248
FXUS62 KGSP 100831
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
331 AM EST SUN NOV 10 2024
SYNOPSIS
COLD AIR DAMMING WILL BE IN PLACE TODAY AHEAD OF AN APPROACHING COLD
FRONT LEADING TO MOSTLY CLOUD SKIES AND BELOW NORMAL TEMPERATURES.
THE COLD FRONT WILL TRACK ACROSS THE AREA ON MONDAY ALLOWING FOR
ANOTHER ROUND OF RAIN, WITH WELL ABOVE NORMAL HIGH TEMPERATURES
RETURNING. DRY HIGH PRESSURE RETURNS TUESDAY INTO WEDNESDAY BEFORE
ANOTHER COLD FRONT ARRIVES ON THURSDAY, BRINGING RAIN CHANCES BACK
TO THE AREA. DRY HIGH PRESSURE THEN BUILDS IN FROM THE WEST
FOR FRIDAY AND SATURDAY.
NEAR TERM /THROUGH TONIGHT/
AS OF 310 AM SUN: DAMMING SFC HIGH HAS CENTERED ALONG THE EAST COAST
FROM NC TO NEW ENGLAND, WHILE MATURE SFC LOW IS MOVING FROM NEBRASKA
TO IOWA. MOIST UPGLIDE IS RAMPING UP AHEAD OF THE MIDWEST SYSTEM
AND OVER THE WEDGE, HAVING ALREADY PRODUCED WIDESPREAD STRATUS
OR STRATOCU WEST OF I-77; THIS CLOUD COVER WILL EXPAND OVER THE
REMAINDER OF THE AREA AND LOWER THROUGH THE MORNING. LIGHT PRECIP
IS ALSO EXPECTED TO DEVELOP BETWEEN THE PREDAWN HOURS THROUGH LATE
MORNING, GENERALLY SW TO NE AS WARM CONVEYOR BELT RIDES OVERHEAD AND
MOISTURE FLUX IMPROVES. SOME DRIZZLE COULD ALREADY BEING GENERATED
ALOFT IN OUR WEST; SFC DEWPOINT DEPRESSIONS HAVE BEGUN TO SHRINK
BUT REMAIN 10 TO 15 DEGREES IN MANY SPOTS, SO NOT MUCH IF ANY IS
REACHING THE SURFACE YET. THE LOWERING CLOUDS WILL HELP TOWARD
DAWN. POPS WILL DEVELOP FROM SOUTH TO NORTH OVER THE COURSE OF THE
MORNING IN MOST AREAS WEST OF I-77, AND ALSO EXPANDING OUTWARD FROM
THE SOUTH-FACING BLUE RIDGE ESCARPMENT IN THAT TIMEFRAME. PERSISTENT
CLOUD COVER AND IN PARTICULAR THE ONSET OF DIABATIC COOLING SHOULD
MAKE FOR A PARTLY NONDIURNAL CURVE IN TEMPS TODAY, WITH MAXES NOT
NECESSARILY EARLY THIS MORNING BUT THE COOLEST PART OF THE DAY
POSSIBLY BEING LATE MORNING TO MIDDAY. MAXES SHOULD BE MOSTLY IN
THE 50S IN AREAS NW OF I-85, EXCEPTING AREAS NEAR THE WEDGE BOUNDARY
(WESTERN MTNS AND SE OF I-85) WHERE TEMPS WILL REACH THE LOWER 60S.
