017
FXUS62 KGSP 221054
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
654 AM EDT SAT AUG 22 2026
WHAT HAS CHANGED
A SLIGHT INCREASE IN POPS TODAY, AND A MARGINAL RISK OF SEVERE
THUNDERSTORMS HAS BEEN ADDED TO MOST OF THE NC MOUNTAINS THIS
AFTERNOON AND EVENING.
AVIATION DISCUSSION WAS UPDATED FOR THE 12Z TAFS.
KEY MESSAGES
1. ISOLATED THUNDERSTORMS POSSIBLE THIS AFTERNOON THROUGH EARLY
EVENING, MAINLY NEAR THE BLUE RIDGE ESCARPMENT AND IN THE MOUNTAINS
NEAR THE TENNESSEE BORDER LATER THIS EVENING. A FEW STORMS MAY
BECOME SEVERE, WITH DAMAGING WIND GUSTS BEING THE MAIN THREAT.
2. DRIER WEATHER RETURNS SUNDAY THROUGH EARLY NEXT WEEK, WITH
AFTERNOON SHOWER AND THUNDERSTORM CHANCES RETURNING BY MIDWEEK.
DISCUSSION
KEY MESSAGE 1: ISOLATED THUNDERSTORMS POSSIBLE THIS AFTERNOON THROUGH
EARLY EVENING, MAINLY NEAR THE BLUE RIDGE ESCARPMENT AND IN THE
MOUNTAINS NEAR THE TENNESSEE BORDER LATER THIS EVENING. A FEW STORMS
MAY BECOME SEVERE, WITH DAMAGING WIND GUSTS BEING THE MAIN THREAT.
CONVECTION HAS FINALLY WANED, LEAVING PLENTY OF STRATUS THAT WILL
LINGER THRU MID TO LATE MORNING. A DIGGING UPPER TROUGH OVER THE
WESTERN GREAT LAKES INTO THE OHIO VALLEY WILL INCREASE NWLY BULK
SHEAR ACROSS THE OHIO VALLEY AND INTO THE SOUTHERN APPALACHIANS
LATER TODAY. DRIER AIR IS STARTING TO FILTER IN BEHIND YESTERDAY'S
FRONTAL PASSAGE, BUT ENOUGH MOISTURE WILL REMAIN TO ALLOW FOR AT
LEAST ISOLATED THUNDERSTORMS TO DEVELOP THIS AFTERNOON ACROSS
THE MOUNTAINS AND ADJACENT FOOTHILLS. THE LATEST CAMS ARE NOT
TOO EXCITED ABOUT COVERAGE OR INTENSITY WITH THIS ACTIVITY. THE
BIGGER CONCERN MAY BE WITH ANYTHING THAT DEVELOPS UPSTREAM OVER
THE OHIO VALLEY. SOME OF THE CAMS SHOW LOOSELY ORGANIZED MULTICELL
CLUSTERS DIVING SE TOWARD THE NC MOUNTAINS. THERE IS SOME CONCERN
THAT SOME OF THESE STORMS COULD BE STRONG TO SEVERE AS THEY CROSS
THE TN/NC LINE THIS EVENING. THE NEW DAY 1 CONVECTIVE OUTLOOK
HAS EXPANDED A MARGINAL RISK INTO THE NC MOUNTAINS TO ACCOUNT
FOR THIS POTENTIAL. WHETHER ANY OF THIS WOULD SURVIVE EAST OF THE
MOUNTAINS REMAINS IN DOUBT. CIN SHOULD BE INCREASING THIS EVENING,
AND MUCAPE WILL BE DECREASING. DESPITE THIS, SOME OF THE CAMS,
ALONG WITH THE ECMWF AND CANADIAN, SUGGEST SOME ACTIVITY MAY TRACK
INTO THE NC NW PIEDMONT LATE EVENING. THE NBM POPS DO NOT REFLECT
THIS, AND ARE ON THE LOW SIDE OVERALL. OTHERWISE, IT SHOULD BE A
TYPICAL LATE AUGUST DAY WITH HIGHS NEAR NORMAL WITH MUGGY DEWPTS.
KEY MESSAGE 2: DRIER WEATHER RETURNS SUNDAY THROUGH EARLY NEXT WEEK,
WITH AFTERNOON SHOWER AND THUNDERSTORM CHANCES RETURNING BY MIDWEEK.
AN UPPER LOW CLOSES OFF OVER THE GREAT LAKES SUNDAY, THEN WOBBLES
SLOWLY EAST INTO QUEBEC THRU THE FIRST HALF OF NEXT WEEK. THIS
WILL RESULT IN A DEEP TROUGH AXIS PERSISTING ROUGHLY ALONG THE
APPALACHIANS TO THE EAST COAST, WHICH WILL PUT THE FORECAST AREA
IN A DRIER W/NW FLOW PATTERN. DEWPTS SHOULD DIP INTO THE 50S TO
LOWER 60S SUNDAY AND MONDAY, COMBINED WITH TEMPS IN THE 80S WILL
BE A REFRESHING BREAK FROM THE HOT, HUMID WEATHER WE'VE BEEN
EXPERIENCING. THE PATTERN WILL GRADUALLY MODIFY, WITH ANOTHER
TROUGH DIGGING INTO THE MIDWEST AND ALLOWING RETURN FLOW TO BRING
MOISTURE BACK INTO THE REGION BY THE MIDDLE OF NEXT WEEK. SOME
DIURNAL CONVECTION MAY RETURN TUESDAY AND WEDNESDAY, THEN MORE
SUBSTANTIAL COVERAGE OF CONVECTIVE ACTIVITY ON THURSDAY WITH AN
APPROACHING COLD FRONT FROM THE NW. TEMPS WILL REMAIN NEAR NORMAL
THRU THE WEEK, BUT HUMIDITY WILL GRADUALLY INCREASE, WITH DEWPTS
BACK INTO THE UPPER 60S TO LOWER 70S BY THURSDAY.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
AT KCLT AND ELSEWHERE: IFR TO MVFR STRATUS SHOULD START TO SCATTER
OUT AND LIFT LATER THIS MORNING TO VFR BY AROUND MIDDAY AT ALL
SITES. MOST RESTRICTIONS ARE DUE TO CIGS RATHER THAN VSBY THIS
MORNING. ISOLATED TO WIDELY SCATTERED CONVECTION MAY DEVELOP AGAIN
THIS AFTN, MAINLY ALONG THE ESCARPMENT. LATEST GUIDANCE HAS TRENDED
A LITTLE HIGHER IN COVERAGE IN THE NC FOOTHILLS AND NW PIEDMONT,
SO HAVE ADDED A PROB30 TO KHKY. OTHERWISE, ONLY KGSP AND KGMU HAVE
HIGH ENOUGH CONFIDENCE FOR PROB30S FOR SOME TSRA IN THE ROUGHLY
20-24Z TIME FRAME. THERE IS ABOUT A 20% CHANCE OF SOME TS AROUND
KCLT, SO NOT HIGH ENOUGH TO MENTION IN THE TAF AT THIS TIME. DRIER
AIR FILTERS IN TONIGHT, WHICH SHOULD KEEP MOST FOG AND STRATUS
POTENTIAL TO THE MOUNTAIN VALLEYS. WINDS WILL BE LIGHT THRU THE
PERIOD, MAINLY OUT OF THE SW EAST OF THE MOUNTAINS AND NNW AT KAVL.
OUTLOOK: NO SIGNIFICANT CHANCE OF CONVECTION UNTIL WEDNESDAY.
MOUNTAIN VALLEY FOG AND LOW STRATUS IS POSSIBLE EACH MORNING.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
ARK
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