FXUS66 KMFR 031226 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 426 AM PST TUE DEC 3 2013 .DISCUSSION... SURFACE OBSERVATIONS, ROAD CAMERAS, AND SPORT MODIS-VIRRS NIGHTTIME RGB SATELLITE IMAGERY INDICATE THAT ONLY A FEW SPRINKLES AND SNOW FLURRIES ARE STILL FALLING, AT MOST, ACROSS THE FORECAST AREA THIS MORNING. SNOW LEVELS WERE SLOW TO FALL BELOW THE 5000 FOOT ELEVATION LEVEL YESTERDAY, SO MOST OF THE SNOW ACCUMULATION WAS ABOVE THAT LEVEL. HOWEVER, IT DOES APPEAR THAT MANY AREAS THAT USUALLY SHOULD BE GETTING SNOW BY THIS TIME OF THE YEAR SUCH AS HIGHWAY 140 NEAR LAKE OF THE WOODS LIKELY RECEIVED UP TO A COUPLE INCHES OF SNOW LAST EVENING THROUGH EARLY THIS MORNING. FOR TODAY STILL COLDER AIR WILL MOVE ACROSS THE AREA FROM THE NORTH AS A 500MB TEMPERATURE OF -24C ON THE MEDFORD SOUNDING THIS MORNING DROPS TO AROUND -31C. A TROUGH EXTENDING WESTWARD INTO OUR AREA FROM THE NORTHERN ROCKIES AS THIS COLD AIR MOVES IN WILL PACK MOST OF WHAT LITTLE MOISTURE IT HAS OVER THE MOUNTAINS AND EAST SIDE. EXPECT SNOW SHOWERS CENTERED IN THE WARNER MOUNTAINS THIS AFTERNOON AND EVENING AND ALSO SOME POSSIBLE IN THE CASCADES. A FEW FLURRIES COULD REACH TO WEST SIDE VALLEY FLOORS, BUT MOST AREAS WILL SEE NO PRECIPITATION. WITH FRESH SNOW IN THE MOUNTAINS AND A DRY AIR MASS ARRIVING FROM THE NORTHEAST, TEMPERATURES WILL PLUMMET UNDER CLEAR SKIES TONIGHT. FOR WEST SIDE VALLEY LOCATIONS SUCH AS MEDFORD IT COULD BE AS WARM AS THE LOW 20S THE NEXT COUPLE OF NIGHTS TO AS COLD AS THE LOWER TEENS DEPENDING ON HOW MUCH MOISTURE HANGS AROUND AND WHETHER OR NOT WE FOG IN. AT THIS POINT EXPECT SOME FOG AND TEMPERATURES BOTTOMING OUT AROUND 17F THURSDAY MORNING, COLDER IN OUTLYING AREAS. ALL ACROSS THE AREA IT SHOULD BE NOTED THAT THESE SORT OF TEMPERATURES WILL BE NEAR DAILY RECORD VALUES AND CAPABLE OF FREEZING PIPES. EXTENDED COLD WEATHER TODAY THROUGH THURSDAY WILL SET THE STAGE FOR WHAT COULD BE A VERY MESSY FRIDAY FOR THE WEST SIDE. AT THIS POINT THE NAM12 IS THE ODD MODEL OUT IN NOT DEPICTING A PRECIPITATING STORM SYSTEM OVER THE AREA ON FRIDAY. THE GFS AND ECMWF HAVE REMAINED QUITE SIMILAR IN PUSHING A COLD SYSTEM INTO THE AREA. THERE IS EXPECTED TO BE SOME HIGH CLOUD COVER AHEAD OF THIS SYSTEM ON THURSDAY AND THURSDAY NIGHT. THE TIMING OF THIS HIGH CLOUD WILL MODULATE HOW COLD THE VALLEYS ARE WHEN THE FRIDAY SYSTEM ARRIVES. SIMILAR PAST SITUATIONS HAVE RESULTED IN COLD AIR REMAINING IN PLACE AND WIDESPREAD SNOWFALL TO VALLEY FLOORS. HOWEVER, SOME GUIDANCE ALSO HINTS AT A BRIEF SURGE IN SOUTHEAST THROUGH WEST WINDS AHEAD OF THIS SYSTEM SUCH THAT MANY VALLEYS WOULD WARM ABOVE FREEZING BEFORE PRECIPITATION BEGINS DUE TO DOWNSLOPE EFFECTS. AT THIS POINT IT APPEARS THAT ACCUMULATING SNOWFALL IS LIKELY ABOVE 2000 FEET AND POSSIBLE BELOW THIS LEVEL. STAY TUNED AS WE DO OUR BEST TO PROVIDE WHAT DETAILS CAN BE SURMISED. THEREAFTER, THERE IS GROWING CONSENSUS AND REASONING IN THE LONGER RANGE IN EXPECTING THAT WET SYSTEMS WITH SNOW LEVELS AT OR BELOW CLIMATOLOGICAL NORMALS SHOULD ARRIVE DURING WEEK TWO. THUS, IT APPEARS WINTER HAS ARRIVED AND IS PLANNING ON STICKING AROUND IN TERMS OF THE WEATHER, NOT JUST ON THE CALENDER! BTL && .AVIATION...BASED ON THE 03/06Z TAF CYCLE. A COLD FRONT HAS PASSED THROUGH THE AREA...LEAVING IN ITS WAKE ISOLATED TO SCATTERED SHOWERS THAT WILL CONTINUE OVERNIGHT AND INTO THE MORNING. FREEZING LEVELS HAVE DROPPED CONSIDERABLY BEHIND THE FRONT...AND AS A RESULT...THE SHOWERS HAVE TURNED TO MOSTLY SNOW...EVEN ACROSS THE WEST SIDE. AS DRIER AIR STARTS TO WORK IN EARLY TOMORROW MORNING...SHOWERS WILL END AND SKIES WILL CLEAR. THIS MAY ALLOW FOG/STRATUS TO FORM BRIEFLY...ESPECIALLY IN THE UMPQUA AND ROGUE VALLEYS. IT WILL STAY MIXED LONG ENOUGH TO LIMIT THIS POSSIBILITY FOR MOST OTHER LOCATIONS. AFTER ANY MORNING STRATUS/FOG DISSIPATES...VFR AND BREEZY NORTH WINDS WILL PREVAIL AT VIRTUALLY ALL LOCATIONS. BPN && .MFR WATCHES/WARNINGS/ADVISORIES... OR...FROST ADVISORY UNTIL 8 AM PST THIS MORNING FOR ORZ021-022. FREEZE WARNING FROM 11 PM THIS EVENING TO 10 AM PST WEDNESDAY FOR ORZ021-022. FREEZE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR ORZ021-022. WINTER WEATHER ADVISORY UNTIL 4 AM PST EARLY THIS MORNING ABOVE 2000 FEET FOR FOR ORZ025. CA...NONE. PACIFIC COASTAL WATERS... - SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST WEDNESDAY FOR PZZ350-356-370-376. - SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST WEDNESDAY FOR PZZ370. - HAZARDOUS SEAS WARNING FROM 10 PM THIS EVENING TO 10 AM PST WEDNESDAY FOR PZZ370-376. - SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST WEDNESDAY FOR PZZ376. $$ BTL/BTL/SBN  FXUS66 KMFR 291200 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 400 AM PST SUN DEC 29 2013 .DISCUSSION...HI RESOLUTION SPORT MODIS-VIIRS NIGHTTIME MICRO-PHYSICS RGB SATELLITE IMAGERY IS SHOWING A DEEPER MOIST LAYER NORTH OF THE UMPQUA DIVIDE COMPARED TO THE LAST COUPLE OF NIGHTS. AS A RESULT, THE CLOUD LAYER IS MORE STRATUS THAN FOG NEAR ROSEBURG THIS MORNING. HOWEVER, IT IS LIKELY THAT DENSE FOG WILL BE ENCOUNTERED AT HIGHER ELEVATIONS SURROUNDING ROSEBURG...ESPECIALLY NEAR CAMAS MOUNTAIN AND ALSO THE PASSES SOUTH OF THE CITY NEAR CANYONVILLE. FOR THIS REASON, HAVE MAINTAINED THE DENSE FOG ADVISORY THROUGH MID MORNING. A SHALLOWER MOIST LAYER IS EVIDENT IN THE ROGUE VALLEY WITH SURFACE OBSERVATIONS AND AREA WEB CAMS INDICATING WIDESPREAD FREEZING FOG FROM GRANTS PASS TO MEDFORD. A FREEZING FOG ADVISORY IS OUT FOR THESE LOCATIONS. THE SOUTH ENDS OF BOTH THE ILLINOIS VALLEY AND ROGUE VALLEY HAVE REMAINED MOSTLY CLEAR OVERNIGHT WITH TEMPERATURES AT THIS EARLY HOUR IN THE LOW TO MID 20S. WITH THE RIDGE AT ITS STRONGEST TODAY, NOT EXPECTING MUCH MIXING OUT OF THE MOIST LAYER IN THE LOW LEVELS, SO WE'LL REMAIN COLD IN THE LOW CLOUDS/FOG HERE IN MEDFORD WITH HIGHS ONLY IN THE MID 30S. ASHLAND THOUGH SHOULD GET SOME SOUTHEAST WIND TODAY TO WARM INTO THE 40S. MEANWHILE, OFFSHORE FLOW WILL BRING PLENTY OF SUNSHINE WITH WARM AND DRY CONDITIONS TO THE MID SLOPES AND RIDGES AROUND THE AREA. THE BROOKINGS EFFECT WILL BE IN FULL FORCE TODAY AND IS ALREADY WITH TEMPS IN THE LOW 60S AT 3AM! MODEL 975 TEMPS ARE INDICATING AROUND 17C THIS AFTERNOON AND THIS SHOULD RESULT IN HIGHS THERE IN THE LOW TO MID 70S. OFFSHORE FLOW WILL WEAKEN SIGNIFICANTLY TONIGHT AND THE RIDGE WILL BEGIN TO FLATTEN ON MONDAY. EVEN SO, THERE IS STILL NO APPRECIABLE MIXING TO SCOUR OUT THESE LOW CLOUDS/FOG. SO, EXPECT ANOTHER DISMAL DAY AROUND MEDFORD. SLIGHTLY COOLER AIR MOVING IN ALOFT AND A GENERAL INCREASE IN MID AND HIGH CLOUDS SHOULD BRING SEVERAL DEGREES OF COOLING TO THE SURROUNDING HILLS. IT WILL ALSO BE A COOLER DAY ALONG THE SOUTH COAST AS THE LOW LEVEL FLOW TURNS SOUTHERLY AND MORE MARINE AIR RETURNS. THE FLOW ALOFT WILL BECOME MORE WESTERLY AND A WEAK DISTURBANCE WILL ZIP OFF TO OUR NORTH MONDAY NIGHT