FORCING FROM THE WARM UPGLIDE LOOKS TO MAXIMIZE THIS AFTERNOON
ACROSS THE AREA, WITH BEST POPS SHIFTING TO THE NC PIEDMONT AND
TAPERING TO SOME DEGREE IN THE WEST AND SOUTH; WINDS WILL VEER
SLIGHTLY THEREAFTER. HEIGHT FALLS ASSOCIATED WITH UPPER LOW,
LAPSE RATES WILL IMPROVE OVER THE WEDGE INVERSION, AND SOME MUCAPE
THUS DEVELOPS MAINLY ACROSS THE SOUTHERN HALF OF THE CWA. SOME
DPVA IS ALSO PROGGED. POPS SEE A SECONDARY PEAK IN MOST OF THE
AREA, BECOMING MORE SHOWERY, WITH THUNDER BECOMING POSSIBLE IN
OUR SE. LOW-LEVEL FLOW TURNS WESTERLY AFTER MIDNIGHT OVER THE
MOUNTAINS AND POPS INCREASE TO LIKELY/CATEGORICAL VIA UPSLOPE AND
LOW-LEVEL CONVERGENCE. THE FRONT LIKELY WILL NOT ARRIVE SOON ENOUGH
TO ERODE THE WEDGE, AND CLOUDS AND VSBY ARE LIKELY TO CRASH AFTER
SUNSET. TEMPS LIKELY WON'T CHANGE MUCH FROM SUNSET AND MAY EVEN
WARM SLIGHTLY AFTER THE STEADIER PRECIP TAPERS OFF.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
AS OF 100 AM EST SUNDAY...
KEY MESSAGES:
1) A COLD FRONT BRINGS ANOTHER ROUND OF RAIN ON MONDAY
2) COLD AIR DAMMING ERODES MONDAY ALLOWING WELL ABOVE NORMAL HIGHS
TO RETURN
3) HIGH PRESSURE BUILDS IN FROM THE NORTH ON TUESDAY LEADING TO
DRIER CONDITIONS
A COLD FRONT WILL CONTINUE PUSHING EAST ACROSS THE FORECAST AREA ON
MONDAY KEEPING RAIN CHANCES AROUND THROUGH AT LEAST THE LATE MORNING
HOURS. THERE MAY BE JUST ENOUGH INSTABILITY TO ALLOW FOR AN ISOLATED
THUNDERSTORM MONDAY MORNING OR EARLY MONDAY AFTERNOON BUT CONFIDENCE
ON THIS REMAINS LOW. RAIN CHANCES WILL QUICKLY TAPER OFF BY LATE
MORNING OR EARLY AFTERNOON AS THE FRONT PUSHES EAST OF THE FORECAST
AREA. THE NW WINDS BEHIND THE FRONT WILL GRADUALLY ERODE THE COLD
AIR DAMMING WEDGE THROUGHOUT THE DAY. THIS WILL ALLOW CLOUD COVER TO
GRADUALLY DIMINISH THROUGHOUT THE DAY, WITH MOSTLY SUNNY SKIES BY
MID AFTERNOON. DECREASING CLOUD COVER AND NW DOWNSLOPING FLOW WILL
ALLOW FOR AMPLE DAYTIME HEATING DESPITE THE COLD FRONT. THUS, HIGHS
SHOULD REBOUND TO ~10 DEGREES ABOVE NORMAL MONDAY AFTERNOON. DESPITE
MOSTLY CLEAR SKIES MONDAY NIGHT, LOWS WILL END UP ~10 DEGREES ABOVE
NORMAL AS WELL. SFC HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE
DEPARTING FRONT MONDAY EVENING INTO TUESDAY NIGHT LEADING TO MOSTLY
CLEAR SKIES AS WELL AS DRIER AND COOLER WEATHER. HOWEVER, HIGHS WILL
REMAIN ~5-8 DEGREES ABOVE NORMAL TUESDAY AFTERNOON. LOWS TUESDAY
NIGHT ARE TRENDING MUCH COOLER, DIPPING INTO THE LOW TO MID 30S
ACROSS THE MOUNTAINS AND THE MID 30S TO MID 40S EAST OF THE
MOUNTAINS. HOWEVER, LOWS WILL STILL END UP NEAR NORMAL TO A FEW
DEGREES ABOVE NORMAL.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
AS OF 130 AM EST SUNDAY...
