FXUS62 KCHS 300755 AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 355 AM EDT WED MAR 30 2011 ...BENEFICIAL RAINS TO FALL OVER DROUGHT AND FIRE STRICKEN AREAS... .SYNOPSIS... A SERIES OF LOW PRESSURE SYSTEMS WILL AFFECT THE REGION WEDNESDAY THROUGH THURSDAY. A COLD FRONT WILL MOVE THROUGH THE REGION FRIDAY NIGHT...WITH HIGH PRESSURE BUILDING BACK INTO THE REGION OVER THE WEEKEND AND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... 30/07Z SURFACE ANALYSIS SHOWED DEVELOPING LOW PRESSURE OVER SOUTHEAST LOUISIANA NEAR NEAR NEW ORLEANS AND LAKE PONTCHARTRAIN. A SHARPENING WARM FRONT WAS NOTED EAST OF THE LOW ALONG THE GULF COAST...DIPPING SOUTH OVER NORTH FLORIDA NEAR GAINSVILLE THEN LINKING UP WITH A COASTAL FRONT CURRENTLY FORMING ALONG THE WESTERN WALL OF THE GULF STREAM OFF THE COAST OF SOUTH CAROLINA... GEORGIA AND NORTHEAST FLORIDA. HIGH PRESSURE EXTENDED SOUTH FROM THE VIRGINA TIDEWATER INTO SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA WITH IN-SITU WEDGING FIRMLY IN PLACE. THE PRIMARY CONCERNS FOR TODAY ARE TEMPERATURES...LOCALLY HEAVY RAINFALL AND THE POTENTIAL FOR AN ISOLATED STRONG-SEVERE TSTM ACROSS THE FAR SOUTHERN ZONES. RAIN HAS BEEN SLOW TO DEVELOP THIS MORNING DESPITE INCREASING ISENTROPIC LIFT ATOP THE WEDGE. CONDENSATION PRESSURE DEFICITS ARE GENERALLY RUNNING 50-100MB PER RUC ISENTROPIC 4-PANELS... SUGGESTING MOST OF THE LIFT IS GOING TOWARDS LOW/MID-LEVEL CLOUD FORMATION VERSUS SHOWER PRODUCTION. ALL OF OUR AVAILABLE SHORT TERM GUIDANCE INDICATES SHOWER ACTIVITY WILL BEGIN TO BLOSSOM TO THE SOUTH OVER THE NEXT SEVERAL HOURS THEN STEADILY BUILD NORTH THROUGH SUNRISE. RADARS TO THE SOUTH INDICATE SHOWERS ARE ALREADY BEGINNING TO BREAK OUT ACROSS NORTH FLORIDA AND THE GEORGIA OFFSHORE WATERS INDICATING THIS PROCESS MAY ALREADY BE WELL UNDERWAY. ONLY ISOLATED-SCATTERED SHOWERS ARE ANTICIPATED THROUGH SUNRISE WITH SLIGHT CHANCE FOR AN ELEVATED TSTM OR TWO...MAINLY SOUTH OF I-16. LOWS WILL RANGE FROM THE LOWER-MID 50S NORTH TO THE UPPER 50S ACROSS THE SOUTH AND ALONG THE BEACHES. LOW PRESSURE OVER LOUISIANA WILL MOVE RAPIDLY EAST ALONG THE WARM FRONT TODAY AND APPROACH THE SOUTHERN ZONES LATE THIS AFTERNOON AS ITS SUPPORTING SHORTWAVE SHEARS OUT ACROSS THE OHIO VALLEY. IT REMAINS TO BE SEEN IF THE IN-SITU WEDGE WILL BREAK DOWN ENOUGH TODAY TO ALLOW THE WARM SECTOR AND ASSOCIATED SURFACE-BASED INSTABILITY TO PENETRATE NORTH/INLAND INTO THE LOCAL FORECAST AREA. THE 30/00Z NAM-12 WOULD SUGGEST ONLY A VERY SMALL AREA ALONG THE IMMEDIATE COAST AND ACROSS THE FAR SOUTH WILL MOVE INTO THE WARM SECTOR WITH THE WEDGE HOLDING FIRM FARTHER INLAND. THE LOWER RESOLUTION GFS IS MUCH QUICKER AND AGGRESSIVE WITH THE EROSION OF THE WEDGE WHICH DOES NOT SEEM REASONABLE WITH DIABATIC PROCESSES BECOMING STRONGLY REINFORCED AS WIDESPREAD RAINS FALL INTO THE CORE OF THE WEDGE. WILL GENERALLY FAVOR THE COOLER NAM-12 WITH THIS FORECAST CYCLE. PINNING DOWN HIGH TEMPERATURES WILL BE EXTREMELY TRICKY WITH THE WEDGE EXPECTED TO HOLD IN PLACE AND WILL BE HEAVILY DEPENDENT ON PRECIPITATION RATES AND WARM FRONT PLACEMENT. HIGH WILL RANGE FROM THE LOWER 60S INLAND TO AROUND 70 AT THE