INTO TUESDAY. PRECIPITATION CHANCES ARE SLIGHT AT BEST WITH THIS FEATURE, BUT THERE MAY BE A LITTLE LIGHT RAIN IN COOS OR DOUGLAS COUNTIES. THIS SYSTEM SHOULD CAUSE MORE MIXING AND WEAKEN THE INVERSION TUESDAY. FOR NOW, HAVE KEPT THE FORECAST ON THE PESSIMISTIC SIDE WITH CLOUDS/PATCHY FOG REMAINING IN SOME OF THE VALLEYS THROUGH THE DAY. SHORT WAVE RIDGING IS EXPECTED NEW YEARS EVE INTO NEW YEARS DAY, SO IT'LL BE DRY. OPERATIONAL MODELS AND ENSEMBLE GUIDANCE INDICATE THE RIDGE PERSISTING INTO THURSDAY, BUT ALL INDICATE A SHIFT IN THE PATTERN TOWARD THE END OF THE WEEK WITH A SHORTWAVE TROUGH MOVING ONSHORE FRIDAY WITH BETTER PRECIPITATION CHANCES THAN WE'VE SEEN IN AWHILE. IT IS STILL TOO EARLY TO SAY IF THIS IS A TREND TOWARD A MORE ACTIVE PATTERN NEXT WEEKEND OR IF THE RIDGE THAT HAS BEEN SO PERSISTENT REBUILDS OFFSHORE AGAIN. WE'LL BE TAKING A CLOSER LOOK AT THIS OVER THE NEXT COUPLE OF DAYS. SPILDE && .AVIATION...A PERSISTENT PATTERN CONTINUES THROUGH THROUGH SUNDAY EVENING WITH HIGH PRESSURE OVER THE AREA BRINGING INLAND VALLEY FOG AND FREEZING FOG WEST OF THE CASCADES. WIDESPREAD IFR/LIFR CIGS AND AREAS OF IFR/LIFR VSBYS WILL CONTINUE IN THE UMPQUA, ILLINOIS, APPLEGATE AND ROGUE VALLEYS INTO SUNDAY AFTERNOON. FOG MAY PARTIALLY CLEAR IN THE LATE AFTERNOON AND CIGS MAY LIFT SLIGHTLY. HOWEVER CIGS AND VSBYS WILL BE LOWEST AND ALSO SLOWEST TO IMPROVE ON SUNDAY IN THE ROGUE VALLEY. ANY IMPROVEMENT AT KMFR INTO EARLY SUNDAY AFTERNOON WILL BE DUE TO FOG SEEDING. LATER SUNDAY AFTERNOON...AS WITH THE PAST FEW DAYS...THERE WILL BE PARTIAL IMPROVEMENT. HOWEVER AREAS OF VALLEY IFR/MVFR CIGS AND VSBYS ARE EXPECTED IN THE UMPQUA, ROGUE, ILLINOIS AND APPLEGATE VALLEYS. THEN SUNDAY EVENING EXPECT A RETURN OF WIDESPREAD VALLEY IFR/LIFR CIGS AND VISIBILITIES IN FOR FOR THESE AREAS ONCE AGAIN. ELSEWHERE...WHICH INCLUDES THE COAST, SISKIYOU COUNTY AND THE AREA EAST OF THE CASCADES...EXPECT VFR CONDITIONS WITH MAINLY CLEAR SKIES. CC && .MFR WATCHES/WARNINGS/ADVISORIES... OR...AIR STAGNATION ADVISORY UNTIL 10 AM PST WEDNESDAY FOR ORZ023>026. DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ023. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST THIS AFTERNOON FOR ORZ022. FREEZING FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ024-026. AIR STAGNATION ADVISORY UNTIL 10 AM PST WEDNESDAY FOR ORZ029>031. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST THIS AFTERNOON FOR PZZ350-356. SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST THIS EVENING FOR PZZ370-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST MONDAY FOR PZZ370-376. HAZARDOUS SEAS WARNING UNTIL 4 PM PST THIS AFTERNOON FOR PZZ370-376. $$ MAS/FJB/CC  FXUS66 KMFR 291657 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 857 AM PST SUN DEC 29 2013 .DISCUSSION...CURRENT VISIBLE IMAGE SHOWS STRATUS OVER THE SAME LOCATIONS AS IN THE PAST FEW DAYS. THE MORNING SOUNDING SHOWS THE MOISTURE LAYER AROUND 1700 FEET WITH RAPID DRYING ABOVE THAT. THIS IS BEING SUPPORTED BY OBSERVATIONS OVER THE MID SLOPES AND RIDGES WHERE RELATIVE HUMIDITIES ARE LOW. THE FOG IN THE ROGUE VALLEY IS EXPECTED TO PERSIST THROUGH EARLY THIS AFTERNOON AND COULD LIFT TO A LOW OVERCAST BRIEFLY BEFORE FOG RETURNS EARLY THIS EVENING. THE WEATHER WILL BE PRETTY MUCH STATUS QUO THROUGH AT LEAST MID WEEK. THE RIDGE WILL FLATTEN OUT SOME MONDAY AND TUESDAY AS WEAK DISTURBANCES MOVE NORTH OF THE FORECAST AREA, BUT WILL HAVE LITTLE OR NO EFFECT FOR US. IT MAY NOT BE UNTIL THE END OF THE WEEK BEFORE WE SEE ANY SIGNIFICANT CHANGE TO OUR WEATHER. -PETRUCELLI && .AVIATION...BASED ON THE 29/12Z TAF CYCLE A PERSISTENT PATTERN CONTINUES FOR THE NEXT 24 HOURS WITH HIGH PRESSURE OVER THE AREA BRINGING INLAND VALLEY FOG AND FREEZING FOG WEST OF THE CASCADES. WIDESPREAD IFR/LIFR CIGS AND AREAS OF IFR/LIFR VSBYS WILL CONTINUE IN THE UMPQUA, ILLINOIS, APPLEGATE AND ROGUE VALLEYS INTO THIS AFTERNOON. FOG MAY PARTIALLY CLEAR IN THE LATE AFTERNOON AND CIGS MAY LIFT SLIGHTLY, BUT CIGS AND VSBYS WILL BE LOWEST AND ALSO SLOWEST TO IMPROVE THE ROGUE VALLEY. ANY IMPROVEMENT AT KMFR MAY ONLY BE FOR A COUPLE OF HOURS LATE THIS AFTERNOON BEFORE FOG RETURNS EARLY THIS EVENING. WIDESPREAD VALLEY IFR/LIFR CIGS AND VISIBILITIES RETURNS IN FOR FOR THESE AREAS ONCE AGAIN THIS EVENING AND TONIGHT. ELSEWHERE...WHICH INCLUDES THE COAST, SISKIYOU COUNTY AND THE AREA EAST OF THE CASCADES...EXPECT VFR CONDITIONS WITH MAINLY CLEAR SKIES. && .PREV DISCUSSION... /ISSUED 400 AM PST SUN DEC 29 2013/ DISCUSSION...HI RESOLUTION SPORT MODIS-VIIRS NIGHTTIME MICRO-PHYSICS RGB SATELLITE IMAGERY IS SHOWING A DEEPER MOIST LAYER NORTH OF THE UMPQUA DIVIDE COMPARED TO THE LAST COUPLE OF NIGHTS. AS A RESULT, THE CLOUD LAYER IS MORE STRATUS THAN FOG NEAR ROSEBURG THIS MORNING. HOWEVER, IT IS LIKELY THAT DENSE FOG WILL BE ENCOUNTERED AT HIGHER ELEVATIONS SURROUNDING ROSEBURG...ESPECIALLY NEAR CAMAS MOUNTAIN AND ALSO THE PASSES SOUTH OF THE CITY NEAR CANYONVILLE. FOR THIS REASON, HAVE MAINTAINED THE DENSE FOG ADVISORY THROUGH MID MORNING. A SHALLOWER MOIST LAYER IS EVIDENT IN THE ROGUE VALLEY WITH SURFACE OBSERVATIONS AND AREA WEB CAMS INDICATING WIDESPREAD FREEZING FOG FROM GRANTS PASS TO MEDFORD. A FREEZING FOG ADVISORY IS OUT FOR THESE LOCATIONS. THE SOUTH ENDS OF BOTH THE ILLINOIS VALLEY AND ROGUE VALLEY HAVE REMAINED MOSTLY CLEAR OVERNIGHT WITH TEMPERATURES AT THIS EARLY HOUR IN THE LOW TO MID 20S. WITH THE RIDGE AT ITS STRONGEST TODAY, NOT EXPECTING MUCH MIXING OUT OF THE MOIST LAYER IN THE LOW LEVELS, SO WE'LL REMAIN COLD IN THE LOW CLOUDS/FOG HERE IN MEDFORD WITH HIGHS ONLY IN THE MID 30S. ASHLAND THOUGH SHOULD GET SOME SOUTHEAST WIND TODAY TO WARM INTO THE 40S. MEANWHILE, OFFSHORE FLOW WILL BRING PLENTY OF SUNSHINE WITH WARM AND DRY CONDITIONS TO THE MID SLOPES AND RIDGES AROUND THE AREA. THE BROOKINGS EFFECT WILL BE IN FULL FORCE TODAY AND IS ALREADY WITH TEMPS IN THE LOW 60S AT 3AM! MODEL 975 TEMPS ARE INDICATING AROUND 17C THIS AFTERNOON AND THIS SHOULD RESULT IN HIGHS THERE IN THE LOW TO MID 70S. OFFSHORE FLOW WILL WEAKEN SIGNIFICANTLY TONIGHT AND THE RIDGE WILL BEGIN TO FLATTEN ON MONDAY. EVEN SO, THERE IS STILL NO APPRECIABLE MIXING TO SCOUR OUT THESE LOW CLOUDS/FOG. SO, EXPECT ANOTHER DISMAL DAY AROUND MEDFORD. SLIGHTLY COOLER AIR MOVING IN ALOFT AND A GENERAL INCREASE IN MID AND HIGH CLOUDS SHOULD BRING SEVERAL DEGREES OF COOLING TO THE SURROUNDING HILLS. IT WILL ALSO BE A COOLER DAY ALONG THE SOUTH COAST AS THE LOW LEVEL FLOW TURNS SOUTHERLY AND MORE MARINE AIR RETURNS. THE FLOW ALOFT WILL BECOME MORE WESTERLY AND A WEAK DISTURBANCE WILL ZIP OFF TO OUR NORTH MONDAY NIGHT INTO TUESDAY. PRECIPITATION CHANCES ARE SLIGHT AT BEST WITH THIS FEATURE, BUT THERE MAY BE A LITTLE LIGHT RAIN IN COOS OR DOUGLAS COUNTIES. THIS SYSTEM SHOULD CAUSE MORE MIXING AND WEAKEN THE INVERSION TUESDAY. FOR NOW, HAVE KEPT THE FORECAST ON THE PESSIMISTIC SIDE WITH CLOUDS/PATCHY FOG REMAINING IN SOME OF THE VALLEYS THROUGH THE DAY. SHORT WAVE RIDGING IS EXPECTED NEW YEARS EVE INTO NEW YEARS DAY, SO IT'LL BE DRY. OPERATIONAL MODELS AND ENSEMBLE GUIDANCE INDICATE THE RIDGE PERSISTING INTO THURSDAY, BUT ALL INDICATE A SHIFT IN THE PATTERN TOWARD THE END OF THE WEEK WITH A SHORTWAVE TROUGH MOVING ONSHORE FRIDAY WITH BETTER PRECIPITATION CHANCES THAN WE'VE SEEN IN AWHILE. IT IS STILL TOO EARLY TO SAY IF THIS IS A TREND TOWARD A MORE ACTIVE PATTERN NEXT WEEKEND OR IF THE RIDGE THAT HAS BEEN SO PERSISTENT REBUILDS OFFSHORE AGAIN. WE'LL BE TAKING A CLOSER LOOK AT THIS OVER THE NEXT COUPLE OF DAYS. SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...AIR STAGNATION ADVISORY UNTIL 10 AM PST WEDNESDAY FOR ORZ023>026. DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ023. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST THIS AFTERNOON FOR ORZ022. FREEZING FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ024-026. AIR STAGNATION ADVISORY UNTIL 10 AM PST WEDNESDAY FOR ORZ029>031. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST THIS AFTERNOON FOR PZZ350-356. SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST THIS EVENING FOR PZZ370-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST MONDAY FOR PZZ370-376. HAZARDOUS SEAS WARNING UNTIL 4 PM PST THIS AFTERNOON FOR PZZ370-376. $$  FXUS66 KMFR 211210 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 410 AM PST TUE JAN 21 2014 .SHORT TERM...THIS MORNING'S SPORT MODIS-VIIRS MICROPHYSICS IMAGERY DEPICTS VERY SIMILAR CONDITIONS COMPARED TO 24 HOURS AGO WITH FOG/LOW CLOUDS OVER THE WEST SIDE VALLEYS. SUBTLE DIFFERENCES ARE EVIDENT WITH LESS COVERAGE OF FOG THROUGH THE SOUTH END OF THE ROGUE VALLEY NEAR TALENT AND ASHLAND. BUT, ONE NOTABLE DIFFERENCE IS THE SURGE OF FOG/STRATUS NORTHWARD THROUGH THE COASTAL WATERS AND ALONG THE IMMEDIATE COAST. THIS IS BEING INDUCED BY A SHORT WAVE TROUGH APPROACHING 130 W AND THE ASSOCIATED SURFACE SOUTHERLIES AHEAD OF IT. A QUICK LOOK AT THE 12Z KMFR SOUNDING INDICATED THE MOIST LAYER DEPTH AT ABOUT 1000FT WITH RAPID DRYING ABOVE ABOUT 945MB. OVERALL, NOT EXPECTING MUCH CHANGE FROM YESTERDAY, EXCEPT PERHAPS A TAD EARLIER BREAK OUT TIMES. THE DEEPER "BOWLS" LIKE GRANTS PASS MAY TAKE THE LONGEST. IT APPEARS THICKEST THERE CURRENTLY. COASTAL AREAS WILL BE SLIGHTLY COOLER THAN YESTERDAY, BUT THE REST OF THE AREA WILL BE SUNNY AND MILD AGAIN. THE AFOREMENTIONED SHORT WAVE TROUGH WILL ZIP BY TO OUR NORTH THIS EVENING. NOT EXPECTING MUCH OUT OF THIS FEATURE...THERE IS A SLIGHT CHANCE OF LIGHT RAIN ALONG THE COAST...BUT THAT'S ALL IT IS...A SLIGHT CHANCE. BY WEDNESDAY...THE SHORT WAVE WILL DIG INTO THE INTERMOUNTAIN WEST AND THE RIDGE WILL REBUILD ALONG 130 W. WITH SURFACE HIGH PRESSURE BUILDING OFFSHORE AND A THERMAL TROUGH DEVELOPING OVER NORTHERN CALIFORNIA...EXPECT ANOTHER ROUND OF OFFSHORE FLOW WEDNESDAY NIGHT INTO THURSDAY. RIGHT NOW, IT APPEARS WINDS WILL BE 15-25 MPH WITH SOME HIGHER GUSTS ON THE MID SLOPES AND RIDGES WITH RH RECOVERIES 30-35% IN SW OREGON AND WESTERN SISKIYOU COUNTY. A SECOND SHORT WAVE DISTURBANCE WILL DIVE SOUTHWARD FROM BRITISH COLUMBIA AND RETROGRADE OVER NORTHERN CALIFORNIA THURSDAY INTO FRIDAY. THIS SYSTEM IS MOISTURE STARVED SO PRECIPITATION IS UNLIKELY...BUT IT WILL KEEP THE OFFSHORE FLOW EVENT GOING THURSDAY NIGHT INTO FRIDAY MORNING. THIS MAY NOT BE THAT NOTABLE IN A NORMAL YEAR, BUT SINCE WE HAVE BEEN VERY DRY SO FAR THIS SEASON, THIS MAY RESULT IN FIRE WEATHER CONCERNS DUE TO THE WINDS AND LOW RHS. BEYOND THAT, OFFSHORE FLOW WILL EASE THIS WEEKEND AND WE'LL REMAIN UNDER THE INFLUENCE OF THE WEST COAST RIDGE, RESULTING IN A CONTINUED DRY PATTERN. IT WON'T BE UNTIL SOMETIME NEXT WEEK WHERE A PACIFIC SYSTEM MAY BE ABLE BREAK THROUGH AND BRING SOME RAIN TO THE AREA. RIGHT NOW...IT LOOKS LIKE THE BEST CHANCE FOR THIS TO OCCUR WOULD BE MONDAY NIGHT INTO TUESDAY. SPILDE && .AVIATION...A SURGE OF FOG AND STRATUS HAS MOVED ONSHORE FROM CHARLESTON SOUTHWARD BUT REMAINS OFFSHORE NORTH OF COOS BAY. KOTH REMAINS VFR AT THIS TIME...BUT STRATUS MAY APPROACH THE AREA LATER THIS MORNING. LIFR CIGS/VSBYS PREVAIL IN THE STRATUS. AREAS OF LIFR CIGS/VSBYS HAVE DEVELOPED OVER THE UMPQUA...ILLINOIS...AND ROGUE VALLEYS AS WELL...INCLUDING KRBG AND KMFR. EXPECT ALL THESE AREAS TO CLEAR TO VFR TUESDAY AFTERNOON...EXCEPT UNDER THE STRATUS OFFSHORE. EXPECT THE LOWER CONDITIONS TO RETURN TO THE SAME WEST SIDE VALLEYS ALONG WITH THE ENTIRE COAST TUESDAY EVENING. ELSEWHERE...VFR CONDITIONS WILL PREVAIL THROUGH TUESDAY EVENING. STOCKTON && .MARINE...ANOTHER ROUND OF LONG PERIOD MODERATE WEST SWELL IS NOW PEAKING AND WILL SUBSIDE INTO TUESDAY. OTHERWISE...HIGH PRESSURE CENTERED OVER INTERIOR BRITISH COLUMBIA WILL RECENTER INLAND OVER THE INTER-MOUNTAIN WEST MONDAY THROUGH TUESDAY CONTINUING SOUTHERLY WINDS. A WEAK FRONT WILL BRUSH BY TUESDAY NIGHT. THE RETURN OF OFFSHORE HIGH PRESSURE WILL LEAD TO STRONGER NORTH WINDS WEDNESDAY INTO THURSDAY. WINDS WILL BECOME OFFSHORE THURSDAY INTO FRIDAY AS HIGH PRESSURE DEVELOPS INLAND. BTL/STOCKTON && .CLIMATE...THE 3 PRIMARY OPERATIONAL MODELS NOW, FOR THE FIRST TIME IN THE LAST WEEK, INDICATE A BREAK DOWN IN THE BLOCKING HIGH PRESSURE RIDGE ALONG THE WEST COAST AROUND DAY 10, JANUARY 28TH. MODELS HAVE BEEN MOSTLY CONSISTENT IN TRENDING IN THIS DIRECTION FOR THE LAST SEVERAL DAYS, AND THERE IS GOOD REASON TO BELIEVE IN THIS TREND. A STRONG AREA OF DEEP TROPICAL CONVECTION IN AND AROUND INDONESIA HAS BEEN PERSISTING THROUGH THE WEEKEND AND IS EVER SO SLOWLY REFOCUSING EASTWARD TOWARD THE INTERNATIONAL DATELINE. THIS FEATURE IS REFLECTED IN FORECAST MJO INDICES. THIS FEATURE ALONG WITH A DIP IN THE JET STREAM COMING OFF OF THE COAST OF ASIA ARE EXPECTED TO SEND FORTH ENOUGH ENHANCED JET STREAM ENERGY ACROSS THE PACIFIC TO WEAKEN AND BUMP THE RIDGE ALONG THE WEST COAST. WHILE THE OPERATIONAL MODELS DO INDICATE A BREAKDOWN IN THE HIGH PRESSURE RIDGE IN PLACE, THEY DIFFER SUBSTANTIALLY ON RELATED DETAILS- PRIMARILY HOW FAST THIS BREAKDOWN OCCURS AND HOW FAST WE GET WET. THE CFS INDICATES THE WET PART WON'T BEGIN UNTIL THE WEEK THAT BEGINS FEBRUARY 2ND, WHEREAS THE FASTER OPERATIONAL ECMWF MODEL INDICATES A NOTABLE STORM ARRIVING ON THE 28TH OF JANUARY. BTL && .MFR WATCHES/WARNINGS/ADVISORIES... OR...DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ021-023. AIR STAGNATION ADVISORY UNTIL 4 AM PST SATURDAY FOR ORZ023-024-026. AIR STAGNATION ADVISORY UNTIL 4 AM PST SATURDAY FOR ORZ029>031. FREEZING FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ024-026. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST WEDNESDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST SATURDAY FOR PZZ370-376. $$ MAS/JRS/BTL/FJB  FXUS66 KMFR 211635 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 835 AM PST TUE JAN 21 2014 .SHORT TERM...THE CURRENT FORECAST REMAINS ON TRACK. AHEAD OF A SHORTWAVE TROUGH AND A WEAK FRONT, SOUTH WINDS OFFSHORE AND ALONG THE COAST HAVE BROUGHT A SURGE OF LOW STRATUS TO THE COAST THIS MORNING. INLAND, MORNING VALLEY FOG IS PRESENT IN THE WEST SIDE VALLEYS. AREAS OF DENSE FOG WITH LIMITED VISIBILITIES ARE ALSO PRESENT, ESPECIALLY IN THE VALLEYS IN DOUGLAS, JACKSON AND JOSEPHINE COUNTIES. VISIBILITIES ARE EXPECTED TO IMPROVE AROUND 10 AM PST THIS MORNING WITH CLEARING EXPECTED IN THE AFTERNOON. AS THE WEAK FRONT MOVES INTO THE COAST LATE THIS EVENING AND TONIGHT THERE IS A SLIGHT CHANCE FOR LIGHT RAIN ALONG THE COAST. OTHERWISE EXPECT HIGH PRESSURE TO PERSIST WITH VALLEY FOG REDEVELOPING TONIGHT AND WEDNESDAY MORNING. && .AVIATION...BASED ON THE 21/12Z TAF CYCLE. A SURGE OF FOG AND STRATUS HAS MOVED UP THE COAST TO AROUND FLORENCE OREGON WITH KOTH HAVING COME BELOW IFR EARLIER THIS MORNING. LIFR CIGS/VSBYS PREVAIL IN THE STRATUS. AREAS OF LIFR CIGS/VSBYS HAVE DEVELOPED OVER THE UMPQUA...ILLINOIS...APPLEGATE AND ROGUE VALLEYS AS WELL...INCLUDING KRBG AND KMFR. EXPECT ALL THESE AREAS TO CLEAR TO VFR THIS AFTERNOON. STRATUS WILL CONTINUE OFFSHORE. THEN EXPECT THE LOWER CONDITIONS TO RETURN TO THE SAME WEST SIDE VALLEYS ALONG WITH THE ENTIRE COAST THIS EVENING. ELSEWHERE...VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING. && .MARINE...LONG PERIOD MODERATE WEST SWELL WILL GRADUALLY SUBSIDE THIS MORNING AND SHOULD FALL BELOW 10 FEET BY LATE THIS AFTERNOON. OTHERWISE...HIGH PRESSURE CENTERED OVER INTERIOR BRITISH COLUMBIA WILL RECENTER INLAND OVER THE INTER-MOUNTAIN WEST TODAY CONTINUING THE SOUTHERLY WINDS. A WEAK FRONT WILL BRUSH BY TONIGHT. THE RETURN OF OFFSHORE HIGH PRESSURE WILL LEAD TO STRONGER NORTH WINDS WEDNESDAY INTO THURSDAY. WINDS WILL BECOME OFFSHORE THURSDAY INTO FRIDAY AS HIGH PRESSURE DEVELOPS INLAND. /FB && .PREV DISCUSSION... /ISSUED 410 AM PST TUE JAN 21 2014/ SHORT TERM...THIS MORNING'S SPORT MODIS-VIIRS MICROPHYSICS IMAGERY DEPICTS VERY SIMILAR CONDITIONS COMPARED TO 24 HOURS AGO WITH FOG/LOW CLOUDS OVER THE WEST SIDE VALLEYS. SUBTLE DIFFERENCES ARE EVIDENT WITH LESS COVERAGE OF FOG THROUGH THE SOUTH END OF THE ROGUE VALLEY NEAR TALENT AND ASHLAND. BUT, ONE NOTABLE DIFFERENCE IS THE SURGE OF FOG/STRATUS NORTHWARD THROUGH THE COASTAL WATERS AND ALONG THE IMMEDIATE COAST. THIS IS BEING INDUCED BY A SHORT WAVE TROUGH APPROACHING 130 W AND THE ASSOCIATED SURFACE SOUTHERLIES AHEAD OF IT. A QUICK LOOK AT THE 12Z KMFR SOUNDING INDICATED THE MOIST LAYER DEPTH AT ABOUT 1000FT WITH RAPID DRYING ABOVE ABOUT 945MB. OVERALL, NOT EXPECTING MUCH CHANGE FROM YESTERDAY, EXCEPT PERHAPS A TAD EARLIER BREAK OUT TIMES. THE DEEPER "BOWLS" LIKE GRANTS PASS MAY TAKE THE LONGEST. IT APPEARS THICKEST THERE CURRENTLY. COASTAL AREAS WILL BE SLIGHTLY COOLER THAN YESTERDAY, BUT THE REST OF THE AREA WILL BE SUNNY AND MILD AGAIN. THE AFOREMENTIONED SHORT WAVE TROUGH WILL ZIP BY TO OUR NORTH THIS EVENING. NOT EXPECTING MUCH OUT OF THIS FEATURE...THERE IS A SLIGHT CHANCE OF LIGHT RAIN ALONG THE COAST...BUT THAT'S ALL IT IS...A SLIGHT CHANCE. BY WEDNESDAY...THE SHORT WAVE WILL DIG INTO THE INTERMOUNTAIN WEST AND THE RIDGE WILL REBUILD ALONG 130 W. WITH SURFACE HIGH PRESSURE BUILDING OFFSHORE AND A THERMAL TROUGH DEVELOPING OVER NORTHERN CALIFORNIA...EXPECT ANOTHER ROUND OF OFFSHORE FLOW WEDNESDAY NIGHT INTO THURSDAY. RIGHT NOW, IT APPEARS WINDS WILL BE 15-25 MPH WITH SOME HIGHER GUSTS ON THE MID SLOPES AND RIDGES WITH RH RECOVERIES 30-35% IN SW OREGON AND WESTERN SISKIYOU COUNTY. A SECOND SHORT WAVE DISTURBANCE WILL DIVE SOUTHWARD FROM BRITISH COLUMBIA AND RETROGRADE OVER NORTHERN CALIFORNIA THURSDAY INTO FRIDAY. THIS SYSTEM IS MOISTURE STARVED SO PRECIPITATION IS UNLIKELY...BUT IT WILL KEEP THE OFFSHORE FLOW EVENT GOING THURSDAY NIGHT INTO FRIDAY MORNING. THIS MAY NOT BE THAT NOTABLE IN A NORMAL YEAR, BUT SINCE WE HAVE BEEN VERY DRY SO FAR THIS SEASON, THIS MAY RESULT IN FIRE WEATHER CONCERNS DUE TO THE WINDS AND LOW RHS. BEYOND THAT, OFFSHORE FLOW WILL EASE THIS WEEKEND AND WE'LL REMAIN UNDER THE INFLUENCE OF THE WEST COAST RIDGE, RESULTING IN A CONTINUED DRY PATTERN. IT WON'T BE UNTIL SOMETIME NEXT WEEK WHERE A PACIFIC SYSTEM MAY BE ABLE BREAK THROUGH AND BRING SOME RAIN TO THE AREA. RIGHT NOW...IT LOOKS LIKE THE BEST CHANCE FOR THIS TO OCCUR WOULD BE MONDAY NIGHT INTO TUESDAY. SPILDE CLIMATE...THE 3 PRIMARY OPERATIONAL MODELS NOW, FOR THE FIRST TIME IN THE LAST WEEK, INDICATE A BREAK DOWN IN THE BLOCKING HIGH PRESSURE RIDGE ALONG THE WEST COAST AROUND DAY 10, JANUARY 28TH. MODELS HAVE BEEN MOSTLY CONSISTENT IN TRENDING IN THIS DIRECTION FOR THE LAST SEVERAL DAYS, AND THERE IS GOOD REASON TO BELIEVE IN THIS TREND. A STRONG AREA OF DEEP TROPICAL CONVECTION IN AND AROUND INDONESIA HAS BEEN PERSISTING THROUGH THE WEEKEND AND IS EVER SO SLOWLY REFOCUSING EASTWARD TOWARD THE INTERNATIONAL DATELINE. THIS FEATURE IS REFLECTED IN FORECAST MJO INDICES. THIS FEATURE ALONG WITH A DIP IN THE JET STREAM COMING OFF OF THE COAST OF ASIA ARE EXPECTED TO SEND FORTH ENOUGH ENHANCED JET STREAM ENERGY ACROSS THE PACIFIC TO WEAKEN AND BUMP THE RIDGE ALONG THE WEST COAST. WHILE THE OPERATIONAL MODELS DO INDICATE A BREAKDOWN IN THE HIGH PRESSURE RIDGE IN PLACE, THEY DIFFER SUBSTANTIALLY ON RELATED DETAILS- PRIMARILY HOW FAST THIS BREAKDOWN OCCURS AND HOW FAST WE GET WET. THE CFS INDICATES THE WET PART WON'T BEGIN UNTIL THE WEEK THAT BEGINS FEBRUARY 2ND, WHEREAS THE FASTER OPERATIONAL ECMWF MODEL INDICATES A NOTABLE STORM ARRIVING ON THE 28TH OF JANUARY. BTL && .MFR WATCHES/WARNINGS/ADVISORIES... OR...DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ021-023. AIR STAGNATION ADVISORY UNTIL 4 AM PST SATURDAY FOR ORZ023-024-026. AIR STAGNATION ADVISORY UNTIL 4 AM PST SATURDAY FOR ORZ029>031. FREEZING FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ024-026. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST WEDNESDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST SATURDAY FOR PZZ370-376. $$ CC  FXUS66 KMFR 221145 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 345 AM PST WED JAN 22 2014 .DISCUSSION...MODIS-VIIRS NIGHTTIME MICROPHYSICS RGB SATELLITE IMAGERY VIA NASA/SPORT REVEALS PRETTY MUCH THE STATUS QUO THIS MORNING. COMPARED TO YESTERDAY'S SATELLITE IMAGE AT ABOUT THE SAME TIME, IT APPEARS NEARLY IDENTICAL WITH RESPECT TO WHERE THE LOW CLOUDS AND FOG ARE...JUST PERHAPS A SLIGHTLY SHALLOWER FOG IN PORTIONS OF THE ROGUE VALLEY. DENSE FOG ADVISORIES (NPWMFR) ARE UP FOR THE UMPQUA/ROGUE VALLEYS UNTIL 10 AM THIS MORNING. COULD ALSO BE SOME SLIPPERY SPOTS ON AREA ROADS WHERE TEMPERATURES HAVE FALLEN BELOW FREEZING. MOST AREAS BROKE OUT YESTERDAY WITH THE EXCEPTION OF GRANTS PASS. EXPECT A SIMILAR SCENARIO TODAY. AS A RESULT, HAVE NUDGED MAX TEMPS HIGHER IN MEDFORD...UP INTO THE LOW 50S...WHILE KEEPING GRANTS PASS DOWN CLOSER TO THE MID 40S. AN UPPER LEVEL SHORT WAVE WILL DIVE SOUTHEASTWARD INTO THE GREAT BASIN TODAY BRINGING SLIGHT COOLING ALOFT TO AREAS EAST OF THE CASCADES. THOSE AREAS SHOULD HAVE MAX TEMPS A FEW DEGREES LOWER THAN YESTERDAY. OFFSHORE FLOW WILL COMMENCE LATER TODAY AND TONIGHT AS THIS SYSTEM MOVES INTO UTAH AND SURFACE HIGH PRESSURE BUILDS TO THE NORTH. ANOTHER FAST-MOVING SHORT WAVE WILL DIVE SOUTHWARD THROUGH OREGON INTO NORTHERN CALIFORNIA TONIGHT INTO THURSDAY. A STRONG RIDGE WILL DEVELOP OFF THE BRITISH COLUMBIA COAST AND THIS WILL ALLOW THE SHORT WAVE TO DEVELOP INTO A CLOSED LOW AS IT MOVES WESTWARD OFFSHORE IN THE EASTERLY FLOW ALOFT. THIS SYSTEM HAS VIRTUALLY NO MOISTURE WITH IT, SO WE'RE NOT EXPECTING ANY PRECIPITATION. STRONG OFFSHORE FLOW DEVELOPS THURSDAY AND PEAKS THURSDAY NIGHT INTO FRIDAY AS A STRONG WEST-EAST SURFACE PRESSURE GRADIENT SETS UP. THIS WILL CAUSE GUSTY WINDS OVER THE EAST SIDE AND OVER THE MID SLOPES AND RIDGES FROM THE CASCADES WEST. DUE TO THE INCREASE IN WINDS AND EXPECTED MIXING, HAVE DECIDED TO END THE AIR STAGNATION ADVISORY EAST OF THE CASCADES A BIT SOONER...THURSDAY MORNING. OVER THE WEST SIDE VALLEYS, CONFIDENCE IS NOT HIGH IN WINDS REACHING THE SURFACE TO MIX OUT THE INVERSION, SO HAVE CONTINUED THE AIR STAGNATION ADVISORY THERE THROUGH EARLY SATURDAY. IT MAY NEED TO BE EXTENDED OR RE- ISSUED AS THE RIDGE ALOFT BUILDS OVERHEAD AGAIN THIS WEEKEND AND OFFSHORE FLOW EASES. THE RIDGE WILL HOLD THROUGH AT LEAST MONDAY, THEN A PACIFIC SYSTEM WILL ATTEMPT TO MOVE ONSHORE MONDAY NIGHT INTO TUESDAY. MODELS CONTINUE TO WAVER ON THE STRENGTH OF THIS SYSTEM, BUT RIGHT NOW MODELS APPEAR WEAK. HAVE MAINTAINED THE GOING FORECAST OF SLIGHT CHANCE TO CHANCE POPS...HIGHEST ON THE COAST. SPILDE && .AVIATION...MARINE STRATUS WITH MVFR CIGS REMAINS LOCKED IN ALONG THE NORTH COAST FROM ABOUT BANDON NORTHWARD. INLAND...FOG/LOW CLOUDS ARE IN NEARLY IDENTICAL LOCATIONS THAT THEY WERE YESTERDAY ACROSS THE WEST SIDE AND COASTAL VALLEYS. LIFR/IFR CIG AND VIS WILL IMPACT KMFR AND KRBG THROUGH THE MORNING BUT SHOULD BURN OFF TO AT LEAST MVFR IN ALL AREAS LATE THIS MORNING. ELSEWHERE, VFR CONDITIONS WILL CONTINUE THROUGH THURSDAY. -WRIGHT/SPILDE && .MARINE...LONG PERIOD MODERATE WEST SWELL BUILDS TONIGHT...SUBSIDE LATE WEDNESDAY...AND BUILD AGAIN LATE THURSDAY. BEHIND A VERY WEAK FRONT THIS EVENING...WINDS WILL INCREASE AND BECOME GUSTY FROM THE NORTH LATE WEDNESDAY INTO THURSDAY...WITH THE HIGHEST WIND SPEEDS IN THE SOUTHERN OUTER ZONE. HIGH PRESSURE LATE IN THE WEEK AND INTO THE WEEKEND WILL SWITCH WINDS TO THE SOUTH AT MAINLY LIGHT SPEEDS. CONFIDENCE IS HIGH THAT NO MAJOR STORMS WILL AFFECT THE COASTAL WATERS THROUGH THIS WEEKEND. SK && .FIRE WEATHER...A SIGNIFICANT OFFSHORE FLOW EVENT IS EXPECTED TO COMMENCE TODAY INCREASING TONIGHT INTO THURSDAY MORNING, THEN PEAKING THURSDAY INTO FRIDAY MORNING. THIS IS IN RESPONSE TO TWO STRONG SHORT WAVE DISTURBANCES TRACKING SOUTHWARD FROM BRITISH COLUMBIA. THE FIRST WILL MOVE INTO THE GREAT BASIN TONIGHT WHILE THE SECOND TAKES A MORE WESTERLY TRAJECTORY THROUGH OREGON INTO NORTHERN CALIFORNIA THURSDAY. MEANWHILE, MID-LEVEL RIDGING WILL DEVELOP ALONG THE BRITISH COLUMBIA COAST. THIS WILL ALLOW THE SECOND SHORTWAVE TO MOVE WESTWARD DEVELOPING INTO A CLOSED LOW AS IT MOVES OFFSHORE IN THE BROAD EASTERLY FLOW ALOFT THURSDAY NIGHT INTO FRIDAY. A STRONG WEST-EAST SURFACE PRESSURE GRADIENT WILL RESULT THURSDAY NIGHT INTO FRIDAY AND THIS WILL ALLOW FOR GOOD MID SLOPE AND RIDGE WINDS IN THE 15-25 MPH RANGE WITH GUSTS TO 35 MPH. COULD SEE SOME GUSTS TO 40 MPH IN CHANNELED AREAS. IT HAS BEEN EXCEPTIONALLY DRY SINCE OCTOBER AND THIS HAS RESULTED IN VERY DRY FUELS FOR THIS TIME OF YEAR. THESE WINDS, COMBINED WITH RH RECOVERIES ONLY IN THE 20-30 PERCENT RANGE COULD RESULT IN FIRE WEATHER CONCERNS. A FIRE WEATHER WATCH (RFWMFR) DETAILS THIS POTENTIAL HAZARD. SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...AIR STAGNATION ADVISORY UNTIL 10 AM PST THURSDAY FOR ORZ029>031. FIRE WEATHER WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR ORZ615>617-619>624. AIR STAGNATION ADVISORY UNTIL 4 AM PST SATURDAY FOR ORZ023-024-026. DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ021-023-024-026. CA...FIRE WEATHER WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR CAZ280>282-284. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 1 AM PST THURSDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST FRIDAY FOR PZZ350-356-370-376. SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 9 PM PST THURSDAY FOR PZZ370-376. $$ MAS/TRW/FJB/SK  FXUS66 KMFR 221652 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 852 AM PST WED JAN 22 2014 .SHORT TERM...THE HIGH PRESSURE RIDGE JUST OFF THE COAST WILL STRENGTHEN TODAY WHILE A SHORTWAVE MOVES DOWN THE EAST SIDE OF THE RIDGE INTO EASTERN OREGON AND IDAHO. THEN ON THURSDAY THE STRONG RIDGE PERSISTS TO THE NORTH WITH AN UPPER LOW SETTING UP TO THE SOUTH OVER NORTHERN CALIFORNIA. THIS PATTERN IS EXPECTED TO BRING CONTINUED DRY WEATHER WITH STRONG OFFSHORE FLOW DEVELOPING OVER THE RIDGES TONIGHT INTO THURSDAY AND FRIDAY. IN THE VALLEYS EXPECT A DECREASE IN FOG BY THURSDAY NIGHT, EXCEPT POSSIBLY IN THE ROSEBURG AND GRANTS PASS AREAS. ON THE RIDGES, THE MAIN CONCERN WILL BE WITH THE STRONG GUSTY WINDS AND DRY AIR. UPDATED THE CURRENT FORECAST FOR TODAY OF FOG AND SKY COVER BASED ON THE LATEST SATELLITE DATA. && .AVIATION...BASED ON THE 22/12Z TAF CYCLE. FOG IS PRESENT THROUGH MANY OF THE VALLEYS IN SW OREGON AND WILL AFFECT KRBG AND KMFR WITH IFR TO LIFR VIS AND CIGS THIS MORNING. THIS FOG AND STRATUS SHOULD BURN OFF TO AT LEAST MVFR IN ALL AREAS LATE THIS MORNING WITH CLEARING TO VFR IN THE AFTERNOON. ELSEWHERE, VFR CONDITIONS WILL CONTINUE THROUGH THURSDAY. && .MARINE...LONG PERIOD MODERATE WEST SWELL WILL SUBSIDE THIS AFTERNOON AND BUILD AGAIN LATE THURSDAY. WINDS WILL INCREASE THIS AFTERNOON AND BECOME GUSTY WITH THE HIGHEST WIND SPEEDS IN THE SOUTHERN OUTER ZONE. HIGH PRESSURE LATE IN THE WEEK AND INTO THE WEEKEND WINDS WILL ALLOW WINDS TO BECOME LIGHT SOUTHERLY. && .PREV DISCUSSION... /ISSUED 345 AM PST WED JAN 22 2014/ DISCUSSION...MODIS-VIIRS NIGHTTIME MICROPHYSICS RGB SATELLITE IMAGERY VIA NASA/SPORT REVEALS PRETTY MUCH THE STATUS QUO THIS MORNING. COMPARED TO YESTERDAY'S SATELLITE IMAGE AT ABOUT THE SAME TIME, IT APPEARS NEARLY IDENTICAL WITH RESPECT TO WHERE THE LOW CLOUDS AND FOG ARE...JUST PERHAPS A SLIGHTLY SHALLOWER FOG IN PORTIONS OF THE ROGUE VALLEY. DENSE FOG ADVISORIES (NPWMFR) ARE UP FOR THE UMPQUA/ROGUE VALLEYS UNTIL 10 AM THIS MORNING. COULD ALSO BE SOME SLIPPERY SPOTS ON AREA ROADS WHERE TEMPERATURES HAVE FALLEN BELOW FREEZING. MOST AREAS BROKE OUT YESTERDAY WITH THE EXCEPTION OF GRANTS PASS. EXPECT A SIMILAR SCENARIO TODAY. AS A RESULT, HAVE NUDGED MAX TEMPS HIGHER IN MEDFORD...UP INTO THE LOW 50S...WHILE KEEPING