Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 240001 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 701 PM EST SUN NOV 23 2014 .SYNOPSIS... MILD TEMPERATURES WITH UNSETTLED WEATHER IS EXPECTED TONIGHT INTO MONDAY AS A WARM FRONT CROSSES THE AREA. A COLD FRONT WILL CROSS THE COAST MONDAY NIGHT AND STALL OFFSHORE TUESDAY. COOL AND WET CONDITIONS ARE EXPECTED WEDNESDAY...AS DEEPENING LOW PRESSURE MOVES NORTH ALONG THE STALLED FRONT AND SKIRTS THE COAST. SKIES WILL CLEAR OUT ON THANKSGIVING...WITH TEMPERATURES RUNNING SEVERAL DEGREES BELOW NORMAL INTO THE COMING WEEKEND. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... AS OF 645 PM SUNDAY...A WAVE OF HEAVY SHOWERS AND EMBEDDED THUNDERSTORMS ACROSS EASTERN GEORGIA AND NOW CROSSING THE SANTEE RIVER INTO SOUTH CAROLINA WILL MOVE ACROSS THE EASTERN CAROLINAS SHORTLY. RAINFALL EARLIER TODAY WAS MAINLY DUE TO ISENTROPIC UPGLIDE AS MOIST WARM ADVECTION WITHIN THE 850-700 MB LAYER PRODUCED GENTLE UNIFORM LIFT. THE BATCH OF PRECIPITATION TO BEGIN SHORTLY IS BEING FORCED BY EXCELLENT UPPER DIVERGENCE WITHIN THE RIGHT-ENTRANCE REGION OF A 250 MB JET STREAK MOVING NORTH THROUGH WESTERN NC/VA THIS EVENING. A WARM FRONT CURRENTLY EXTENDING FROM NEAR BEAUFORT SC WESTWARD ACROSS AUGUSTA GA WILL MOVE NORTHWARD AT A GOOD CLIP OVER THE NEXT FEW HOURS...BRINGING A NEARLY TROPICAL AIRMASS NORTHWARD ACROSS THE AREA. MODEST SURFACE BASED INSTABILITY ON THE ORDER OF 300-600 J/KG SHOULD DEVELOP ACROSS AREAS WHERE TEMP/DEWPOINTS ARE ABLE TO REACH 70 DEGREES F. WHEN COMBINED WITH 0-1 KM HELICITY VALUES OF 400-600 M^2/S^2 THE POTENTIAL EXISTS FOR SOME OF THESE CELLS TO ROTATE. I FEEL THE OVERALL SEVERE WEATHER RISK REMAINS LOW SINCE SURFACE-BASED INSTABILITY SHOULD NOT DEVELOP UNTIL THE WARM FRONT ARRIVES AND WINDS BELOW 925 MB VEER MORE SOUTHWESTERLY. THIS WILL MAKE THE VERTICAL WIND PROFILE UNIDIRECTIONAL REDUCING THE POTENTIAL FOR TORNADIC STORMS. IF TEMPS/DEWPOINTS REMAIN BELOW 70 F MODEL FORECAST SOUNDINGS INDICATE THE BOUNDARY LAYER WOULD BE STABLE WITH CONVECTION REMAINING ELEVATED AND THEREFORE INHERENTLY LESS DANGEROUS. WE WILL MONITOR RADAR CLOSELY THROUGH THE EVENING WATCHING FOR ANYTHING THAT MIGHT WARRANT A STATEMENT OR SEVERE WEATHER WARNING. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... AS OF 4 PM SUNDAY...ODDLY MILD CONDITIONS TO ENGULF THE EASTERN CAROLINAS MONDAY WITH STRONG WARM AIR ADVECTION PATTERN IN PLACE AND A COLD FRONT AND UPPER TROUGH WEST OF THE FORECAST AREA. 65-70 TEMPERATURE RANGE TO GREET MOST AREAS DAYBREAK MONDAY...AS MAXIMUM TEMPERATURES CLIMB INTO THE MIDDLE AND UPPER 70S...LIKELY UNDER A CANOPY OF CLOUDS DUE TO EXTENT OF UPSTREAM CONVECTION. THE LOW-LVL WIND FIELD REMAINS STRONG MONDAY...AND ANY SURFACE HEATING MONDAY AFTERNOON COULD LEAD TO CONVECTION CAPABLE OF DAMAGING WIND...AND EVEN SHOWERS WILL BRING LOCALLY STRONGER GUSTS. SPC MAINTAIN A LOW END RISK NEAR THE COAST AHEAD OF A COLD FRONT. TUESDAY A POST-FRONTAL DAY WHERE WEATHER HAZARDS WANE. THE UPSTREAM TROUGH ALIGN HOWEVER WILL SUPPORT MORE IMPULSES RISING OUT OF THE GULF. CYCLOGENESIS OFFSHORE OF NORTHERN FLORIDA OCCUR VERY LATE IN THE PERIOD AND BECOME A WEATHER PLAYER BEYOND DAYBREAK WEDNESDAY AND POP VALUES DO GRADUALLY RAMP UP TO THIS FEATURE LATE TUESDAY. RECORD HIGH TEMPS MONDAY ARE ILM 79...FLO 83...CRE 76...LBT 78. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 4 PM SUNDAY...MAIN FOCUS FOR THE PERIOD REMAINS LOW PRESSURE PASSING JUST OFF THE COAST WED. SHORTWAVE CROSSING THE WESTERN GULF LATE TUE WILL ENHANCE SURFACE WAVE JUST OFF THE FL GULF COAST WED MORNING. THIS LOW WILL TRAVEL NORTHEAST ALONG A STALLED BOUNDARY WED INTO WED NIGHT WITH DEEP MOISTURE SPREADING OVER THE CAROLINAS. LOW WILL REMAIN EAST OF THE COASTAL WATERS WITH INCREASING NORTHERLY FLOW...CLOUD COVER...AND PERIODS OF HEAVY RAIN KEEPING TEMPERATURES IN THE 40S FOR MUCH OF THE AREA. PRESENCE OF DEEP MOISTURE AND STRONG LIFT/DIVERGENCE ALOFT WILL ENSURE PLENTY OF RAIN FALLS ACROSS THE AREA WED. MID LEVEL TROUGH MOVES INTO THE AREA WED EVENING WITH SIGNIFICANT AMOUNT OF DRY AIR MOVING IN...ENDING THE RAIN THREAT. SUBTLE MID LEVEL TROUGHING IN THE WAKE OF THE EXITING SYSTEM REMAINS OVER THE SOUTHEAST FRI...PUSHING A DRY COLD FRONT ACROSS THE AREA. MID LEVEL PATTERN FLATTENS OUT FOR THE WEEKEND AND FLOW ALOFT BECOMES PROGRESSIVE. HIGH PRESSURE BUILDING IN FOR THE WEEKEND QUICKLY SHIFTS OFFSHORE WITH RETURN FLOW DEVELOPING AND TEMPS CLIMBING BACK CLOSE TO CLIMO. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... AS OF 00Z...A MIXTURE OF MVFR/IFR/POSSIBLE LIFR EXPECT TONIGHT AND THROUGH THE OVERNIGHT HOURS AS UNSETTLED WEATHER ALLOWS FOR SHRA/TSRA TO CREATE PERIODS OF HEAVY RAIN AND WIND...ALONG WITH LOW CIGS AND FOG...TO AFFECT THE AREA. RAIN TAPERS OFF INTO THE EARLY MORNING HOURS...THOUGH AREAS OF LOW CIGS AND FOG ARE ANTICIPATED THROUGH THE PERIOD...WITH IMPROVEMENT TO VFR POSSIBLE INLAND DURING THE AFTERNOON HOURS ON MONDAY. LATEST RADAR IMAGERY DEPICTS LIGHT -SHRA MOVING ACROSS THE AREA THIS EVENING WHILE OBS ARE REPORTING LOW CIGS AND AREAS OF FOG CREATING MVFR/IFR AT ALL TAF SITES. WHILE ACTIVITY IS LIGHT NOW...SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATER TONIGHT INTO THE EARLY OVERNIGHT HOURS...WITH ISOLATED SEVERE STORMS POSSIBLE. WITH ANY STRONGER STORM COULD SEE HEAVY RAINFALL. AS FOR WINDS EXPECT SOUTHEASTERLY AROUND 10 KTS WITH GUSTS UP TO 20 KTS...AND HIGHER GUSTS POSSIBLE IN ANY TSRA. LATE OVERNIGHT...ANY SHRA/TSRA WILL TAPER OFF...BUT WILL CONTINUING TO SEE DETERIORATED CONDITIONS AS LOW CIGS AND FOG PERSISTS. WHILE LIFR CANNOT BE RULE OUT...OVERALL ANTICIPATE MVFR/IFR. INTO MONDAY...WITH GUSTY SOUTHWEST WINDS...LOW CIGS WITH AREAS OF FOG WILL PERSIST...THUS EXPECT MVFR/IFR. COULD SEE IMPROVEMENT TO VFR IN THE AFTERNOON HOURS IN SPOTS...BUT TOWARDS THE END OF THE PERIOD CONDITIONS WILL DETERIORATE BACK TO MVFR/IFR. EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AFTERNOON THROUGH WEDNESDAY NEAR THE COAST...WITH OCCASIONAL SHOWERS AND MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY NIGHT...THROUGH FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 645 PM SUNDAY...THE WARM FRONT HAS MOVED THROUGH SAVANNAH AND IS RACING UP THE COAST AT A PRETTY GOOD CLIP. MOST RECENT MODELS ARE TOO FAST WITH THE FRONTAL TIMING...BUT AMONG THOSE THAT SEEM TO HAVE A GOOD HANDLE (21Z HRRR, 22Z RUC, 12Z ECMWF) THE LATEST THINKING IS FOR FRONT TO CROSS THE SANTEE RIVER 8-9 PM...CAPE FEAR AROUND 11 PM...AND TO BE NORTH OF TOPSAIL ISLAND BY MIDNIGHT. THE FRONT WILL BE HERALDED BY A SHIFT FROM SOUTHEAST TO SOUTH WINDS. ANOTHER HEAVY WAVE OF SHOWERS AND EMBEDDED THUNDERSTORMS IN EASTERN GEORGIA AND NOW CROSSING THE SAVANNAH RIVER INTO SOUTH CAROLINA SHOULD ARRIVE IN THE NEXT COUPLE OF HOURS. HEAVY RAINFALL AND LIGHTNING ARE THE LARGEST THREATS. WINDS HAVE BEEN GUSTING OVER GALE FORCE AT THE FRYING PAN SHOALS BUOY FOR THE PAST THREE HOURS. BUOY 41004 EAST OF CHARLESTON IS IN THE SAME ENVIRONMENT AND HAS ALSO GUSTED OVER GALE FORCE EARLY THIS EVENING. CLOSER TO SHORE THE COLDER OCEAN WATER TEMPERATURE ON THE SHALLOW CONTINENTAL SHELF IS INDUCED A MUCH MORE STABLE ATMOSPHERIC BOUNDARY LAYER WITH LESS WIND ABLE TO MIX DOWN FROM ALOFT. DESPITE WINDS JUST 1000 FEET ABOVE THE SURFACE EXPECTED TO REACH 50 KNOTS IN JUST A COUPLE HOURS...WIND SPEEDS DOWN AT THE OCEAN SURFACE SHOULD REMAIN 20-30 KNOTS ACROSS THE SC WATERS...AND 25-35 KNOTS ACROSS THE NC WATERS WITH A HIGHER GUSTS WELL AWAY FROM SHORE WHERE WATER TEMPERATURES ARE STILL IN THE RELATIVELY MILD MID 60S. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 4 PM SUNDAY...MONDAY MARINE CONDITIONS REMAIN DANGEROUS WITH SEAS OF 5-9 FEET LIKELY AND HIGHEST AWAY FROM SHORE AND NEAR THE FRYING PAN SHOALS. 20-30 KT SSW WINDS MONDAY...BECOMING WEST LATE TUESDAY NIGHT OR EARLY MONDAY AS A SURFACE COLD FRONT MOVES ACROSS THE WATERS. STRONG TSTMS REMAIN POSSIBLE MONDAY THROUGH TUESDAY MORNING ON THE 0-20 NM WATERS. LARGE SSW-SE WAVES WILL MAKE UP THE SEA SPECTRUM IN MIXED WAVE PERIODS OF 5-6 SECONDS AND 8-9 SECONDS. IMPROVING CONDITIONS TUESDAY ALTHOUGH WAVE RECOVERY WILL STILL BE UNDERWAY EARLY TUESDAY. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 4 PM SUNDAY...PERIOD OF HEADLINES SEEMS LIKELY WED INTO WED NIGHT AS DEEPENING LOW PRESSURE PASSES JUST EAST OF THE WATERS. WINDS WILL BACK FROM NORTH-NORTHEAST TO WEST WED INTO WED NIGHT AS THE LOW LIFTS NORTHEAST. SPEEDS WILL PEAK IN THE 20 TO 25 KT RANGE WITH SEAS NEAR 20 NM FLIRTING WITH 6 TO 7 FT. OFFSHORE FLOW WEAKENS LATE WED NIGHT INTO THU AS SURFACE HIGH TO THE WEST BUILDS EAST. SPEEDS REMAIN CLOSE TO 15 KT THU WITH A SLIGHT INCREASE FRI AS DRY COLD FRONT PASSES AND BRIEF COLD ADVECTION DEVELOPS. AN OFFSHORE COMPONENT WILL KEEP SEAS WITHIN 20 NM IN THE 2 TO 4 FT RANGE THU AND FRI. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR AMZ254-256. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST TUESDAY FOR AMZ250-252. GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR AMZ250-252. && $$ SYNOPSIS...MJC/TRA NEAR TERM...TRA SHORT TERM...MJC LONG TERM...III AVIATION...SGL

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