185
FXUS62 KGSP 101751
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1251 PM 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 1116 AM SUNDAY: EVOLUTION SEEMS TO BE TAKING PLACE FASTER
THAN EXPECTED AND THE ISENTROPIC LIFT MORE PRODUCTIVE, SO PRECIP
PROBS WILL BE RAISED WHILE THE TIMING MOVED UP.
OTHERWISE...THE PREVIOUS THOUGHTS ARE STILL VALID. A DAMMING
SFC HIGH EXTENDS ALONG THE EAST COAST FROM NC TO NEW ENGLAND,
NOW CENTERED OFFSHORE. MATURE SFC LOW IS MOVING FROM NEBRASKA TO
IOWA, WITH COLD FRONT TRAILING INTO THE LOWER MS VALLEY. MOIST
UPGLIDE CONTINUES TO INCREASE OVER THE SFC WEDGE WITH WARM CONVEYOR
BELT. PERSISTENT CLOUD COVER AND IN PARTICULAR THE ONSET OF DIABATIC
COOLING SHOULD MAKE FOR A PARTLY NONDIURNAL CURVE IN TEMPS TODAY,
WITH TEMPS CONTINUING TO COOL AFTER ONSET OF PRECIP INTO THE
AFTERNOON, BUT POSSIBLY REBOUNDING SLIGHTLY LATE IN THE DAY. 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 /18Z SUNDAY THROUGH FRIDAY/
AT KCLT AND ELSEWHERE: SEEING THE EFFECTS OF THE COLD AIR DAMMING
WEDGE SLOWLY TAKE OVER ACROSS THE REGION EARLY THIS AFTERNOON, WITH
LIGHT PRECIP AND LOW CLOUDS EXPANDING NORTHEASTWARD TO ENCOMPASS
MOST OF THE REGION. THIS DEVELOPMENT SHOULD ESTABLISH THE NE
WIND SLOWLY BACKING TO MORE NORTHARLY. KCLT MAY BE IN-AND-OUT OF
THE MVFR OVER THE NEXT FEW HOURS, BUT THE REST OF THE TERMINALS
SHOULD BE IN THE CEILING RESTRICTION FROM NOW THROUGH THE PASSAGE
OF THE COLD FRONT MONDAY MORNING. THE CEILING/VIS IS EXPECTED
TO DROP DOWN THROUGH MVFR AND INTO IFR AFTER IT GETS DARK, WITH
IFR/LIFR PREVAILING THROUGH AT LEAST DAYBREAK MONDAY AS LOW LEVEL
SOUTHERLY MOIST UPGLIDE CONTINUES ABOVE THE SHALLOW NORTHEASTERLY
SFC LAYER. THE WINDS ALOFT DO NOT APPEAR TO BE STRONG ENOUGH FOR
LLWS AT THIS POINT. MODEL GUIDANCE SHOWS THE FRONTAL ZONE MOVING
THROUGH IN THE MIDDLE OF THE DAY, WHICH SUGGESTS THAT WE SHOULD
BE ABLE TO STRIP OUT THE LOWEST CLOUD DECK, BUT WILL NOT SCATTER
OUT CLOUDS AS QUICKLY AS GUIDANCE DOES TOWARD THE END OF THE
PERIOD. EXPECT IT WILL TAKE A FEW MORE HOURS TO GET THE DOWNSLOPE
BEHIND THE FRONT TO DO THE TRICK. WIND WILL BE TRICKY MONDAY
MORNING, WITH A SHIFT TO SW IMMEDIATELY AHEAD OF THE BOUNDARY,
AND THEN MORE SW AFTER ITS PASSAGE.
OUTLOOK: 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...PM/WIMBERLEY
SHORT TERM...AR
LONG TERM...AR
AVIATION...PM
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