Area Forecast Discussion
Issued by NWS Raleigh/Durham, 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 KRAH 211904 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 304 PM EDT TUE OCT 21 2014 .SYNOPSIS....A COLD FRONT WILL CROSS CENTRAL NC LATE THIS AFTERNOON AND THIS EVENING. AN UPPER LEVEL LOW WILL SETTLE SOUTHEAST ACROSS THE MIDDLE ATLANTIC REGION TONIGHT...AND LINGER OVER THE REGION THROUGH WEDNESDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1100 AM TUESDAY... A COLD FRONT CROSSING THE OH AND TN VALLEYS LATE THIS MORNING WILL CROSS CENTRAL NC LATE THIS AFTERNOON AND TONIGHT. STEADY SW FLOW AHEAD OF THIS FEATURE ALONG WITH AMPLE SUNSHINE WILL PUSH TEMPERATURES INTO THE LOW-MID 70S NORTH...AND MID-UPPER 70S SOUTH. AS THE FRONT GETS CLOSER...MAY SEE AN INCREASE IN CLOUDINESS...MAINLY ACROSS THE NORTH HALF. WHILE MOISTURE IS LIMITED (AS PER 12Z GSO SOUNDING)...ENOUGH LIFT GENERATED BY THE FRONT AND ATTENDANT S/W MAY CAUSE A STRAY SHOWER OR A FEW SPRINKLES ACROSS THE FAR NORTHERN-NE COUNTIES LATE THIS AFTERNOON THROUGH THIS EVENING. NW WINDS BEHIND THE FRONT WILL BE BLUSTERY AT TIMES AS LOW LEVEL COLD AIR ADVECTION COMMENCES. MIN TEMPS MID 40S WEST TO UPEPR 40S EAST-SE. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... AS OF 340 AM TUESDAY... THE UPPER LOW WILL DRIFT ACROSS THE CHESAPEAKE BAY AND DELMARVA ON WED...THEN LIFT SLOWLY UP THE MIDDLE ATLANTIC COAST WED NIGHT AND BEYOND. ASSOCIATED SURFACE COASTAL LOW PRESSURE WILL DEEPEN BY ABOUT 10 MB (FROM JUST UNDER 1010 MB TO JUST UNDER 1000 MB) FROM 12Z WED TO 12Z THU...AS IT TOO LIFTS UP THE MIDDLE ATLANTIC COAST. THE COLDEST TEMPERATURES/STEEPEST LAPSE RATES ALOFT ASSOCIATED WITH THE UPPER LOW...THE FORMER IN EXCESS OF MINUS 20 C AND THE LATTER BETWEEN 6.5-7 C/KM...WILL CONSEQUENTLY BRUSH THE NORTHEAST PIEDMONT AND NORTHERN-CENTRAL COASTAL PLAIN...AND RESULT IN A CHANCE OF "INSTABILITY" SHOWERS OR SPRINKLES WITH DIURNAL HEATING. IT WILL OTHERWISE BE COOLER AND BREEZY...WITH NORTHWESTERLY DAYTIME WIND GUSTS UP TO 25 MPH OWING TO THE DEEPENING COASTAL LOW...AND HIGHS IN THE 60S. CLEARING AND SIMILARLY COOLER WED NIGHT...WITH LOWS MOSTLY IN THE LOWER TO MIDDLE 40S. && .LONG TERM /THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
AS OF 3 PM TUESDAY... THURSDAY THROUGH FRIDAY NIGHT: WEAK SHORTWAVE RIDING WILL BRIEFLY APPROACH/BUILD OVER THE AREA ON THURSDAY INTO THURSDAY NIGHT AS THE DEEP MID LEVEL LOW SLOWLY CONTINUES TO LIFT OFF TO THE NORTHEAST. THIS WILL YIELD MOSTLY SUNNY/SUNNY SKIES-CLEAR/MOSTLY CLEAR SKIES. HOWEVER... WITH THE DEPARTING SYSTEM... WE MAY SEE SUSTAINED NORTHWESTERLY WINDS IN THE 10 TO 15 MPH RANGE... WITH SOME GUSTS OF AROUND 20 MPH OR SO DURING THE DAYLIGHT HOURS OF THURSDAY. AFTERNOON LOW LEVEL THICKNES VALUES AREA EXPECTED TO BE IN THE 1350S TO 1360S. THUS... GIVEN FULL SUN IS EXPECTED ALONG WITH SOMEWHAT OF A DOWNSLOPE FLOW WILL GO WITH HIGH TEMPS RANGING FROM THE MID TO UPPER 60S. LOWS THURSDAY NIGHT WITH CLEAR/MOSTLY CLEAR SKIES AND A WEAKENING WIND ARE EXPECTED TO BE IN THE LOWER TO MID 40S... WITH A FEW UPPER 30S NOT OUT OF THE QUESTION IN THE USUAL RURAL COLD SPOTS. ONE LAST S/W