FXUS62 KGSP 271739
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1239 PM EST FRI NOV 27 2009

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE REGION TODAY AND REMAIN IN CONTROL 
THROUGH THE WEEKEND. A COLD FRONT WILL THEN MOVE OVER THE CAROLINAS 
ON MONDAY AND MONDAY NIGHT. ANOTHER LOW PRESSURE SYSTEM WILL MAKE 
ITS WAY OUT OF THE GULF OF MEXICO AND MOVE OVER THE AREA BY MID WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
LATEST IR IMAGERY INDICATES RAPID WARMING OCCURRING TO CLOUD TOPS 
WITHIN UPSLOPE CLOUDINESS ALONG THE TENN BORDER. IN FACT...MOST 
AREAS SOUTH OF I-26 ARE MOSTLY SUNNY TO SUNNY. THE WSW HAS ALREADY 
BEEN DROPPED...ALTHOUGH SOME LINGERING FLURRIES WILL BE POSSIBLE 
ACROSS THE NORTHERN MTNS THROUGH EARLY AFTERNOON.   

CALLS TO MOUNTAIN COUNTIES REVEAL VIRTUALLY NO ISSUES WITH THE WIND 
THIS MORNING. THIS ISN/T LIKELY TO CHANGE OWING TO THE WEAKENING LLJ 
AND RELAXING GRADIENT. WE WILL MAINTAIN THE ADVISORY FOR MARGINAL 
CRITERIA ROUGHLY EAST/NORTH OF HIGHWAY 441...BUT DOWNGRADE TO A LAKE 
WIND ADVISORY FOR THE SMOKIES/NANTAHALAS AND SURROUNDING VALLEYS. 

WE SHOULD SEE A TYPICAL CAA/NORTHWEST FLOW/DOWNSLOPE WARMING  
TEMPERATURE DISTRIBUTION TODAY...WITH A VERY STRONG LAPSE RATE 
(20-25 DEGREE CHANGE BETWEEN THE HIGHEST PEAKS/RIDGETOPS AND THE 
PIEDMONT) BETWEEN THE MOUNTAINS AND THE LEE. THE CURRENT FORECAST 
HAS THIS WELL IN HAND.    

TONIGHT...WEAKENING WINDS AND DECREASING CLOUD COVER WILL ALLOW 
TEMPERATURES TO FALL STEADILY AFTER SUNSET. MOS GUIDANCE SUPPORTS 
WIDESPREAD FREEZING TEMPERATURES...RANGING FROM THE MID TO U20S 
ACROSS THE MTNS AND L30S EAST.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 130 AM FRIDAY...STILL LOOKS LIKE A PERIOD OF QUIET WEATHER 
SATURDAY AND SATURDAY NIGHT AS AN UPPER RIDGE AND SURFACE HIGH 
PRESSURE BUILD OVER THE SOUTHEAST. KEPT TEMPS CLOSE TO A GUIDANCE 
BLEND. THE PATTERN REMAINS PROGRESSIVE THOUGH...SO THIS WILL BE 
SHORT LIVED. A WEAK UPPER WAVE WILL FLATTEN THE RIDGE ON SUNDAY AND 
COULD BRING SOME MID/HIGH LEVEL CLOUDS...BUT NOT ENOUGH TO KEEP 
TEMPS FROM WARMING WELL INTO THE 60S IN THE AFTERNOON.

