959
FXUS62 KGSP 271108
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
708 AM EDT TUE MAY 27 2025
SYNOPSIS
COOL HIGH PRESSURE MOVING ACROSS THE GREAT LAKES AND NEW YORK WILL
CAUSE UNSEASONABLY COOL WEATHER TODAY FOR THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA WITH A BRIEF WEDGE PATTERN. OCCASIONAL SHOWERS
WILL FOLLOW FROM WEST TO EAST ALONG A STATIONARY FRONT LOCATED JUST
SOUTH OF OUR AREA THROUGH MID WEEK. A SLOW MOVING WEAK COLD FRONT
WILL DRIFT ACROSS OUR REGION THURSDAY AND FRIDAY BRINGING IN DRIER
WEATHER FOR THE WEEKEND.
NEAR TERM /THROUGH TONIGHT/
AS OF 3:25 AM EDT TUESDAY: A COOL-AIR DAMMING WEDGE REMAINS IN
PLACE ACROSS THE WESTERN CAROLINAS AS A BROAD AREA OF LIGHT TO
MODERATE PRECIP CONTINUES TO SPREAD OVER OUR CWA FROM WEST TO
EAST. THESE SHOWERS ARE EXPECTED TO CONTINUE WELL INTO THE MORNING
AS ISENTROPIC UPGLIDE REMAINS ROBUST AND LOW-LEVEL WINDS VEER IN
RESPONSE TO A WEAK LOW MOVING UP THE WEST SIDE OF THE APPALACHIANS.
THIS SET UP SHOULD HELP LOCK IN THE WEDGE FOR THE BULK OF THE NEAR-
TERM PERIOD. LOWS THIS MORNING SHOULD BE ROUGHLY 5 DEGREES BELOW
NORMAL.
OTHERWISE, WE CAN EXPECT MOSTLY RAIN AND/OR DRIZZLE THROUGH THE
MORNING. MOST OF THE LATEST NEAR-TERM GUIDANCE DEPICTS A REDUC-
TION IN PRECIP COVERAGE GENERALLY FROM WEST TO EAST DURING THE
AFTERNOON AND INTO THE EVENING. IN ADDITION, ALTHOUGH WE EXPECT
TO HAVE LITTLE IF ANY SFC-BASED INSTABILITY ACROSS OUR CWA TODAY,
WE COULD SEE A FEW ISOLATED, ELEVATED THUNDERSTORMS THIS AFTERNOON/
EVENING AS SOME AMOUNT OF ELEVATED CAPE WILL LIKELY BE PRESENT,
ESPECIALLY OVER OUR SOUTHERN ZONES. ALSO, MOST OF THE NEAR-TERM
GUIDANCE HAS PRECIP COVERAGE INCREASING AGAIN FROM THE WEST LATER
THIS EVENING AND THEN TAPERING OFF TOWARDS THE END OF THE PERIOD
EARLY WEDNESDAY MORNING. REGARDLESS, IT'S GONNA BE A WET AND CLOUDY
TUESDAY WITH HIGH TEMPS ROUGHLY 20 DEGREES BELOW NORMAL OUTSIDE THE
MTNS. AS FOR THE FLOODING POTENTIAL, WPC DOES HAVE OUR AREA UNDER
A MARGINAL RISK FOR EXCESSIVE RAINFALL FOR TODAY/TONIGHT. THIS
SUGGESTS THAT ISOLATED FLASH FLOODING WILL BE POSSIBLE, MOSTLY
WHERE ANY HEAVIER SHOWERS TRAIN OVER THE SAME LOCATIONS.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
AS OF 250 AM TUESDAY: WSW FLOW ALOFT WILL PERSIST ACROSS THE REGION
THROUGH THE SHORT TERM...AS UPPER LOW REMAINS MORE OR LESS STATIONARY
ACROSS THE UPPER MISS VALLEY...WITH A COUPLE OF SHORT WAVE TROUGHS
PASSING S=> E OF THE CENTER. ONE OF THESE WILL BE LIFTING NORTH OF
OUR CWA AT THE START OF THE PERIOD...WITH ATTENDANT WAVE DEVELOPING
ALONG THE BAROCLINIC ZONE NEAR THE SOUTHEAST AND MID-ATLANTIC COAST
DRAGGING DEEPER MOISTURE AWAY FROM OUR FORECAST AREA. THIS WILL
RESULT IN A LULL IN ANY SUBSTANTIAL PRECIP CHANCES ACROSS OUR AREA
UNTIL AT LEAST WED AFTERNOON. HAVING SAID THAT, WITH SYNOPTIC
SURFACE HIGH PRESSURE FORECAST TO BE CENTERED SEVERAL HUNDRED MILES
OFF THE MID-ATLANTIC COAST AND PERSISTENT WESTERLY FLOW CONTINUING,
REMNANT COLD AIR DAMMING SHOULD ERODE ACROSS MUCH OF THE AREA BY
LATE AFTERNOON...WITH MODERATE INSTABILITY EXPECTED TO BE REALIZED.
