths and pwats pushing 1.5 to 2.0 inches across the southern half of the forecast area. Some areas across the south central to southwest have already had around 1 to nearly 3 inches of rain over the past 12 hours, and could see another widespread 1 to 2 inches through early Saturday morning. However with the efficient rainfall production expected and convective possibility, isolated higher amounts of 2 to 3+ inches will be possible. With lowered FFG values in the far southwest around 1 to 2.5 inches for 1 hr up to 6hr values. Therefore with the combination of several rounds of precip expected, efficient rainfall production, and lowered FFG due to antecedent conditions will issue a flash flood watch for the far southwestern portion of the forecast area through tonight. Def zone precip to wrap up through the forecast area late tonight as the sfc low lifts into NE IA with the back edge of the precip expected to be approaching western IA toward 12Z Saturday. .LONG TERM.../Saturday through Thursday/ Issued at 356 AM CDT Fri Oct 6 2017 Bottom Line Up Front... Uncertainty still reigns supreme in this long term fcst period. Sunday will be the warmest day of the week, with temperatures well into the 70s. Precip chances try to manifest Monday into Tuesday, followed by a cool-down into the middle of this week. This Weekend... 00z Fri ECMWF and GFS solutions remain stubborn in their respective outputs for departing the system described in the short-term out of the CWA. ECMWF still slower and deeper with the sfc low, the GFS is the fastest solution, and the rest of the models fall somewhere in between, though trends are favoring the ECMWF. Thus, have again held wrap-around precip into the afternoon period along and east of I-35. Cross sections picking up on near- sfc drier air punching in to increase sfc dwpt depressions, however, cloud thickness above 900mb around 2km, which is enough to justify keeping light rain mention...with only a few hundredths of QPF at most. Sunshine then returns for Sunday as dry air entrains into Iowa from the southwest. Monday and Beyond... As introduced last night, details become somewhat murky for Monday and beyond... Though Monday and Tuesday coming into slightly better focus. 00z ECMWF and 00z GFS slowly coming into agreement with featuring a longwave trough off a low near the Hudson Bay digging southwestward into the Four Corners region by 12z Mon. By 18z Tue, both models develop a westward-tilting cut- off low somewhere over the Midwest, with its sfc reflection pulling ahead. As was the case with Saturday afternoon, both these long- range operational models remain stubborn in their respective run- to-run solutions... The GFS is holding a more northern solution which would mean more rain for Iowa, whereas the ECMWF is holding a much more southerly solution that may actually leave Iowa out of any precip chances. The GEM more closely echos the ECMWF solution, as does the GFS Ensemble output. So have left precip in the forecast, but have removed 'likely' wording. Should the GFS solution pan out, precip looks mainly to be confined to the morning hours, and PWAT values around 1.5 to 1.75 inches, which when coupled with a decent slug of theta-e advection, 950 to 900mb frontogenetical forcing, and 850mb moisture convergence, would suggest a potential for a moderate amount of rainfall. Beyond Tuesday, the only thing to be confident about is a lack of confidence. Long-range model run-to-run consistency and agreement remain low. On a grander scale, a dominant and robust area of 850- 300mb anticyclonic flow sets up over the Gulf of Mexico. This will keep Iowa in westerly to southwesterly flow at 500mb through the remainder of the week. Models then struggle with trying to propagate a sfc high through the Midwest, where yesterday, there was a shortwave pushing through the Midwest. CAA will follow the Monday/Tuesday system, but then another thermal ridge looks to begin to build towards the end of the week...indicating a potential for warmer temperatures towards next weekend. && .AVIATION.../For the 06Z TAFS through 06Z Friday night/ Issued at 1131 PM CDT Thu Oct 5 2017 Area of convection over southern Iowa mainly only affecting KOTM at this time. Isentropic lift resulting in some showers north of KDSM moving NE toward KALO/KFOD/KMCW. Showers/lower vsby will remain through 12z with some lowering to MVFR possible IFR vsby between 12-15z. Hires and synoptic models suggest most widespread shower/thunder coverage will arrive aft 19-20z as better lift approaches though most of overnight/Friday MVFR/IFR conditions will continue. From 23z Fri to 06z Sat widespread rain/possible thunder with worst overall period of wx expected. Next update will detail coverage/timing. /rev && .DMX WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch from 7 AM CDT this morning through Saturday morning for IAZ070>072-081>083-092>094. && $$ SHORT TERM...Beerends LONG TERM...Kotenberg AVIATION...REV  FXUS63 KDMX 270844 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 344 AM CDT Fri Oct 27 2017 .SHORT TERM.../Today through Tonight/ Issued at 344 AM CDT Fri Oct 27 2017 Bottom Line up Front... Today will be another day of strong winds across Iowa, with sustained winds of 15 to 25 mph and gusts of 30 to 40 mph for most of the area. Additionally, 1 to 2 inches of snow is likely across northern Iowa, potentially leading to travel difficulties when combined with the strong winds. Temperatures will only warm around 3 to 7 degrees after sunrise, at best...making today by far the coldest day of the new season. Today... At 09z Fri, a broad area of low pressure, centered over western Wisconsin has continued to become better-organized. 500mb vorticity continues to show this low taking on more of a classic comma shape. By around 06z to 09z Sat, the low is slated to have propagated towards the U.P. of Michigan, taking along with it the rain/snow mix and stronger winds. 850mb temps remain more or less unchanged throughout the day. Given the cloud cover an precipitation, confidence high in the temperatures only warming up 3 to 7 degrees... with the greatest rises in southern Iowa. Precipitation... Trends for the highest snowfall amounts have slightly shifted eastward, from NR Iowa towards the MN/WI border. Lack of saturation/moisture will be biggest limiting factor in precipitation amounts. Forecast soundings, in particular, KMCW, are in good agreement with cloud thickness around 5000ft, which is enough for light snow. Cross-section from KEST to KLSE shows a pocket of ascent through a nearly-saturated DGZ... challenge is tat it appears this pocket of stronger ascent will be just northeast of the DMX CWA and into SE MN. Ultimately have 1 to 2 inches in the north, with precip exiting the DMX CWA between 06z-09z Sat. Worth noting that with pavement temperatures likely bear to above freezing during much of this event, will be difficult for snow to accumulate on roadways... much of the snow accumulation may be confined to grassy surfaces. Winds... Confidence high in yet another windy day across Iowa. Pressure gradient on the backside of the low generally continues around 3mb/60km within the area of tighter gradient. Forecast soundings show winds on avg around 30kts to 40 kts through the mixed layer. KEST to KMCW looks to be where the strongest winds will likely occur. With Winter Weather Advisory already in play, do not have these locations mentioned in a Wind Advisory... even though KEST especially will quite possibly gust to 45 to 50 mph today. As the low moves away towards tomorrow, winds will "relax" to the 10 to 20 mph range. .LONG TERM.../Saturday through Thursday/ Issued at 344 AM CDT Fri Oct 27 2017 Long wave trof will be shifting eastward on Saturday with influence on Iowa waning through the day. With the decrease in cyclonic curvature and low level moisture, clearing should spread from west to east over the remainder of the forecast area by afternoon. The state will be on the backside of the thermal trof with temperatures remaining well below normal as northwest winds persist. Surface ridging will pass through the state on Saturday night with warm advection increasing as the night progresses. There will likely be some non-diurnal temps in western Iowa as south winds begin to strengthen overnight. Thermal ridge will pass across the state on Sunday with southwest winds and temperatures a good 10 to 15 degrees warmer than Saturday, although increasing clouds will keep readings from climbing too much. A front is expected to pass into the state by late in the day with increased kinematic forcing as a shortwave approaches from the northwest. Scattered light rain is expected in the north and northeast, especially by later in the afternoon to early evening with the passage of the boundary. Thereafter, cold advection will persist on Monday into Tuesday as Canadian air drops into the upper Midwest. The thermal trof will build into the state by midday Tuesday with each day seeing successively colder highs. The upper pattern will begin to undergo a significant change after this point through the end of the work week. The large eastern trof will lift northeast with a gradually deepening trof across the