Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 250937
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
437 AM EST TUE NOV 25 2014

.SYNOPSIS...
A COLD FRONT WILL PUSH THRU THE AREA THIS MORNING AND STALL ALONG
THE SOUTHEAST COAST. LOW PRESSURE WILL DEVELOP ALONG THIS FRONT AND
MOVE UP THE ATLANTIC SEABOARD WEDNESDAY. AN UPPER LEVEL SYSTEM WILL
CROSS WESTERN NORTH CAROLINA EARLY THURSDAY. DRY HIGH PRESSURE WILL
RETURN FRIDAY AND LINGER INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
COLD FRONT REMAINS IN ABSOLUTELY NO HURRY THIS MORNING...AND
TEMPERATURES ARE IN FACT STILL IN THE MID-60S ACROSS PORTIONS OF THE
PIEDMONT. ONCE THE FRONT FINALLY DOES PUSH EAST (ASSUMING IT EVER
DOES)...TEMPS WILL BE SLOW TO CLIMB TODAY...ESP IN EASTERN AREAS
WHERE EXTENSIVE HIGH CLOUDS WILL PERSIST THROUGH MUCH OF THE DAY.

POTENT SOUTHERN STREAM SHORT WAVE TROUGH WILL EJECT FROM TEXAS/
NORTHWEST GULF OF MEXICO LATER TODAY...INITIATING CYCLOGENESIS BY
THIS AFTERNOON ACROSS THE NORTHEAST GULF. LOW PRESSURE IS THEN
EXPECTED TO DEEPEN AS IT MOVES NORTHEAST AND REDEVELOPS OFF THE
SOUTHEAST ATLANTIC COAST IN CLASSIC MILLER-A FASHION. AS THIS
OCCURS...A BAND OF STRONG/DEEP FRONTOGENETICAL FORCING WILL BECOME
ESTABLISHED ACROSS THE CAROLINAS...RESULTING IN PRECIP DEVELOPMENT
AS FAR WEST AS THE SOUTHERN APPALACHIANS BY LATE EVENING. THERMAL
PROFILES SUPPORT PRIMARILY A SNOW EVENT ABOVE ABOUT 3000 FEET ACROSS
THE NORTHERN NC MTNS...AND ABOVE 4000 FEET OR SO ACROSS THE SOUTHERN
AND CENTRAL MTNS...WITH PRECIP LIKELY ENDING AS SNOW OR A RAIN/SNOW
MIX IN THE LOWER VALLEYS. WITH LIQUID EQUIV QPF EXPECTED TO BE IN
THE NEIGHBORHOOD OF 0.50 INCHES FROM ROUGHLY THE BLUE RIDGE COUNTIES
EAST...THERE IS THE POTENTIAL FOR BORDERLINE HEAVY SNOWFALL CRITERIA
ACROSS MUCH OF THE NORTHERN MTNS. HOWEVER...WITH UNCERTAINTY
REGARDING THE DURATION OF ANY RAIN...ESP IN THE LOWER VALLEYS...DO
NOT HAVE ENOUGH CONFIDENCE TO ISSUE A WATCH OR WARNING ATTM...AND
WILL INSTEAD HOIST A WINTER WX ADVISORY FOR THE NORTHERN
MTNS...WITH THE EXCEPTION BEING AVERY COUNTY...WHICH SHOULD SEE
PRIMARILY SNOW...SUPPORTING A WINTER STORM WARNING. AN ADVISORY
WILL ALSO BE ISSUED FOR THE HIGH ELEVATIONS OF BUNCOMBE...
HAYWOOD...JACKSON...AND TRANSYLVANIA COUNTIES FOR 2-4 INCHES OF
SNOW.

