Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 281846 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 246 PM EDT THU AUG 28 2014 .SYNOPSIS...A BACK DOOR COLD FRONT WILL TRACK SOUTHWARD FROM VIRGINIA INTO NORTH CAROLINA THROUGH TONIGHT...THEN STALL OUT ACROSS THE REGION THROUGH FRIDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 200 PM THURSDAY... EXPECT THE DAMPENING UPPER LEVEL RIDGE TO DRIFT EAST TONIGHT...WITH THE H85 FRONT SLOWLY SLIDING SOUTH TOWARD THE NC/VA BORDER. A WEAK DISTURBANCE AT H5 TRAVERSING THE RIDGE OVER VA ALONG THE FRONT MAY HELP GENERATE SOME ISOLATED SHOWER ACTIVITY LATE THIS AFT AND EVE. AT THE SURFACE...THE BACKDOOR COLD FRONT WILL CONTINUE TO APPROACH THE AREA THROUGH THIS EVENING...STALLING AROUND THE NC/VA BORDER OVERNIGHT. AS LOW-MID LEVEL MOISTURE IS ADVECTED IN AHEAD OF THE FRONT DEWPOINTS WILL INCREASE ACROSS THE NORTH AND PW`S WILL INCREASE TO AROUND 1.75" THIS EVENING. THE NAM CONTINUES TO BE MORE ROBUST WITH THE INSTABILITY...FORECASTING MLCAPE OF 1000-1500 J/KG WHILE THE GFS STILL HAS AROUND 500 J/KG. MOST OF THE HI-RES CONVECTION ALLOWING MODELS ARE STILL GENERATING SOME SHOWERS AROUND 21Z THIS AFTERNOON...MAINLY ACROSS THE NORTHERN HALF OF THE REGION...DRIFTING SOUTH THROUGH THE EVENING...HOWEVER THE COVERAGE HAS DECREASED OVER THE PAST SEVERAL RUNS. WILL CONTINUE TO INDICATE THE CHANCE FOR CONVECTION THROUGH AROUND 06Z...BUT COVERAGE IS EXPECTED TO BE ISOLATED AT BEST. LOWS TONIGHT WILL DEPEND SOME ON WHAT HAPPENS WITH THE FRONT...BUT WILL GENERALLY BE IN THE UPPER 60S. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 200 PM THURSDAY... FRIDAY AND FRIDAY NIGHT: THE UPPER LEVEL RIDGE WILL AMPLIFY OVER THE MID-ATLANTIC ON FRIDAY. AT THE SURFACE...THE FRONT WILL BE STALLED IN THE VICINITY OF THE NC/VA BORDER DURING THE DAY BEFORE SLOWLY RETREATING TO THE NE OVERNIGHT. MUCH OF THE WEATHER WILL DEPEND ON THE LOCATION OF THE FRONTAL BOUNDARY THROUGHOUT THE DAY. THE LOWER TEMPS WILL BE ALONG AND NORTH OF THE FRONT...WITH HIGHER HIGHS ACROSS THE SOUTH. ANY CONVECTION THAT DEVELOPS WILL BE MAINLY ALONG AND SOUTH OF THE FRONT...BUT EXPECT COVERAGE TO BE ISOLATED AT BEST AND CONFIDENCE THAT IT WILL DEVELOP IS NOT TERRIBLY HIGH AT THIS TIME. CONTINUED MID LEVEL MOISTURE ADVECTION SHOULD RESULT IN CLOUDY CONDITIONS THROUGH A GOOD PART OF THE DAY. NORTHEASTERLY WINDS ALONG AND NORTH OF THE FRONT AND SOUTHWESTERLY SOUTH OF IT DURING THE DAY/EVENING SHOULD BECOME GENERALLY SOUTHEASTERLY ACROSS THE AREA OVERNIGHT. HIGHS EXPECTED TO RANGE FROM THE MID 80S NORTH TO LOW 90S SOUTH. LOWS IN THE UPPER 80S TO AROUND 70 DEGREES. -KC SATURDAY AND SATURDAY NIGHT: NORTH CAROLINA WILL STILL BE UNDER THE INFLUENCE OF A STRONG UPPER LEVEL RIDGE AND AN EXITING SURFACE HIGH PRESSURE TO THE NORTHEAST. THIS WILL KEEP WEATHER DRY AND SETTLED ON SATURDAY AND SATURDAY AFTERNOON. CONDITIONS WILL BE STABLE AND A SLIGHT DECREASE IN MOISTURE MAY HELP HIGH TEMPERATURES TO REACH THE LOWER 90S IN MOST LOCATIONS WITH UPPER 80S ACROSS THE NORTHERN COUNTIES. WINDS WILL BE OUT OF THE SOUTH AT AROUND 5 KTS GUSTING TO 10 KTS. THE HIGH WILL CONTINUE TO MOVE OFFSHORE SATURDAY NIGHT...ALLOWING MOISTURE TRANSPORT OUT OF THE GULF OF MEXICO TO INCREASE AS A DISSIPATING LOW PRESSURE SYSTEM MOVES EASTWARD OUT OF THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION. THIS WILL SET THE STAGE