western United States. With time, height will increase across the central United States meaning temperatures will warm from Wednesday through the end of next week. The threat of precipitation will be relatively minimal through this time as moisture remains limited. && .AVIATION.../For the 06Z TAFS through 06Z Friday night/ Issued at 1150 PM CDT Thu Oct 26 2017 Upper trough of low pressure to move across the state tonight and Friday which will bring MVFR cigs to all TAF locations and some light snow to northern TAF locations. Strong wind will also accompany this feature which will increase some after 15Z especially north. Snow to end by 00Z but MVFR cigs will continue through the TAF period. && .DMX WATCHES/WARNINGS/ADVISORIES... Freeze Warning until 9 AM CDT this morning for IAZ007-016-017- 024>026-033>036-044>047-057-058-070-071-081-082-092-093. Winter Weather Advisory until 7 PM CDT this evening for IAZ004>007-015>017. Wind Advisory until 7 PM CDT this evening for IAZ023-033-034-044- 045. && $$ SHORT TERM...Kotenberg LONG TERM...Cogil AVIATION...FAB  FXUS63 KDMX 300842 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 342 AM CDT Mon Oct 30 2017 .SHORT TERM.../Today through Tonight/ Issued at 342 AM CDT Mon Oct 30 2017 Bottom Line up Front... Strong and gusty winds return to Iowa today, lasting into the evening hours. Temperatures this evening will be in the 30s across the state...when combined with winds in the 15 to 25...will produce wind chills below freezing across most of Iowa, including Des Moines. If you and/or your family are going to be outside this evening, make sure additional/sufficient layers of clothing are being worn. Today... 08z GOES-R water vapor imagery picking up on an upper low spinning over the Minnesota/Canada border, slowly propagating to the southeast towards Lake Superior. From this imagery, it is somewhat easy to discern an upper level jet oriented from w-e ranging from Iowa, across Nebraska, and into Wyoming. Models are picking up on a strong PV anomaly/lobe with this jet. Aided with mid to upper-level q-vector convergence, mid to upper level clouds have been present across much of central to southern Iowa through this morning, helping to keep radiative cooling to a minimum. This lobe/band PV anomaly should continue to follow the jet as it traverses into northern Missouri and Illinois throughout the day today...taking along the high-mid level clouds with it. In the low-levels, closer to 850mb, wrap-around moisture from our upper low looks to make it into northern Iowa by mid morning, spreading into southern Iowa by around noon. Accompanying this moisture will be strong CAA and strong winds. 850mb temps fall from the -2C to -5C range near sunrise, to the -6C to -9C range by sunset. Factoring the cloud cover, temperatures will only warm a few degrees, if that, during the daytime hours. RAP/HRRR BUFKIT soundings show cloud thickness to be not much more than 1-1.5KM, which may be the only saving grace from temperatures actually falling throughout the daytime... if this were December, with the subsequent reduction of insolation, temperatures would absolutely be falling today. BUFKIT soundings also pick up a somewhat decently well mixed layer of around 30 to 35 kts, with 35 to 45kts atop, depending upon location. Thus have upped winds vs guidance... but kept at levels below Wind Advisory criteria. Worth noting that forecast soundings showing mixing to continue into the 10 pm hour, meaning that winds will not decouple with sunset and that this evening will remain gusty. As mentioned earlier, this will rapidly drop wind chills into the 20s and low 30s after sunset. .LONG TERM.../Tuesday through Sunday/ Issued at 342 AM CDT Mon Oct 30 2017 Confidence is increasing for the medium range with model solutions showing good agreement through mid-week with some divergence toward the end of the week into next weekend. Large broad upper troughing in place across the central US, with dry and chilly conditions expected for Tuesday. Another shortwave trough drops down into the region late Tuesday into Wednesday with increasing cloudiness expected Tuesday night and WAA setting up in advance of a developing area of surface low pressure moving through the Dakotas. May see some light snow/transitioning to rain across the far north Wednesday/Wednesday night with this system as the upper trough moves through ND/MN during the period. The associated cold front drops through Wednesday night with dry conditions expected into Thursday as a zonal flow pattern sets up aloft. The zonal flow pattern starts to transition to more of a southwest flow pattern toward latter portion of the weekend as a trough digs into the Pacific Northwest. This will set up a more active pattern across the region toward Sunday into early next week. An area of low pressure will develop in lee of the Rockies by late Saturday night, with the sfc low lifting ENE through the northern/central Plains into Sunday. This will set up a large area of WAA and moisture advection across the state with precipitation potential through the weekend into early next week. The state to be in the warm sector Sunday night into Monday, and have added in some thunder mention with the pops at this time. As for temperatures through the period, chilly conditions continue this week, with a push toward the seasonal averages Thursday and again Saturday. Sunday should be the warmest day with highs moving back above average into the 50s/60s, before the cold front moves through sending temps back to near or below average for Monday. && .AVIATION.../For the 06Z TAFS through 06Z Monday night/ Issued at 1108 PM CDT Sun Oct 29 2017 VFR conditions returning to northern sites in the wake of the first frontal passage. Mid to high level clouds and increasing winds aft 15z will accompany the passage of the second front. Cigs still look to lower to possible MVFR conditions for KMCW/KALO and briefly at KFOD between 16-23z. Northwest winds increase to 20 to 30kts aft 15z through 00z as well. Northwest flow expected through remainder of period above 12kts most sites...though should relax toward 12z Tues 10/31 as ridge builds east./rev && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...Kotenberg LONG TERM...Beerends AVIATION...REV  FXUS63 KDMX 220946 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 346 AM CST Wed Nov 22 2017 .SHORT TERM.../Today through Tonight/ Issued at 346 AM CST Wed Nov 22 2017 Bottom Line up Front... A chilly, but hazard-free forecast is in store for Iowa today. The biggest noticeable weather impacts will be from wind chill temperatures in the teens through single digits for most of the morning hours, and the potential for flurries/wintry precip for portions of east-central/northeast Iowa this afternoon and evening. Temperatures... 09z Water vapor image picking up on large ridge building over the intermountain west beginning to reach into southern Canada. Additionally, there is an upper low over the eastern Hudson bay, with the accompanying longwave trough digging into the Ohio Valley region. This large-scale setup will have Iowa socked into northwesterly flow aloft once again today. Closer to home, there is an 1032mb sfc high pushing southeastward into northeastern Kansas. This sfc high should make it into eastern/southeastern Missouri by this afternoon, gradually pushing Iowa into S/SW flow at the sfc. Yesterday, 850mb temps fell to the -4C across the south to -10C range across northern Iowa, which is the range they are close to for this morning. Though 850mb temps will notably rise later today as the WAA/return flow arrives into Iowa as the thermal ridge begins to crash over the state, the arrival will be a little too late to boost temps very much after the noon hour, as temperature values should stay fairly flat, especially across northeastern Iowa, where there will likely be more extensive, thicker cloud cover... Wintry precip... Models are picking up on a PV anomaly/ill-formed shortwave interjected into the mix in ahead leading edge of our thermal ridge. Models are also picking up on a 1015mb or so sfc reflection low propagating E/SE into western MN by 00z Thu. There is generally good clustering with this feature... though worth noting the hi-res models are trending slightly faster with this push. Leading this sfc low is a very well-defined band of 850mb theta-e advection oriented from N-S that makes it all the way down to I-80. This band looks to pass through Iowa from 18z Wed to 00z Thu. Properly captured right behind this band of theta-e advection is a slug of moisture, phased with ascent through the dendritic growth zone. The only mitigating factor keeping this from being a noteworthy precip event is the lack of near-sfc moisture. From around 800mb to the sfc, there is a clear lack of saturation, which will push to evaporate a lot of the precip before it reaches the sfc. Ultimately, cloud thickness will have no problem supporting sufficient droplet growth, but it will be a rough journey upon cloud departure. In terms of precip type, fcst soundings early on clearly suggest flurries. Leaned slightly towards HRRR sounding, though the RAP and general consensus okay enough to use as well. As 00z