Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 280006 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 806 PM EDT FRI MAR 27 2015 .SYNOPSIS...A POTENT UPPER LEVEL TROUGH WILL MOVE THROUGH THE REGION OVERNIGHT. DRY HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE WEEKEND. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 230 PM FRIDAY... AMPLIFYING UPPER LEVEL TROUGH DIGGING SOUTHWARD INTO THE SOUTHERN APPALACHIANS WILL PROGRESS ACROSS THE CAROLINAS OVERNIGHT. STRONG DPVA /LAYER LIFTING/ AND COLD ADVECTION ALOFT (H7 TEMPS FALLING 10C BETWEEN 21Z-03Z IN THE TRIAD) WILL RESULT IN MARGINAL NOCTURNAL DESTABILIZATION AND A POTENTIAL FOR ISOLD TO SCT LOW-TOPPED SHOWERS FROM WEST-EAST IN THE 02-08Z TIME FRAME. THE LATEST GUIDANCE SUGGESTS THAT LOW-LEVEL THERMAL PROFILES WILL BE EXCLUSIVELY SUPPORTIVE OF RAIN DURING THE TIME-FRAME IN WHICH SHOWER ACTIVITY WILL BE POSSIBLE. LOWS WILL BE DRIVEN BY A COMBINATION OF COLD ADVECTION AND RADIATIONAL COOLING BETWEEN 06-12Z AS SYNOPTIC SUBSIDENCE /CLEARING/ COMMENCES IN THE WAKE OF THE UPPER LEVEL TROUGH AND THE MSLP GRADIENT TIGHTENS. LOWS RANGING FROM LOWER 30S IN THE NW PIEDMONT TO UPPER 30S/NEAR 40 IN THE SE COASTAL PLAIN. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 230 PM FRIDAY... ...FREEZE WATCH HAS BEEN ISSUED FOR SOUTHER PORTIONS OF THE FORECAST AREA SATURDAY NIGHT/SUNDAY MORNING... A DEEP UPPER TROUGH(H5 2 TO 3 STANDARD DEVIATIONS BELOW NORMAL)...WITH EQUALLY ANOMALOUS H8 TEMPERATURES OF -8 TO -10C WILL BE IN PLACE ACROSS THE EASTERN US SATURDAY-SATURDAY. DESPITE COMPLIMENTS OF FULL SUNSHINE...HIGHS SATURDAY WILL AVERAGE 15 TO 20 DEGREES BELOW NORMAL...WITH A STEADY 10 TO 15 MPH NWLY BREEZE MAKING IT FEEL EVEN COLDER. HIGHS RANGING FROM LOWER 40S NORTHWEST TO AROUND 50 SOUTHEAST. STRENGTHENING 1030MB SURFACE SLIDING EAST OVER THE CAROLINAS UNDERNEATH DRY DEEP NWLY FLOW ALOFT WILL PROVIDE OPTIMAL RADIATIONAL CONDITIONS. THUS...EXPECT LOWS SUNDAY MORNING TO LIE WITHIN THE COOLER 1275-1280M OBSERVED THICKNESS RANGE. LOWS IN THE LOWER TO MID 20S...WHICH WILL CHALLENGE RECORD MIN TEMPS AT AREA CLIMATE SITES. WILL ISSUE A FREEZE WATCH WITH THE AFTERNOON PACKAGE ACROSS THE SOUTHERN PORTIONS OF THE FORECAST AREA WHERE THE SPRING FROST/FREEZE PROGRAM IS ACTIVATED. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 210 PM FRIDAY... TO BEGIN THE PERIOD...HIGH PRESSURE WILL QUICKLY MIGRATE OVER THE AREA...BECOMING SITUATED OFF THE SOUTHEAST COAST BY SUNDAY AFTERNOON/EVENING. AS A RESULT...TEMPS WILL BEGIN TO MODERATE SOME AS RETURN FLOW BEGINS TO SET UP OVER THE REGION...WITH GENERALLY MID 50S EXPECTED. OVERNIGHT...CLOUDS WILL INCREASE THROUGH THE OVERNIGHT HOURS AS ANOTHER SHORT WAVE/ASSOCIATED COLD FRONT APPROACHES THE AREA. THIS (ALONG WITH SOME WARM AIR ADVECTION) WILL KEEP TEMPS IN THE MID/UPPER 30S. AS THE AFOREMENTIONED FRONT CROSSES THE AREA ON MONDAY...PRECIP CHANCES WILL INCREASE. ALTHOUGH WITH VERY LIMITED MOISTURE RETURN EXPECTED...WILL NOT GO ANY HIGHER THEN LOW END CHANCE POP. DESPITE THE FRONTAL PASSAGE AND ITS ASSOCIATED CLOUDS AND LIGHT PRECIP... TEMPS WILL WARM EVEN MORE ON MONDAY (OVER SUNDAY) GIVEN THE WESTERLY DOWNSLOPE FLOW. HIGHS SHOULD RISE INTO THE 60S. EVEN MORE MODIFICATION WILL OCCUR INTO MID WEEK GIVEN MORE IN THE WAY OF SUNSHINE. HIGHS ON TUESDAY WILL BE MOSTLY IN THE UPPER 60S (MAYBE APPROACHING 70 DEGREES ACROSS THE SOUTH)...WITH MOSTLY LOWER 70S EXPECTED BY WEDNESDAY. OUR NEXT SOUTHERN STREAM SYSTEM IS PROGGED TO APPROACH THE AREA BY THE LATTER HALF OF THE WEEK. AS CAN BE EXPECTED THIS FAR OUT IN THE FORECAST PERIOD...CONFIDENCE IN THE EXACT DETAILS IS NOT HIGH. FOR NOW...WILL INTRODUCE POPS BACK INTO THE FORECAST BY THURSDAY...WITH PRECIP LINGERING INTO FRIDAY. TEMPS ARE EXPECTED TO REMAIN SLIGHTLY ABOVE NORMAL. && .AVIATION /00Z SATURDAY THROUGH TUESDAY/...
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AS OF 805 PM FRIDAY... 24-HR TAF PERIOD: MAINLY VFR CONDITIONS ACROSS THE AREA... WITH THE EXCEPTION OF SOME BRIEF MVFR CIGS/VISBYS WITH PATCHES OF LIGHT RAIN/DRIZZLE IN ASSOCIATION WITH AN UPPER LEVEL TROUGH CROSSING THE AREA. SKIES SHOULD BEGIN TO CLEAR BETWEEN 09-12Z... AND WINDS WILL BE FROM THE NW WITH GUSTS OF 15-20 KTS DURING THE AFTERNOON HOURS. LOOKING AHEAD: VFR CONDITIONS WILL RULE OVER THE WEEKEND AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST/NW. THE NEXT POTENTIAL FOR ADVERSE CONDITIONS WILL BE ASSOC/W AN UPPER LEVEL DISTURBANCE MONDAY AFTERNOON...WITH VFR CONDITIONS EXPECTED THEREAFTER.
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&& .CLIMATE... WE COULD APPROACH RECORD LOW TERRITORY SUNDAY MORNING ON THE 29TH. BELOW ARE THE LIST OF THE RECORD MINIMUM TEMPERATURES FOR MARCH 29TH. RECORD MINIMUM TEMPERATURE GSO 20-1966 RDU 20-1966 FAY 24-1982 && .RAH WATCHES/WARNINGS/ADVISORIES... FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR NCZ028-042-043-073>078-083>086-088-089. && $$ SYNOPSIS...CBL/VINCENT NEAR TERM...CBL/VINCENT SHORT TERM...CBL LONG TERM...KRD AVIATION...RAH/CBL CLIMATE...CBL

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