ISOLATED/WIDELY SCATTERED CONVECTION SHOULD DEVELOP DURING THE
AFTERNOON...GENERALLY FAVORING THE MOUNTAINS AND FOOTHILLS. MAX
TEMPS SHOULD BE MUCH CLOSER TO NORMAL, BUT ARE STILL EXPECTED TO
FALL A COUPLE OF DEGREES SHY OF CLIMO.
A RELATIVELY QUIET AND SEASONABLY WARM WED NIGHT IS EXPECTED TO BE
FOLLOWED BY AN UPTICK IN SHOWER AND THUNDERSTORM CHANCES ON
THURSDAY, AS HEIGHTS BEGIN TO FALL NORTHWEST OF THE AREA, WITH UPPER
LOW BEGINNING TO PUSH OUT TOWARD THE OHIO VALLEY. THIS IS FORECAST TO
RESULT IN ACTIVATION OF THE BAROCLINIC ZONE DRAPED ACROSS THE
REGION, WHILE MODERATELY UNSTABLE CONDITIONS APPEAR LIKELY DURING
THE AFTERNOON UNDER SEASONABLY WARM CONDITIONS. 50-60 POPS ARE
WARRANTED ACROSS THE ENTIRE FORECAST AREA BY AFTERNOON/EVENING. WITH
BETTER INSTABILITY/POTENTIAL FOR STRONGER UPDRAFTS AND INCREASED
OVERALL CONVECTIVE COVERAGE, THERE MAY BE AN UPTICK IN THE POTENTIAL
FOR ISOLATED SEVERE STORMS AND LOCALLY EXCESSIVE RAINFALL, BUT THOSE
THREATS APPEAR MARGINAL-AT-WORST AT THIS JUNCTURE.
LONG TERM /FRIDAY THROUGH MONDAY/
AS OF 315 AM TUESDAY: ACTIVE WEATHER IS EXPECTED TO CONTINUE INTO
THE EARLY PART OF THE EXTENDED...AS RATHER STRONG UPPER LOW CENTERED
OVER THE OHIO VALLEY AT START OF THE PERIOD IS FORECAST TO OPEN UP
AS IT MOVES INTO THE MID-ATLANTIC BY FRIDAY NIGHT. ATTENDANT TROUGH
AND COLD FRONTAL ZONE ARE FORECAST TO SWEEP ACROSS OUR FORECAST AREA
ON FRIDAY...WITH POPS RAMPING UP AHEAD OF THE FRONT LATE THU NIGHT
INTO FRIDAY...PEAKING AT AROUND 70% ACROSS MUCH OF THE AREA DURING
THE DAYLIGHT HOURS. WITH MID-LEVEL FLOW ACCELERATING IN RESPONSE TO
INCREASING HEIGHT GRADIENT SOUTHEAST OF THE LOW, FORECAST WIND
SHEAR PARAMETERS ARE MORE THAN ADEQUATE FOR ORGANIZED CONVECTION ON
FRIDAY...SO ANY SEVERE STORM POTENTIAL WILL DEPEND UPON THE
MAGNITUDE OF INSTABILITY...WHICH WILL DEPEND AT LEAST IN PART ON THE
TIME OF DAY THAT THE FRONT SWEEPS ACROSS THE AREA. THIS REMAINS
SOMEWHAT UP IN THE AIR...AS QUESTIONS REGARDING THE TIMING OF THE
UPPER LOW WILL PERSIST FOR ANOTHER DAY OR TWO. NEVERTHELESS, THERE
IS SOME POTENTIAL FOR SEVERE STORMS.