approaches, WAA will have reached KMCW and the rest of our CWA, suggesting a trend towards sleet/fz rain. However, by 00z Thu, hi-res models showing the best ascent wast of the DMX CWA. Thus, have wintry precip chances ending somewhat abruptly before sensible wintry precip impacts are felt. Did not want this flurry/wintry precip potential to go unmentioned, but hazardous impacts from this should effectively be nil. .LONG TERM.../Thursday through Tuesday/ Issued at 346 AM CST Wed Nov 22 2017 Fairly warm pattern expected through much of the mid/long range, with main issue being winds Friday into Saturday and again Monday into Tuesday. Broad upper ridge in place across the western US with westerly to northwesterly upper level flow across the region to begin the period. Area of high pressure in control at the surface with waa for Thanksgiving Day. H85 temps around +5C to +9C which should result in highs in the 40s/lower 50s as sfc winds begin to shift around to the south late Thursday. Southerly flow and WAA to increase late Thursday night into Friday ahead of the next cold front expected to drop through the state mid Friday into Friday night associated with an area of low pressure moving through Ontario. May still see a shower clip the far north, but again low confidence the area will see anything more than an increase in clouds with the frontal passage. Bigger issue is the winds behind the front with strong CAA, tightened sfc pressure gradient and higher pressure rises. BUFKIT winds showing 35-40 kts at the top of the mixed layer with a decent period of strong/gusty winds possible in the afternoon/early evening hours. Winds expected to be gusty again Saturday with strong flow throughout the lower levels, with sunny skies and a large area of high pressure building into the central Plains. With mixing could get some of the stronger winds aloft to mix down, however expect winds to begin to diminish toward late afternoon/early evening as the high builds into Iowa and the flow aloft begins to decrease. Western US upper ridge to then shift eastward into the central US during the upcoming holiday weekend. The sfc high will shift off to the south and east as return flow sets up across the state into Monday. An upper trough digs into the intermountain west with southerly to southwesterly flow increasing ahead of it with a strong push of much warmer air into the state for Monday. H85 temps increase to around +15C by late Monday with our warmest southwesterly flow in place. For now have gone slightly above guidance grids with temps into the 50s to around 60. Would not be surprised though if temps ended up substantially warmer with much of the area into the mid 50s to mid 60s or warmer. Will be monitoring in the coming days and adjust temps upward if current solutions still expected. The western US upper trough to eject eastward into Tuesday/Wednesday with the sfc low lifting through IA during the day Tuesday. May see some precip chances on the backside of this system across the far north, otherwise majority of precip associated with this system to remain to the north/west of the state. Strong cold front to drop through late Tuesday which will send temps plummeting with highs by Wednesday only in the mid 30s to mid 40s again. && .AVIATION.../For the 06Z TAFS through 06Z Wednesday night/ Issued at 1052 PM CST Tue Nov 21 2017 Winds continue to decrease this evening and will continue to do so as high pressure settles into the area toward sunrise as skies remain mainly clear. As the high moves off to the east, winds will become from the southwest Wednesday morning. Clouds will pass over the terminals later tomorrow morning through Wednesday evening, but will be VFR with bases well above any ceiling restrictions. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...Kotenberg LONG TERM...Beerends AVIATION...Ansorge  FXUS63 KDMX 221126 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 526 AM CST Wed Nov 22 2017 ...Updated for 12z Aviation Discussion... .SHORT TERM.../Today through Tonight/ Issued at 346 AM CST Wed Nov 22 2017 Bottom Line up Front... A chilly, but hazard-free forecast is in store for Iowa today. The biggest noticeable weather impacts will be from wind chill temperatures in the teens through single digits for most of the morning hours, and the potential for flurries/wintry precip for portions of east-central/northeast Iowa this afternoon and evening. Temperatures... 09z Water vapor image picking up on large ridge building over the intermountain west beginning to reach into southern Canada. Additionally, there is an upper low over the eastern Hudson bay, with the accompanying longwave trough digging into the Ohio Valley region. This large-scale setup will have Iowa socked into northwesterly flow aloft once again today. Closer to home, there is an 1032mb sfc high pushing southeastward into northeastern Kansas. This sfc high should make it into eastern/southeastern Missouri by this afternoon, gradually pushing Iowa into S/SW flow at the sfc. Yesterday, 850mb temps fell to the -4C across the south to -10C range across northern Iowa, which is the range they are close to for this morning. Though 850mb temps will notably rise later today as the WAA/return flow arrives into Iowa as the thermal ridge begins to crash over the state, the arrival will be a little too late to boost temps very much after the noon hour, as temperature values should stay fairly flat, especially across northeastern Iowa, where there will likely be more extensive, thicker cloud cover... Wintry precip... Models are picking up on a PV anomaly/ill-formed shortwave interjected into the mix in ahead leading edge of our thermal ridge. Models are also picking up on a 1015mb or so sfc reflection low propagating E/SE into western MN by 00z Thu. There is generally good clustering with this feature... though worth noting the hi-res models are trending slightly faster with this push. Leading this sfc low is a very well-defined band of 850mb theta-e advection oriented from N-S that makes it all the way down to I-80. This band looks to pass through Iowa from 18z Wed to 00z Thu. Properly captured right behind this band of theta-e advection is a slug of moisture, phased with ascent through the dendritic growth zone. The only mitigating factor keeping this from being a noteworthy precip event is the lack of near-sfc moisture. From around 800mb to the sfc, there is a clear lack of saturation, which will push to evaporate a lot of the precip before it reaches the sfc. Ultimately, cloud thickness will have no problem supporting sufficient droplet growth, but it will be a rough journey upon cloud departure. In terms of precip type, fcst soundings early on clearly suggest flurries. Leaned slightly towards HRRR sounding, though the RAP and general consensus okay enough to use as well. As 00z approaches, WAA will have reached KMCW and the rest of our CWA, suggesting a trend towards sleet/fz rain. However, by 00z Thu, hi-res models showing the best ascent wast of the DMX CWA. Thus, have wintry precip chances ending somewhat abruptly before sensible wintry precip impacts are felt. Did not want this flurry/wintry precip potential to go unmentioned, but hazardous impacts from this should effectively be nil. .LONG TERM.../Thursday through Tuesday/ Issued at 346 AM CST Wed Nov 22 2017 Fairly warm pattern expected through much of the mid/long range, with main issue being winds Friday into Saturday and again Monday into Tuesday. Broad upper ridge in place across the western US with westerly to northwesterly upper level flow across the region to begin the period. Area of high pressure in control at the surface with waa for Thanksgiving Day. H85 temps around +5C to +9C which should result in highs in the 40s/lower 50s as sfc winds begin to shift around to the south late Thursday. Southerly flow and WAA to increase late Thursday night into Friday ahead of the next cold front expected to drop through the state mid Friday into Friday night associated with an area of low pressure moving through Ontario. May still see a shower clip the far north, but again low confidence the area will see anything more than an increase in clouds with the frontal passage. Bigger issue is the winds behind the front with strong CAA, tightened sfc pressure gradient and higher pressure rises. BUFKIT winds showing 35-40 kts at the top of the mixed layer with a decent period of strong/gusty winds possible in the afternoon/early evening hours. Winds expected to be gusty again Saturday with strong flow throughout the lower levels, with sunny skies and a large area of high pressure building into the central Plains. With mixing could get some of the stronger winds aloft to mix down, however expect winds to begin to diminish toward late afternoon/early evening as the high builds into Iowa and the flow aloft begins to decrease. Western US upper ridge to then shift eastward into the central US during the upcoming holiday weekend. The sfc high will shift off to the south and east as return flow sets up across the state into Monday. An upper trough digs into the intermountain west with southerly to southwesterly flow increasing ahead of it with a strong push of much warmer air into the state for Monday. H85 temps increase to around +15C by late Monday with our warmest southwesterly flow in place. For now have gone slightly above guidance grids with temps into the 50s to around 60. Would not be surprised though if temps ended up substantially warmer with much of the area into the mid 50s to mid 60s or warmer. Will be monitoring in the coming days and adjust temps upward if current solutions still expected. The western US upper trough to eject eastward into Tuesday/Wednesday with the sfc low lifting through IA during the day Tuesday. May see some precip chances on the backside of this system across the far north, otherwise majority of precip associated with this system to remain to the north/west of the state. Strong cold front to drop through late Tuesday which will send temps plummeting with highs by Wednesday only in the mid 30s to mid 40s again. && .AVIATION.../For the 12Z TAFS through 12Z Thursday morning/ Issued at 524 AM CST Wed Nov 22 2017 High confidence in VFR conditions throughout entire TAF period. Largest concern will be chance of flurries/light wintry mix to impact KMCW and KALO... with KFOD and KOTM likely just missing out. Am not expecting sensible impacts to aviation activities, as flurries should be light and not accumulate on surfaces, for the short duration they may occur. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Kotenberg LONG TERM...Beerends AVIATION...Kotenberg  FXUS63 KDMX 252133 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 333 PM CST Sat Nov 25 2017 .SHORT TERM.../Tonight through Sunday/ Issued at 330 PM CST Sat Nov 25 2017 Bottom Line Up Front... An extremely quiet weekend weather-wise, with well above-normal temperatures expected to continue through tomorrow. Aloft, 20z Water vapor imagery easily picking up on large ridge that expands northward well into central Canada. At the sfc, a well- defined 1025mb sfc high was centered over Kansas and propagating fairly quickly to the ESE. Large-scale subsidence and dry-air entrainment are clearly dominating as vis sat imagery shows little to no cloud cover. 850mb temps started today around the +1C to 4C range across the DMX CWA. For 12z Sun, they should be around +2C to +5C. Models are trying to bring some upper-level clouds currently located over the Pacific NW into Iowa during the day tomorrow. However, upper level jet loses structure as it pushes into the Midwest, so although there will likely some upper level clouds tomorrow, am not expecting overcast day. In all, persistence will be a close forecast for Sunday temperatures. For this evening into tonight, winds quickly decouple after sunset. With little to no cloud cover expected, could be a decent radiational cooling night... though not "textbook" as WAA will be ongoing/continuing. .LONG TERM.../Sunday night through Saturday/ Issued at 330 PM CST Sat Nov 25 2017 Bottom Line Up Front... Record to near-record high temperatures expected once again across Iowa for Monday afternoon. Generally above-normal temperatures should continue for the rest of the upcoming week, with slight rain chances towards mid-week. Monday... As has been well-advertised, core of the thermal ridge will crash down over Iowa Monday. There is value in comparing the overall setup from Friday, where record temperatures were set at numerous locations across the state. Overall pattern very similar. 850mb temps of +15C to +18C are a degree or two warmer, if anything, than they were for Friday. Minimal cloud cover expected, so parameters in place for near-record highs in central to southern Iowa. Interesting that the record high at Estherville is 75, and Mason City is 71, while Des Moines is at 68... all records in 1998. Tuesday into Thursday... Tuesday and Wednesday PM/Thursday AM will bring out best chances for (light) precip all week. model consensus us building that a frontal boundary will push through Iowa from west to east on Tuesday morning. Actually a well-defined band of frontogenetical forcing from 925mb through 700mb. This forcing does seem to be phased with a pocket of moisture from around 900mb to 800mb... leading to 5kft cloud thicknesses. Dry air above and below will be major hindrances to actual light to moderate rainfall. Last week, a somewhat similar setup produced sprinkles to light rain, so have added sprinkle wording... with a strong possibilitiy of precip being upgraded to slight chance overnight or tomorrow afternoon. Strong subsidence behind this boundary, so skies should clear into Wednesday morning. Long-range models showing decent agreement with racing a shortwave across Canada Wednesday, and dropping an attendant boundary through Iowa Wednesday into Thursday. Forecast soundings show slightly better saturation and support aloft on this second round. Frontogenetical forcing is also easily discernible, so think going precip chances are warranted...and could be raised in subsequent updates to better resemble a high POP/low QPF depiction. Beyond Thursday... The past several runs of the GFS and ECMWF have suggested the thermal ridge to slowly build again over the intermountain west... pointing towards above normal temperatures continuing into next weekend, and possibly another day of near- record to record high temperatures at some point towards next weekend. && .AVIATION.../For the 18Z TAFS through 18Z Sunday afternoon/ Issued at 1125 AM CST Sat Nov 25 2017 VFR conditions forecast throughout TAF period. Winds above 10 kts primarily at KMCW, KALO, and KOTM, will diminish after sunset tonight. Slight chance for freezing fog tomorrow morning at KMCW and KALO, however, confidence not high enough to warrant mention at this time. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Kotenberg LONG TERM...Kotenberg AVIATION...Kotenberg  FXUS63 KDMX 211041 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 441 AM CST Sun Jan 21 2018 .SHORT TERM.../Today/ Issued at 441 AM CST Sun Jan 21 2018 A well-advertised area of low pressure is coming off the Oklahoma panhandle and is beginning to churn towards Iowa. In advance of this area of low pressure, a well-defined boundary has been pushing northward through Iowa. The 290K surface picks up on this boundary well, with a decent slug of isentropic lift accompanying it. At 09z Sun, the boundary was near I-80. Temperatures along and south of the boundary were in the upper 30s to low 40s. North of this boundary, skies cleared for a brief period early this morning, allowing temperatures to fall to the mid to upper 20s. Hi-res models have been a little over-aggressive with low ceilings this morning, calling for CIGs near 500 ft, where in reality, they have struggle to reach much below 2500 ft. This lack of shallow moisture has kept vsbys from plummeting as much as advertised behind the boundary. for the rest of today, expect forcing to persist behind the boundary, aided by weak, but sufficient sfc convergence. Fcst soundings have cloud thicknesses under 5000ft. In all, this supports widespread drizzle across Iowa as this boundary slowly pushes northward. Across northern Iowa, primarily along and north of Highway 30, freezing drizzle is possible. With any ice accums expected to be little to none, icing should be a very minimal impact today. Visibility may be reduced to the 1 to 3 mile range throughout today. .LONG TERM.../Tonight through Saturday/ Issued at 441 AM CST Sun Jan 21 2018 Surface low pressure will be lifting north into eastern Kansas by this evening then will continue to lift slowly northeast into Iowa by Monday morning. Areas of drizzle and some fog will be ongoing across much of central Iowa to start the period and temperatures should be at or above freezing for most locations except for the far northwest through the night. A region of convection should lift into central and southeast Iowa this evening as the short wave approaches from the southwest and the low level jet and steeping mid level lapse rates help generate MUCAPEs to near 500 J/kg. This convection likely will produce graupel and/or small hail as it quickly moves through. The precipitation will transition to snow over the northwest once the residual mid level dry air erodes and the deformation band begins to form. Convective elements withing the deformation band look possible as the steepening lapse rates to near moist adiabatic, modest MUCAPES and good negative EPV are all present. This could produce very heavy snow fall rates of 1 to 2 inches per hour for a period. Model proximity soundings show a nearly isothermal layer between 0C and -2C from near the surface to around 725 mb. This profiles setup suggests the initial snowfall could be very wet and heavy and would be very sticky. Past events with similar profiles have had instances with power outages with snowfall of 3 inches or more with these properties due to tree damage. Should this wet and heavy snow occur, the increasing winds would increase the potential for tree damage and subsequent power outages would be possible. Snow ratios will increase through the day over the northwest as colder air begins to move into the area leading to a fluffier snowfall. Only minor adjustments to the forecast snowfall with a band of 6 to 12 inches still possible with