Area Forecast Discussion
Issued by NWS Raleigh/Durham, 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 KRAH 241122 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 622 AM EST MON NOV 24 2014 .SYNOPSIS...WARM SOUTHWEST FLOW WILL RESULT IN MUCH ABOVE NORMAL TEMPERATURES TODAY. A COLD FRONT WILL CROSS CENTRAL NC THIS EVENING. AN AREA OF LOW PRESSURE WILL FORM OFF THE SOUTHEAST U.S. COAST TUESDAY NIGHT AND TRACK ALONG THE CAROLINA COAST WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 313 AM MONDAY... TODAY...WARM AIR MASS HAS OVERSPREAD CENTRAL NC WITH PRE DAWN TEMPS IN THE LOW-MID 60S...COMPARABLE TO OUR NORMAL DAYTIME HIGHS FOR THIS TIME OF YEAR. WATER VAPOR IMAGERY DEPICTS A MATURE CYCLONE LIFTING NWD ACROSS THE EASTERN LAKES THIS MORNING WITH ITS ASSOCIATED DRY SLOT PROGRESSING NWD ACROSS OUR REGION. THUS...ATMOSPHERE ABOVE 8K- 10K HAS LIKELY DRIED OUT APPRECIABLY COMPARED TO THE 00Z GSO SOUNDING. MAIN FORECAST CHALLENGES FOR TODAY REVOLVE AROUND HIGH TEMPS...THREAT OF SHOWERS AND ISOLATED THUNDERSTORMS...AND STRENGTH OF WIND GUSTS LATER TODAY. LOW LEVEL FLOW SW WILL PERSIST TODAY IN ADVANCE OF A COLD FRONT WELL TO OUR WEST. THIS FLOW WILL CONTINUE TO PULL WARM AIR OVER OUR REGION. IF BREAKS IN THE LOW-MID LEVEL CLOUDS OCCUR (VERY PLAUSIBLE)...THE PARTIAL SUN WILL WARM TEMPS INTO THE 70S. FAVOR MAX TEMPS IN THE MID-UPPER 70S CONSIDERING THAT TEMPS STARTING OUT IN THE 60S. WHILE THESE HIGH TEMPS ARE WELL ABOVE NORMAL...THEY ARE STILL SEVERAL DEGREES BELOW RECORD HIGHS FOR THE 24TH. SW 850MB FLOW EXPECTED TO BE AS STRONG AS 50-55KTS OVER THE REGION TODAY. DOES NOT APPEAR THAT WE WILL MIX THAT HIGH. MOMENTUM TRANSFER TOOL OFF THE BUFKIT SOUNDINGS SUGGEST MAX WIND GUSTS IN THE NEIGHBORHOOD OF 30KTS LATE THIS MORNING THROUGH EARLY AFTERNOON. IF SUBSTANTIAL SUNSHINE WERE TO OCCUR...GUSTS AROUND 35KTS OR SLIGHTLY STRONGER COULD BE REALIZED. APPROACH OF THE MID LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT WILL LIKELY INITIATE SCATTERED SHOWERS ALONG AND EAST OF I-95 LATER THIS AFTERNOON. KINEMATICS STILL RATHER IMPRESSIVE THOUGH INSTABILITY MARGINAL AT BEST. IF ENOUGH HEATING WERE TO OCCUR...THEN WE WOULD HAVE A BETTER PROBABILITY OF A STRONG/LOCALLY SEVERE THUNDERSTORM OVER OUR FAR EAST-SE COUNTIES CONSIDERING THE STRENGTH OF THE LOW LEVEL JET. MAJORITY OF CONVECTIVE ALLOWING MODELS DEPICT SCATTERED SHOWERS ALONG AND EAST OF THE I-95 CORRIDOR. THUS WILL INCREASE POP TO HIGH CHANCE OVER THE FAR SE COUNTIES...TRENDING TO SLIGHT CHANCE TO NEAR/JUST EAST OF THE TRIANGLE AREA. TONIGHT...SURFACE COLD FRONT WILL CROSS CENTRAL NC. ASIDE FROM A VEERING LOW LEVEL WIND...FRONTAL PASSAGE WILL OCCUR RELATIVELY UNNOTICED. LOW LEVEL FLOW WILL VEER TO A WEST-NW DIRECTION. UPSTAIRS...850MB TROUGH REMAINS WEST OF THE REGION THROUGH 12Z TUESDAY. SINCE LOW LEVEL FLOW HAS A DOWNSLOPE COMPONENT...INITIAL COLD AIR ADVECTION WILL BE OFFSET OR DELAYED. THUS WILL RAISE MIN TEMPS SEVERAL DEGREES FROM PREVIOUS FORECAST. MIN TEMPS AROUND 50 NW TO NEAR 60 FAR SE. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... AS OF 313 AM MONDAY... TUESDAY...SURFACE FRONT STALLS OFFSHORE AS IT BECOMES PARALLEL TO SW FLOW ALOFT. THIS FLOW WILL CONTINUE TO STREAM MID-HIGH LEVEL MOISTURE ACROSS CENTRAL NC. A SURFACE WAVE EXPECTED TO DEVELOP ON TEH STALLED OFF THE GA COAST LATES TUESDAY. THIS FEATURE WILL BEGIN TO ADVECT LOW LEVEL MOISTURE INTO OUR REGION TOWARD SUNSET. LIFT ASSOCIATED WITH AN UPPER LEVEL JET EXITING OUR REGION COUPLED WITH THE INCREASINGLY MOIST AIR MASS MAY ALLOW PATCHES OF LIGHT RAIN TO DEVELOP IN VICINITY OF THE SC BORDER PRIOR TO SUNSET. MAX TEMPS TUESDAY DEPENDENT UPON EXTENT OF CLOUD COVERAGE AND EXPECTED ONSET OF SPOTTY LIGHT RAIN. MOS GUIDANCE HAS TRENDED WARMER SO WILL FOLLOW TREND OF UPPER 50S TO AROUND 60 NW TO MID 60S SE. IF CLOUDS THICKER/LOWER THAN CURRENTLY ANTICIPATED....MAX TEMPS CLOSER TO MID 50S NW-LOWER 60S SE MAY BE CLOSER TO REALITY. -WSS TUESDAY NIGHT THROUGH THURSDAY: S/W ENERGY CURRENTLY LOCATED ACROSS THE NORTHWESTERN U.S. WILL DIVE SOUTHEASTWARD INTO THE GULF COAST STATES AND SHIFT EASTWARD AND HELP TO INDUCE CYCLOGENESIS FROM THE GULF OF MEXICO TO ALONG THE SOUTHEAST U.S. COAST ALONG THE STALLED SURFACE FRONT. THE SURFACE LOW WILL LIFT NORTH-NORTHEASTWARD ALONG/NEAR THE MID-ATLANTIC COASTLINE TUESDAY INTO WEDNESDAY.... SPREADING PRECIP ACROSS CENTRAL NC TUESDAY NIGHT INTO WEDNESDAY. MEANWHILE... A 1025 MB SURFACE HIGH LOCATED JUST TO THE NORTH OF THE REGION WILL EXTEND SOUTHWARD INTO CENTRAL NORTH CAROLINA. HOWEVER... THIS SURFACE HIGH WILL NOT DELIVER ANY SIGNIFICANT DRY AIR (ULTRA LOW DEWPOINTS... INSTEAD THE LOWEST DEWPOINTS AHEAD OF ANY PRECIP WILL BE IN THE 30S). WITHOUT THE ULTRA LOW DEWPOINTS IT APPEARS THAT WE WILL NOT HAVE MUCH OF A CHANCE FOR ANY ACCUMULATING SNOW... IF ANY AT ALL... ESPECIALLY AS MODEL GUIDANCE IS TRENDING WARMER WITH THE THERMAL PROFILES ACROSS THE AREA. WHEN THERMAL PROFILES WOULD SUPPORT A POSSIBLE CHANGE OVER... WE WILL BEGIN TO LOSS SATURATION IN THE KEY -10 TO -20 DEGREES CELSIUS LAYER OF THE ATMO. THUS... HAVE REMOVED SNOW FROM THE FORECAST FOR WEDNESDAY... EXPECT IN THE FAR NORTHWEST PIEDMONT ON WEDNESDAY MORNING... WHERE WE WOULD STILL NEED HIGH PRECIP RATES TO ALLOW SOME SNOW TO MIX IN WITH THE RAIN TO OVERCOME AROUND A 3 KFT PLUS ABOVE FREEZING LAYER (SFC-3KFT THAT IS). REGARDLESS TEMPS ARE EXPECTED TO ABOVE TEMPS AND IF WE DO INDEED SEE ANY SNOW MIX IN WE WILL NOT HAVE ANY TRAVEL PROBLEMS. LOWS WEDNESDAY MORNING ARE EXPECTED TO BE IN THE UPPER 30S NW TO LOWER 40S SE. TEMPS ON WEDNESDAY ARE NOT EXPECTED TO RECOVER MUCH WITH WIDESPREAD RAIN EXPECTED FOR WEDNESDAY MORNING INTO THE EARLY AFTERNOON. THUS... WILL