THE GFS AND ECMWF ARE IN FAIRLY GOOD AGREEMENT WITH DIGGING AN UPPER 
TROF DOWN ACROSS THE PLAINS SUNDAY NIGHT. MOISTURE WILL RETURN FROM 
THE GULF AHEAD OF A COLD FRONT ASSOCIATED WITH THIS UPPER TROF. 
THERE IS THE POSSIBILITY THAT SOME SHOWER ACTIVITY WILL REACH THE 
MOUNTAINS BEFORE SUNRISE ON MONDAY BUT THAT SEEMS REMOTE. INSTEAD... 
MOST OF THE SHOWER ACTIVITY WILL DEVELOP ACROSS THE FORECAST AREA ON 
MONDAY AS THE FRONT APPROACHES FROM THE WEST AND THE SRN BRANCH OF 
THE JET MOVES OVERHEAD. THIS SHOULD GIVE US A DECENT SHOT AT SEEING 
SHOWERS...SO WENT WITH THE LIKELY ON THE TN BORDER AND CHANCE 
ELSEWHERE. THE FRONT SHOULD PUSH ACROSS THE REGION MONDAY EVENING 
BUT KEPT CHANCE POP ALL NIGHT IN CASE TIMING SLIPS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 2 AM FRIDAY...THE MEDIUM RANGE FORECAST PICKS UP AT 12Z ON 
TUESDAY WITH SFC HIGH PRESSURE BRIEFLY IN CONTROL OVER THE CWFA AND 
PREDOMINATELY DRY AIR OVER THE REGION. AS THE UPPER LOW DEEPENS OVER 
THE SW CONUS THE ASSOCIATED SFC CYCLONE STRENGTHENS OVER THE 
NORTHERN GULF OF MEX. LATEST 00Z GFS CONTINUES TO TRACK THE SFC LOW 
RIGHT OVER THE CAROLINAS AND IS ABOUT 12 HOURS FASTER THAN THE ECMWF 
AND GEM. THE LOW MOVES RAPIDLY UP THE EASTERN SEABOARD TOWARDS THE 
END OF THE PERIOD AS A ANOTHER SFC RIDGE PUSHES ITS WAY IN FROM THE 
NW. FOR THE MOST PART THE MODELS REMAIN IN GOOD AGREEMENT EXCEPT FOR 
THE OVERALL FASTER PROGRESSION OF THE GFS AND ITS TENDENCY TO PUSH 
THE LOW ON MORE OF AN EASTERLY TRACK. MODEL SOUNDINGS SHOW LITTLE 
EVIDENCE THAT ANY FROZEN PRECIP SHOULD BE EXPECTED SO I KEPT ALL QPF 
AS LIQUID. TEMPS SHOULD MODERATE BY THURSDAY AND INCREASE TO NEAR 
NORMAL WITH THE FLOW TURNING FROM THE S AND SW DURING THE DAY.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...DRY HIGH PRESSURE BUILDING INTO THE REGION WILL RESULT IN 
CLEAR SKIES OVER THE NEXT 24 HOURS...LEAVING MAINLY A WIND FORECAST. 
UNFORTUNATELY...A CROSS-RUNWAY...OR QUASI-CROSS-RUNWAY WIND IN THE 
9-12 KT RANGE SHOULD PERSIST FOR MOST OF THE AFTERNOON. WIND SHOULD 
EVENTUALLY BECOME SLIGHTLY NORTH OF DUE WEST...AND WILL FORECAST 
THIS TO OCCUR AROUND 20Z. 

ELSEWHERE...VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. 
WEST/NORTHWEST WINDS OF 10-15 KT WILL PERSIST THROUGH THE AFTERNOON. 
OCCASIONAL GUSTS TO AROUND 20 KT WILL BE POSSIBLE FROM TIME TO 
TIME...BUT WILL BE MORE PERSISTENT AT KAVL. WINDS WILL BECOME LIGHT 
AT MOST TERMINALS THIS EVENING.   

OUTLOOK...DRY HIGH PRESSURE WILL DOMINATE THE AREA THROUGH SATURDAY 
NIGHT AND WILL GRADUALLY WEAKEN ON SUNDAY. A COLD FRONT IS EXPECTED 
TO REACH THE WESTERN CAROLINAS LATE SUNDAY NIGHT AND SWEEP ACROSS 
THE REGION ON MONDAY...WITH PRECIPITATION AND RESTRICTIONS POSSIBLE. 
CONDITIONS SHOULD IMPROVE ON TUESDAY.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...LAKE WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR GAZ010.
NC...WIND ADVISORY UNTIL 6 AM EST SATURDAY FOR NCZ033-049-050-501-
     503-505.
     WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR NCZ048-052-053-
     059-063>065-507-509.
     LAKE WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR NCZ051-058-
     062.
SC...NONE.

&&

$$
SYNOPSIS...JPT
NEAR TERM...JDL/NED
SHORT TERM...PM
LONG TERM...JPT
AVIATION...JDL