the heaviest amounts confined to Emmet county and adjacent areas to the west and north. Still expect subtle adjustments to the exact track of the snow band but even a 20 nm shift would have big impacts especially along the southern edge of the snowfall. In addition, strong and gusty northwest winds will develop as the surface low pressure begins to move into eastern Iowa and northern Illinois causing the pressure gradient to increase and the cold advection and good mixing arrive. Wind gusts in excess of 40 mph are likely. Considering the forecast snowfall amounts and these winds, will be upgrading portions of the northwest to a Blizzard Warning with the primary blizzard impacts during the day on Monday and into the evening. A winter storm warning has been issued for a few counties just south of the blizzard headlines. This area had 4 inches or more of snowfall forecast in the northwest corners of these counties along with the strong winds to produce blowing snow. Warm air will encompass much of the remainder of the forecast area. A deformation snow band will move east across the forecast area by late Monday and into the evening. Any snowfall amounts would generally be one inch or less but could have some travel impacts. Little change to the remainder of the forecast as the cold advection will not last long with a transition back to ridging and later southwest flow by Thursday into Friday. The next precipitation chances will be Friday night into early Saturday. && .AVIATION.../For the 06Z TAFS through 06Z Sunday night/ Issued at 1134 PM CST Sat Jan 20 2018 Brief clearing/lifting of cigs is allowing br to form and this will bring MVFR vsbys to TAF's. Moisture will deepen and low cigs will develop overnight. If we can get drizzle to develop across northern TAF locations aft 09Z FZDZ would be possible for a few hours this A.M. but confidence in this is not high enough to include in TAF's. After 15Z DZ will begin to develop further reducing cigs/vsbys to IFR with rain developing late in the period. && .DMX WATCHES/WARNINGS/ADVISORIES... Blizzard Warning from midnight tonight to midnight CST Monday night for IAZ006-023-033. Winter Storm Warning from midnight tonight to midnight CST Monday night for IAZ007-016-024-034. Blizzard Warning from 9 PM this evening to midnight CST Monday night for IAZ004-005-015. && $$ SHORT TERM...Kotenberg LONG TERM...Donavon AVIATION...FAB  FXUS63 KDMX 101012 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 412 AM CST Sat Feb 10 2018 .SHORT TERM.../Today through Tomorrow/ Issued at 340 AM CST Sat Feb 10 2018 Bottom Line Up Front... Southern Iowa focus for two snow systems... one ongoing, and the second one expected to cruise through tonight. Cannot rule out need for another Winter Wx Advisory tonight...would likely be in southern two tiers of our Iowa counties. Ongoing System Through Today... A deep low near the Hudson Bay, with slight enhancement from a huge blocking high riding off the British Columbia coastline through southern Alaska, has helped place most of the CONUS under the influence of a longwave trough. Within this trough, a narrow PV anomaly has been pushing west to east through Iowa overnight. Well-phased with this anomaly has been a band of 750-600mb frontogenetical forcing, which cuts right through the DGZ. This has helped produce some decent dendrites and snowfall rates approaching 1 inch/hr over southern Iowa. Most of this forcing should be east of the DMX CWA by Sat 12z-15z and saturation profile will begin to break up... suggesting junky stratocu in southern Iowa. Filtered sunshine likely today across the rest of the CWA. With overall airmass/850mb temps today similar to where they were yesterday, expecting similar temperatures. Ever-so- slowly-approaching sfc high, winds should fall to 10 mph or less this afternoon. Tonight's system... Another banded PV anomaly will swing through southern Iowa tonight. Comparing the system tonight with the past one from this morning, forcing is slightly weaker with tonight's system, and saturation/cloud thicknesses are slightly less with tonight's system as well. Thus QPF is less for tonight. The NAM is a far northern outlier once again and its solution has been discounted. The IA/MO will be the best focus for precip. As mentioned above, Winter WX Adv. cannot be ruled out in southern two tiers of Iowa counties as snowfall amounts look to near 3 inches. By 12z Sun, forcing should be east of our area. .LONG TERM.../Sunday Night through Friday/ Issued at 340 AM CST Sat Feb 10 2018 After a very active past several days, the long term looks much more quiet. Next precip chances come Tuesday morning into the afternoon as yet another PV anomaly swings through Iowa. GFS has been much more optimistic with this solution than the ECMWF and now the NAM... so confidence is not high. However, the GFS solution has a decent slug of 850mb moisture convergence phased with a pocket of ascent through the DGZ. Over the past several runs, the GFS has focused on this potential precip being over our NW CWA at 12z Tue and pushing eastward throughout the day. Could be minor accumulations if it pans out. Otherwise, Wednesday may bring a brief respite to the longwave trough rut keeping Iowa cool as an area of high pressure slips through the Great Lakes Region and into the Ohio Valley Region by Wednesday afternoon. Models still zoning in on how far northward to push warmer air, but 40s are very possible in Iowa. Beyond Wednesday, long-range models have been hinting at some sort of a system for next weekend. However, confidence extremely low at this time as run-to-run consistency very poor. && .AVIATION.../For the 06Z TAFS through 06Z Saturday night/ Issued at 1141 PM CST Fri Feb 9 2018 Area of snow will impact mainly KDSM/KOTM over the next several hours with IFR/LIFR conditions at times in vsbys and cigs. Conditions in these areas will improve Saturday morning and become widespread VFR. Another system will impact southern Iowa by Saturday evening bringing lowering cigs and another round of snow. Mainly VFR conditions through the period at the other sites. Northerly winds will continue. && .DMX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 7 AM CST this morning for IAZ059>062-071>075-081>086-092>097. && $$ SHORT TERM...Kotenberg LONG TERM...Kotenberg AVIATION...Donavon  FXUS63 KDMX 080924 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 324 AM CST Thu Mar 8 2018 .SHORT TERM.../Today through Tonight/ Issued at 323 AM CST Thu Mar 8 2018 Upper low pressure which moved across the western Great Lakes region on Wednesday will be moving east towards Pennsylvania today. Despite the transition to the east, upper northwest flow will persist today. At the surface, a ridge of high pressure will move into Iowa today. Thermal profiles will remain near to slightly warmer than Wednesday and temperatures will remain seasonably cold with highs in the mid to upper 20s north to the mid to upper 30s south. Generally mostly sunny skies to start the day except for the far southwest where a few clouds are passing through. Cirrus overtopping the surface ridge may arrive by this afternoon. The forecast area will remain dry through this evening. The combination of a short wave passing across Minnesota and Wisconsin and warm advection developing in the wake of the departing ridge may result in light snow developing across South Dakota and approaching northwest Iowa by late tonight. Have kept the the forecast dry with any precipitation chances remaining to the northwest. .LONG TERM.../Friday through Wednesday/ Issued at 323 AM CST Thu Mar 8 2018 Bottom Line up Front... Sensible weather impacts confined to this weekend via a potentially low-impact wintry weather system. General trend towards above normal temperatures next week. Saturday through Sunday... An upper low currently located off the Pacific Coast looks to come onshore today, riding along the U.S./Canada border and dropping down through the Plains Region Saturday into Sunday. Models initialize well with this low, but are somewhat struggling with run-to-run consistency of its track on the leeward side of the Rockies... dropping confidence to medium/low-medium. Continued from the previous AFD, the GFS has been the most bullish with this system as it develops a closed sfc low which it propagates through Nebraska and into western Missouri Saturday into Sunday morning. The 00z Thu ECMWF/00z NAM tend to have a more flatter wave/inverted trough versus the closed sfc low of the GFS. At this point, find it difficult to back either of the general solution camps, so have gone with a blend. Obviously, if the GFS solution pans out, snowfall amounts and subsequent impacts will have to be increased. Forecast sounding analysis keeps low-level cloud thicknesses around 3kft and under through around 00z Sun. Therefore have gone with drizzle for ptype as temps into the 40s across most of the CWA. Lower levels gradually begin to Saturday evening into Saturday night. Temperatures also fall to near to below freezing Saturday night. GFS and NAM sounding profiles drop to below-freezing aloft, with no warm nose aloft. With CAA continuing, warm nose aloft to not develop Sunday, so keeping with either