DISTURBANCE IS FORECAST TO TRACK SOUTHEASTWARD FROM THE NORTHERN PLAINS/UPPER MIDWEST ON THURSDAY AND MOVE ACROSS CENTRAL NC ON FRIDAY INTO FRIDAY NIGHT. THE ECMWF CONTINUES TO BE MUCH STRONGER WITH THIS FEATURE THAN THE GFS AND NAM. HOWEVER... WITH SUCH A DRY AIRMASS IN PLACE PRECEDING THE FEATURE AND LACK OF ANY REAL MOISTURE RETURN IN ADVANCE OF IT MODELS DO NOT SHOW ANY PRECIP BEING GENERATED ACROSS CENTRAL NC AS IT ACROSS THE AREA. THUS... WILL JUST SHOW AN INCREASE IN CLOUD COVER ON FRIDAY. HOW STRONG THE SYSTEM ENDS UP BEING WILL HAVE AN AFFECT ON HIGH TEMPS THOUGH (WITH CLOUD COVER BEING THE VARIABLE IN QUESTION). FOR NOW WILL JUST SHOW PARTLY SUNNY SKIES ON FRIDAY... WITH HIGH TEMPS IN THE UPPER 60S TO NEAR 70 SOUTH. LOWS FRIDAY NIGHT WITH CLEARING SKIES ARE EXPECTED TO BE IN THE 40S. SATURDAY THROUGH TUESDAY: QUITE WEATHER IS EXPECTED TO CONTINUE FOR THE UPCOMING WEEKEND AND INTO NEXT WEEK. MID LEVEL RIDGING IS FORECAST TO BUILD OVER THE AREA FROM THE CENTRAL U.S. BY EARLY NEXT WEEK... YIELDING A WARMING TREND. EXPECT TEMPS WILL BE NEAR NORMAL TEMPS TO START THE PERIOD... INCREASING TO HIGH TEMPS A CATEGORY OR TWO ABOVE NORMAL BY EARLY NEXT WEEK. THIS YIELDS HIGH TEMPS THIS WEEKEND AROUND 70/LOWER 70S... WITH TEMPS WARMING TO THE LOWER TO MID 70S BY MONDAY AND TUESDAY... WITH POSSIBLY SOME UPPER 70S BY TUESDAY. GIVEN THE PATTERN CHANCE TO RIDING ALOFT... SKIES ARE EXPECTED TO GENERALLY BE MOSTLY SUNNY/MOSTLY CLEAR FOR THIS ENTIRE PERIOD. THIS SHOULD YIELD A NICE DIURNAL TEMP RANGE... GIVEN THE DRY CONDITIONS AND RATHER LIGHT WINDS EXPECT FROM SUNDAY ONWARD. LOWS ARE EXPECTED TO BE IN THE 40S... TO AROUND 50 ACROSS OUR FAR SOUTHEAST BY EARLY NEXT WEEK.
-- End Changed Discussion --
&& .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 115 PM TUESDAY... A COLD FRONT WILL CROSS CENTRAL NC LATE THIS AFTERNOON THROUGH EARLY THIS EVENING. THE FRONTAL PASSAGE WILL BE NOTED BY THE SURFACE WINDS VEERING FROM THE WEST-SW TO THE N-NW WITH SUSTAINED WINDS 8-12KTS AND GUSTS AROUND 20KTS. A LOW END VFR CEILING 3500-5000FT MAY ALSO ACCOMPANY THE FRONT BETWEEN 20Z-02Z...MAINLY ACROSS THE NORTHERN COUNTIES IN VICINITY OF THE TRIAD TERMINALS AS WELL AS KRDU AND KRWI. ENOUGH LIFT MAY OCCUR TO PRODUCE A SHOWER OR TWO BUT CONFIDENCE THAT A SHOWER WILL OCCUR IN VICINITY OF A TERMINAL IS TOO LOW TO MENTION IN THE AERODROME FORECAST AT THIS TIME. SKIES ARE EXPECTED TO TEMPORARILY CLEAR AFTER 04Z. FOR WEDNESDAY...BLUSTERY N-NW WINDS WILL PERSIST WITH GUSTS 18-23KTS HIGHLY PROBABLE. THE CLOSE PROXIMITY OF AN UPPER LEVEL LOW OVER THE NORTHERN MID ATLANTIC WILL CAUSE PERIODS OF CLOUDINESS WITH CEILINGS 3500-5000FT IN VICINITY OF KRDU AND KRWI. A SHOWER OR TWO MAY OCCUR IN VICINITY OF KRWI...BUT MORE SO NEAR THE VIRGINIA BORDER. A HIGH PROBABILITY OF VFR CONDITIONS WILL PERSIST THURSDAY THROUGH SUNDAY. THE UPPER LEVEL LOW IS PROJECTED TO LIFT TO THE NE THURSDAY AND THURSDAY NIGHT. THIS WILL ALLOW AN AREA OF HIGH PRESSURE TO BUILD THEN SETTLE OVER CENTRAL NC THROUGH THE WEEKEND. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...WSS SHORT TERM...MWS 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.