COAST AND FAR SOUTH...BUT CONFIDENCE IS LOW ESPECIALLY ACROSS THE FAR INLAND AREAS WHERE HIGHS COULD EASILY STALL IN THE MID-UPPER 50S SHOULD MODERATE RAINS INITIATE EARLIER THAN EXPECTED. INGREDIENTS APPEAR TO BECOMING TOGETHER FOR SOME BENEFICIAL RAINS TO FALL ACROSS DROUGHT AND FIRE STRICKEN AREAS. GOES/POES BLENDED TOTAL PRECIPITABLE WATER PRODUCTS SHOW A TROPICAL MOISTURE PLUME ADVECTING STEADILY NORTHWARD ACROSS FLORIA WITH PWATS AS HIGH AS 1.75 INCHES. THE PLUME WAS SAMPLED WELL AT 30/00Z WITH THE KTBW RAOB MEASURING A PWAT OF 1.63 INCHES. THIS MOISTURE WILL CONTINUE TO ADVECT NORTH THIS MORNING AND BE SOLIDLY IN PLACE ACROSS THE FORECAST AREA LATER TODAY AS SYNOPTIC DYNAMICS PEAK...RANGING FROM 1.45 INCHES ACROSS THE NORTH TO 1.70 INCHES ACROSS THE SOUTH. PWATS THIS HIGH ARE SLIGHTLY HIGHER THAN 2 STANDARD DEVIATIONS ABOVE CLIMATOLOGY. TROPICAL MOISTURE COUPLED WITH IMPRESSIVE Q-G FORCING ASSOCIATED WITH A COUPLED JET STRUCTURE SETTING UP BETWEEN DUAL JET STREAKS OVER NORTH CAROLINA AND ALABAMA WILL SUPPORT WIDESPREAD RAINS...MAINLY FROM LATE MORNING THROUGH LATE AFTERNOON. GENERAL RAIN AMOUNTS OF 0.5-1 INCH APPEAR LIKELY WITH AMOUNTS POTENTIALLY REACHING 1.25-1.5 INCHES ACROSS THE SOUTH AND UP ALONG THE COAST WHERE A BAND OF MODERATE-HEAVY RAIN WILL LIKELY TRAIN FOR SEVERAL HOURS. THERE IS SOME GUIDANCE THAT SUGGESTS A SEVERE MESOSCALE CONVECTIVE SYSTEM /MCS/ WILL DEVELOP ALONG THE GULF COAST LATER THIS MORNING AND SPREAD INTO NORTHERN FLORIDA THIS AFTERNOON. THIS MAY SEVERELY CURTAIL STRONG THETA ADVECTION THIS FAR NORTH AND COULD LIMIT RAIN AMOUNTS. THIS WILL HAVE TO WATCHED MONITORED THROUGHOUT THE DAY. FORECAST SOUNDING DEPICT NO ANY SIGNIFICANT SURFACE BASED INSTABILITY...BUT ELEVATED INSTABILITY WILL BE PRESENT WITH SHOWALTER VALUES OF -1 TO -2C. WILL FORECAST POPS NEAR 100 PERCENT WITH A CHANCE FOR TSTMS FOR ALL ZONES TODAY AND MENTION THAT THE RAIN COULD BE LOCALLY HEAVY AT TIMES...MAINLY SOUTH AND COASTAL AREAS. FLOODING SHOULD NOT BE TOO MUCH OF A CONCERN OUTSIDE OF URBAN AND LOW-LYING AREAS. THERE IS A LOW POTENTIAL FOR SEVERE WEATHER. FORECAST SOUNDINGS AT DARIEN AND LUDOWICI SUGGEST LITTLE IF ANY SIGNIFICANT SURFACE BASED INSTABILITY WILL DEVELOP THIS AFTERNOON DESPITE SURFACE TEMPERATURES RISING INTO THE UPPER 60S. SATURATED SOUNDINGS AND POOR MID-LEVEL LAPSE RATES OF 5-5.5 C/KM ARE CERTAINLY NOT CONDUCIVE FOR SEVERE TSTM FORMATION DESPITE IMPRESSIVE Q-G FORCING AND 0-6KM BULK SHEAR OF 45-50 KT. HOWEVER...GUIDANCE SUGGESTS SOME SORT OF SEVERE MCS WILL MOVE ACROSS NORTH FLORIDA LATER TODAY...THE NORTHERN EXTENT OF WHICH MAY BRUSH LOCATIONS SOUTH OF A LUDOWICI-HALFMOON LANDING LINE. ALTHOUGH ANY SUCH ACTIVITY WILL LIKELY STEADILY WEAKEN AS IT MOVES INTO THE MORE STABLE AIRMASS THERE MAY BE JUST ENOUGH CONVECTIVE INERTIA TO PRODUCE AN REPORT OF TWO OF WIND DAMAGE IN THE AFOREMENTIONED AREAS. A BRIEF TORNADIC SPIN-UP COULD ALSO OCCUR ALONG THE SOUTHERN EDGE OF THE WEDGE FRONT. WILL CONTINUE TO HIGHLIGHT AN ISOLATED SEVERE RISK FOR LONG/MCINTOSH AND LIBERTY COUNTIES IN THE HAZARDOUS WEATHER OUTLOOK...BUT WE DO NOT ANTICIPATE AN ORGANIZED SEVERE EVENT THIS FAR NORTH ATTM. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... WIDESPREAD RAINS WILL QUICKLY DIMINISH THIS EVENING AS THE STRONGEST FORCING SHIFTS OFFSHORE AS DOES LOW PRESSURE. WINDS WILL TURN NORTH IN THE WAKE OF THE LOW...BUT EXTENSIVE LOW/MID-LEVEL CLOUDINESS ALONG WITH WEAK SPOKES OF VORTICITY PASSING THROUGH THE LAST FLOW ALOFT WILL KEEP A RISK FOR DRIZZLE AND/OR ISOLATED- SCATTERED SHOWERS GOING THROUGH MUCH OF THE NIGHT. COMPLICATING MATTERS IS THE POTENTIAL FOR STRATUS BUILD-DOWN FROM LATE EVENING ON WHICH COULD RESULT IN FOG SOME OF IT DENSE. WILL FORECAST 30-40 PERCENT POPS THIS EVENING THEN DROPPING TO 20-30 PERCENT AFTER MIDNIGHT. AREAS OF FOG WILL ALSO BE INCLUDED IN THE GRIDS AND TEXT PRODUCTS. LATER SHIFTS WILL BE ABLE TO BETTER PIN DOWN THE FOG POTENTIAL AS ADDITIONAL DATA SETS ARE RECEIVED. LOWS WILL RANGE FROM AROUND 50 WELL INLAND TO THE LOWER 60S ACROSS MCINTOSH COUNTY. MODEL SOLUTIONS ARE IN GOOD AGREEMENT WITH THE OVERALL SYNOPTIC PATTERN EVOLUTION THROUGH THE SHORT TERM PERIODS...ALTHOUGH MINOR TRACK AND TIMING DIFFERENCES CONTINUE TO EXIST. THURSDAY AND THURSDAY NIGHT...OPERATIONAL MODELS ARE IN GOOD AGREEMENT LIFTING A WAVE OF LOW PRESSURE NORTHEASTWARD THROUGH THE SOUTHEAST STATES OR JUST OFF THE COAST ON THURSDAY. OBVIOUSLY THE TRACK WILL HAVE LARGE IMPLICATIONS ON FORECAST TEMPERATURES...WITH ONLY MINOR IMPACTS TO THE SENSIBLE WEATHER FORECAST. THE AREA WILL BE OVERSPREAD WITH DEEP MOISTURE AND STRONG FORCING FROM THE ENTRANCE REGION OF 160+ KNOT H25 JET...SO WILL CARRY LIKELY POPS ALL LOCALES ON THURSDAY...WITH HIGHEST PROBABILITIES IN THE MORNING ACROSS SOUTHEAST GEORGIA AND IN THE AFTERNOON ACROSS SOUTHERN SOUTH CAROLINA. GUIDANCE CONTINUES TO SHOW IMPRESSIVE ELEVATED INSTABILITY...SO WILL KEEP THUNDER IN THE FORECAST AS WELL. THE AREA OF LOW PRESSURE WILL TRACK OFF TO THE NORTHEAST AND AWAY FROM THE REGION THURSDAY NIGHT...SO WILL ALLOW THINGS TO DRY OUT THURSDAY EVENING ACROSS SOUTHEAST GEORGIA WHILE KEEPING SLIGHT CHANCE/LOW CHANCE POPS IN PLACE ACROSS SOUTHERN SOUTH CAROLINA FOR SOME LINGERING SHOWERS. AFTER MIDNIGHT...THE GFS AND NAM SHOW AN INCREASE IN DEEP MOISTURE ACROSS THE NORTHWESTERN TWO THIRDS OF THE FORECAST AREA...ALONG WITH SOME FORCING FOR ASCENT IN THE LEFT FRONT QUAD OF A 100+ KNOT NORTHWEST TO SOUTHEAST ORIENTED H25 JET. GIVEN THE WESTERLY BOUNDARY LAYER FLOW...WE ARE NOT ANTICIPATING MUCH IN THE WAY OF RAINFALL COVERAGE...BUT THERE REMAINS ENOUGH OF A CHANCE FOR SOME ISOLATED LIGHT RAIN SHOWERS TO WARRANT SLIGHT CHANCE POPS ACROSS THE NORTHWESTERN TWO THIRDS OF THE FORECAST AREA. TEMPERATURES WILL BE QUITE DIFFICULT TO PIN DOWN THURSDAY AND WILL BE HIGHLY DEPENDENT ON THE TRACK OF THE AREA OF LOW PRESSURE THROUGH THE REGION. WILL TREND FORECAST TEMPERATURES TOWARD THE HIGHER RESOLUTION NAM SOLUTION...WHICH RESULTS IN HIGHS IN THE MID/UPPER 50S ACROSS NORTHERN ZONES...AND IN LOW/MID 60S ACROSS THE SOUTH. OVERNIGHT LOWS WILL BOTTOM OUT IN THE MID TO UPPER 40S AREA WIDE. FRIDAY AND FRIDAY NIGHT...HIGH PRESSURE WILL BUILD SOUTH OF THE FORECAST AREA ON FRIDAY...WITH A WEAK FRONTAL BOUNDARY OR AXIS OF DEEPER MOISTURE REMAINING IN PLACE ACROSS