Area Forecast Discussion
Issued by NWS Wilmington, NC

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KILM 010526 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 126 AM EDT FRI AUG 1 2014 .SYNOPSIS...
-- Changed Discussion --
A COASTAL FRONT JUST OFFSHORE WILL PUSH INLAND ON FRIDAY...THEN SHOULD STALL OVER THE AREA DURING THE WEEKEND. THIS WILL BRING GOOD RAIN CHANCES...WITH PERIODS OF HEAVY RAINFALL POSSIBLE FRIDAY THROUGH MONDAY. MORE SEASONABLE WEATHER WILL DEVELOP THE MIDDLE OF NEXT WEEK.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM THIS MORNING/...
-- Changed Discussion --
AS OF 1:30 AM FRIDAY...SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS ONGOING ACROSS THE FORECAST AREA. MOISTURE TAP SEEMS TO BE GRADUALLY SHIFTING EASTWARDS. FORECAST UPDATED ACCORDINGLY. PREVIOUS DISCUSSION FOLLOWS: SEVERAL THINGS HAVE TRANSPIRED (OR IS IT CONSPIRED?) OVER THE FEW HOURS TO CHANGE THE FORECAST PRETTY DRAMATICALLY. A MOIST CONVEYOR ORIGINATING FROM THE EDGE OF THE GULF STREAM OFF THE SOUTH CAROLINA COAST IS FEEDING INTO GEORGETOWN COUNTY AND HAS ITS EYES FIXED ON THE I-95 CORRIDOR/PEE DEE REGION FOR THE NEXT FEW HOURS. JUST GIVEN THE OBSERVED TRAJECTORY ON RADAR THIS MOISTURE IS ENCOUNTERING RATHER SIGNIFICANT ISENTROPIC ASCENT AS IT MOVES UP INTO THE IN-SITU COLD DOME IN PLACE ACROSS THE CENTRAL CAROLINAS. EVEN THOUGH THE 00Z CHS SOUNDING SHOWED DRY AIR ABOVE 700 MB AND A PRECIPITABLE WATER VALUE OF ONLY 1.55 INCHES...AMSU + SSM/I BLENDED TOTAL PRECIPITABLE WATER SATELLITE DATA HAD A RELATIVE MAXIMUM ACROSS THE SANTEE RIVER INTO THE PEE DEE REGION OF 1.9 INCHES. THIS IS CO-LOCATED WITH THE HEAVY RAINFALL BAND OBSERVED ON RADAR. I HAVE INCREASED AREAL AVERAGE RAINFALL FORECASTS TO AROUND 0.75 INCHES ACROSS FLORENCE AND MARION NORTHWARD INTO DILLON AND BENNETTSVILLE OVERNIGHT...WITH THE EXPECTATION THAT ISOLATED AREAS WILL SEE 2 TO 2.5 INCHES. THE HAZARDOUS WEATHER OUTLOOK HAS BEEN UPDATED WITH THE POTENTIAL FOR MINOR FLOODING OVERNIGHT AS WELL. OBVIOUSLY FORECAST POPS ACROSS THIS CORRIDOR ARE 100 PERCENT. THE HRRR IS TOO FAR WEST WITH THE CURRENT CONVECTIVE ACTIVITY...BUT SHOWS THAT ONCE THIS HEAVY RAIN MOVES NORTHWARD INTO CENTRAL NORTH CAROLINA THE NEXT WAVE OF CONVECTION MAY DEVELOP OVER THE COASTAL WATERS OFF THE SC COAST MOVING NORTHWARD INTO COASTAL SE NORTH CAROLINA AROUND OR SHORTLY AFTER DAYBREAK.
