Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 311034 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 633 AM EDT SUN AUG 31 2014 .SYNOPSIS... STRENGTHENING BERMUDA HIGH PRESSURE OFFSHORE WILL BRING SUMMERTIME HEAT AND HUMIDITY THROUGH THE LABOR DAY WEEKEND WITH A FEW SHOWERS AND THUNDERSTORMS POSSIBLE. A WEAK COLD FRONT WILL APPROACH FROM THE NORTH LATE NEXT WEEK...BUT WILL LIKELY STALL BEFORE REACHING THE AREA. BERMUDA HIGH PRESSURE AND A PIEDMONT TROUGH WILL REMAIN THE DOMINANT FEATURES INTO NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MUCH OF THE WESTERN AND CENTRAL ATLANTIC OCEAN. THE UPPER LEVEL RIDGE IS CENTERED JUST OFF THE CAROLINA COAST AND SHOULD KEEP ANY SYNOPTIC IMPULSES DEFLECTED AWAY TO OUR NORTH AND WEST. 850 MB TEMPERATURES AROUND +18C THIS AFTERNOON SHOULD RESULT IN HIGH TEMPERATURES IN THE MID 90S FROM MARION AND FLORENCE WESTWARD INTO DARLINGTON COUNTY. ONSHORE WINDS CLOSER TO THE COAST SHOULD KEEP TEMPERATURES A LITTLE COOLER...GENERALLY IN THE UPPER 80S TO LOWER 90S. ALTHOUGH THERE IS CONSIDERABLE DRY AIR ALOFT DUE TO THE UPPER RIDGE (COLUMN PRECIP WATER VALUES ARE ONLY 1.5 INCHES) VERY RICH MOISTURE EXISTS IN THE LOWEST LEVELS OF THE ATMOSPHERE. DEWPOINTS IN THE MID 70S THIS MORNING WILL FORTUNATELY MIX DOWN TO NEAR 70 THIS AFTERNOON INLAND...BUT THAT WILL STILL BE ENOUGH TO PUSH HEAT INDICES TO 100-103 DEGREES ACROSS MOST OF OUR FORECAST AREA. THIS MOISTURE MAY ALSO FUEL WIDELY SCATTERED SHOWERS NEAR THIS COAST LATER THIS MORNING...PROBABLY BECOMING LESSER IN COVERAGE THIS AFTERNOON AS DRIER AIR MIXES DOWNWARD. FORECAST POPS RANGE FROM 20-30 PERCENT... VIRTUALLY ALL EAST OF I-95 AND HIGHEST IN A STRIPE ACROSS LELAND TO BURGAW AS CONSISTENTLY INDICATED BY HOURLY HRRR MODEL RUNS THROUGH THE NIGHT. ANY LINGERING DAYTIME CUMULUS SHOULD QUICKLY DIE AWAY THIS EVENING... WITH ONLY A LITTLE PATCHY FOG OR LOW STRATUS EXPECTED TO DEVELOP OVERNIGHT. LOWS SHOULD FALL INTO THE LOWER 70S FOR MOST LOCALES...A FEW DEGREES WARMER NEAR THE BEACHES. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM SUNDAY...BERMUDA HIGH AND STRENGTHENING PIEDMONT TROUGH WILL BE THE MAIN SURFACE FEATURES THROUGH THE PERIOD. ALOFT A FLAT MID LEVEL RIDGE WILL EXTEND ACROSS MUCH OF THE SOUTHERN CONUS. DEEP WESTERLY FLOW IN THE MID LEVELS WILL PUSH TROPICAL MOISTURE EXPANDING NORTH FROM THE WESTERN GULF OF MEXICO OVER THE REGION MON AND TUE. INCREASING MOISTURE ALOFT ALONG WITH LOW LEVEL MOISTURE ADVECTION AROUND WEST SIDE OF BERMUDA HIGH WILL PUSH PRECIPITABLE WATER VALUES OVER 2 INCHES FOR MUCH OF THE PERIOD. FLAT MID LEVEL PATTERN MEANS LITTLE TO NO FORCING ALOFT WILL BE PRESENT. HOWEVER THE COMBINATION OF LOW LEVEL MOISTURE AND SURFACE HEATING WILL PUSH ML CAPE VALUES TO 1K-2K J/KG FOR MON AND OVER 2K J/KG ON TUE. CONVECTION WILL INITIALLY BE SLOW TO DEVELOP BUT ONCE SEA BREEZE AND PIEDMONT TROUGH TAKE SHAPE SHOWERS AND THUNDERSTORMS SHOULD START POPPING UP. WILL MAINTAIN CHC POP FOR EACH AFTERNOON BUT WITH SLIGHTLY HIGHER VALUES ON TUE GIVEN SLIGHTLY HIGHER CAPE VALUES. TEMPERATURES WILL RUN ABOVE CLIMO THROUGH THE PERIOD. HIGHS WILL RANGE FROM UPPER 80S ALONG THE IMMEDIATE COAST TO MID 90S INLAND. LOWS WILL BE