FOR A MORE UNSETTLED PATTERN BEGINNING ON SUNDAY. LOWS SATURDAY NIGHT UPPER 60S TO LOWER 70S. -ELLIS && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 245 PM THURSDAY... SUNDAY THROUGH TUESDAY NIGHT: A MORE UNSETTLED PERIOD OF WEATHER WILL BEGIN ON SUNDAY WITH HIGH PRESSURE OFFSHORE SETTING UP A RETURN FLOW REGIME OVER CENTRAL NC THAT WILL TRANSPORT MOISTURE INTO THE AREA FROM THE GULF OF MEXICO AND SOUTHWESTERN ATLANTIC. AS PW VALUES CREEP UP OVER TWO INCHES THE CHANCES FOR CONVECTION WILL INCREASE...MAINLY DRIVEN BY INSTABILITY DURING THE DIURNALLY FAVORABLE TIMES AS SHEAR WILL REMAIN VERY WEAK. HIGH TEMPERATURES ARE EXPECTED TO RISE INTO THE LOWER 90S EACH DAY WITH LOWS IN THE LOWER 70S. WEDNESDAY AND THURSDAY: A MORE DEFINED FRONTAL SYSTEM WILL MOVE IN ON WEDNESDAY AS LOW PRESSURE MOVES THROUGH SOUTHERN QUEBEC AND A STRONG SURFACE HIGH BUILDS IN OVER THE GREAT LAKES AND EXTENDING DOWN INTO THE OHIO VALLEY. WITH THE LOW RAPIDLY MOVING OFF TO THE NORTHEAST...FORCING ALONG THE ATTENDANT COLD FRONT WILL REMAIN WEAK AS SHOWN BY SMALL STRAIGHT HODOGRAPHS THROUGH THE LOWEST 6KM ON MODEL FORECAST SOUNDINGS. TIMING OF THE FRONT AND ASSOCIATED PRECIPIATION IS IN QUESTION AT THIS TIME WITH MODELS HINTING AT A LATE WEDNESDAY/EARLY THURSDAY ARRIVAL AND THEN STALLING OUT SOMEWHERE OVER THE AREA FOR LATE WEEK. MOST CONVECTIVE ACTIVITY WILL REMAIN DIURNAL WITH THE SLIGHT CHANCES OVERNIGHT. TEMPERATURES SLIGHTLY COOLER WITH MORE ANTICIPATED CLOUD COVER AND SLIGHT AIRMASS CHANGE. UPPER 80S TO NEAR 90 FOR HIGHS WITH LOWS UPPER 60S TO NEAR 70 DEGREES. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 120 PM THURSDAY... 24-HOUR TAF PERIOD: EXPECT VFR CONDITIONS FOR THE REMAINDER OF TODAY...WITH A SLIGHT CHANCE FOR SOME ISOLATED CONVECTION ACROSS THE NORTH (KINT/KGSO/KRDU/KRWI) BETWEEN 21Z TODAY AND 06Z FRIDAY AS A BACKDOOR COLD FRONT APPROACHES FROM THE NORTH. WITH THE COVERAGE AND CONFIDENCE BEING LIMITED...WILL NOT INCLUDE IN TAFS BUT MAY NEED TO AMEND SHOULD SHOWERS DEVELOP OVER THE NEXT SEVERAL HOURS. THE INCREASING MOISTURE AHEAD/SOUTH OF THE FRONT...MAINLY ACROSS THE NORTHERN HALF OF THE AREA...COULD RESULT IN SOME LOW STRATUS DEVELOPING BETWEEN 10Z AND 12Z FRIDAY MORNING...WITH CIGS OF 500- 1500 FT POSSIBLE. WITH THE FRONT STALLING ALONG THE NC/VA BORDER FRIDAY...CLOUDS COULD REMAIN BROKEN TO SCATTERED AROUND 3 KFT THROUGH THE DAY AT THE AFOREMENTIONED TERMINALS. FOR NOW WILL KEEP CIGS SCATTERED BUT THERE IS THE CHANCE FOR THE NORTHERN TERMINALS TO HAVE HIGH END MVFR TO LOW END VFR CIGS THROUGH THE REMAINDER OF THE 24 HOUR TAF PERIOD. THE CHANCE FOR ISOLATED CONVECTION IN THE VICINITY OF THE FRONT WILL ALSO BE PRESENT...BUT AGAIN CONFIDENCE IS STILL LOW AT THIS TIME. LOOKING AHEAD: CONFIDENCE REMAINS BELOW NORMAL IN THIS PERIOD. EXPECT THE FRONT TO SLOWLY LIFT NNE AWAY FROM THE REGION FRIDAY NIGHT...WITH AN INCREASE IN SOUTHERLY RETURN FLOW INTO THE REGION... INCREASING LOW TO MID LEVEL MOISTURE THROUGH THE WEEKEND. THIS WILL YIELD INCREASED CHANCES FOR LOW CEILINGS IN THE PRE-DAWN HOURS THROUGH EARLY NEXT WEEK. FOR NOW EXPECT SATURDAY TO BE DRY...WITH INCREASING CHANCES FOR CONVECTION...MAINLY IN THE AFT/EVE...SUNDAY NIGHT THROUGH TUESDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...KC SHORT TERM...KC/ELLIS LONG TERM...ELLIS AVIATION...KC

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