647
FXUS62 KGSP 080553
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
153 AM EDT FRI AUG 8 2025
SYNOPSIS
COLD AIR DAMMING GRADUALLY WEAKENS OVER THE NEXT FEW DAYS. HIGH
TEMPERATURES REMAIN BELOW NORMAL THROUGH THE WEEKEND BEFORE WARMING
UP TO NEAR NORMAL INTO NEXT WEEK. ISOLATED TO SCATTERED AFTERNOON
SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH DAY.
NEAR TERM /THROUGH TONIGHT/
AS OF 150 AM EDT FRIDAY: A WEAK UPPER LOW AND SHORT WAVE START OUT
OVER THE AREA AND MOVE EAST OF THE AREA DURING THE DAY TODAY, ALONG
WITH THE WEAK TROUGH OVER THE EAST COAST. HEIGHTS DON'T RISE
SIGNIFICANTLY AS THE AREA REMAINS IN WEAK NORTHERLY FLOW BETWEEN THE
DEPARTING TROUGH AND A RIDGE TO OUR WEST. AT THE SURFACE, HIGH
PRESSURE REMAINS RIDGED DOWN THE EAST COAST IN A COLD AIR DAMMING
FASHION. DEEP LAYER DRYING TAKES PLACE THROUGH THE PERIOD AS DRIER
AIR MOVES IN FROM THE NORTH. HOWEVER, LOW LEVEL MOISTURE REMAINS
QUITE HIGH IN THE LOW LEVEL EASTERLY FLOW. THIS WILL KEEP LOW CLOUDS
AND PATCHY RAIN/DRIZZLE IN PLACE EARLY THIS MORNING. THE LOW CLOUDS
LIFT AND RAIN/DRIZZLE END THROUGH THE MORNING AS MIXING BEGINS. THE
CLOUDS EVEN SCATTER OUR ACROSS MUCH OF THE AREA FOR THE AFTERNOON.
VERY LITTLE IN THE WAY OF INSTABILITY SEEN TODAY, EXCEPT FOR THE
MOUNTAINS. CAMS LIMIT ANY DIURNAL CONVECTION TO THOSE AREAS, SO HAVE
FOLLOWED THAT TREND AS WELL. HIGHS SHOULD BE WARMER TODAY WITH MORE
AFTERNOON SUN, BUT UNDERCUT MODEL BLEND SLIGHTLY GIVEN THE MORNING
CLOUDS KEEPING THEM BELOW NORMAL.
DIURNAL CONVECTION ENDS ACROSS THE MOUNTAINS EARLY IN THE EVENING,
BUT A SPOTTY SHOWER WILL BE POSSIBLE OVERNIGHT. EXPECT MORE LOW
CLOUDS TO DEVELOP OVERNIGHT AS LOW LEVEL MOISTURE RETURNS ON THE
EASTERLY FLOW. LOWS WILL BE A LITTLE BELOW NORMAL.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
KEY MESSAGES:
1) COLD AIR DAMMING WEAKENS ALLOWING WARMER TEMPERATURES TO BUILD IN.
2) ISOLATED TO SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS RETURN
BY THE END OF THE WEEKEND.
AS OF 125 AM EDT FRIDAY: NOT MUCH CHANGE HAS OCCURRED IN THE SHORT
TERM. PICKING UP ON SATURDAY, SURFACE HIGH PRESSURE REMAINS THE
DOMINANT FEATURE ACROSS THE NORTHEAST, LOCKING IN THIS CONTINUED
COLD AIR DAMMING SCENARIO THROUGH THE FORECAST PERIOD. SYNOPTICALLY,
A RIDGE PERSISTS OVER THE EASTERN CONUS WHILE AN UPPER TROUGH STARTS
TO DIP INTO THE CENTRAL REGION OF THE U.S. SATURDAY LOOKS TO REMAIN
RELATIVELY DRY AS GUIDANCE KEEPS A RELATIVELY DRY UPPER PROFILE AND
NOT A WHOLE LOT OF MOISTURE TO WORK WITH FOR SHOWERS. FOR THIS, POPS
STAY MOSTLY UNMENTIONABLE WITH A FEW LOCATIONS IN THE SOUTHERN ZONES
BARELY IN THE SLIGHT CHANCE (15-20%) RANGE. AS THE AXIS OF THE
SURFACE HIGH WOBBLES MORE EASTWARD, MOISTURE ADVECTION INCREASES BY
SUNDAY AS SURFACE WINDS TURN EASTERLY/SOUTHEASTERLY. FROM THIS,
GUIDANCE INCREASE PWATS INTO AND ABOVE THE 2 INCH MARK EVERYWHERE
EAST OF THE NC MOUNTAINS. WHILE FLOW ALOFT REMAINS WEAK AND
INSTABILITY SHOULD BE IN THE LOWER RANGE, THE ADDED MOISTURE INTO
THE AREA INCREASES POP CHANCES (30-55%) ON SUNDAY WITH MORE
DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS. TEMPERATURES FOR THE
WEEKEND KEEP TO THE LOW TO MID 80S AS THE WEAKENING CAD PERSISTS.