rain or snow mix and have nixed sleet/freezing rain mention. Even with the more ambitious general forcing with the GFS, profile does not saturate very much per the GFS soundings. So finding it plausible to begin a downward trend to QPF.... and subsequently any snow accumulation. Impact-wise, impacts from this system appear to be minimal at this time. By Sunday late morning/early afternoon, temperatures should be near to above freezing across most of the CWA. This means any snow that may have accumulated should melt off of most roadways and surfaces. Impacts will likely arise from slippery surfaces and reduced visibility confined to the time period of Saturday night through Sunday morning. Monday and Beyond... Behind this weekend's system, long-range models have been extremely consistent in blasting a 1035mb sfc high pressure through the upper Midwest. Slight forecast changes have been to slow the propagation of this high. Yesterday's 00z runs had the high near western Iowa by 06z Tue. Today's 00z runs have the high near western Iowa by 06z Wed. So, have lowered Wednesday and Thursday highs in anticipation of WAA being delayed until Thu-Fri. By late-week, as this high propagates east of the CWA, 850mb temps of +10C may make it to Iowa... which would likely translate to highs in the 50s and probably 60s across Iowa. && .AVIATION.../For the 06Z TAFS through 06Z Thursday night/ Issued at 1128 PM CST Wed Mar 7 2018 Band of low clouds continues to diminish in size tonight and this will continue as subsidence increases over the state. Expect VFR conditions for the forecast period at TAF sites with northwest surface flow through tomorrow before becoming light tomorrow night. Visibilities will remain unrestricted for the duration of the forecast. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Donavon LONG TERM...Kotenberg AVIATION...Cogil  FXUS63 KDMX 222047 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 347 PM CDT Thu Mar 22 2018 .SHORT TERM.../Tonight through Friday/ Issued at 347 PM CDT Thu Mar 22 2018 Bottom Line up Front... Confidence remains high in winter system to impact Iowa Friday through Saturday. Accumulating snow and strong winds likely in northern Iowa, and moderate to heavy rainfall in central to southern Iowa. 20z GOES-R Water vapor imagery picking up on huge upper low still spinning off the British Columbia coastline. On the southern side of this low, an impulse is being ejected onshore in California. Models have been in good agreement with propagating this upper low through the Four Corners tonight, and into the Plains States by Friday afternoon. Models also continue strong agreement with developing a sfc low in response... placing the low over western KS by 00z Sat and northern Missouri by 12z Sat. Overall, there have been little changes to the overall mesoscale features of this event. There is still a huge slug of low-level frontogenetical forcing, especially evident at 900mb that sets up over southern to south-central IA. With this system tilting northwestward with height, there is good response with 700mb frontogenetical forcing further northward along the I-80 corridor. Confidence increasing slightly in being able to pin down a slug of strong isentropic adiabatic ascent propagating through southern Iowa at some point during the 06z Sat to 12z Sat timeframe. Thus, may see some higher localized rainfall rates and even some thunder. Precip type across northern Iowa will be very touchy. Very temperature-dependent. Trend is to be slightly cooler with sfc temps, which would drop accumulating snow slightly further south, closer to the Highway 30 corridor. Snow ratios also touchy with this event. Obviously, the cooler temps would support higher snow ratios... but if the track shifts 40 miles northward, snow ratios could drop to 4:1 range... which would hammer snow amounts. For this reason, have held current Winter Storm Watch as is, anticipating overnight shift making final adjustments. Our far northeastern counties may need to be upgraded to a Winter Storm Warning, while the rest of the Watch area could be transitioned to a Winter Weather Advisory. Factoring into impacts will be easterly winds in the 15 to 25 mph range. This would reduce visibility to one mile or less... possibly even 1/4 mile during periods of more heavy snow. Going backwards in time, slight concern event start time may need to be pushed earlier. The GFS is especially picking up on band of isentropic ascent phasing with deep enough low-level moisture for cloud thicknesses to support light precip by 15z Fri. Will watch in next shift, but cannot rule out earlier start time of any headlines. .LONG TERM.../Saturday night through Thursday/ Issued at 347 PM CDT Thu Mar 22 2018 System will have departed by Saturday evening with weak surface ridging sliding into the state. Model sounding continue to indicate plenty of low level moisture lingering, especially the south and west, therefore cloudiness is expected to persist into the overnight and Sunday for much of the area. Exception may be northeast areas where drying will extend a bit deeper into the boundary layer. Warm advection begins into Sunday as next large trof moves onto the west coast and into the intermountain region. Increasing isentropic lift into the afternoon produces some deeper saturation across the far west by later in the afternoon with some sprinkles/light rain possible. Strong theta-e advection and moisture transport arrive late Sunday night into Monday which should spur shower development across central Iowa during the early morning hours on Monday. Elevated instability will increase across the area on Monday with the strong southerly flow with some isolated thunderstorms expected with the shower activity. By late Monday afternoon, low pressure will be approaching southwest Iowa near the Omaha area with surface instability edging into the southwest CWA. Models would indicate some potential for stronger deep convection, nearly surface based in eastern Nebraska into Kansas by late afternoon. Some of this may be able to reach the far southwest portions of the forecast area by Monday evening, although this time of year, weakening usually occurs after sunset limiting overall severe threat. Much of the rest of the forecast area will see widespread showers and some thunderstorms as the surface front passes through the state Monday night. Lingering showers will persist into the southeast on Tuesday before the system departs and subsidence increases. Some quieter weather is expected into the middle of next week with seasonable temperatures expected. && .AVIATION.../For the 12Z TAFS through 12Z Friday morning/ Issued at 647 AM CDT Thu Mar 22 2018 Thin band of light rain possibly mixed with a frozen mix moving across IA through 19z associated with warm air advection. Mid level clouds will remain through the period though a few breaks in the cloud cover will be possible. Winds remain generally east through the period as well and under 12kts. Major changes on the way for Friday 03/23...especially aft 18z. Those concerns will be address in next few packages. /rev && .DMX WATCHES/WARNINGS/ADVISORIES... Winter Storm Watch from Friday evening through Saturday afternoon for IAZ006-007-016-017-026>028-038-039-050. && $$ SHORT TERM...Kotenberg LONG TERM...Cogil AVIATION...Small  FXUS63 KDMX 072103 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 403 PM CDT Mon May 7 2018 .SHORT TERM.../Tonight through Tuesday/ Issued at 402 PM CDT Mon May 7 2018 Bottom Line up Front... Spotty shower and thunderstorm chances exist tomorrow. There is a chance that a few storms may be strong in southern Iowa during the evening hours tomorrow, with a slim chance for severe potential. Hail is the primary severe threat. 20z sfc analysis showed a 1023mb sfc high centered over northern Illinois. GOES-R Water vapor imagery picked up on several upper lows. For the short-term, the upper low of impact will be the one centered over Montana. Sfc analysis in this region picks up on the sfc reflection low crossing into western South Dakota. 