Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 KRAH 070630 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 230 AM EDT THU MAY 7 2015 .SYNOPSIS...THE LOW PRESSURE SYSTEM OFF THE SOUTHEAST COAST MAY EVOLVE INTO A SUBTROPICAL OR TROPICAL CYCLONE OVER THE NEXT 12 TO 24 HOURS AS IT DRIFTS SLOWLY NORTHWARD AND THEN NORTHWESTWARD TOWARDS THE CAROLINAS THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 AM THURSDAY... GIVEN WEAK STEERING FLOW ALONG THE SOUTHERN AND EASTERN PERIPHERY OF CONTINUED RIDGING ALOFT THAT EXTENDS FROM THE NORTHWEST GOM NEWD INTO THE NORTHEAST US...THE DEEPENING LOW OFF THE SOUTHERN COAST OF GEORGIA WILL INITIALLY DRIFT NORTHWARD TODAY...WITH INDICATIONS OF A SLIGHTLY MORE NORTHWESTWARD JOG OVERNIGHT AND THROUGH THE DAY ON FRIDAY. WHILE SOME OF THE FIRST OUTER RAIN BANDS ARE CURRENTLY MOVING ASHORE THE SC/NC COASTS...SENSIBLE WX IMPACTS TODAY AND TONIGHT STILL LOOK VERY MINIMAL WITH MOST OF THE FORECAST STILL UNDER THE INFLUENCE OF SUBSIDENCE ALOFT AND DRY AIR SURFACE RIDGE EXTENDING FROM THE DELMARVA COAST SOUTHWESTWARD DOWN THE EASTERN SLOPES OF THE SOUTHERN APPALACHIANS. THE EXCEPTION MAY BE ACROSS THE FAR SE ZONES IN PROXIMITY TO THE STRENGTHENING ONSHORE FLOW/MOISTURE CONVERGENCE. HAVE KEPT SLIGHT TO SMALL CHANCE POPS ACROSS THE SOUTHERN COASTAL PLAIN AND SANDHILL COUNTIES. ASSOCIATED THICKENING CLOUDS SHIELD WILL TEMPER DAYTIME HEATING IN THESE AREAS AS WELL...WITH HIGHS RANGING FROM MID TO UPPER 70S ACROSS THE SOUTHEAST TO LOWER 80S OVER THE WESTERN-CENTRAL PIEDMONT. BROKEN/OVERCAST SKIES COUPLED WITH MORE HUMID AIR BEING DRAWN INTO THE AREA OVERNIGHT WILL RESULT IN MILDER OVERNIGHT LOWS IN THE UPPER 50S TO LOWER 60S. && .SHORT TERM /FRIDAY AND FRIDAY NIGHT/... AS OF 230 AM THURSDAY... THE SYSTEM IS EXPECTED TO LARGELY MEANDER SOUTH OF CAPE FEAR FRIDAY- FRIDAY NIGHT. ONCE AGAIN...OUTSIDE OF THE SE ZONES...IMPACTS ARE EXPECTED TO BE FAIRLY MINIMAL. HOWEVER...ISOLATED CONVECTION COULD BE MORE APT TO DEVELOP WELL INLAND OWING TO RISING HUMIDITY LEVELS/DEWPOINTS AND RESULTANT WEAK TO MODERATE DESTABILIZATION FRIDAY AFTERNOON. NO SEVERE STORMS ARE EXPECTED AT THIS TIME GIVEN WEAK FIELD AND WEAK FORCING. WITH NO CHANGE IN AIRMASS...HIGHS AGAIN IN THE UPPER 70S TO LOWER 80S...BUT ULTIMATELY DEPENDENT BY CLOUDS AND CONVECTIVE COVERAGE. LOWS 60-65. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 300 PM WEDNESDAY... MUCH OF THE LONG TERM WILL BE DOMINATED BY THE SUBTROPICAL OR TROPICAL SYSTEM THAT IS EXPECTED TO FORM OFF OF THE SOUTH CAROLINA COAST. THIS SYSTEM WILL MEANDER ALONG THE SC AND NC COASTLINES THROUGH AT LEAST MONDAY AND POSSIBLY INTO TUESDAY. MODEL FORECASTS DIVERGE SIGNIFICANTLY BY SUNDAY AND CONFIDENCE IN THE LOCATION AND INTENSITY OF THE SYSTEM BECOMES LOWER. NEAR THE END OF THE PERIOD A COLD FRONT APPROACHES FROM THE WEST AND HELPS TO USHER THE TROPICAL