NORTHERN ZONES OR JUST NORTH OF THE FORECAST AREA. THIS BOUNDARY WILL THEN SHIFT SOUTHWARD THROUGH THE REGION FRIDAY NIGHT. WILL CARRY SLIGHT CHANCE POPS ACROSS NORTHERN ZONES FRIDAY IN CLOSEST PROXIMITY TO THE WEAK FRONTAL BOUNDARY/AXIS OF DEEPER MOISTURE. WILL THEN CARRY SLIGHT CHANCE POPS ALL AREAS FRIDAY NIGHT AS THE FRONTAL BOUNDARY SLIPS SOUTHWARD THROUGH THE REGION. HIGHS ON FRIDAY SHOULD REBOUND BACK CLOSER TO NORMAL UNDER A MIX OF SUN AND CLOUDS AND WESTERLY DOWNSLOPE BOUNDARY LAYER FLOW. WE EXPECT HIGHS TO RANGE FROM AROUND 70/LOWER 70S NORTH TO THE MID 70S ACROSS THE SOUTH. LOWS FRIDAY NIGHT SHOULD BOTTOM OUT IN THE UPPER 40S TO AROUND 50 ACROSS NORTHERN AREAS...AND IN THE LOW/MID 50S ACROSS SOUTHERN LOCALES. SATURDAY...THE WEAK FRONTAL BOUNDARY/AXIS OF DEEPER MOISTURE WILL CONTINUE TO SHIFT SOUTH OF THE FORECAST AREA. EXPECT ANY MORNING CLOUDS TO GIVE WAY TO PLENTY OF SUNSHINE BY MID/LATE MORNING. WESTERLY DOWNSLOPE FLOW WILL ALLOW FOR TEMPERATURES TO REBOUND NICELY BACK INTO THE MIDDLE 70S MOST AREAS. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... MODEL SOLUTIONS ARE IN GOOD AGREEMENT THROUGH THE EARLY NEXT WEEK...WITH SOME TIMING DIFFERENCES NOTED WITH THE APPROACH OF A COLD FRONT DURING THE EARLY TO MIDDLE PORTION OF NEXT WEEK. OVERALL...EXPECT HIGH PRESSURE TO BUILD OVER THE AREA SATURDAY NIGHT THROUGH MONDAY NIGHT RESULTING IN RAIN FREE WEATHER. FOR NOW WILL CARRY SLIGHT CHANCE POPS TUESDAY THROUGH WEDNESDAY GIVEN THE UNCERTAINTY WITH THE TIMING OF THE NEXT COLD FRONT...AND REFINE AS DETAILS BECOME MORE CLEAR. TEMPERATURES ARE EXPECTED TO BE WITHIN A FEW DEGREES OF NORMAL MOST PERIODS...WITH THE EXCEPTION OF MONDAY THROUGH TUESDAY WHEN ABOVE TO MUCH ABOVE NORMAL TEMPERATURES ARE ANTICIPATED. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... CONDITIONS WILL STEADILY DETERIORATE AT KCHS/KSAV TODAY AS A WEDGE OF HIGH PRESSURE HOLDS FIRM AND WEAK LOW PRESSURE APPROACHES FROM THE SOUTHWEST. INCREASING ISENTROPIC LIFT WILL SUPPORT LOWERING CIGS THROUGH SUNRISE WITH IFR CIGS EXPECTED TO DOMINATE BY SUNRISE. COULD SEE SOME PATCHY BUILD-DOWN FOG AT BOTH TERMINALS WITH VSBYS POSSIBLY DROPPING AS LOW AS 4-5 MILES. RAIN WILL BLOSSOM OVER THE REGION AFTER SUNRISE WITH THE HEAVIEST RAINS IMPACTING THE TERMINALS FROM LATE MORNING THROUGH LATE AFTERNOON. THE MOST SIGNIFICANT REDUCTIONS IN VSBYS WILL AFFECT KSAV WHERE VSBYS COULD DROP TO AS LOW AS 1/2SM IN +RA IN A WINDOW FROM 18-21Z. VSBYS LOOK TO GO NO LOWER THAN 1 1/2SM AT KCHS...BUT STEADY RAINS WILL KEEP CONDITIONS LIFR TO LOW-END IFR THROUGH MUCH OF THE DAY INTO THE LATE EVENING. THE STEADIER RAINS WILL MOVE EAST OF THE TERMINALS BY SUNSET BUT CONSIDERABLE LOW-LEVEL MOISTURE COUPLED WITH A RE-INTENSIFICATION OF ISENTROPIC ASSENT WILL KEEP AREAS OF DRIZZLE AND LOW CIGS IN PLACE. SOME GUIDANCE SUGGESTS DENSE FOG COULD FORM TOWARDS THE END OF THE TAF PERIOD...BUT CONFIDENCE IS LOW THIS FAR OUT. WINDS WILL BE ALL OVER THE PLACE TODAY AS WEAK LOW PRESSURE RIDES ALONG THE LINGERING WEDGE FRONT. WINDS WILL REMAIN WELL BELOW 12 KT. AMENDMENTS WILL MOST CERTAINLY BE ISSUED THROUGHOUT THE DAY AS RADAR...VSBYS AND CIG TRENDS