Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 291144 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 744 AM EDT FRI APR 29 2016 .SYNOPSIS... A WEAK COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING. VERY WARM AND DRY CONDITIONS WILL FOLLOW FOR FRIDAY...BEFORE SLIGHTLY COOLER BUT CONTINUED DRY WEATHER OCCURS ON SATURDAY DUE TO WEAK AND TEMPORARY HIGH PRESSURE RIDGING IN FROM THE NORTH. A LOW PRESSURE SYSTEM MAY IMPACT THE AREA BEGINNING SUNDAY...BRINGING SEVERAL DAYS OF UNSETTLED WEATHER WITH PERIODS OF RAINFALL SUN THROUGH MON...BECOMING MORE ISOLATED IN THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM FRIDAY...THIS UPDATE CONCERNED WITH THE SHALLOW STRATUS DROPPING SOUTHWARD BEHIND THE COLD FRONT. BASED ON CURRENT TRENDS...ITS MOST SOUTHERN EXTENT WILL STOP SEVERAL HRS AFTER DAYBREAK...WHICH PUTS IT 3/4 OF THE WAY THRU THE ILM CWA. PATCHY TO AREAS OF FOG 2 TO 5 MILES IN VSBY WILL QUICKLY DISPERSE BY 9 AM. THE DAYS INSOLATION AND THE W TO NW FLOW ALOFT WILL ACT TOGETHER TO SCOUR OUT THE LOW LEVEL STRATUS BY MIDDAY THE LATEST. ENOUGH MOISTURE IN THE LOW LEVELS WILL BE LEFTOVER FOR FEW/SCT AFTERNOON DIURNALLY DRIVEN CU TO DEVELOP. PREVIOUS................................................... AS OF 330 AM FRIDAY...BY DAYBREAK...THE SFC LOW WILL BE POSITIONED OVER THE ATL WATERS OFF THE OUTER BANKS. ITS ASSOCIATED COLD FRONT WILL HAVE DROPPED SOUTHWARD...ABOUT HALFWAY THRU THE ILM CWA. THE COLD FRONT WILL FURTHER DROP SOUTH OF THE ILM CWA BEFORE STALLING LATER THIS MORNING. NOT MUCH OF A SFC PG AFTER ITS PASSAGE WITH THE SFC PRESSURE PATTERN YIELDING A NW DIRECTION INITIALLY THEN VEERING TO THE N OR NE THIS AFTN. LOOKING AT MODEL SOUNDINGS...FROM SFC TO 850MB...NW WINDS WILL DIMINISH TO LESS THAN 10 KT THIS AFTN. THIS WILL ENABLE BOTH THE FORMATION OF THE MESOSCALE SEA BREEZE DURING THE MIDDAY HRS...AND ALSO ALLOW ITS PROGRESSION INLAND THIS AFTN THRU EARLY THIS EVENING. THE DIFFERENCE BETWEEN AFTN TEMPS AND LOCAL SSTS WILL RUN 15+ DEGREES FURTHER FUELING ITS PUSH INLAND. OTHER THAN ISOLATED MORNING SHOWERS ALONG THE IMMEDIATE COAST AHEAD OF THE COLD FRONT...THE FA TODAY WILL BE PCPN-FREE. CONVECTIVE DEBRIS CLOUDS WILL SCOUR OUT THIS MORNING AS FLOW ALOFT BECOMES W TO NW DUE TO SOME AMPLIFICATION TO THE RIDGING ALOFT AFFECTING THE SE STATES. LEFTOVER LOW LEVEL MOISTURE WILL BE ENOUGH FOR DIURNALLY DRIVEN CU TO OCCUR THIS AFTN...WITH