12z Mon 850mb temps were around +10C to +12C. For 12z Tue, 850mb temps should jump to +12C to +15C as WAA accompanies the system coming off the Rockies. Compared to yesterday at this time, it appears precipitation timing has sped up slightly as the wing of 850mb theta-e advection, well- phased with solid moisture advection will be nearer to I-35 by 15z Tue... whereas yesterday, this mesoscale setup was still over west- central Iowa. In terms of model guidance, the 12z Mon NAM is a slightly faster, farther north/northeast outlier, so have leaned towards a non-NAM blend. With the faster progression trend of this system, the chance for strong thunderstorms has popped up a bit in the far south- central/southwestern portion of the DMX CWA. There does appear to be a surge of moisture advection/moisture flux convergence riding along the nose of a LLJ that races northward from eastern Kansas and may clip SW IA during peak heating. LLJ keeps pumping north and eastward overnight into Wednesday morning. Kept thunder going as overturning convection processes in play from 06z Wed-12z Wed. .LONG TERM.../Tuesday night through Monday/ Issued at 402 PM CDT Mon May 7 2018 Bottom Line up Front... Widespread Thunderstorm chances exist Thursday into Saturday. At this time, the threat for severe weather is generally low. The threat for flooding issues may become a concern across northern Iowa...especially places currently dealing with flood/river flood issues. Thursday Into Next Weekend... Long-range models still trying to take focus on the system slated to impact Iowa for this weekend. Disagreement still remains amongst the medium to long-range models, so confidence in mesoscale features are low to medium. Synoptically, the solution that presented itself yesterday seems to have locked in... The large upper low currently located around 1000km off the Pacific coastline will establish itself as a closed upper low near the Four Corners Region by Saturday. The newer development that seems to be locking on is this upper low will stall out over the southwestern US into the beginning of next week... the implications of which will be discussed below. Additionally, models still picking up on an impulse ejecting ahead of the upper low mentioned above and passing though Iowa sometime Friday. Both the 12z Mon GFS and 12z Mon ECMWF hint at this solution. Both models also rapidly advect moist air into Iowa via a 50kt LLJ that surges into southern Iowa. PWATs make it to the 1.5 inch range in Iowa, with warm cloud thickness a widespread 3500m... so could see some moderate precip amounts. A few rivers in northern Iowa are still at flood stage, so an additional .5 to 1.0 inch of rain would obviously not help alleviate flooding. Another surge of moisture makes it into Iowa Saturday. Interestingly, this setup is somewhat similar to last week, with the multiple sfc lows and a warm front/stationary boundary to serve as a trigger for potential convection. At this time, the boundary appears weaker than it did last week and may possibly be located from Creston through Dubuque or so. Confidence not high in this placement as still a lot of time for shifting... but if this setup holds severe weather potential will need to be monitored. Long-range models are now kicking a sizable 1020mb sfc high off the Rockies across the Dakotas. With the upper low potentially stagnating over the southwestern US, quiet weather may be on tap for Sunday into the middle of next week as we remain under the influence of this high. With the high to our east, we would be on the return flow side, so would expect persistent temperatures to continue in the mid 70s to low 80s across Iowa. && .AVIATION.../For the 18Z TAFS through 18Z Tuesday afternoon/ Issued at 1225 PM CDT Mon May 7 2018 High confidence in continued VFR categories throughout this TAF period. Winds will be sustained around 10 kts, with occasional gusts near 15kts this afternoon... decreasing to under 10 kts after sunset... and then rising to over 10 kts around 14z to 15z Tuesday. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Kotenberg LONG TERM...Kotenberg AVIATION...Kotenberg  FXUS63 KDMX 031049 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 549 AM CDT Sat Nov 3 2018 ...Updated for Near Term Weather Trends and 12z Aviation Discussion... .UPDATE... Issued at 549 AM CDT Sat Nov 3 2018 Issued a Dense Fog Advisory about an hour ago for area of fog that formed before the clouds moved in from the west. Initial thinking was that there may be pockets of dense fog ahead of the arriving clouds with visibilities improving as the clouds arrived. However, as the clouds arrived, the fog persisted. Places such as Webster City, Boone, and Ames have been under the clouds for over an hour with 1/2 to 1/4 mile visibility common at those sites. GOES-16 Nighttime Microphysics RGB only offers glimpses of the fog when there is clearing. However, the satellite + model fused Fog and Low Stratus MVFR/IFR/LIFR probabilities shows the area quite well with the probabilities of MVFR conditions expanding in coverage and increasing in probability. High resolution guidance such as the RAP and WRF-NMM were/are handling this area of dense fog the best. CONSShort has come around as well, though earlier runs of this model blend favored low ceilings so downplayed the fog initially. In any regard, visibilities should improve within the next few hours. && .DISCUSSION.../Today through Friday/ Issued at 346 AM CDT Sat Nov 3 2018 Overview of the next 7 days has an action packed weather pattern with several low pressure systems passing from the central Plains and generally southeast of Iowa into the Great Lakes. This will bring repeated rounds of precipitation through the state. The highest impacts at this point are expected on Tuesday with gusty northwest winds and by the end of next week with colder air. GOES-16 clean IR shows broad area of clouds from Saskatchewan into Kansas with upper low dropping into eastern Montana and western North Dakota early this morning. These clouds are moving eastward with roughly the western 2/3rds of the state mostly cloudy. Beneath these clouds, some pockets of fog have formed with visibilities under a mile in a few places. Strong low and mid-level Q-vector convergence ahead of this low along with low level theta-e advection will bring a prolonged period of rain showers today. Regional radar already shows a wide area of rain moving into eastern Nebraska. This rain should reach our western forecast area shortly after daybreak and spread eastward and northeastward with many places across central Iowa having showers toward midday today. Adjusted high temperatures down a few degrees from previous forecast with the cloud cover and rain providing for a chilly, dreary day. The rain will continue through the afternoon and overnight as low pressure lifts into southeast Iowa by 12z Sunday. Rain may mix with snow over northwest Iowa early Sunday morning, but not expecting accumulations. The rain will come to an end from southwest to northeast as large scale subsidence moves into the state on Sunday. There will be a 12 to 18 hour break in the rain before the next shortwave trough moves into the region. Currently, this shortwave is over the Gulf of Alaska, but will move into the Pacific Northwest before it digs into the central Plains. This will bring mainly rain into central Iowa Monday morning as Q-vector convergence increase, but best Q-vector convergence and theta-e advection will be south of the state so highest rain amounts look to be that direction. The rain may mix with snow perhaps over northern Iowa in the morning, but again not expecting any impacts at this point. Surface low pressure associated with this shortwave will rapidly deepen as it moves from the Ozarks Monday night into the Great Lakes on Tuesday evening. This will create a tight pressure gradient across the state with winds at the top of the mixed layer of 35 to 40 knots. Bumped winds up from early Tuesday morning through 00z Wednesday and may very well end up needing a Wind Advisory on Tuesday. As the low pressure moves into the Great Lakes, rain will end across the state. At this point, Wednesday is looking like an overall quiet day ahead of the next weather system. It is also the day with the best chance for some sunshine across parts of central Iowa over the next 7 days. However, any sunshine will be short-lived as the next trough moves into the region Wednesday evening. The 00z GFS has precipitation over the southern 2/3rds of Iowa later Wednesday night, which is a northward shift compared to its last several runs. Not to be outdone, the 00z ECMWF has also shifted northward compared to its 12z run; however, not as much as the GFS. Needless to say, this now brings precipitation in the form of snow late Wednesday night into early Thursday morning before transitioning to rain as the low levels warm. However, a rain/snow mix may continue over northern Iowa. The precipitation will transition to snow before ending Thursday night or Friday morning. On the heels of this precipitation will be some very cold air with 1000 to 500mb thickness of around 505dm and 850mb temperatures in the low to middle teens below zero on Friday. CIPS analogs have a strong signal for below normal temperatures with temperatures averaging 5 degrees below normal. Highs were nudged downward similar to previous shift with highs in the 30s, which is 20 degrees below normal in many places. && .AVIATION.../For the 12Z TAFS through 12Z Sunday morning/ Issued at 549 AM CDT Sat Nov 3 2018 Low ceilings and visibilities will be a concern through this TAF period. Pockets of dense fog and low ceilings have developed and expanded with MCW and FOD reporting IFR ceilings. Both DSM and OTM may be impacted, but have only included in at OTM as TEMPO group at this time. Otherwise, rain will spread in today with MVFR restrictions common and near borderline IFR by this afternoon in most places. Conditions will fall into IFR overnight as the rain persists through 12z Sunday. && .DMX WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 9 AM CDT this morning for IAZ048>050- 061-062-074-075-084>086-095>097. && $$ UPDATE...Ansorge DISCUSSION...Ansorge AVIATION...Ansorge  FXUS63 KDMX 022129 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 329 PM CST Sat Feb 2 2019 .SHORT