GRANTS PASS DOWN CLOSER TO THE MID 40S. AN UPPER LEVEL SHORT WAVE WILL DIVE SOUTHEASTWARD INTO THE GREAT BASIN TODAY BRINGING SLIGHT COOLING ALOFT TO AREAS EAST OF THE CASCADES. THOSE AREAS SHOULD HAVE MAX TEMPS A FEW DEGREES LOWER THAN YESTERDAY. OFFSHORE FLOW WILL COMMENCE LATER TODAY AND TONIGHT AS THIS SYSTEM MOVES INTO UTAH AND SURFACE HIGH PRESSURE BUILDS TO THE NORTH. ANOTHER FAST-MOVING SHORT WAVE WILL DIVE SOUTHWARD THROUGH OREGON INTO NORTHERN CALIFORNIA TONIGHT INTO THURSDAY. A STRONG RIDGE WILL DEVELOP OFF THE BRITISH COLUMBIA COAST AND THIS WILL ALLOW THE SHORT WAVE TO DEVELOP INTO A CLOSED LOW AS IT MOVES WESTWARD OFFSHORE IN THE EASTERLY FLOW ALOFT. THIS SYSTEM HAS VIRTUALLY NO MOISTURE WITH IT, SO WE'RE NOT EXPECTING ANY PRECIPITATION. STRONG OFFSHORE FLOW DEVELOPS THURSDAY AND PEAKS THURSDAY NIGHT INTO FRIDAY AS A STRONG WEST-EAST SURFACE PRESSURE GRADIENT SETS UP. THIS WILL CAUSE GUSTY WINDS OVER THE EAST SIDE AND OVER THE MID SLOPES AND RIDGES FROM THE CASCADES WEST. DUE TO THE INCREASE IN WINDS AND EXPECTED MIXING, HAVE DECIDED TO END THE AIR STAGNATION ADVISORY EAST OF THE CASCADES A BIT SOONER...THURSDAY MORNING. OVER THE WEST SIDE VALLEYS, CONFIDENCE IS NOT HIGH IN WINDS REACHING THE SURFACE TO MIX OUT THE INVERSION, SO HAVE CONTINUED THE AIR STAGNATION ADVISORY THERE THROUGH EARLY SATURDAY. IT MAY NEED TO BE EXTENDED OR RE- ISSUED AS THE RIDGE ALOFT BUILDS OVERHEAD AGAIN THIS WEEKEND AND OFFSHORE FLOW EASES. THE RIDGE WILL HOLD THROUGH AT LEAST MONDAY, THEN A PACIFIC SYSTEM WILL ATTEMPT TO MOVE ONSHORE MONDAY NIGHT INTO TUESDAY. MODELS CONTINUE TO WAVER ON THE STRENGTH OF THIS SYSTEM, BUT RIGHT NOW MODELS APPEAR WEAK. HAVE MAINTAINED THE GOING FORECAST OF SLIGHT CHANCE TO CHANCE POPS...HIGHEST ON THE COAST. SPILDE FIRE WEATHER...A SIGNIFICANT OFFSHORE FLOW EVENT IS EXPECTED TO COMMENCE TODAY INCREASING TONIGHT INTO THURSDAY MORNING, THEN PEAKING THURSDAY INTO FRIDAY MORNING. THIS IS IN RESPONSE TO TWO STRONG SHORT WAVE DISTURBANCES TRACKING SOUTHWARD FROM BRITISH COLUMBIA. THE FIRST WILL MOVE INTO THE GREAT BASIN TONIGHT WHILE THE SECOND TAKES A MORE WESTERLY TRAJECTORY THROUGH OREGON INTO NORTHERN CALIFORNIA THURSDAY. MEANWHILE, MID-LEVEL RIDGING WILL DEVELOP ALONG THE BRITISH COLUMBIA COAST. THIS WILL ALLOW THE SECOND SHORTWAVE TO MOVE WESTWARD DEVELOPING INTO A CLOSED LOW AS IT MOVES OFFSHORE IN THE BROAD EASTERLY FLOW ALOFT THURSDAY NIGHT INTO FRIDAY. A STRONG WEST-EAST SURFACE PRESSURE GRADIENT WILL RESULT THURSDAY NIGHT INTO FRIDAY AND THIS WILL ALLOW FOR GOOD MID SLOPE AND RIDGE WINDS IN THE 15-25 MPH RANGE WITH GUSTS TO 35 MPH. COULD SEE SOME GUSTS TO 40 MPH IN CHANNELED AREAS. IT HAS BEEN EXCEPTIONALLY DRY SINCE OCTOBER AND THIS HAS RESULTED IN VERY DRY FUELS FOR THIS TIME OF YEAR. THESE WINDS, COMBINED WITH RH RECOVERIES ONLY IN THE 20-30 PERCENT RANGE COULD RESULT IN FIRE WEATHER CONCERNS. A FIRE WEATHER WATCH (RFWMFR) DETAILS THIS POTENTIAL HAZARD. SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...AIR STAGNATION ADVISORY UNTIL 10 AM PST THURSDAY FOR ORZ029>031. FIRE WEATHER WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR ORZ615>617-619>624. AIR STAGNATION ADVISORY UNTIL 4 AM PST SATURDAY FOR ORZ023-024-026. DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ021-023-024-026. CA...FIRE WEATHER WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR CAZ280>282-284. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 4 PM THIS AFTERNOON TO 1 AM PST THURSDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 1 AM PST THURSDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR WINDS FROM 4 PM THIS AFTERNOON TO 4 PM PST THURSDAY FOR PZZ370. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST FRIDAY FOR PZZ370-376. SMALL CRAFT ADVISORY FOR WINDS FROM 1 PM THIS AFTERNOON TO 4 PM PST THURSDAY FOR PZZ376. $$ CC  FXUS66 KMFR 211141 AAA AFDMFR AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MEDFORD OR 441 AM PDT FRI MAR 21 2014 UPDATED AVIATION AND MARINE SECTIONS .DISCUSSION...AT THE SURFACE A THERMAL TROUGH IS LOCATED ALONG THE NORTHERN CALIFORNIA AND SOUTHERN OREGON COAST WITH HIGH PRESSURE OFFSHORE. THIS IS BRINGING VERY GUSTY WINDS TO THE COASTAL MOUNTAINS AND TO THE COASTAL WATERS THIS MORNING...WITH THE GUSTY WINDS EXPECTED TO CONTINUE OVER THE COASTAL WATERS AND ALONG THE COAST THROUGH THIS EVENING. MEANWHILE, ALOFT NORTHWEST FLOW IS BRINGING A COUPLE WEAK SHORTWAVES INTO THE AREA TODAY BUT EXPECT CONTINUED DRY CONDITIONS. THEN ON THE WEEKEND , A HIGH PRESSURE RIDGE WILL BUILD OVER THE REGION BRINGING WARMER TEMPERATURES AS WELL AS CONTINUED DRY CONDITIONS. ON MONDAY THE RIDGE IS FORECAST TO SHIFT EAST WITH A FRONTAL SYSTEM APPROACHING THE COAST MONDAY EVENING AND NIGHT. THIS WILL BRING A CHANGE TO A WETTER AND COOLER REGIME. THIS MORNING SOME HIGH CLOUDS ARE PRESENT OVER THE AREA. ALSO LIGHT WINDS HAVE CONTINUED IN MANY INLAND VALLEY LOCATIONS. AS A RESULT TEMPERATURES HAVE BEEN SLOW TO DROP TONIGHT. STILL EXPECT AREAS OF FREEZING AND BELOW FREEZING TEMPERATURES IN WEST SIDE VALLEYS, ESPECIALLY IN OUTLYING AREAS OF THE ROGUE VALLEY, THE APPLEGATE AND ILLINOIS VALLEYS AND INTO THE SHASTA VALLEY. GIVEN DEW POINTS IN THESE AREAS RANGING FROM 22 TO 30 DEGREES F EARLY THIS MORNING, EXPECT LOCATIONS THAT ARE PROTECTED FROM WIND TO DROP INTO THE UPPER 20S. A WEAK SHORTWAVE TROUGH TO THE NORTHWEST WILL MOVE INTO THE AREA TODAY AND THEN SHIFT EASTWARD THIS EVENING. THE GFS AND ECMWF MODELS CONTINUE TO SHOW SOME LIGHT ISOLATED PRECIPITATION OVER MODOC COUNTY AND OVER AREAS FURTHER SOUTH THIS AFTERNOON AND EVENING WHILE THE NAM AND RUC KEEP THE AREA DRY. GIVEN THE LACK OF GOOD MOISTURE EXPECT MAINLY JUST SOME CLOUD COVER WITH NO PRECIPITATION. OTHERWISE, ACROSS THE AREA EXPECT MILD TEMPERATURES AND MOSTLY SUNNY SKIES TODAY. GUSTY WINDS ARE EXPECTED ALONG THE COAST THIS MORNING, INCREASING THIS AFTERNOON AND CONTINUING INTO THE EVENING. THE WINDS ALONG THE COAST AND OVER THE COASTAL WATERS WILL WEAKEN SOME TONIGHT INTO SATURDAY. STILL EXPECT GUSTY WINDS TO CONTINUE ON SATURDAY FOR SOME COASTAL AREAS AND FOR THE COASTAL WATERS, ESPECIALLY SOUTH OF CAPE BLANCO. THEN ON SUNDAY AS THE UPPER RIDGE AXIS MOVES INLAND OVER THE REGION, THE THERMAL TROUGH WILL SHIFT INLAND AND WINDS ALONG THE COAST WILL WEAKEN. MEANWHILE INLAND LOCATIONS WILL SEE A WARMING TREND AS THE RIDGE BUILDS INTO THE AREA THIS WEEKEND. THESE WARM TEMPERATURES WILL CONTINUE FOR INLAND ON MONDAY. THEN MODELS ARE SHOWING GOOD AGREEMENT WITH A MOIST AND COOL PATTERN DEVELOPING MONDAY NIGHT AND TUESDAY AS AN UPPER LOW SETS UP IN THE GULF OF ALASKA. THIS IS EXPECTED TO BRING A SERIES OF FRONTS INTO THE AREA NEXT WEEK. THE FIRST OF THESE IS A MOIST FRONTAL SYSTEM WHICH MODELS SHOW APPROACHING THE COAST MONDAY EVENING AND MOVING INLAND MONDAY NIGHT AND TUESDAY. HAVE RAISED POPS DURING THIS PERIOD. SNOW LEVELS