SUBSIDENCE ALOFT PREVENTING ANY FURTHER VERTICAL DEVELOPMENT TO THE CU. THE MID-LEVEL RIDGE AXIS WILL REACH THE ILM CWA BY SAT DAYBREAK... WHICH WILL ALLOW CI/CS TO PARTIALLY MOVE OVERHEAD VIA VARIOUS MODEL RH TIME HEIGHT DISPLAYS. TODAYS MAX TEMPS WILL EXPERIENCE SOME HELP FROM A DOWNSLOPE TRAJECTORY IN THE WIND FIELD SFC THRU ALOFT. HOWEVER...THE SFC PRESSURE PATTERN THIS AFTN AND EVENING WILL YIELD A VEERING WIND TO THE N OR NE ESPECIALLY CLOSER TO THE COAST...WITH SPEEDS 10 MPH OR LESS. THE SEA BREEZE WILL NOT REMAIN PINNED DUE TO WINDS ALOFT DIMINISHING. LOOKING AT MID TO UPPER 80S FOR HIGHS...WITH LOWER 80S OCCURRING ALONG THE IMMEDIATE COAST PRIOR TO THE SEA BREEZE. WIDESPREAD 60S FOR TONIGHTS LOWS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 330 AM FRIDAY...THE MID-LEVEL RIDGE AXIS WILL MOVE OFF THE CAROLINA COASTS EARLY SAT...WITH WINDS IN THE MID LEVELS BECOMING SW-WSW FOR THE REMAINDER OF THE SHORT TERM PERIOD. THIS WILL ENABLE MOISTURE TO INCREASE ACROSS THE FA BOTH IN THE MID AND UPPER LEVELS. AT THE SFC...RIDGING WILL TEMPORARILY PUSH SOUTHWARD FROM THE NE STATES ACROSS THE FA EARLY SAT. ITS RIDGE AXIS BY SAT EVENING WILL EXTEND OFF THE CAROLINA COASTS FROM ITS CENTER WHICH WILL HAVE MOVED OFF THE COAST FROM THE NE STATES. A STALLED FRONTAL BOUNDARY IS PROGGED TO RETURN NORTHWARD...ACROSS THE FA SAT NIGHT TO NORTH OF THE FA DURING SUNDAY. MODELS THERE-AFTER ARE SOMEWHAT DIFFERENT IN HOW FAR SOUTH AND EAST AND DEEP THE MOISTURE BECOMES ACROSS THE FA. EMBEDDED MID-LEVEL S/W TROFS OR VORTS WILL SPORADICALLY PUSH ACROSS THE FA SUN THRU SUNDAY NIGHT. THEIR DYNAMICS AND AN UNSTABLE ATM WILL YIELD SHOWERS AND THUNDERSTORM ACTIVITY FROM LATE SUN MORNING THRU DAYBREAK MON. AM CONCERNED THAT POPS EXHIBITED BY THE MODELS ARE RUNNING TOO HIGH ACROSS THE ILM CWA. HAVE TWEAKED THEM LOWER TO 50 PERCENT OR LESS...AND KEPT THE HIER POPS NORTH OF THE ILM CWA. AS FOR TEMPS...STAYED ACTUALLY CLOSER TO THE WARMER GFS MOS GUIDANCE DUE TO LOWER POPS AND LESS CLOUDS ESPECIALLY ON SAT. THE ONSHORE AND VEERING WINDS THIS PERIOD...NE-E SAT VEERING TO SE-S SUN...WILL KEEP MAX TEMPS IN CHECK ALONG THE COAST. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 330 AM FRIDAY...NORTHERN STREAM SHORTWAVES WILL ROTATE AROUND A BROADER TROUGH OVER THE GREAT LAKES MON INTO TUES. LOW PRESSURE WILL SHIFT OFF THE NORTHEAST COAST DRAGGING A COLD FRONT INTO THE CAROLINAS ON MONDAY. SOUTHWESTERLY FLOW OF WARM AND MOIST AIR AHEAD OF THIS FRONT WILL PRODUCE SHWRS/TSTMS ON MONDAY. A SHORTWAVE DIGS DOWN MON NIGHT PUSHING THIS FRONT SOUTH AND EAST ON MONDAY WITH WEAK HIGH PRESSURE BUILDING IN BEHIND IT. THE ECMWF IS LESS AGGRESSIVE WITH DIGGING SHORTWAVE AND DOES NOT PUSH THE FRONT SOUTH...BUT INSTEAD IT LINGERS OVER NC/SC AS LOW PRESSURE DEVELOPS ALONG IT PRODUCING UNSETTLED WEATHER THROUGH MID WEEK. THE GFS KEEPS THE FRONT WELL SOUTH AS LOW PRESSURE MOVES ALONG IT TOWARD THE SOUTHEAST COAST BRINGING CLOUDS AND PCP BACK IN THE FORECAST FOR TUES NIGHT INTO WED. THEREFORE GFS MAINTAINS A DRIER AIR MASS WITH WEAK HIGH PRESSURE OVER THE AREA LATE MON INTO TUES WHILE THE ECMWF KEEPS WETTER WEATHER FOR TUES. WILL KEEP SOME CLOUDS AND LOWER END POPS MON NIGHT INTO TUES TO ACCOUNT FOR THE UNCERTAINTY AT THIS POINT. BY WED A MUCH MORE AMPLIFIED MID TO UPPER LEVEL PATTERN EVOLVES WITH A DIGGING TROUGH ACROSS THE EAST PUSHING A COLD FRONT EAST BY THURSDAY NIGHT. THIS SHOULD PRODUCE COOLER AND DRIER WEATHER HEADING INTO NEXT WEEKEND. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/...
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AS OF 12Z...A WEAK COLD FRONT IS SHIFTING TO THE SOUTH WITH EXTENSIVE MVFR/IFR BEHIND IT. THE CIGS HAVE SHIFTED SOUTH INTO KLBT AND KFLO...BUT SHIFTING SE AT A SLOWER PACE TOWARDS KILM AND THE COASTAL TERMINALS. MODEL MOS GUIDANCE SUGGESTS THE BEST CHANCE OF IFR EARLY THIS MORNING WILL BE AT KFLO/KLBT/KILM. BEST CHANCE OF VFR THIS MORNING WILL BE AT KCRE/KMYR. CEILINGS ARE THIN...AND WITH STRONG INSOLATION WILL SCOUR OUT QUICKLY BY MID-MORNING WITH ALL TERMINALS BECOMING VFR. W-NW WINDS WILL BECOME NW-NE AT 5-10 KT OR LESS THIS MORNING. THE SFC PRESSURE PATTERN AND RELAXING GRADIENT WILL ALLOW AN ACTIVE SEA BREEZE TODAY...WITH WINDS BECOMING 140-170 AROUND 10 KT AT THE COASTAL TERMS THIS AFTN. ENOUGH MOISTURE IN THE LOWER LEVELS AND THE DAYS INSOLATION COULD PRODUCE FEW/SCT CU...OTHERWISE SKC TO PREVAIL INTO THRU THIS EVENING. DO NOT EXPECT MUCH VERTICAL DEVELOPMENT WITH THE CU DUE TO SUBSIDENCE ALOFT. UNDER CLEAR SKIES AND LIGHT WINDS COULD BE SOME FOG ISSUES AFTER MIDNIGHT. BEST CHANCE WILL BE AT KFLO/KLBT...AND AT KCRE DUE TO INCREASED MOISTURE WITH A RETURN FLOW. HAVE NOT ADDRESSED IN TAFS ATTM EXTENDED OUTLOOK...MVFR/IFR POSSIBLE FROM CONVECTION SUNDAY INTO THROUGH TUESDAY. OTHERWISE VFR.