TERM.../Tonight through Sunday/ Issued at 322 PM CST Sat Feb 2 2019 Confidence: Medium Plenty of concerns...mainly in the form of fog and later a period of light freezing precipitation Sunday night over the north. Moisture transport continues to be maintained over the region this afternoon and will continue tonight. This has resulted in snow melt, increasing dew points and temperatures and areas of fog. Though some of the south and southeast has been spared so far...and some improvement has occurred over the north; tonight will see a renewed increase in fog with more widespread dense fog overnight. Timing of start/end times remains a challenge...as the warm air advection over the south may help to mitigate some of the visby issues there after 03z. For now, will leave the end time over the southwest/west at 03z...though fully aware that this may need to be extended until 12z or later on Sunday morning. The evening crew will need to evaluate. For the remainder of the additional fog advisory which covers much of central through east/northeast areas, bridging the fog advisory issued early this morning...fog is likely to fill in around or after 00z and get worse overnight. Some modulation in visibility is likely, but overall poor enough conditions are expected that an advisory seems warranted. Tonight drizzle will become more likely as well and this will add to the fog as it falls onto the snow cover. Lows tonight will not fall much, or just remain steady as moisture streams north into Iowa. Sunday we should see highs recover and warm a bit over the region with upper 40s to lower 50s possible south...mid to upper 40s central and upper 30s to lower 40s north. By later in the morning, models are in good agreement with increased forcing and likelihood that a general heavier drizzle or very light rain will move into the region Sunday as low pressure moves from western Iowa at 06z to near KMSP by 12z. This should continue into the evening with a colder air quickly arriving on the back side of the departing low. It still looks like a brief period of light freezing precipitation and minor icing may accompany the changeover on the back side of the system between 06 and 12z Monday as shallow cold air quickly undercuts the lingering warm layer aloft and temperatures at the surface fall into the mid to upper 20s over the northwest. .LONG TERM.../Sunday night through Saturday/ Issued at 322 PM CST Sat Feb 2 2019 Monday... Weather Highlights: Wintry precip, strong winds Wintry precip: From 12z-18z Mon, Wintry precip will be departing Iowa to the east. Looking at source region for the cold air mass behind this system as described in the short-term AFD section, medium to long- range models doing awful with initializing the cold air mass on the backside. Looking at obs across southern Manitoba, models, especially the 12Z GFS a solid 5 to 10 degrees to warm & not recognizing tight temperature gradient. 12z NAM handling this the best, so leaned towards it. With the colder temperatures in mind, have amplified/accelerated rain --> snow transition, shortening the duration and areal coverage of freezing rain/ice pellets. From northwestern to central Iowa (Estherville to Des Moines), 12z Mon 850mb temperatures range from around 0 to +5C. By 18z, northwestern to central Iowa temperatures range from around -8C to 0C... and this may not be cool enough. So, needless to say, high max temperatures for Monday will likely occur during the morning hours, with falling temperatures across Iowa throughout the daytime hours. Strong winds: Confidence is high in strong winds arriving Monday morning through the afternoon hours. By 15z Mon, ~998mb sfc low to be near northeastern Wisconsin, with 1040mb sfc high over the Canadian side of the Rockies propagating towards the Upper Midwest beginning to have influence on Iowa. The nature of these winds will begin with a surge of strong gusts behind the cold front, and then prolonged sustained strong winds throughout the daytime Monday. The pressure gradient caused by this synoptic gradient is around 3mb/60 km through the daytime. Further, there is a surge of pressure rises that peak at 8mb/3-hr through Monday. There is also large-scale subsidence in the low levels to bring down the already low mixed- layer winds. Ultimately, thinking at this time there is a low-medium chance for Wind Advisory criteria to be reached late Monday morning through Monday afternoon. Will have to monitor. Impacts: Potential sustained winds from NW @ 20 to 30 mph, with gusts to 40 mph. These winds may lead to travel difficulties as vehicles may be blown sideways, especially high-profile vehicles. Additionally, with falling temperatures likely throughout the daytime, wind chill values will near 0 degrees by the afternoon hours. The need for any wind chill headlines is slim to none, but it will feel chilly Monday afternoon/evening nonetheless and 30 to 45 min frostbite considerations will be in play. Tuesday-Wednesday... Weather Highlight: Wintry precipitation An inverted trough-type feature passes through the Midwest on Tuesday, bringing the next chances for wintry precip. This trough is probably best visible on the 950mb sfc. Dissecting the mesoscale features with this system, this will likely be a tricky setup. Similar to the Sunday-Monday system, there clearly appears to be a notable surge of gulf moisture. As of now, this moisture surge touches into southern Iowa sometime Tuesday afternoon. POPs/QPF may need to be boosted as a result. Temperature profile seems to support some sort of sleet/snow blend. Certainly one of those features that could shift north or south 25 miles in the last 6-12 hours leading up to the event, notably throwing off the forecast. Meanwhile, the 12z Sat GFS especially, is trying to bring a ~west- east oriented band of precip across northwestern to northeastern Iowa Tuesday into Wednesday. Parameters to support this as ribbon of 500mb-300mb Q-Vector convergence leading what is trying to be a ribbon of low-level frontogenetical forcing, phased with 850mb moisture flux convergence. Will need to watch this area closely for enhancement. Temperature profile solidly in the 100% snow range. Decent cloud thicknesses through the DGZ worth noting as well... initially suggestive of higher snow ratio potential. Impacts: Again, certainly worth watching how this event plays out over the next few days... especially the potential northern Iowa swath of snow. Winds across Iowa through this time window look to be on the lighter-ish side... in the 5 to 10 mph range, with occasional gusts to 15 mph. This would suggest more gently falling "snow globe snow" versus wind-driven snow. Nonetheless, if more amplified snow amounts/rates occur, visibility could fall to the 1-2 mile range fairly easily. Adverse impacts would be mainly to roads, sidewalks, etc. Thursday and Beyond... Weather Highlights: Cold + Potential Winter Wx System Cold potential: For the past couple of days, models have been focusing on another blast of cold air impacting the Midwest. Run- to-run consistency of this feature is high, lending to high confidence in this cold air occurring. The timing and magnitude of this cold air, however, has had a medium-high amount of variability, acting to lower confidence of when specifically when the coldest air will be here, and how cold it will actually be. The "good news" is that 850mb temps, at worst look to be "only" near -15C to -20C. This past week's record-setting cold had 850mb temperatures in the -30C to - 40C range. Wintry precip potential: The 12z Sat ECMWF in particular is aggressive with bringing a wintry precip system through Iowa on Friday. This system can actually be traced back to the upper low currently showing up over central Alberta. The 12z GFS effectively stalls this system out over the Rockies and brings a weaker version of it through the Midwest Saturday-Sunday. Ultimately, confidence is extremely low at this time, so will not attempt to dissect the details of it now. Impacts: Though record-setting cold seems highly unlikely, will need to at least keep an eye on possible need for Wind chill headlines to be issued during mid-week shifts. Again, a lot of time for things to change... but trend certainly seems to favor colder, below normal temperatures versus warmer, above normal temperatures. Of course, will need to monitor potential for winter system, though confidence is very low at this time. && .AVIATION.../For the 18Z TAFS through 18Z Sunday afternoon/ Issued at 1152 AM CST Sat Feb 2 2019 Lots of concerns with cigs/FG and drizzle this period. The low vsby/cigs and will likely remain a moving target and confidence somewhat with those considerations. Drizzle expected to increase aft 20z through end of period; especially north where weak upglide lift will likely aid formation of drizzle as lower layers become more saturated. /rev && .DMX WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 9 PM CST this evening for IAZ057-058- 070-071-081>084-092>095. Dense Fog Advisory until noon CST Sunday for IAZ039-047>050- 059>062-072>074. Dense Fog Advisory until noon CST Sunday for IAZ006-007-016-017- 025>028-036>038. && $$ SHORT TERM...REV LONG TERM...Kotenberg AVIATION...REV