-- End Changed Discussion --
&& .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/... AS OF 230 PM THURSDAY...PERIOD CONTINUES TO LOOK UNSETTLED WITH INCREASING DEEP MOISTURE AND DEVELOPING LOW LEVEL CONVERGENCE. MID LEVEL TROUGH HANGING OVER THE EASTERN CONUS THE PAST SEVERAL DAYS STARTS TO WEAKEN AND SHIFT WEST AS 5H RIDGE OVER THE WESTERN ATLANTIC EXPANDS. MEANWHILE AT THE SURFACE WESTERN ATLANTIC HIGH WILL EXTEND WEST...PUSHING FRONT STALLED OFF THE COAST INTO THE REGION. DEEP SOUTHWEST FLOW...TAPPING GULF MOISTURE...COMBINED WITH LOW LEVEL SOUTHEAST FLOW...TAPPING ATLANTIC MOISTURE...WILL PUSH PRECIPITABLE WATER VALUES TO AND ABOVE 2 INCHES FOR MUCH OF THE PERIOD. DIVERGENT FLOW ALOFT AND LOW LEVEL CONVERGENCE ALONG THE QUASI-STATIONARY BOUNDARY IN A MODERATELY UNSTABLE ENVIRONMENT SHOULD PRODUCE PLENTY OF SHOWERS AND THUNDERSTORMS. NOT ANTICIPATING ANY WIDESPREAD STRONG TO SEVERE STORMS BUT GIVEN THE TIME OF YEAR CANNOT RULE OUT AN ISOLATED STRONGER STORM. ALTHOUGH THERE IS LIKELY TO BE A DIURNAL INCREASE IN ACTIVITY PRECIP CHANCES WILL REMAIN ELEVATED OVERNIGHT GIVEN FAVORABLE CONDITIONS. HIGH TEMPERATURES WILL CONTINUE TO RUN BELOW CLIMO WITH CLOUD COVER AND PRECIP KEEPING HIGHS IN THE LOW TO MID 80S. SOUTHERLY FLOW...INCREASING MOISTURE...AND CLOUD COVER WILL KEEP LOWS NEAR TO SLIGHTLY ABOVE CLIMO...LOW TO MID 70S. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 230 PM THURSDAY...ATYPICALLY WELL DEFINED (FOR THE TIME OF YEAR) MID AND UPPER LEVEL TROUGHINESS TO OUR WEST ON SUNDAY. DECAYING SURFACE BOUNDARY TO PROVIDE LOW LEVEL LIFT...WHICH WILL THEN BE AIDED BY MID LEVEL PVA AND UPPER DIVERGENCE ASSOC WITH RIGHT ENTRANCE OF UPPER JET STREAK ACROSS NORTHEAST AND MID ATLANTIC. AND WHILE RAIN CHANCES SEEM TO WARRANT LIKELY POPS MODELS ARE NOT SUGGESTIVE OF HIGH QPF AMOUNTS. THIS MAY BE DUE TO IT BEING SUCH A CLOUDY DAY THAT VERY LITTLE INSTABILITY MANAGES TO DEVELOP SAVE FOR PERHAPS ALONG THE IMMEDIATE COAST. THESE PLAYERS ALL REMAIN NEARLY IN PLACE HEADING INTO MONDAY ALTHOUGH ALL OF THEM WEAKEN. LOOKING FOR ANOTHER DAY OF HIGH POPS AND SUPPRESSED AFTERNOON TEMPS. TUESDAY SHOULD BRING LOWER RAIN CHANCES BUT STILL ONES THAT ARE HIGHER THAN NORMAL. THE UPPER JET CONTINUES TO WEAKEN AND LIFT OUT TO THE NORTHEAST WHILE THE MID LEVEL TROUGH WEAKENS...BUT ALSO SENDS ITS REMAINING VORT CENTER ACROSS THE CAROLINAS. IN RESPONSE TO THIS THE GFS STRAIGHTENS THE PIEDMONT TROUGH AT THE SURFACE. WE ALSO MAY SEE A BIT MORE SUNSHINE IN CONTRAST TO THE EARLY PARTS OF THE PERIOD. TUESDAY MAY THUS BE A DAY WHERE WE TRANSITION TO MORE SCATTERED AND DEEPER CONVECTION ESP IF TEMPS START BOUNCING BACK TOWARDS CLIMO. WEDNESDAY AND THURSDAY LOOK SEASONABLE WITH RESPECT TO BOTH TEMPERATURES AND AREAL COVERAGE OF CONVECTION. MID LEVEL FLOW SHOULD BE OF A DRIER WESTERLY DIRECTION WHILE SOME SEMBLANCE OF A PIEDMONT TROUGH REMAINS. && .AVIATION /05Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