SYSTEM OUT TO SEA. AS BEST AS DETAILS CAN BE IRONED OUT RIGHT NOW EXPECT THE MOST RAIN TO BE IN THE SOUTH EASTERN COUNTIES BUT AT THIS TIME MOISTURE DOES NOT LOOK HIGH ENOUGH TO PRODUCE SIGNIFICANT RAINFALL THAT WOULD RESULT IN ANY KIND OF FLOODING. A WESTWARD SHIFT IN TRACK WOULD RAISE THE POTENTIAL FOR SIGNIFICANT RAIN IN THE EASTERN COUNTIES OVER THE WEEKEND AND INTO EARLY NEXT WEEK. FORECAST SOUNDINGS ARE DEPICTING INSTABILITY DURING THE AFTERNOON HOURS EACH AFTERNOON/EVENING BUT THE OVERNIGHT/MORNING HOURS SHOULD BE MOSTLY CHARACTERIZED BY CONVECTIVE SHOWERS. SEVERE POTENTIAL LOOKS MINIMAL AT THIS TIME AND WIND SHEAR VALUES ARE LOW ENOUGH THAT THE THREAT FOR TROPICAL TORNADOES ALSO LOOKS MINIMAL AT THIS TIME. IN GENERAL WINDS WILL BE OUT OF THE NORTHEAST AT AROUND 10 KTS GUSTING TO 15-20 KTS. ON MONDAY NIGHT A COLD FRONT IS EXPECTED TO MOVE THROUGH FROM THE WEST WITH SOME SHOWERS AND THUNDERSTORMS POSSIBLE WITH GOOD INSTABILITY BUT ONLY ABOUT 20 KTS OF SHEAR SUGGESTIVE OF MULTICELLULAR CONVECTION AT BEST. AFTER FRONTAL PASSAGE...WINDS WILL BECOME NORTHWESTERLY AND DEWPOINTS ARE EXPECTED TO DROP BACK INTO THE 50S. UNTIL THEN EXPECT HIGHS IN THE 80S WITH LOWS IN THE LOW TO MID 60S. A RETURN TO DRY WEATHER AND SLIGHTLY COOLER TEMPS IS EXPECTED ON WEDNESDAY. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 125 AM THURSDAY... 24-HOUR TAF PERIOD: VFR CONDITIONS ARE EXPECTED TO HOLD OVERNIGHT AND THROUGH THE DAYLIGHT HOURS WITH MID/HIGH CLOUDS GRADUALLY THICKENING AND LOWERING BY THE AFTERNOON. LIGHT AND VARIABLE OVERNIGHT WILL BECOME NELY BY DAYBREAK OWING TO THE SLOW APPROACH OF THE OFFSHORE CYCLONE...INCREASING THROUGHOUT TH DAY WITH GUSTS BETWEEN 15 TO 20KTS ACROSS CENTRAL AND EASTERN TERMINALS. ANY SHOWERS SHOULD REMAIN CONFINED TO KFAY. ASSOCIATED CYCLONIC ONSHORE FLOW WILL BEGIN TO ADVECT LOW-LEVEL MARITIME MOISTURE INTO THE AREA LATE IN THE PERIOD(BETWEEN 00 TO 06Z)...WITH SUB-VFR CEILINGS SPREADING EAST TO WEST THROUGH DAYBREAK FRIDAY. LOOKING AHEAD: THE EVENTUAL SUBTROPICAL OR TROPICAL LOW WILL DRIFT SLOWLY NORTHWARD ALONG THE SOUTHEAST U.S. COAST...STALLING AND MEANDERING SOMEWHERE IN THE VICINITY OF SOUTH CAROLINA OR NORTH CAROLINA LATE IN THE WEEK AND THROUGH THE WEEKEND. ALTHOUGH MODEL AGREEMENT CONTINUES TO GET BETTER WITH THIS SYSTEM... THERE IS STILL A LOT OF UNCERTAINTY WITH RESPECT TO THE PATH OF THIS SYSTEM...BUT REGARDLESS...THIS SYSTEM COULD RESULT IN SOME ADVERSE AVIATION IMPACTS IN WIDESPREAD SHOWERS AND THUNDERSTORMS...AND COULD PERSIST THROUGH SUNDAY...ESPECIALLY ACROSS SOUTHERN AND EASTERN NC. ADDITIONALLY...ENHANCED EASTERLY ONSHORE FLOW FROM THIS SYSTEM COULD BRING AN INCREASE THREAT FOR MORNING STRATUS/FOG. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CBL NEAR TERM...CBL SHORT TERM...CBL LONG TERM...ELLIS AVIATION...CBL

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