BECOME MORE APPARENT. EXTENDED AVIATION OUTLOOK...VFR/IFR CONDITIONS ARE EXPECTED TONIGHT THROUGH THURSDAY EVENING AS A SERIES OF LOW PRESSURE SYSTEMS MOVE THROUGH THE AREA. SHOULD SEE VFR CONDITIONS RETURN AFTER MIDNIGHT THURSDAY AND CONTINUE THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. && .MARINE... THERE ARE NO MAJOR CONCERNS THROUGH TONIGHT AS BOTH WINDS AND SEAS WILL REMAIN WELL BELOW FLAG THRESHOLDS. WIND DIRECTIONS WILL BE TRICKY TODAY AS LOW PRESSURE APPROACHES FROM THE WEST AND A COASTAL FRONT APPROACHES THE COAST. RAIN WILL BE LOCALLY HEAVY AT TIMES TODAY WITH VSBYS DROPPING TO LESS THAN 1 NM. FOG/STRATUS IS LIKELY TONIGHT ACROSS THE NEARSHORE WATERS WHICH MAY RESULT IN AREAS OF FOG. THURSDAY THROUGH MONDAY...AN AREA OF LOW PRESSURE WILL TRACK OVER OR JUST EAST OF THE WATERS ON THURSDAY. HIGH PRESSURE WILL THEN BRIEFLY BUILD BACK IN THURSDAY NIGHT...BEFORE A COLD FRONT APPROACHES FROM THE WEST ON FRIDAY. THE COLD FRONT WILL THEN PUSH THROUGH THE WATERS FRIDAY NIGHT...WITH HIGH PRESSURE BUILDING BACK INTO THE REGION OVER THE WEEKEND AND INTO EARLY NEXT WEEK. COULD SEE SOME MARGINAL SMALL CRAFT CONDITIONS ACROSS PORTIONS OF THE WATERS FRIDAY NIGHT AND SATURDAY BEHIND THE COLD FRONT. OTHERWISE WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW ADVISORY THRESHOLDS. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$  FXUS62 KCHS 150904 AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 404 AM EST FRI JAN 15 2016 .SYNOPSIS... LOW PRESSURE WILL PASS OVER OR NEAR THE AREA TODAY. ANOTHER LOW IS EXPECTED TO PASS OFFSHORE ON SUNDAY. A COLD FRONT WILL THEN MOVE THROUGH SUNDAY NIGHT...USHERING IN MUCH COLDER TEMPERATURES FOR EARLY TO MID NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... SURFACE CYCLOGENESIS IS ONGOING ACROSS THE NORTH-CENTRAL GULF OF MEXICO THIS MORNING WITH 1003 HPA LOW PRESSURE CENTERED JUST SOUTHWEST OF MOBILE BAY PER 15/08Z SURFACE ANALYSIS. CYCLOGENESIS IS BEING DRIVEN ALONG A SHARPENING WEST-EAST ORIENTED BAROCLINIC BOUNDARY BY A POTENT NEGATIVELY TILTED SHORTWAVE DIGGING ACROSS THE LOWER MISSISSIPPI VALLEY. THE SOUTHERN STREAM SHORTWAVE AND ATTENDANT SURFACE LOW WILL MOVE RAPIDLY EAST TODAY WITH THE LOW EXPECTED TO PASS ACROSS CENTRAL/EASTERN PORTIONS OF SOUTH CAROLINA AND GEORGIA. A LARGE CORRIDOR OF STRONG FORCING IS POISED TO TRAVERSE THE FORECAST AREA FROM MID-MORNING INTO THE AFTERNOON AS THE AGEOSTROPHIC CIRCULATION ASSOCIATED WITH THE LEFT EXIT REGION OF A POWERFUL SUBTROPICAL JET COUPLES WITH INCREASING DPVA AHEAD OF THE NEGATIVELY TILTED TROUGH AND STRENGTHENING LOW- LEVEL CONVERGENCE ALONG AN INLAND MOVING COASTAL FRONT. THIS DEEP LAYERED FORCING FOR ACCENT WILL INTERACT WITH A RIBBON OF PWATS IN EXCESS OF 1.50 INCHES AND STRONG LOW-LEVEL INFLOW TO SUPPORT AN AREA OF WIDESPREAD MODERATE TO HEAVY RAIN TODAY...WHICH WILL IMPACT ALL OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. POPS NEAR 100 PERCENT WILL BE MAINTAINED FOR ALL AREAS WITH THE GREATER RAIN CHANCES SHIFTING FROM SOUTHEAST GEORGIA INTO SOUTHEAST SOUTH CAROLINA LATER THIS AFTERNOON AS A DRY SLOT BEGINS TO PROPAGATES INTO THE AREA FROM THE SOUTHWEST. THE TRACK