ARE EXPECTED TO REMAIN HIGH, MAINLY ABOVE 7000 FEET, AHEAD OF THE FRONT AND THEN LOWER BEHIND THE FRONT TUESDAY AND TUESDAY NIGHT TO AROUND 5000 FEET. /CC && .AVIATION...BASED ON THE 21/12Z TAF CYCLE. LOW CLOUDS DEVELOPED IN THE UMPQUA VALLEY IN THE LAST HOUR OR SO. THIS WILL BRING MVFR TO KRBG FOR AT LEAST A FEW HOURS THIS MORNING BEFORE BURNING OFF BY AROUND 17Z. PATCHY IFR FOG IS ALSO EVIDENT IN THE MODIS-VIIRS NIGHTTIME MICROPHYSICS RGB IMAGERY THIS MORNING OVER PORTIONS OF THE COQUILLE VALLEY AND THE LOWER UMPQUA BASIN NEAR REEDSPORT. THE REMAINDER OF THE AREA WILL BE VFR FOR THE NEXT 24 HOURS, THOUGH GUSTY NORTH WINDS TO AROUND 30KT WILL DEVELOP THIS AFTERNOON ALONG THE COAST NEAR KOTH. SPILDE && .MARINE...NORTH GALES WILL CONTINUE OVER THE OUTER WATERS SOUTH OF CAPE BLANCO TODAY AS A THERMAL TROUGH PERSISTS OVER NORTHERN CALIFORNIA. GALES WILL NUDGE INTO THE SOUTHERN INNER ZONE AGAIN THIS AFTERNOON AND CONTINUE INTO THIS EVENING. THIS WILL BRING STEEP TO VERY STEEP WIND DRIVEN SEAS, ESPECIALLY BETWEEN 5 AND 40 NM OFFSHORE. HAZARDOUS CONDITIONS TO SMALL CRAFT WILL EXIST OVER THE ENTIRE WATERS. THE THERMAL TROUGH WILL WEAKEN TONIGHT, SO WINDS AND SEAS SHOULD EASE SOMEWHAT INTO SATURDAY. OFFSHORE HIGH PRESSURE WILL PERSIST THROUGH THE WEEKEND. A WETTER AND WINDIER PATTERN WITH MOSTLY SOUTHERLY WINDS WILL DEVELOP MONDAY NIGHT WHEN THE FIRST OF SEVERAL FRONTS MOVES THROUGH THE WATERS. SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR ORZ024-026. FREEZE WARNING UNTIL 9 AM PDT THIS MORNING FOR ORZ024-026. CA...FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR CAZ081. FREEZE WARNING UNTIL 9 AM PDT THIS MORNING FOR CAZ081. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT SATURDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT SATURDAY FOR PZZ350-356. GALE WARNING FROM 2 PM THIS AFTERNOON TO 11 PM PDT THIS EVENING FOR PZZ356. HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ350-356-370. SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT SATURDAY FOR PZZ370-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS EVENING TO 11 PM PDT SATURDAY FOR PZZ370-376. GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. HAZARDOUS SEAS WARNING UNTIL 5 AM PDT SATURDAY FOR PZZ376. $$ MAS/CC  FXUS66 KMFR 130339 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 839 PM PDT THU JUN 12 2014 .DISCUSSION...JUST MADE AN UPDATE TO ADJUST MANY OF THE HEADLINES. IN SUMMARY, EXPIRED THE RED FLAG WARNING FOR THE EAST SIDE, CANCELLED THE WIND ADVISORY FOR THE WEST SIDE, AND EXTENDED THE BLOWING DUST ADVISORY FOR AREAS DOWNWIND (EAST) OF SUMMER LAKE UNTIL 11 PM. THE FROST/FREEZE AND MARINE HEADLINES FOR TOMORROW AND BEYOND WERE NOT CHANGED. IT GOT PRETTY WINDY WEST OF THE CASCADES TODAY, AT LEAST IN THE ROGUE VALLEY AND ADJACENT AREAS. WE RECEIVED A COUPLE OF REPORTS OF TREES DOWN AND POWER OUTAGES. WHILE THE DROUGHT MAY HAVE HAD SOMETHING TO DO WITH THE STABILITY OF THESE TREES, IT WAS PRETTY WINDY, NONETHELESS, AS EVIDENCED BY A PEAK GUST OF 36 MPH AT THE MEDFORD AIRPORT. IT WAS WINDY AND ALSO VERY DRY EAST OF THE CASCADES AND IN NORTHEAST CALIFORNIA TODAY. RED FLAG CONDITIONS WERE OBSERVED ALMOST ALL DAY TODAY IN SOME AREAS, SUCH AS MODOC COUNTY. WHILE HUMIDITIES HAVE CREPT UP ENOUGH TO GET US OUT OF RED FLAG CRITERIA, IT IS STILL QUITE WINDY IN SPOTS EVEN AT THIS HOUR. FOR EXAMPLE, ENHANCED VISIBLE SATELLITE AND MODIS IMAGERY STILL CLEARLY SHOWS BLOWING DUST EAST OF SUMMER LAKE WHICH EXTENDS ALL THE WAY TO HIGHWAY 395 AND BEYOND. HAVEN'T HAD ANY REPORTS OF IMPACTS, BUT THE SATELLITE SIGNATURE IS PRETTY IMPRESSIVE, SO THE BLOWING DUST ADVISORY WAS EXTENDED FOR A FEW MORE HOURS (UNTIL 11 PM). AFTER THAT, WINDS SHOULD DECREASE ENOUGH FOR DUST TO SETTLE DOWN. ALSO ADJUSTED SKY AND WIND GRIDS, BUT THOSE EDITS WERE MINOR. NO OTHER UPDATES PLANNED THIS EVENING. -WRIGHT && .AVIATION...BASED ON 13/00Z TAF ISSUANCE... GUSTY WINDS THIS EVENING WILL SETTLE DOWN FOR THE MOST PART BY LATE EVENING. OVERNIGHT MVFR CEILINGS WITH SOME RAIN SHOWERS ARE EXPECTED TO DEVELOP ALONG THE COAST AND IN THE UMPQUA BASIN LEADING TO PARTIAL TERRAIN OBSCURATIONS IN THE COASTAL MOUNTAINS AND ACROSS THE UMPQUA DIVIDE. CONFIDENCE IS HIGHER TONIGHT THAN LAST NIGHT THAT CLOUDS WILL GET TO THE CASCADES AND SISKIYOUS TO INCLUDE MOST OF JACKSON COUNTY BY SUNRISE, BUT EXPECT THESE CLOUDS TO REMAIN VFR IN THE MEDFORD AREA. MVFR IN THE UMPQUA AND ALONG THE COAST WILL LIFT LATE MORNING THROUGH EARLY AFTERNOON. EXPECT ALL AREAS TO BECOME VFR DURING THE AFTERNOON AND WINDS WILL ALSO BE MUCH LIGHTER. IT WILL STILL BE A BIT GUSTY IN THE LATE AFTERNOON TO EARLY EVENING ACROSS MAINLY THE EAST SIDE. BTL && .MARINE...UPDATED UPDATED 12/8PM PDT... SOUTH WINDS WILL LINGER ALONG AND NEAR THE COAST, ESPECIALLY NORTH OF CAPE BLANCO, TONIGHT INTO FRIDAY MORNING. NORTH WINDS WILL REDEVELOP THROUGH MIDDAY FRIDAY AND THEN WILL INCREASE FRIDAY AFTERNOON THROUGH FRIDAY EVENING AS HIGH PRESSURE BUILDS IN FROM THE WEST. BREEZY NORTH WINDS AND STEEPENING SEAS WILL CONTINUE THROUGH THE WEEKEND AND LIKELY THROUGH NEXT WEEK...ESPECIALLY SOUTH OF CAPE BLANCO...AS THE WEATHER PATTERN REMAINS PERSISTENT. SMALL CRAFT ADVISORY CONDITIONS ON FRIDAY AFTERNOON AND EVENING WILL BE LOW END, BUT ARE LIKELY TO INCREASE IN COVERAGE AND SEVERITY THIS WEEKEND INTO EARLY NEXT WEEK, ESPECIALLY SOUTH OF CAPE BLANCO, WHERE SOME WARNING CONDITIONS ARE POSSIBLE, PARTICULARLY WITH SEAS. BTL && .PREV DISCUSSION... /ISSUED 803 PM PDT THU JUN 12 2014/ DISCUSSION...AN UPPER LOW AND ASSOCIATED COLD FRONT ARE MOVING THROUGH THE FORECAST AREA THIS AFTERNOON. TEMPERATURES ARE 5 TO 10 DEGREES COOLER THAN 24 HOURS AGO AT MOST LOCATIONS. ITS BECOMING WINDY EAST OF THE CASCADES WITH GUSTS TO NEAR 40 MPH AT THIS HOUR...AND BREEZY CONDITIONS ARE EXPECTED WEST OF THE CASCADES THIS AFTERNOON. CRITICAL FIRE WEATHER CONDITIONS CONTINUE OVER NORTHEASTERN CALIFORNIA AND SOUTHERN LAKE AND KLAMATH COUNTIES THROUGH EARLY THIS EVENING. A RED FLAG WARNING AT RFWMFR CONTINUES FOR LOW HUMIDITIES AND GUSTY WINDS. PLEASE SEE THE FIRE WEATHER DISCUSSION BELOW FOR MORE DETAILS. SOME LIGHT RAIN HAS BEEN OBSERVED OVER COOS AND DOUGLAS COUNTIES THIS AFTERNOON...AND THIS WILL BE THE PRIMARY AREA FOR RAINFALL...THOUGH IT SHOULD BE MAINLY LIGHT...THROUGH FRIDAY MORNING AS ENERGY AND MOISTURE WITH THE TROUGH TRANSITS THE FORECAST AREA. FRIDAY THROUGH SUNDAY MODELS ARE IN GENERAL AGREEMENT WITH DEEP NORTHWEST FLOW KEEPING TEMPERATURES BELOW NORMAL INITIALLY...CREEPING UP TO NEAR NORMAL BY SUNDAY. LITTLE TO NO PRECIPITATION IS EXPECTED THROUGH SUNDAY. FRIDAY NIGHT INTO SATURDAY MORNING WILL FEATURE BELOW NORMAL TEMPERATURES...AND FROST AND FREEZE CONDITIONS ARE LIKELY EAST OF THE CASCADES. A HOST OF FROST ADVISORIES AND FREEZE WARNINGS HAVE BEEN ISSUED AT NPWMFR. A MOSTLY CLEAR NIGHT...WITH A HINT OF JUST SOME HIGH CLOUDS PASSING