LONG TERM /MONDAY THROUGH THURSDAY/
KEY MESSAGES
1) TEMPERATURES WARM AND RETURN TO NORMAL AUGUST CONDITIONS BY MID-
WEEK.
2) AFTERNOON SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH DAY THROUGH
THE PERIOD.
AS OF 115 AM EDT FRIDAY: THE EXTENDED PERIOD LOOKS TO BE RATHER
UNEVENTFUL AS WELL. BIG SHOCKER BUT THE REGION REMAINS UNDER THE
INFLUENCE OF HIGH PRESSURE, ONE AREA OFF TO THE WEST AND THE BERMUDA
HIGH TO THE EAST. DEPENDING ON HOW MUCH THE WESTERN HIGH AMPLIFIES
AND CONTRACTS DURING THE WEEK WILL DETERMINE WHERE THE WEST FRINGE
OF THE BERMUDA HIGH SETS UP. AS A CONTINUED STREAM OF MOISTURE STAYS
PUT, DAILY SHOWER AND THUNDERSTORM CHANCES ALSO REMAIN. POPS VARY A
BIT BUT REMAIN AT LEAST ABOVE CHANCE (50-65%) DURING THE DAYTIME
HOURS THROUGH AT LEAST MIDWEEK. AS USUAL, THE HIGHER CHANCES ARE
OVER THE MOUNTAINS. TEMPERATURES CONTINUE TO SLOWLY INCREASE BACK
TOWARD THE NORMAL RANGE THROUGH THE PERIOD.
AVIATION /06Z FRIDAY THROUGH TUESDAY/
AT KCLT AND ELSEWHERE: DECK OF LOW STRATUS WILL CONTINUE TO
HANG OUT ACROSS THE AREA THROUGH THE OVERNIGHT AND FIRST HALF
OF FRIDAY. GUIDANCE TRIES TO LIFT THIS DECK AND SCATTER IT OUT
LATER FRIDAY AFTERNOON AND EVENING. NOT VERY CONFIDENT IN THIS AS
GUIDANCE HAS NOT HAD A GOOD HANDLE ON THE PATTERN RECENTLY. MVFR
CIGS ARE EXPECTED TO BE WIDESPREAD BY THE OVERNIGHT HOURS THROUGH AT
LEAST DAYBREAK. VFR MAY RETURN FRIDAY AFTERNOON AND THAT IS WHAT'S
CURRENTLY IN THE TAF, BUT IS SUBJECT TO CHANGE. NORTHEASTERLY WINDS
EXPECTED THROUGH THE PERIOD AT 5-10 KTS, WITH SLIGHTLY LOWER VALUES
OVERNIGHT. KAVL WILL MAINTAIN A SOUTH TO SOUTHEASTERLY COMPONENT
THROUGH THE PERIOD. CAN'T RULE OUT AN OCCASIONAL LOW-END GUST
DURING PEAK HEATING.
OUTLOOK: THE WEDGE REMAINS IN PLACE THROUGH AT LEAST THE FIRST
HALF OF THE WEEKEND, KEEPING PERIODIC RESTRICTIONS AND -RA CHANCES
AROUND. DAILY DIURNAL SHOWERS AND THUNDERSTORMS CAN BE EXPECTED,
MAINLY ACROSS THE MOUNTAINS THE REST OF THIS WEEK INTO THE WEEKEND.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...CP
NEAR TERM...RWH
SHORT TERM...CP
LONG TERM...CP
AVIATION...RWH
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