OTHERWISE...AN ALL RAIN EVENT IS EXPECTED ACROSS THE PIEDMONT/
FHILLS...WITH RAINFALL AMOUNTS IN THE 0.5-1.0 INCH RANGE EXPECTED
FROM THIS EVENING THROUGH WED MORNING.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUE...SFC LOW WILL CONTINUE TO LIFT UP THE EAST COAST
LATE WED WITH THE AXIS OF THE LONGWAVE UPPER TROUGH REACHING THE SRN
APPALACHIANS AROUND 06Z THU. EMBEDDED WITHIN IS A CLIPPER SHORTWAVE
WHICH SHOULD PROVIDE A BURST OF OMEGA CONCURRENT WITH DEEP LAYER
SATURATION. THUS...WHILE NEARLY ALL OF THE PIEDMONT WILL SEE PRECIP
END WED AFTN...THERE LOOKS TO BE ONLY A BRIEF LULL IN THE MTNS BEFORE
THE ARRIVAL OF THE CLIPPER. A PERIOD OF DYNAMICALLY DRIVEN
PRECIP...MAINLY SNOWFALL...IS EXPECTED IN THE MTNS AT THIS TIME.
HOWEVER IN THE WAKE OF THE WAVE THE FLOW WILL VEER TO NW...ALLOWING
LIGHT OROGRAPHIC SNOWFALL TO CONTINUE THRU THURSDAY NIGHT.

TEMPS DURING WED AFTN WILL BE WARM ENOUGH FOR RAIN THROUGHOUT THE
CWFA BUT WILL DIP NEAR OR BELOW FREEZING DIURNALLY IN THE EARLY
EVENING. SIMULTANEOUSLY...JUST AHEAD OF THE INCOMING WAVE...THE GFS
AND PARTICULARLY THE NAM SHOW A BRIEF PERIOD OF SOUTHERLY LLVL FLOW
AND WAA AROUND 900 MB. THIS MAY LEAD TO THE DEVELOPMENT OF A SMALL WARM
NOSE AND COULD ALLOW SLEET OR FREEZING RAIN TO BRIEFLY OCCUR IN SOME
OF THE HIGHER ELEVATIONS. HOWEVER BY THE TIME THE DEEPER MOISTURE ARRIVES
AND RATES PICK UP THE FLOW SHOULD HAVE VEERED AGAIN AND NEUTRAL TO
COLD ADVECTION WILL AGAIN LEAD TO ALL-SNOW PROFILES WHICH PERSIST
THRU WED NIGHT. THE CONTINUING NW FLOW ACTIVITY LOOKS TO CHANGE TO
RAIN IN THE LOWER ELEVATIONS THU BEFORE CHANGING BACK TO ALL SNOW FOR
THU NIGHT. WHILE THE MOISTURE PROFILES AND WINDS REMAIN STEADILY
FAVORABLE THRU THURSDAY THE MOISTURE BECOMES AN ISSUE THU NIGHT WHEN
ACCUMULATIONS SHOULD BECOME MINIMAL.

TEMPS REMAIN BELOW CLIMO THRU THURSDAY...THOUGH SOME REBOUND WILL BE
NOTED OUTSIDE THE NW FLOW AREAS ON THU UNDER DOWNSLOPING WINDS AND
MOSTLY CLEAR SKIES. THE CONTINUED COLD ADVECTION HOWEVER WILL ALLOW
THICKNESSES TO CONTINUE DROPPING THU NIGHT...AND BRING LOWS INTO THE
20S ACRS MOST OF THE AREA FRI MRNG.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 330 AM TUE...LITTLE CHANGE FROM THE PREVIOUS FORECAST FOR
THE MEDIUM RANGE. DRY HIGH PRESSURE WILL PREVAIL ACRS THE SOUTHEAST
FRI IN THE WAKE OF THE DEPARTING UPPER TROUGH. THIS HIGH SETS UP
OFFSHORE SATURDAY AS THE UPPER FLOW BECOMES ESSENTIALLY ZONAL. A
POTENT NRN STREAM LOW WILL MOVE ACRS ONTARIO AND QUEBEC SAT NIGHT
INTO SUNDAY PULLING A COLD FRONT INTO THE OHIO VALLEY. SWLY RETURN
FLOW WILL RETURN ENOUGH MOISTURE INTO THE AREA OVER THE WEEKEND THAT
BY SUNDAY SCHC POPS RETURN TO THE SW MTNS. POPS SLOWLY RETURN OVER
MORE OF THE AREA THRU EARLY NEXT WEEK AS THE COLD FRONT SAGS IN FROM
THE NORTH. GIVEN THE WARM SFC FLOW...TEMPS WILL MODERATE TO NEAR
CLIMO BY LATE WEEKEND.