KEY MESSAGES:
1) DRY CONDITIONS LINGER THROUGH WEDNESDAY WITH HIGH TEMPERATURES
NOW TRENDING BELOW NORMAL WEDNESDAY AND THURSDAY
2) A COLD FRONT INCREASES RAIN CHANCES AGAIN ON THURSDAY WITH DRIER
CONDITIONS EXPECTED FRIDAY INTO SATURDAY BEHIND THE FRONT
3) ABOVE NORMAL TEMPERATURES RETURN FRIDAY INTO SATURDAY
THE SOUTHERN PERIPHERY OF DRY HIGH PRESSURE WILL EXTEND ACROSS THE
SOUTHEAST THROUGH LATE WEDNESDAY BEFORE ANOTHER COLD FRONT TRACKS
ACROSS THE FORECAST AREA ON THURSDAY. MODEL GUIDANCE HAS BEEN
INCONSISTENT REGARDING HOW MUCH MOISTURE WILL BE ASSOCIATED WITH
THIS FRONT, SO CONFIDENCE ON POPS REMAINS LOW WEDNESDAY NIGHT INTO
THURSDAY. THE LATEST CANADIAN AND ECMWF SHOW RAIN OVER THE ENTIRE
FORECAST AREA WITH THE FRONT WHILE THE GFS IS MUCH DRIER AND HAS
RAIN CONFINED TO THE FAR WESTERN PORTIONS OF THE FORECAST AREA.
THUS, CAPPED POPS TO CHANCE FOR NOW. HIGHS ON WEDNESDAY WILL END UP
A FEW DEGREES BELOW NORMAL THANKS TO GRADUALLY INCREASING CLOUD
COVER AND COLD AIR DAMMING. HIGHS ON THURSDAY WILL END UP SLIGHTLY
WARMER AS THE COLD FRONT GRADUALLY ERODES THE WEDGE BUT TEMPS WILL
STILL END UP NEAR NORMAL TO A FEW DEGREES BELOW NORMAL THANKS TO
RAIN AND SOME LINGERING CLOUD COVER. DRY HIGH PRESSURE WILL BUILD IN
FROM THE WEST BEHIND THE FRONT FRIDAY INTO SATURDAY LEADING TO DRIER
AND WARMER CONDITIONS. HIGHS ON BOTH FRIDAY AND SATURDAY SHOULD END
UP SEVERAL DEGREES ABOVE NORMAL THANKS TO MOSTLY SUNNY SKIES. LOWS
WILL REMAIN A FEW TO SEVERAL DEGREES ABOVE CLIMO THROUGH THE LONG
TERM
AVIATION /09Z SUNDAY THROUGH THURSDAY/
AT KCLT AND ELSEWHERE: A BROAD AREA OF STRATUS OR STRATOCU
HAS DEVELOPED AT LOW VFR LEVEL WITHIN WARM UPGLIDE REGIME OVER
COLD-AIR DAMMING WEDGE. DEWPOINT DEPRESSIONS ARE LARGE AT 06Z AND
VSBY RESTRICTIONS ARE NOT ANTICIPATED THRU DAYBREAK. MVFR STRATUS
SHOULD ADVECT INTO THE AREA FROM THE SOUTH AROUND THAT TIME, WITH
THE LOWER CIGS REACHING KAND AROUND 12Z AND CONTINUING NORTH FROM
THERE. PRECIP CHANCES FOLLOW, AND FURTHER LOWERING IS ANTICIPATED
AFTER PRECIP BEGINS, WITH IFR CIGS LIKELY AT ALL TERMINALS IN THE
LATE AFTERNOON TO EVENING, ALONG WITH AT LEAST MVFR VSBY POSSIBLE
DURING PRECIP. THESE RESTRICTIONS WILL CONTINUE INTO MON MORNING,
WITH VSBY ALSO LIKELY TO FALL TO IFR OVERNIGHT. WINDS IN TYPICAL
WEDGE CONFIGURATION, MAINLY NE AT ALL SITES EXCEPT KAVL WHICH
WILL REMAIN SE TO SSE. LLWS NOT OUT OF THE QUESTION EITHER THIS
MORNING OR TONIGHT, BUT SPEEDS MOST LIKELY WILL BE TOO LIGHT SO
MENTION NOT MADE.
OUTLOOK: A WEDGE REGIME WILL PERSIST UNTIL A COLD FRONT PASSES
MONDAY. DRY AND MOSTLY VFR WEATHER EXPECTED TUE-WED. MOISTURE
BEGINS TO RETURN FROM THE SOUTHWEST ON THURSDAY.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...AR
NEAR TERM...WIMBERLEY
SHORT TERM...AR
LONG TERM...AR
AVIATION...WIMBERLEY
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