THROUGH...IS EXPECTED EAST OF THE CASCADES WITH LIGHT WINDS...CREATING FAVORABLE CONDITIONS FOR COLD TEMPERATURES. MOST POPULATION CENTERS LIKE KLAMATH FALLS AND ALTURAS SHOULD REMAIN ABOVE FREEZING...BUT PLENTY OF MORE RURAL AREAS WILL DIP WELL BELOW FREEZING. ON MONDAY MODELS START TO DIVERGE SIGNIFICANTLY. GFS SUGGESTS RIDGING...THE ECMWF DEEP TROUGHING JUST TO OUR EAST...AND THE CANADIAN IS SOMEWHERE IN BETWEEN. WE ARE FAVORING THE EC SOLUTION BASED ON EXPECTED UPSTREAM BLOCKING...AND THE IDEA THAT THE GFS IS TOO PROGRESSIVE...FOLLOWING THE THINKING OF MY COLLEAGUE ON LAST NIGHT'S SHIFT. SO HAVE LEANED TOWARDS THE ECMWF WHICH BASICALLY MEANS KEEPING TEMPERATURES RELATIVELY COOL THROUGH TUESDAY. THEN...BOTH MODELS AGREE ON A WARMUP. FIRE WEATHER...CURRENT OBSERVATIONS ACROSS PORTIONS OF LAKE...KLAMATH AND MODOC COUNTIES INDICATE GUSTY WINDS OF OVER 20 MPH...WITH HUMIDITIES DROPPING BELOW 15 PERCENT. THEE CONDITIONS ARE RESULTING FROM A DRY COLD FRONT CURRENTLY SWEEPING ACROSS THE AREA. WATER VAPOR IMAGERY DEPICTS SOME VERY DRY AIR ALOFT...AND MODEL SOLUTIONS ARE PRODUCING 700 MB WINDS IN EXCESS OF 35 MPH. WITH DAYTIME HEATING TODAY...THESE SHOULD EASILY MIX TOT HE SURFACE...AND THIS HAS PROMPTED THE RED FLAG WARNING IN EFFECT UNTIL 8 PM PDT TONIGHT. AFTER SUNSET...WINDS SHOULD DECOUPLE AND WEAKEN CONSIDERABLY...AND OVERNIGHT RH RECOVERIES SHOULD BE GOOD. COOLER TEMPERATURES AND MUCH CALMER WINDS ARE EXPECTED THROUGH THE WEEKEND...ALTHOUGH THE DAYTIME HUMIDITIES WILL REMAIN DRY. THERE IS A LARGE AMOUNT OF UNCERTAINTY REGARDING THE LONG TERM FORECAST...BUT SOME MODEL SOLUTIONS ARE SUGGESTING THAT CONVECTION COULD BE POSSIBLE MID TO LATE NEXT WEEK. CONFIDENCE IN THUNDERSTORM FORECAST IS MUCH TOO LOW FOR ANY DETAILS ON PROBABILITIES...TIMING...OR LOCATION...BUT USERS SHOULD BE AWARE OF THE POSSIBILITY OF LIGHTNING DURING THE EXTENDED FORECAST TERM. -BPN && .MFR WATCHES/WARNINGS/ADVISORIES... OR...FREEZE WARNING FROM 2 AM TO 7 AM PDT SATURDAY FOR ORZ030. BLOWING DUST ADVISORY UNTIL 11 PM PDT THIS EVENING FOR ORZ031. FROST ADVISORY FROM 2 AM TO 7 AM PDT SATURDAY FOR ORZ031. FREEZE WARNING FROM 2 AM TO 7 AM PDT SATURDAY FOR ORZ031. FROST ADVISORY FROM 2 AM TO 7 AM PDT SATURDAY FOR ORZ029. FREEZE WARNING FROM 2 AM TO 7 AM PDT SATURDAY FOR ORZ029. CA...FROST ADVISORY FROM 2 AM TO 7 AM PDT SATURDAY FOR CAZ084. FROST ADVISORY FROM 2 AM TO 7 AM PDT SATURDAY FOR CAZ085. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 PM FRIDAY TO 5 AM PDT SATURDAY FOR PZZ350-370. HAZARDOUS SEAS WATCH FROM SATURDAY MORNING THROUGH LATE SATURDAY NIGHT FOR PZZ356-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 PM FRIDAY TO 5 AM PDT SUNDAY FOR PZZ356-376. $$  FXUS66 KMFR 120934 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 234 AM PDT WED AUG 12 2015 .DISCUSSION...AN UPPER LOW CENTERED OVER THE OFFSHORE WATERS NEAR 40N 130W WILL REMAIN NEARLY STATIONARY FOR THE NEXT 24 HOURS BEFORE BEGINNING A JOG TO THE NORTHEAST TOWARDS THE OREGON COAST. DRY AIR EAST OF THE LOW WILL AFFECT THE AREA TODAY...BRINGING PARTLY TO MOSTLY SUNNY SKIES OUTSIDE OF ANY SMOKE...AND INCREASING TEMPERATURES BY SEVERAL DEGREES TO NEAR OR ABOVE NORMAL READINGS. THE LARGEST CURRENT IMPACT FROM THE SMOKE CENTERS NEAR THE NATIONAL CREEK COMPLEX NEAR CRATER LAKE...WHERE HIGHWAY 230 IS CLOSED NOW BETWEEN MILE MARKERS 12 AND 24...PER ODOT'S TRIPCHECK.COM WEBSITE. MODIS IMAGERY SHOWS PLENTY OF RECENT BURNING AT THAT FIRE...AND WITH LIGHT DOWNSLOPE FLOW THIS MORNING EXPECT SMOKE TO CONTINUE TO IMPACT HIGHWAY 230 THROUGH THE MORNING. BY THIS AFTERNOON...WEST WINDS SHOULD PUSH SOME OF THE SMOKE AWAY FROM THE HIGHWAY. ELSEWHERE...EXPECT GENERALLY PATCHY SMOKE TODAY...MOSTLY ALOFT...IN SOUTHWESTERN OREGON AND NORTHWESTERN CALIFORNIA. TONIGHT...THE MARINE LAYER AT THE COAST WILL DEEPEN AND PATCHY DRIZZLE IS EXPECTED MAINLY AT THE COAST AND JUST INLAND. ON THURSDAY THE UPPER LOW NUDGES CLOSER TO LAND AND USHERS IN ENOUGH MOISTURE TO BRING SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS TO AREAS ALONG AND WEST OF THE CASCADES. IT IS NOTABLE HOW DRY THE AIR MASS REMAINS ON THURSDAY IN THE UPPER LEVELS ALONG AND WEST OF THE CASCADES...AND EVEN DRIER EAST OF THE CASCADES. THIS DRY AIR...AND WEAK INSTABILITY...SUPPORTS THE IDEA OF JUST A SLIGHT CHANCE OF THUNDERSTORMS THURSDAY AFTERNOON AND EVENING. ALSO...THIS VERY DRY AIR WILL LIMIT THE AMOUNT OF RAINFALL THAT FALLS ANYWHERE...SO WE ARE EXPECTING ONLY SMALL AMOUNTS OF RAIN ON THURSDAY WITH THIS SYSTEM. PLUS...STEERING FLOW IS FAST FROM THE SOUTH SO ANY SHOWERS WON'T STAY IN ONE SPOT FOR VERY LONG. WE ARE TAKING A LITTLE LIBERTY WITH THE THUNDERSTORM POTENTIAL ON THURSDAY DESPITE THE WEAK INSTABILITY AND LOW MIDLEVEL MOISTURE VALUES...GIVEN THE STRONG DYNAMICS ASSOCIATED WITH THE UPPER LOW AND THE ANOMALOUSLY LOW 500MB TEMPERATURES. ANOMALY TABLES SUGGEST THE SOUTH TO NORTH WIND SPEEDS AHEAD OF THE LOW OVER THE EAST SIDE AND IN THE SHASTA VALLEY REPRESENT A TOP 5 TO 10 PERCENT EVENT FOR MID AUGUST. THESE WINDS IN COMBINATION WITH THE DRY AIR MASS COULD CREATE CRITICAL FIRE WEATHER CONDITIONS...AND A FIRE WEATHER WATCH AT RFWMFR HIGHLIGHTS THIS. ADDITIONALLY...WE EXPECT SOME BLOWING DUST IN AND DOWNSTREAM FROM SOME OF THE DRIER AREAS OF NORTHEAST SISKIYOU...MODOC...AND LAKE COUNTIES. DRY AND STABLE AIR RUNS THE SHOW FRIDAY THROUGH THE WEEKEND...WITH BELOW NORMAL TEMPERATURES ON FRIDAY THEN WARMING CONDITIONS SATURDAY THROUGH EARLY NEXT WEEK. && .AVIATION...FOR THE 12/06Z TAF CYCLE...A MIX OF MVFR/IFR CIGS ALONG THE COAST WILL SPREAD INTO THE UMPQUA BASIN...PERHAPS AS FAR AS KRBG...BEFORE CLEARING BACK TO THE COAST BY 20Z. AREAS OF MVFR CIGS ARE EXPECTED TO PERSIST ALONG THE COAST THIS AFTERNOON...THEN BECOME WIDESPREAD MVFR CIGS AND LOCAL IFR CIGS DURING THE EVENING. ELSEWHERE, INLAND AREAS WILL BE VFR THROUGH TODAY...EXCEPT THAT WILDFIRE SMOKE COULD CAUSE LIMITED VISIBILITY IN SOME AREAS. /CC && .MARINE...UPDATED 200 AM PDT WEDNESDAY 12 AUGUST 2015...A WEAK SURFACE PRESSURE PATTERN WILL RESULT IN LIGHT WINDS AND LOW SEAS THROUGH THURSDAY...BUT LOW PRESSURE ALOFT COULD BRING ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THURSDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE COAST LATE FRIDAY INTO THE WEEKEND, BRINGING WITH IT STRONG NORTH WINDS AND CHOPPY SEAS, ESPECIALLY IN THE OUTER WATERS SOUTH OF CAPE BLANCO. ALTHOUGH STILL TOO FAR OUT IN RANGE TO BE CERTAIN, GALES AND VERY STEEP SEAS ARE POSSIBLE THIS WEEKEND INTO EARLY NEXT WEEK. /CC && .MFR WATCHES/WARNINGS/ADVISORIES... OR...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR ORZ624-625. CA...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR CAZ285. RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM PDT THIS EVENING FOR CAZ281. FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR CAZ281. PACIFIC COASTAL WATERS...NONE. $$ NSK/NSK/CC