&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
AT KCLT...A BAND OF LOW LEVEL MOISTURE PRECEDING A COLD FRONT WILL
GRADUALLY PUSH EAST ACROSS THE PIEDMONT THIS MORNING...RESULTING IN
PERSISTENCE OF LOW MVFR CIGS THROUGH ABOUT 09Z. A BRIEF PERIOD OF
IFR WILL ALSO BE POSSIBLE DURING THAT TIME. OTHERWISE...VFR
CONDITIONS WILL RETURN BY DAYBREAK...WITH BKN/OVC MID/HIGH LEVEL
CLOUDS PERSISTING THROUGH THE DAY. SW WINDS WILL BECOME LIGHT W/NW
BEHIND THE FRONT AROUND DAYBREAK...AND GENERALLY PERSIST IN THE 4-7
KT RANGE THROUGH THE PERIOD. LOW PRESSURE DEVELOPING NEAR THE
SOUTHEAST COAST WILL THEN SPREAD MOISTURE AND RAIN TOWARD KCLT BY
THE END OF THE PERIOD.

ELSEWHERE...COLD FRONT HAS PUSHED THROUGH KAVL...BRINGING LOWER
DEWPOINTS AND ENDING ANY POTENTIAL FOR FLT RESTRICTIONS THIS
MORNING. THE FRONT WILL MOVE THROUGH KAND VERY SOON...AND THROUGH
KHKY/KGMU/KGSP WITHIN THE NEXT COUPLE OF HOURS. PERIODIC MVFR VISBY
WILL BE POSSIBLE PRIOR TO FROPA...PARTICULARLY AT KGSP...BUT DRIER
AIR FILTERING IN SHOULD END ANY POTENTIAL FOR FLT RESTRICTIONS BY 08-
09Z. WINDS WILL BECOME LIGHT NW BEHIND THE FRONT...POSSIBLY BECMG
LIGHT NE DURING THE AFTERNOON...BEFORE RETURNING TO THE NW BY TUE
EVENING...AS LOW PRESSURE BEGINS TO FORM OFF THE SOUTHEAST COAST.
THIS LOW WILL SPREAD MOISTURE AND RAIN TOWARD THE AREA THIS
EVENING...POSSIBLY REACHING KAND BY THE END OF THE PERIOD.

OUTLOOK...PRECIPITATION AND ASSOCIATED RESTRICTIONS WILL OVERSPREAD
THE AREA TUE NIGHT/EARLY WEDNESDAY...WITH A MIX OF RAIN AND SNOW
FROM KAVL TO KHKY...WITH MAINLY RAIN EXPECTED FROM KGSP TO KCLT AND
POINTS SOUTH. DRIER CONDITIONS WILL RETURN BY LATE WEEK.

CONFIDENCE TABLE...

            09-15Z        15-21Z        21-03Z        03-06Z
KCLT       HIGH  94%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH  86%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...WINTER STORM WARNING FROM 9 PM THIS EVENING TO 4 PM EST
     WEDNESDAY FOR NCZ033.
     WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON EST
     WEDNESDAY FOR NCZ052-053-059-064.
     WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 4 PM EST
     WEDNESDAY FOR NCZ049-050.
SC...NONE.

&&

$$
SYNOPSIS...CSH
NEAR TERM...JDL
SHORT TERM...WIMBERLEY
LONG TERM...ARK/WIMBERLEY
AVIATION...JDL


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