OF THE SURFACE LOW IS CRITICAL TO DETERMINING HOW FAR INLAND THE WARM SECTOR WILL PENETRATE AS THE COASTAL FRONT MOVES WEST. GENERALLY FAVOR THE TIMING/POSITION DEPICTED BY THE 15/00Z ECMWF...WHICH SHOWS THE CYCLONE MOVING ACROSS EAST-CENTRAL GEORGIA LATER THIS MORNING AND INTO THE CSRA AND MIDLANDS BY EARLY AFTERNOON BEFORE EXITING INTO EASTERN NORTH CAROLINA THIS EVENING. THE GFS LOOKS A BIT TOO FAR OFFSHORE WHILE THE NAM SHOWS MORE OF A MILLER-B DOUBLE BARREL CYCLONIC STRUCTURE...WHICH IS NOT CURRENTLY SUPPORTED GIVEN THE LACK OF A STRONG INLAND COLD AIR DAMMING REGIME. WITH THE LOW EXPECTED TO TRACK INLAND...EXCEPT THE WARM SECTOR TO OVERSPREAD MUCH OF THE FORECAST AREA LATER THIS MORNING WITH HIGHS REACHING INTO THE LOWER 60S WELL INLAND WITH MID-UPPER 60S CLOSER TO THE COAST...WARMEST IN THE SAVANNAH- LUDOWICI-DARIEN CORRIDOR. THERE IS A SMALL WINDOW FOR A ISOLATED STRONG TSTMS TO DEVELOP LATER TODAY AS THE SURFACE LOW PASSES BY. SHEAR PARAMETERS ARE CERTAINLY IMPRESSIVE GIVEN THE STRONG FIELDS THAT ARE FORECAST TO DEVELOP AS LOW-LEVEL JETTING TAKES HOLD...BUT NEAR SATURATED THERMODYNAMIC PROFILES SUGGEST VERY LITTLE IN THE WAY OF MEANINGFUL SURFACE-BASED INSTABILITY WILL BE PRESENT. HOWEVER... THERE ARE SOME SIGNALS THAT A SMALL CORRIDOR OF WEAK INSTABILITY COULD DEVELOP ACROSS PARTS OF THE CHARLESTON TRI-COUNTY AREA...WHICH COULD CONDITIONALLY SUPPORT 1 OR 2 LOW-TOPPED SUPERCELLS. AN ISOLATED TORNADO OR STRONG WIND GUSTS CAN THEREFORE NOT BE RULED OUT IN THIS AREA...BUT THE OVERALL RISK IS ACCESSED TO LOW. && .SHORT TERM /TONIGHT THROUGH MONDAY/... TONIGHT...LOW PRESSURE WILL BE LOCATED ACROSS EASTERN NORTH CAROLINA AS SUBSIDENCE/DNVA OVERSPREAD THE AREA IN THE WAKE OF PASSING SHORTWAVE ENERGY. CLEARING WILL BE WELL UNDERWAY BY EARLY EVENING WITH MOST OF THE RAIN EXITING THE CHARLESTON TRI-COUNTY AREA BY 8-10 PM. EXPECT DRY CONDITIONS TO PREVAIL FOR THE REMAINDER OF THE NIGHT. ALTHOUGH LOW/MID-LEVEL CLOUD DECKS WILL SCOUR OUT AS DRIER AIR ADVECTS IN WITH THE DRY SLOT...THE PERSISTENT SUBTROPICAL JET ALOFT WILL KEEP THICK CIRRUS IN PLACE FOR MUCH OF THE NIGHT. LOWS WILL RANGE FROM THE MID 40S INLAND TO THE LOWER 50S AT THE COAST. SATURDAY...DRY CONDITIONS ARE EXPECTED. SUNNY SKIES...WESTERLY FLOW AND POSSIBLY SOME DOWNSLOPE FROM THE APPALACHIAN MOUNTAINS WILL GIVE US ABOVE NORMAL TEMPERATURES FOR THIS TIME OF YEAR...IN THE MID 60S AND APPROACHING 70 IN SOME PARTS OF GEORGIA. MODELS INDICATE AN UPPER LEVEL SHORTWAVE WILL APPROACH FROM THE WEST SATURDAY NIGHT. AT THE SAME TIME A STRENGTHENING SURFACE LOW WILL BE MOVING FROM THE NORTHEASTERN PORTION OF THE GULF OF MEXICO ACROSS THE FLORIDA PENINSULA. SHOWERS ASSOCIATED WITH THIS LOW WILL OVERSPREAD OUR AREA FROM SOUTH TO NORTH OVERNIGHT. MOST OF THE 00Z MODELS HAVE PLACED MORE QPF OVER OUR AREA SO BUMPED UP THE POPS AND THE QPF...THE HIGHEST BEING IN OUR GEORGIA COUNTIES. COULD HAVE GONE LIKELY POPS IN SOME OF THESE SPOTS BUT DECIDED TO HOLD OFF TO GIVE THE DAY CREW A CHANCE TO SEE WHAT THE 12Z MODELS SHOW AND ADJUST AS NECESSARY. SUNDAY...THE UPPER LEVEL SHORTWAVE MOVES TO OUR EAST AND THE STRENGTHENING SURFACE LOW PASSES WELL