AS OF 06Z...SHOWERS WILL BE LIKELY THIS TAF VALID PERIOD AT ALL TERMINALS. THUNDERSTORMS WILL BE POSSIBLE THIS MORNING NEAR THE COASTAL TERMINALS...THEN RE-DEVELOP THIS AFTERNOON ACROSS MAINLY INLAND LOCATIONS. TEMPO PERIODS OF MVFR CAN BE EXPECTED WITH THE ACTIVITY. DUE TO THE QUICK MOVEMENT OF CELLS ONLY BRIEF PERIODS OF IFR EXPECTED. WINDS WILL BE E-ESE AROUND 10KT...EXCEPT VRBL TO 20 KT NEAR CONVECTION. RADAR AND SATELLITE TRENDS SUGGEST THAT THE COASTAL TERMINALS WILL BE MOST LIKELY TO EXPERIENCE SHRA/TEMPO MVFR THROUGH SUNRISE. SHOWERS AT THE COASTAL TERMINALS SHOULD END 12-15Z. LIGHT RA SHOULD END OVER THE NEXT SEVERAL HOURS AT KFLO/KLBT. MVFR CIGS/VSBYS SHOULD DEVELOP AFTERWARDS AT KFLO/KLBT AND PERSIST THROUGH SUNRISE. EXTENDED OUTLOOK...SHRA/TSRA LIKELY WITH PERIODS OF MVFR CONDITIONS THROUGH MON AS A FRONT STALLS AND FINALLY DISSIPATES OVER THE EASTERN CAROLINAS. A CHANCE OF SHOWERS CONTINUES ON TUE.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/... AS OF 1:30 PM FRIDAY...NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: THE PINCHED PRESSURE GRADIENT ALONG THE WEST SIDE OF THE COASTAL TROUGH/WARM FRONT OFFSHORE HAS PUSHED WIND SPEEDS TO 20 KNOTS WITH GUSTS AS HIGH AS 24 KNOTS ALONG THE HORRY COUNTY SC COAST EARLIER. THIS IS STRONGER THAN ANY MODEL INDICATED...AND THIS MOST-RECENT FORECAST UPDATE IS BASED MORE ON CURRENT OBSERVATIONS THAN ANY COMPUTER MODEL. EAST WINDS AROUND 20 KNOTS SHOULD BEGIN TO DIMINISH AROUND 2-3 AM AS THE FRONT GETS A LITTLE CLOSER TO THE COAST AND THE BAGGIER PRESSURE GRADIENT SURROUNDING THE BOUNDARY ARRIVES. SEAS HAVE RESPONDED TO THE HIGHER WIND SPEEDS WITH 5 FEET SHOWING UP AT THE NEARSHORE WRIGHTSVILLE BEACH CORMP BUOY. THIS IS A FULL 3 FEET HIGHER THAN FORECASTS JUST SIX HOURS AGO AND SHOWS HOW QUICKLY CONDITIONS HAVE DETERIORATED HERE. AN EXERCISE CAUTION HEADLINE HAS BEEN ADDED TO THE FORECAST THROUGH 3 AM FOR ALL WATERS. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 230 PM THURSDAY...PERIOD WILL BE DOMINATED BY SOUTHEAST FLOW AS FRONT STALLED OFFSHORE MOVES TO THE COAST FRI THEN PUSHES ONSHORE SAT. GRADIENT WILL BE WEAK FOR MUCH OF THE PERIOD WITH THE ONLY POSSIBLE EXCEPTION DURING FRI NIGHT WHEN GRADIENT SHARPENS AS BOUNDARY BECOMES A LITTLE MORE DEFINED. SPEEDS FRI NIGHT MAY TOUCH 15 KT BUT OTHERWISE SPEEDS WILL BE ON THE LOWER END OF THE 10 TO 15 KT RANGE. SEAS 2 TO 3 FT EARLY IN THE PERIOD INCREASE TO A SOLID 3 FT GIVEN THE PROLONGED SOUTHEAST WINDS AND DEVELOPMENT OF EAST-SOUTHEAST WIND WAVE. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 230 PM THURSDAY...LIGHT SOUTHERLY WINDS ON SUNDAY WITH FRONTAL BOUNDARY JUST INLAND OF THE COAST. WIND CHOP WILL BE COINCIDENT WITH 11 SECOND SOUTHEASTERLY SWELL. THE WEAKENING BOUNDARY WILL MOVE FURTHER INLAND FOR THE REMAINDER OF THE PERIOD AND THE WEST ATLANTIC HIGH POKES A BIT WESTWARD FURTHER INTO THE CAROLINAS. THIS COULD LEAD TO AN OCCASIONAL INCREASE IN FLOW BY A FEW KNOTS AND ALSO A SLIGHT VEER FROM S TO SW.
-- End Changed Discussion --
&& .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...III NEAR TERM...REK/TRA/SGL SHORT TERM...III LONG TERM...MBB AVIATION...MRR MARINE...REK/TRA/III/MBB/SGL

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.