492
FXUS62 KGSP 100606
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
106 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 TODAY/
AS OF 1250 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, BUT SFC
DEWPOINT DEPRESSIONS REMAIN 15 TO 20 DEGREES AND NOT MUCH IF ANY IS
REACHING THE SURFACE YET. THE LOWERING CLOUDS WILL HELP. POP TRENDS
FROM PREVIOUS FCST CYCLE STILL LOOK ON TRACK FOR THIS MORNING,
INITIALLY ARRIVING FROM THE SOUTH BUT EXPANDING OUT FROM NEAR THE
SOUTH-FACING BLUE RIDGE ESCARPMENT AS WELL. NONETHELESS, WILL BE
REVISING THE NUMBERS FOR THE 330 AM PACKAGE. EVAPORATIVE COOLING
FROM PRECIP AND PERSISTENT CLOUD COVER WILL MAKE FOR A CLASSIC FALL
WEDGE WITH HIGHS HELD BELOW NORMAL, MOSTLY IN THE 50S IN AREAS NW
OF I-85, EXCEPTING THE LOWER MOUNTAIN VALLEYS NEAR THE TN BORDER.
SHORT TERM /TONIGHT 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 116 PM EDT SATURDAY: AS SURFACE HIGH PRESSURE CONTINUES TO
WORK ITS WAY EAST UNDER A PROGRESSIVE UPPER PATTERN, WE'LL GRADUALLY
REVERT TO A NORTHEAST-FLOW CAD-LIKE PATTERN ON TUESDAY AND
WEDNESDAY. PROFILES LOOK TO REMAIN DRY ENOUGH, HOWEVER, AND
ISENTROPIC ASCENT WEAK ENOUGH, TO PRECLUDE THE USUAL DREARY WEATHER
ASSOCIATED WITH ESTABLISHED COLD-AIR DAMMING. INSTEAD, EXPECT
ENOUGH AFTERNOON MIXING FOR SCATTERED CLOUD COVER ONLY. TEMPERATURES
WILL CLIMB INTO THE 70S ON TUESDAY, BUT BY WEDNESDAY, THE INTRUSION
OF COOLER AIR FROM THE NORTHEAST WILL RESULT IN AFTERNOON HIGHS IN
THE MID 60S.
WEDNESDAY NIGHT OR EARLY THURSDAY, A COLD FRONT IS STILL EXPECTED TO
MAKE TRACKS ACROSS THE AREA. THIS WILL RESULT IN A BRIEF PERIOD OF
SHOWERS FROM WEDNESDAY NIGHT THROUGH THE FIRST HALF OF THE DAY
THURSDAY. SYNOPTIC FORCING WILL BE MODEST AT BEST, AND WITH A WEAK
FRONTAL CIRCULATION GIVEN HOW FAR REMOVED THE PARENT LOW WILL BE.
BEHIND THE FRONT, ROBUST HIGH PRESSURE WILL BUILD IN FROM THE
CENTRAL U.S. THIS WILL SOMEWHAT DECREASE TEMPERATURES, BUT THE
EFFECT WILL BE MORE NOTICEABLE AT NIGHT - WITH THURSDAY AND FRIDAY
NIGHT'S LOWS FALLING INTO THE 40S OR EVEN UPPER 30S IN SOME SPOTS -
THAN DURING THE DAY, WHEN SOLAR HEATING AND WEAK DOWNSLOPE FLOW
COULD OFFSET ANY CAA-INDUCED COOLING.
AVIATION /06Z 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...MPR
AVIATION...WIMBERLEY
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page