OFFSHORE...MOVING NORTHEASTWARD AND AWAY FROM OUR AREA. ANY LINGERING SHOWERS...ESPECIALLY ALONG THE COAST...SHOULD DIMINISH IN THE MORNING AS DRIER AND COOLER AIR MOVES IN FROM THE WEST. TEMPERATURES SHOULD BE NEAR NORMAL...IN THE UPPER 50S. A DRY COLD FRONT WILL PASS THROUGH THE REGION SUNDAY NIGHT...USHERING IN COLDER TEMPERATURES FROM THE CENTRAL U.S. MINIMUM TEMPERATURES WILL BE IN THE 30S...CLOSE TO NORMAL BECAUSE THE MAIN COLD AIR ADVECTION APPEARS TO ARRIVE CLOSER TO SUNRISE. MONDAY...DRY AND COLD CONDITIONS WILL PREVAIL AS SURFACE HIGH PRESSURE OVER THE MIDDLE MISSISSIPPI VALLEY EXPANDS TOWARDS THE SOUTHEAST. NORTHWEST FLOW WILL ONLY ALLOW HIGHS TO REACH INTO THE UPPER 40S ACROSS MOST OF THE AREA AND THE LOWER 50S ACROSS PARTS OF GEORGIA. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... THE SURFACE HIGH PRESSURE WILL SHIFT FROM THE MIDDLE MISSISSIPPI VALLEY TOWARDS THE SOUTHEAST BY WEDNESDAY. TUESDAY WILL BE COLD WITH TEMPERATURES COMPARABLE TO MONDAY. TEMPERATURES WILL BEGIN TRENDING UPWARDS ON WEDNESDAY AS WINDS TURN SOUTHERLY AHEAD OF A DEVELOPING STORM SYSTEM OVER THE CENTRAL U.S. THE MODELS VARY SIGNIFICANTLY WITH THE TRACK OF THIS SYSTEM IN THE LONG RANGE FORECASTS. OPTED TO LEAN MORE TOWARDS THE ONGOING DRY FORECAST ON THURSDAY UNTIL THE MODELS COME INTO BETTER AGREEMENT WITH THE TRACK OF THE SYSTEM. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... CONDITIONS WILL DETERIORATE AT THE TERMINALS THIS MORNING AS LOW PRESSURE APPROACHES FROM THE SOUTHWEST. LIGHT RAIN WILL INTENSIFY THROUGH THE MORNING WITH HIGH RESOLUTION DATA SUGGESTING THE HEAVIEST RAINS WILL OCCUR AT KCHS WITHIN AN AXIS OF ENHANCED PWATS. EXPECT WIDESPREAD LOW-END MVFR CIGS TO ENCOMPASS BOTH TERMINALS BY MID-MORNING WITH RAIN REDUCED VSBYS TO 3-4SM. THERE IS A RISK FOR IFR OR LOWER VSBYS...BUT HIGHEST AT KCHS WHERE HEAVIER RAINS ARE EXPECTED. LLWS WL BE AN ISSUE AT BOTH TERMINALS ROUGHLY 14-20Z WHERE 1500 FT WINDS PEAK 40-45 KT. EXPECT IMPROVING CONDITIONS BY MID AFTERNOON ON AT KSAV AND LATE AFTERNOON INTO THIS EVENING AT KCHS. EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS ARE POSSIBLE LATE SATURDAY NIGHT INTO SUNDAY MORNING...AS LOW PRESSURE PASSES JUST OFFSHORE. && .MARINE... TODAY...VERY TRICKY AND COMPLICATED MARINE FORECAST FOR TODAY. LOW PRESSURE IS EXPECTED TO TRACK INLAND TODAY WHICH WILL KEEP THE MARINE AREA IN THE WARM SECTOR OF THE CYCLONE. A STRONG 925 HPA LOW-LEVEL JET UPWARDS OF 45-55 KT WILL SETTLE IN LATER THIS MORNING...BUT SURFACE MIXING WILL BE SUBDUED BY THE STABLE NEAR SURFACE ENVIRONMENT INDUCED BY THE COLD SHELF WATERS. AN EXCEPTION WILL BE ACROSS THE EASTERN PORTIONS OF THE GEORGIA OFFSHORE LEG WHERE THE LATEST USABLE NOAA-18 AVHRR SST ANALYSIS FROM 13 JANUARY PLACED THE WESTERN WALL OF THE GULF STREAM WITHIN 40 NM OF THE GEORGIA COAST. MIXING PROFILES IN THIS AREA WILL SUPPORT FREQUENT GUSTS TO GALE FORCE...THUS A GALE WARNING WILL BE ISSUED FOR THIS AREA THROUGH SUNSET. THERE WILL BE A LARGE RANGE OF CONDITIONS ACROSS THE GEORGIA OFFSHORE LEG GIVEN THE LARGE SST GRADIENT THAT IS PLACE. EXPECT WINDS AS HIGH AS 20-25 KT WESTERN PORTIONS WITH 25-30 KT WITH GUSTS