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&& .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM FRIDAY...THE SFC COLD FRONT WILL DROP ACROSS AND SOUTH OF THE ILM WATERS BEFORE STALLING THIS MORNING. INITIALLY...WINDS TO BECOME W TO NW 10 KT THIS MORNING. THE WEAK SFC PRESSURE PATTERN AND RELAXED SFC PG...WILL RESULT IN WINDS FURTHER VEERING TO THE N TO NE AT 10 KT OR LESS THIS AFTN. FOR TONIGHT...A VARIABLE WIND DIRECTION CAN BE EXPECTED HOWEVER WILL TRY TO IDENTIFY A DOMINATING DIRECTION. THE RELAXED GRADIENT WILL RESULT IN 10 KT OR LESS FOR SPEEDS. OTHER THEN ISOLATED -SHRA EARLY THIS MORNING...THE WATERS SHOULD REMAIN PCPN-FREE THRU TONIGHT. SIGNIFICANT SEAS WILL BASICALLY SUBSIDE TO 2 TO 3 FT THRUOUT TODAY...DROPPING TO 2 FT ACROSS THE ILM SC WATERS. WIND WAVES AT 4 TO 5 SECOND PERIODS WILL DOMINATE THE SEAS SPECTRUM THIS MORNING. A 1 TO 2 FOOT EASTERLY GROUND SWELL AT 9 SECOND PERIODS WILL THEN BECOME DOMINANT PLAYER THIS AFTN THRU TONIGHT. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 400 AM FRIDAY...SFC RIDGING FROM THE CENTER OF HIGH PRESSURE OVER THE NE STATES...WILL PARTIALLY AFFECT THE ILM NC WATERS SATURDAY. THIS WILL PROVIDE A BRIEF NE-E 15 KT MINI SURGE ACROSS THE WATERS FROM CAPE FEAR NORTHWARD. THE PROGRESSION OF THE SFC RIDGE AXIS OFF THE CAROLINA COASTS WILL OCCUR SAT NIGHT THRU SUN WITH WINDS VEERING TO THE E-SE THRUOUT SAT NIGHT. A WARM FRONT WILL LIFT NORTHWARD ACROSS THE WATERS EARLY SUN...RESULTING IN WINDS FURTHER VEERING TO THE S TO SW SUN THRU SUN NIGHT. THE SFC PG WILL TIGHTEN-SOME AFTER THE WFP...RESULTING WITH 10 TO 15 KT SPEEDS...WITH GUSTS UP TO 20 KT SUN NIGHT. FOR SAT...SIGNIFICANT SEAS AT 2 TO 3 FT WILL BE DOMINATED BY WIND DRIVEN WAVES AT 3 TO 5 SECONDS ACROSS THE WATERS FROM CAPE FEAR NORTHWARD...AND AN EASTERLY GROUND SWELL AT 8 TO 9 SECOND PERIODS ELSEWHERE. WIND DRIVEN WAVES AT 4 TO 5 SECONDS WILL DOMINATE SAT NIGHT THRU SUN NIGHT...AND BUILD TO 3 TO 5 FT BY DAYBREAK MON. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 330 AM FRIDAY...SHOULD SEE SW FLOW AHEAD OF AN APPROACHING COLD FRONT ON MONDAY. LOW PRESSURE MOVING OFF THE NORTHEAST COAST SHOULD DRAG THIS COLD FRONT INTO THE WATERS BY MONDAY NIGHT. SHOULD SEE A PERIOD OF NORTHERLY WINDS BEHIND IT THROUGH TUES AS WEAK HIGH PRESSURE BUILDS DOWN FROM THE NORTH. THERE IS A POSSIBILITY THIS FRONT MAY LINGER ACROSS THE WATERS ON TUES POTENTIALLY KEEPING A MORE VARIABLE FLOW BUT FOR NOW WILL KEEP NORTHERLY WINDS ACROSS ALL WATERS ON TUES. SEAS GENERALLY 2 TO 4 FT WILL REACH UP TO 4 TO 5 FT IN OUTER WATERS MON AFTN AHEAD OF COLD FRONT BUT SHOULD DROP BACK DOWN SLOWLY IN NORTHERLY FLOW HEADING INTO TUES. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RGZ NEAR TERM...DCH SHORT TERM...DCH LONG TERM...RGZ AVIATION...MRR .

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