ONLY SHOW HIGH TEMPS AROUND 40 N/NW TO THE UPPER 40S SE. A SECOND NORTHERN STREAM DISTURBANCE WILL DIVE SOUTHEASTWARD AND INTO THE BASE OF THE MAIN TROUGH AS IT SHIFTS EASTWARD ACROSS OUR REGION. THE CORE OF THE DISTURBANCE WILL NOT DIVE FAR ENOUGH SOUTH TO BRING ANY APPRECIABLE PRECIP TOO OUR REGION. THUS... WILL KEEP THE FORECAST DRY WEDNESDAY NIGHT INTO THURSDAY FOR NOW. HOWEVER... WE CANT COMPLETELY RULE OUT SOME SPRINKLES/FURRIES OR BRIEF SHOWER ACROSS OUR FAR NORTHERN COUNTIES DURING THIS TIME FRAME. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN THE LOWER TO MID 30S. HIGHS THURSDAY IN THE UPPER 40S TO LOWER 50S. -BSD && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... AS OF 315 AM MONDAY... THURSDAY NIGHT THROUGH SUNDAY: SURFACE HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION LATE THIS WEEK... BEFORE SHIFTING TO THE EAST AND SOUTH OF THE AREA FOR THE WEEKEND. THE MID LEVEL FLOW IS EXPECTED TO BECOME MORE FLAT ACROSS OUR AREA... WITH MID LEVEL RIDGING NUDGING NORTHWARD INTO OUR AREA FROM THE SOUTH OVER THE WEEKEND. THIS WILL HELP TO HOLD THE NEXT COLD FRONT TO THE NORTH OF CENTRAL NC THROUGH THE WEEKEND. HIGH TEMPS FRIDAY WILL AGAIN BE IN THE UPPER 40S TO LOWER 50S... BEFORE WARMING OVER THE WEEKEND WITH A WARMING RETURN FLOW. HIGHS FOR THE WEEKEND LOOK TO BE IN THE 50S AND 60S. LOWS DURING THE PERIOD WILL BE ON THE CHILLY SIDE UNTIL THE SURFACE HIGH SHIFTS TO THE EAST AND SOUTH OF THE AREA. THUS... EXPECT LOWS FRIDAY MORNING WILL BE IN THE 20S TO LOWER 30S. LOWS OVER THE WEEKEND WILL GENERALLY BE IN THE 30S TO LOWER 40S. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 622 AM MONDAY... A WARM MOIST SW LOW LEVEL FLOW WILL CAUSE AREAS OF MVFR CEILINGS INTO THE FIRST HALF OF THIS MORNING. CEILINGS WILL GRADUALLY LIFT INTO THE VFR CATEGORY LATE THIS MORNING THROUGH THIS AFTERNOON. A SW WIND WILL BE BREEZY WITH SUSTAINED WINDS AROUND 15 MPH EXPECTED AFTER DAYBREAK WITH FREQUENT GUSTS 30-35 MPH. THE WINDS SHOULD SUBSIDE AFTER 21Z. A FEW SHOWERS AND POSSIBLY A THUNDERSTORM WILL OCCUR LATER THIS MORNING AND PERSIST INTO THE AFTERNOON HOURS OVER SECTIONS OF OUR COASTAL PLAIN...MAINLY JUST EAST OF KFAY AND KRWI. A COLD FRONT WILL CROSS CENTRAL NC TONIGHT...USHERING IN A STABLE AIR MASS. VFR CONDITIONS ANTICIPATED TONIGHT THROUGH TUESDAY. AN AREA OF LOW PRESSURE WILL DEVELOP OFF THE GA COAST TUESDAY NIGHT THEN TRACK ALONG THE CAROLINA COAST WEDNESDAY. THIS SYSTEM WILL SPREAD MOISTURE BACK INTO CENTRAL NC LATE TUESDAY INTO WEDNESDAY...RESULTING IN A PERIOD OF MVFR-IFR CEILINGS AND AREAS OF RAIN. IMPROVING WEATHER CONDITIONS EXPECTED THANKSGIVING DAY INTO FRIDAY AS HIGH PRESSURE BUILDS INTO THE REGION. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...WSS SHORT TERM...WSS/BSD LONG TERM...BSD AVIATION...WSS

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