TO 40 KT EASTERN PORTIONS. ACROSS THE NEARSHORE WATERS...WINDS WILL GENERALLY REMAIN 15-20 KT WITH HIGHER CONVECTIVELY INDUCED GUSTS POSSIBLE. SEAS WILL BUILD 4-7 FT NEARSHORE WATERS AND 7-10 FT OFFSHORE WATERS. SMALL CRAFT ADVISORIES...MAINLY FOR SEAS...WILL BE MAINTAINED FOR BOTH SOUTH CAROLINA NEARSHORE ZONES. A SMALL CRAFT ADVISORY WILL NOT BE ISSUED FOR THE GEORGIA NEARSHORE ZONE PER COORDINATION WITH WFO JACKSONVILLE. CONDITIONS JUST LOOK TOO MARGINAL IN THIS AREA FOR AN ADVISORY ATTM. TONIGHT...CONDITIONS WILL STEADILY IMPROVE TONIGHT AS LOW PRESSURE MOVES AWAY FROM THE REGION. SATURDAY THROUGH TUESDAY...A QUICK-MOVING STORM SYSTEM COULD MOVE CLOSE TO THE AREA LATE SATURDAY NIGHT INTO SUNDAY FOLLOWED BY A COLD FRONT SUNDAY NIGHT. DEPENDING ON THE TRACK OF THE STORM SYSTEM... ADVISORIES COULD BE NEEDED SUNDAY INTO MONDAY...ESPECIALLY FOR THE OFFSHORE WATERS. && .HYDROLOGY... STRONG UPPER FORCING WILL INTERACT WITH A RIBBON OF PWATS IN EXCESS OF 1.5 INCHES AND STRONG LOW-LEVEL INFLOW TO SUPPORT WIDESPREAD MODERATE TO HEAVY RAIN TODAY. THE LATEST GUIDANCE SUPPORTS STORM TOTAL AMOUNTS OF 1-1.5 INCHES ACROSS MUCH OF THE FORECAST AREA WITH AN AREA OF 2-2.25 INCHES ACROSS PARTS OF THE CHARLESTON TRI-COUNTY AREA. LOCALIZED AMOUNTS IN EXCESS OF 3 INCHES COULD OCCUR JUST ABOUT ANYWHERE TODAY...BUT MAINLY FOCUSED THE CHARLESTON TRI-COUNTY AREA. THE LATEST CPC SOIL MOISTURE ANALYSIS SHOWS THE GROUND ACROSS MUCH OF THE CHARLESTON TRI-COUNTY AREA REMAINS SUPERSATURATED BELOW THE FIRST INCH OF TOP SOIL WITH ANOMALIES RUNNING 160+ PERCENT ABOVE NORMAL FOR MID JANUARY. MUCH OF THIS MOISTURE IS A RESIDUAL FROM THE HISTORIC FLOODS THAT OCCURRED BACK IN OCTOBER. GIVEN THE SATURATED SOIL MOISTURE PROFILE AND CONSIDERING MUCH OF THE RAIN WILL LIKELY FALL IN ABOUT A 4-6 HOUR PERIOD TODAY...THERE WILL BE AN ENHANCED RISK FOR FLOODING...DESPITE THE RELATIVELY LOW STORM TOTAL QPF. A FLASH FLOOD WATCH WILL THEREFORE BE ISSUED FOR CHARLESTON-BERKELEY- DORCHESTER COUNTIES UNTIL SUNSET. COMPLICATING MATTERS IS THAT THERE ARE SIGNALS IN SOME OF THE HIGHER RESOLUTION MESOSCALE MODELS THAT A BAND OF HEAVY RAIN COULD FALL ACROSS THE CHARLESTON METRO AREA WITHIN AN HOUR OF AN ALREADY ELEVATED HIGH TIDE. THIS WOULD ELEVATED THE FLOOD RISK EVEN MORE FOR PARTS OF WEST ASHLEY...DOWNTOWN CHARLESTON...MOUNT PLEASANT AS WELL AS NORTH CHARLESTON. && .TIDES/COASTAL FLOODING... A STRENGTHENING ONSHORE WINDS COMBINED WITH ALREADY SLIGHTLY POSITIVE TIDAL DEPARTURES COULD PUSH TIDE LEVELS IN THE CHARLESTON HARBOR NEAR 7.0 FT MLLW WITH HIGH TIDE LATE THIS MORNING. CURRENT TRENDS SUGGEST TIDE LEVELS SHOULD FALL JUST SHORT OF SHALLOW COASTAL FLOODING THRESHOLDS...ALTHOUGH IT WILL BE CLOSE. WILL HOLD OFF ON THE ISSUANCE OF A COASTAL FLOOD ADVISORY AND CONTINUE TO MONITOR TRENDS. && .CLIMATE... DAILY RAINFALL RECORDS FOR 01/15/2016... KCHS 1.40/1966. KCXM 1.53/1966. KSAV 1.39/1966. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ044-045-050-052. MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR AMZ352. SMALL CRAFT ADVISORY UNTIL 5 AM EST SATURDAY FOR AMZ350. GALE WARNING UNTIL 7 PM EST THIS EVENING FOR AMZ374. && $$ ST/MS