IN THE LOW TO MID 70S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH ALONG WITH ELONGATED MID LEVEL RIDGE WILL REMAIN THE SIGNIFICANT FEATURES THROUGH THE PERIOD. A COUPLE COLD FRONTS WILL TRY AND MAKE A RUN TO THE AREA DURING THE NEXT WEEK BUT THEY ARE LIKELY TO STALL AND WASH OUT JUST NORTH OF THE FORECAST AREA. THE SURFACE AND MID LEVEL PATTERNS ARE NOT ONES THAT GENERALLY SUPPORT FRONTS MOVING INTO AND SOUTH OF THE CAPE FEAR REGION. PRECIPITABLE WATER VALUES WILL REMAIN AROUND 2 INCHES THROUGH THE END OF THE WEEK. DIURNAL HEATING AND SOUTHWEST FLOW WILL RESULT IN ML CAPE VALUES ABOVE 2K J/KG FOR MUCH OF THE PERIOD. WEAK GRADIENT WILL ALLOW SEA BREEZE DEVELOPMENT AND PIEDMONT TROUGH SHOULD BE WELL DEFINED. TYPICAL SUMMER PATTERN WITH NEAR CLIMO PWATS AND TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO SUGGEST POP WILL BE NEAR CLIMO FOR MUCH OF THE PERIOD...30 PERCENT. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 06Z...STILL EXPECT MVFR/IFR CIGS TO DEVELOP EARLY THIS MORNING WITH THE BEST CHANCES FOR IFR INLAND AT KLBT/KFLO. HAVE BACKED OFF THE FOG A BIT GIVEN THE INCREASING DEBRIS CLOUDS SPREADING INTO OUR AREA. WOULD NOT RULE OUT TEMPO IFR VSBYS INLAND...BUT MVFR SEEMS MORE LIKELY ATTM. EXPECT PERIODS OF MVFR CIGS ALONG THE COAST BEGINNING AROUND DAYBREAK...WITH THE POTENTIAL FOR SOME ISOLATED SHOWERS MOVING ONSHORE AS WELL. THE HRRR MODEL SHOWS A FEW SHOWERS SKIRTING THE COAST THIS MORNING...SO WILL MAINTAIN VCSH FOR KILM/KCRE/KMYR. THE MVFR CIGS MAY LINGER THROUGH MUCH OF THE MORNING...BUT CONDITIONS WILL IMPROVE TO VFR BY MIDDAY AND PERSIST THROUGH THE REST OF THE PERIOD. WINDS WILL BE SOUTH 6-10 KT DURING THE DAY...POSSIBLY A BIT HIGHER ALONG THE COAST. COULD SEE SOME ISOLATED SHOWERS ALONG THE SEABREEZE FONT IN THE AFTN...BUT CONFIDENCE IN TIMING/LOCATION IS TOO LOW TO MENTION IN THE TAFS. EXTENDED OUTLOOK...INCREASING CHANCES FOR AFTN SHOWERS/TSTMS MONDAY THROUGH THURSDAY WITH BRIEF AND LOCALIZED PERIODS OF MVFR POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MOST OF THE WESTERN AND CENTRAL ATLANTIC OCEAN. THIS SHOULD PRODUCE A SOUTH-SOUTHEAST WIND TODAY...VEERING MORE SOUTHWESTERLY TONIGHT. SEAS CURRENTLY AROUND 2 FEET MAY OCCASIONALLY REACH 3 FEET IN A COMBINATION OF SOUTHEASTERLY SWELL AND LOCAL WIND WAVES...WITH ANY SCATTERED MORNING SHOWERS EXPECTED TO DISSIPATE BY EARLY AFTERNOON. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH WILL MAINTAIN SOUTHWEST FLOW OVER THE WATERS THROUGH THE PERIOD. SPEEDS 10 KT OR LESS WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING AS THE PIEDMONT TROUGH STRENGTHENS. SEAS IN THE 2 TO 3 FT RANGE. LONG TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 3 AM SUNDAY...MINIMAL CHANGE FOR THE LONG TERM PERIOD. BERMUDA HIGH REMAINS IN PLACE AS DOES THE PIEDMONT TROUGH. LATE IN THE PERIOD A WEAKENING COLD FRONT WILL APPROACH FROM THE NORTH BUT IS EXPECTED TO STALL BEFORE REACHING THE AREA. SOUTHWEST FLOW AROUND 10 KT WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING. SEAS WILL RUN 2 TO 3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...III LONG TERM...III AVIATION...BJR/TRA

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