CONVECTION SHOULD CLEAR THE AREA LATE FRI OR DURING THE EARLY PART
OF FRI NIGHT, WITH NW FLOW/UPSLOPE RAIN SHOWERS REMAINING A
POSSIBILITY ACROSS THE MOUNTAINS INTO SATURDAY. MUCH OF THE AREA
SHOULD OTHERWISE BE DRY SAT/SAT NIGHT. ANOTHER SHORT WAVE DIVING
INTO THE BASE OF THE TROUGH ACROSS THE EAST ON SUNDAY COULD RESULT
IN A BAND OF SHOWERS MOVING ACROSS AT LEAST WESTERN AREAS DURING THE
AFTERNOON...WARRANTING MAINLY 20-30% POPS. OTHER THAN PERHAPS SOME
ISOLATED DIURNALLY-DRIVEN MOUNTAIN SHOWERS ON MONDAY, THE REMAINDER
OF THE EXTENDED IS FORECAST TO BE DRY AND SEASONABLY WARM.
AVIATION /11Z TUESDAY THROUGH SATURDAY/
AT KCLT AND ELSEWHERE: EXPECT COOL-AIR DAMMING REGIME TO KEEP
IFR CIGS AND MVFR TO IFR VISBY IN PLACE ACROSS OUR AREA FOR MOST
OF THE 12Z TAF PERIOD. WE'VE CURRENTLY GOT WIDESPREAD SHOWERS
MOVING OVER THE AREA FROM THE WEST. I HAVE TEMPOS FOR HEAVIER
SHOWERS OVER THE FIRST FEW HRS OF THE PERIOD WITH IFR TO LIFR
RESTRICTIONS. PER THE LATEST CAM GUIDANCE, I STILL EXPECT A LULL
IN PRECIP ACTIVITY/COVERAGE DURING THE AFTERNOON, HOWEVER CIGS
ARE NOT LIKELY TO IMPROVE MUCH THRU THE DAY. EXPECT ANOTHER ROUND
OF MORE WIDESPREAD PRECIP BY THE LATE EVENING THAT WILL LIKELY
CONTINUE THRU ROUGHLY 06 TO 08Z WED MORNING. WE COULD SEE SOME
ELEVATED INSTABILITY DEVELOP AROUND THE PERIPHERY OF THE WEDGE
TODAY, BUT I THINK ANY THUNDER THEY MIGHT OCCUR IN OUR FCST AREA
WILL BE TOO ISOLATED TO MENTION IN THE TAFS. OTHERWISE, WINDS WILL
REMAIN NELY OUTSIDE THE MTNS BECOMING MORE NLY LATER IN THE PERIOD
WITH SOME SPORADIC LOW-END GUSTS POSSIBLE ESPECIALLY AT THE UPSTATE
TERMINALS THIS AFTN. AT KAVL, WINDS WILL FAVOR A SLY TO SELY DIREC-
TION THRU THE PERIOD.
OUTLOOK: SHOWER AND THUNDERSTORM CHANCES AND ASSOCIATED RESTRICTIONS
CONTINUE THRU THE WEEK WITH DRIER CONDITIONS EXPECTED BY THE START OF
THE WEEKEND.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...JDL
NEAR TERM...JPT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...JPT
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