Area Forecast Discussion
Issued by NWS Wilmington, NC

Current Version | Previous Version | Graphics & Text | 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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KILM 021020 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 620 AM EDT TUE SEP 2 2014 .SYNOPSIS... SUMMERTIME CONDITIONS WILL PERSIST MUCH OF THE WEEK AS BERMUDA HIGH PRESSURE REMAINS ANCHORED OFF THE COAST. THUNDERSTORMS WILL BE POSSIBLE EACH DAY. A STRONGER COLD FRONT MAY BRING ABOUT AN INCREASE IN SHOWERS AND THUNDERSTORMS FOR THE START OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 620 AM TUESDAY...LIGHT MIST HAS DEVELOPED UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS EARLY THIS MORNING PRIOR TO DAYBREAK BUT NOT OF DENSITY OR COVERAGE TO BE PROBLEMATIC FOR COMMUTERS. NO BIG CHANGES TO THE ONGOING FORECAST WITH THE DAYBREAK UPDATE. WILL SCALE BACK CLOUD COVER A SHADE IN THE EARLY GOING UNDER NEAR FULL MORNING SUNSHINE...TRANSITIONING TO A PARTLY SUNNY SKY IN AFTN AS CU BUILDUPS BEGIN TO TOWER INLAND. MOSTLY SUNNY FOR MANY OF OUR BEACHES TODAY FOLLOWING AN EARLY SEA BREEZE PASSAGE A LITTLE LATER THIS MORNING. THE PREVIOUS A.M. DISCUSSION FOLLOWS. SUBTLE DISTINCTIONS IN THE SYNOPTIC PATTERN WILL IMPACT SENSIBLE WEATHER ACROSS OUR FORECAST AREA MOST NOTABLY THIS AFTERNOON. WEAK BUT WIDESPREAD HEIGHT FALLS SHOULD ALLOW STRONGER DEVELOPMENT OF A PIEDMONT SURFACE TROUGH THIS AFTERNOON AND ORIENTATION OF THIS FEATURE ALONG THE SANDHILLS WILL PROMPT A MODERATE SOUTH WIND FLOW ONTO THE COAST. THIS WILL AID ACCELERATION AN ALREADY ROBUST SEA BREEZE BOUNDARY POWERED BY THE EXPECTED LAND VERSUS SEA TEMPERATURE DIFFERENTIAL DURING THE AFTERNOON. AS CONVECTIVE TRIGGER TEMPERATURES ARE REALIZED...THIS BAND OF LOW-LEVEL CONVERGENCE SHOULD BE POSITIONED FROM THE BLADEN COUNTY LAKES SW TO FAIR BLUFF TO MARION TO FLORENCE AND DEEP INTO THE SC INTERIOR ZONES. NO LACKING OF SB-CAPES AND VAPOR CONTENT TODAY WITH PRECIPITABLE WATER VALUES RUNNING AROUND 1.75-1.85 INCHES PRESENTLY PER LATEST SNAPSHOTS FROM SPACE. THE NAM-12 DEPICTION BOOSTS THESE VALUES AT OR ABOVE 2 INCHES THIS AFTERNOON. STEERING WINDS REMAIN WEAK AND DEVELOPING CONVECTION WILL BE GUIDED VERY SLOWLY TO THE E-SE. THIS SETS UP THE POSSIBILITY FOR HEAVY RAINFALL AND LARGE PCPN ACCUMULATIONS FOR AREAS BENEATH BLOSSOMING CONVECTION. STORM INHIBITION WILL BE LOWER TODAY WITH SLIGHT MID-LEVEL COOLING IN THE AFTERNOON HOURS. COASTAL LOCALS COULD SEE RAIN LATE...AS THE CONVECTION IS PUSHED E-SE AND BEGINS TO GRADUALLY WANE PAST THE PEAK OF DIURNAL HEATING/LOW-LEVEL INSTABILITY. MAXIMUM APPARENT TEMPERATURES NOT AS STINGING TODAY...BUT SUMMER FEEL WILL STILL BE FULL-ON. MAXIMUM HEAT INDICES OF 101-103 OVER THE SC INTERIOR TO 97-101 OVER INLAND NC ARE ANTICIPATED. MINS EARLY WED SHOULD BE SIMILAR TO THIS MORNINGS WITH UPPER 70S NEAR THE SEA AND 72-76 OVER A GOOD SWATH OF OUR INLAND ZONES AS WED MORNING BREAKS. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...BERMUDA HIGH AND MID LEVEL RIDGING WILL REMAIN IN CONTROL DURING THE PERIOD. A WEAKENING FRONT WILL STALL NORTHWEST OF THE AREA WED THEN DISSIPATE ON THU. THIS FEATURE MAY LEAD TO SOME ENHANCEMENT OF PIEDMONT TROUGH CONVECTION...BUT BOTH THE SEA BREEZE AND PIEDMONT TROUGH WILL BE ACTIVE EACH AFTERNOON SO ITS IMPACT MAY BE HARD TO DISTINGUISH. ALOFT A FLAT 5H RIDGE WILL EXTEND WEST ACROSS MUCH OF THE SOUTHERN STATES...ELIMINATING ANY NOTEWORTHY MID LEVEL FEATURES. THE 5H RIDGE IS ON THE WEAK SIDE AND THE ASSOCIATED MID LEVEL SUBSIDENCE/DRYING WILL BE LIMITED. IN FACT DEEP MOISTURE WILL REMAIN IN PLACE ON BOTH WED AND THU WITH PRECIPITABLE WATER VALUES EXCEEDING 2 INCHES. ABUNDANT MOISTURE AND PRESENCE OF SEA BREEZE AND PIEDMONT TROUGH...AS WELL AS ANY LINGERING OUTFLOWS...WILL HAVE LITTLE TROUBLE DEVELOPING AFTERNOON CONVECTION. SHOWERS AND THUNDERSTORMS WILL...FOR THE MOST PART...BE DIURNALLY DRIVEN WITH ACTIVITY WINDING DOWN IN THE EVENING. STORM MOTIONS WILL BE UNDER 5 KT THROUGH THE PERIOD WHICH COMBINED WITH DEEP WARM CLOUD LAYER DOES SUGGEST A FLOODING THREAT. THERE IS NO SIGNIFICANT SEVERE THREAT BUT AN ISOLATED WET MICRO BURST CANNOT BE RULED OUT. TEMPERATURES WILL BE ABOVE CLIMO. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 3 AM TUESDAY...BERMUDA HIGH AND MID LEVEL RIDGING WILL CONTINUE THROUGH THE WEEKEND CONTINUING THE CHANCE FOR AFTERNOON AND EARLY EVENING CONVECTION ALONG THE PIEDMONT TROUGH AND THE SEA BREEZE. LATE IN THE PERIOD DIFFERENCES BETWEEN THE MEDIUM RANGE SOLUTIONS START TO DEVELOP. FRI THROUGH SUN WILL BE A CONTINUATION OF THE WEEK WITH CHC DIURNAL POP AND TEMPERATURES NEAR TO ABOVE CLIMO. ON MON A COLD FRONT WILL MOVE IN FROM THE NORTHWEST BUT HOW FAR SOUTH THE FRONT PUSHES REMAINS IN QUESTION. GFS HAS BEEN INSISTENT IN PUSHING THE BOUNDARY SOUTH OF THE AREA DURING MON WITH DRIER AND COOLER HIGH PRESSURE SETTLING OVER THE REGION. PREVIOUS ECMWF SOLUTIONS MAINTAINED A STRONGER RIDGE AND KEPT THE FRONT STALLED NORTH AND WEST OF THE AREA. THE 00Z ECMWF HAS COME MORE IN LINE WITH THE OPERATIONAL GFS...WHICH ALSO HAS SUPPORT FROM MOST OF THE GFS ENSEMBLE MEMBERS. THE MID LEVEL RIDGING IS WEAKENING DURING THE PERIOD AND THERE IS A SECONDARY WAVE CROSSING SOUTHEAST CANADA WHICH SHOULD HELP PUSH THE FRONT FARTHER SOUTH. THE BERMUDA HIGH IS ALSO DISPLAYING A WEAKENING TREND WITH THE HIGH TRAILING COLD FRONT ALMOST 10 MB STRONGER BY MON. INHERITED FORECAST DOES HAVE THE BOUNDARY PUSHING SOUTH MON AND SEE NO REASON TO CHANGE AT THIS POINT. LATE PERIOD FORECAST CONFIDENCE IS LOW...THOUGH IT IS INCREASING...AND SIGNIFICANT CHANGES DURING THE NEXT FEW DAYS REMAIN POSSIBLE. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... AS OF 06Z...VFR CONDITIONS TONIGHT MAY GIVE WAY TO PATCHY AREAS OF MVFR/IFR CIGS EARLY THIS MORNING. LAMP GUIDANCE AND FCST SOUNDINGS INDICATE KFLO/KLBT HAVE THE BEST CHANCES OF SEEING TEMPO IFR/LIFR CIGS DEVELOP JUST AFTER DAYBREAK. GIVEN EXTENSIVE DEBRIS CLOUDINESS AND NOCTURNAL LOW LEVEL JETTING...FOG SEEMS LESS LIKELY THAN LAST NIGHT...SO WILL JUST INCLUDE MVFR VSBYS FOR THE INLAND TERMS. ALONG THE COAST...HAVE INCLUDED TEMPO MVFR CIGS AS 1-2KFT CLOUDS MAY CLIP THESE SITES DURING THE EARLY MORNING HOURS. LIGHT SOUTHWEST FLOW SHOULD KEEP SHOWER ACTIVITY OFFSHORE...SO NO VCSH FOR THE COASTAL TERMS ATTM. VFR WILL PREVAIL DURING THE DAY AS SOUTHWEST WINDS AROUND 5 KT BECOME SOUTH AROUND 10 KT IN THE AFTN BEHIND THE SEA BREEZE. WE COULD SEE INCREASED SHOWER/TSTM ACTIVITY AFTER MIDDAY AS SOUNDINGS DO SHOW DEEPER MOISTURE AVAILABLE. BUT WILL HOLD OFF ON INCLUDING VCSH SINCE COVERAGE WOULD LIKELY BE ISO/SCT AT BEST. EXTENDED OUTLOOK...CHANCE OF SCATTERED AFTN SHOWERS/TSTMS THROUGH FRIDAY. PATCHES OF MVFR/IFR FOG OR STRATUS MAY ALSO DEVELOP EACH MORNING. BUT OVERALL VFR CONDITIONS SHOULD PREVAIL. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 620 AM TUESDAY...MODERATE SW WINDS WILL PREVAIL...AND WILL PERSIST OVER THE WATERS AS A TYPICAL BERMUDA HIGH PATTERN HOLDS. WINDS WILL BACK TO S AND PICK UP IN SPEED ALONG THE COAST AS THE SEA BREEZE CIRCULATION BOLSTERS. GUSTS TO 20 KT CAN BE EXPECTED DURING THE AFTERNOON HOURS AND THROUGH EARLY EVENING. SEAS 2.5-3.5 FT TODAY IN A MIX OF SE WAVES 1-2 FT EVERY 9 SECONDS AND S WAVES 1.5-2 FT EVERY 4 SECONDS. TSTMS IF ANY WILL BE FAVORED MAINLY TONIGHT INTO EARLY WEDNESDAY. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...SOUTH TO SOUTHWEST FLOW CONTINUES OVER THE WATERS WED AND THU WITH SURFACE HIGH CENTERED TO THE NORTHEAST. ALTHOUGH GRADIENT WILL BE WEAK DIURNAL DEVELOPMENT OF THE SEA BREEZE AND THE PIEDMONT TROUGH WILL LEAD TO AN INCREASE IN SPEEDS. WINDS WILL RANGE FROM 10 KT OR LESS AT TIMES TO A SOLID 15 KT IN THE AFTERNOON AND EVENING. SEAS 2 TO 3 FT. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 AM TUESDAY...HIGH PRESSURE OFF THE COAST WILL MAINTAIN SOUTH TO SOUTHWEST FLOW FRI AND SAT. SPEEDS WILL INCREASE FROM AROUND 10 KT IN THE MORNING TO A SOLID 15 KT IN THE AFTERNOON AS THE PIEDMONT TROUGH AND SEA BREEZE DEVELOP/STRENGTHEN. SEAS 2 TO 3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...COLBY SHORT TERM...III LONG TERM...III AVIATION...MRR/8

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