006
FXUS62 KGSP 171036
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
636 AM EDT WED SEP 17 2025
SYNOPSIS
DRIER CONDITIONS EXPECTED AS A COASTAL LOW LIFTS NORTHWARD OVER THE
MID-ATLANTIC TODAY BEFORE PULLING AWAY FROM THE EAST COAST THURSDAY.
WEAK HIGH PRESSURE BUILDS OVER THE SOUTHEAST THROUGH SATURDAY BEFORE
STRONGER HIGH PRESSURE BUILDS OVER THE REGION LATE THIS WEEKEND INTO
EARLY NEXT WEEK, ALLOWING MOSTLY DRY CONDITIONS TO CONTINUE. A
WARMING TREND STARTS TODAY AND PEAKS ON FRIDAY BEFORE A COOLING
TREND RETURNS BRIEFLY THIS WEEKEND.
NEAR TERM /THROUGH TONIGHT/
AS OF 630 AM WED: MOUNTAIN VALLEY FOG DISSIPATES BY MID MORNING. THE
COASTAL SURFACE LOW, AND THE ASSOCIATED UPPER LOW, MOVE NORTHEAST
AWAY FROM THE AREA TODAY. THERE WILL BE ANOTHER WEAK SHORT WAVE
ROTATING AROUND THE LOW AND NEAR THE AREA AS IT IS DEPARTING. WHILE
SOME MOISTURE LINGERS, THERE WILL BE LITTLE IN THE WAY OF
INSTABILITY DEVELOPING. THE CAM GUIDANCE HINTS AS SOME ISOLATED
SHOWERS DURING THE DAY, BUT THEY DON'T AGREE ON COVERAGE OR
LOCATION. THE MODEL BLEND SHOWS A DRY FORECAST, SO HAVE FOLLOWED
THAT TREND BUT DON'T BE SURPRISED IF AN AFTERNOON SHOWER OR TWO
DEVELOPS. COPIOUS MORNING STRATOCU SHOULD SCATTER OUT BY AFTERNOON.
HIGHS WILL BE AROUND NORMAL.
DRY CONDITIONS CONTINUE TONIGHT WITH CLEARING SKIES. EXPECT ANOTHER
ROUND OF MOUNTAIN VALLEY FOG OVERNIGHT. LOWS WILL BE AROUND NORMAL.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
AS OF 100 AM EDT WEDNESDAY...
KEY MESSAGES:
1) MOSTLY DRY WITH ABOVE NORMAL TEMPERATURES
2) WARMING TREND CONTINUES WITH FRIDAY EXPECTED TO BE THE WARMEST
DAY OF THE WEEK
3) MOSTLY SUNNY EACH DAY AND MOSTLY CLEAR EACH NIGHT
UPPER TROUGHING REMAINS IN PLACE OVER THE SOUTHEAST THROUGH DAYBREAK
FRIDAY BEFORE BRIEF AND WEAK UPPER RIDGING DEVELOPS THE REST OF THE
PERIOD. AT THE SFC, WEAK HIGH PRESSURE SITS OVER THE REGION THROUGH
THE PERIOD KEEPING MOSTLY DRY AND MOSTLY SUNNY/MOSTLY CLEAR
CONDITIONS AROUND. CANNOT ENTIRELY RULE OUT SOME ISOLATED CONVECTION
EACH DAY BUT CONFIDENCE IS VERY LOW AS MOST OF THE HIGH-RES AND
GLOBAL MODEL GUIDANCE SOURCES ARE DRY. THE WARMING TREND CONTINUES,
PEAKING ON FRIDAY WITH HIGHS EAST OF THE MOUNTAINS CLIMBING INTO THE
MID TO UPPER 80S. HIGHS THURSDAY WILL RUN ~5 DEGREES ABOVE NORMAL,
RUNNING ~7-9 DEGREES ABOVE NORMAL FRIDAY. LOWS EACH NIGHT WILL RUN
~2-5 DEGREES ABOVE NORMAL, WITH THE 50S EXPECTED ACROSS THE
MOUNTAINS AND THE THE UPPER 50S TO MID 60S ELSEWHERE.
LONG TERM /SATURDAY THROUGH TUESDAY/
AS OF 130 AM EDT WEDNESDAY...
KEY MESSAGES:
1) TRENDING DRIER THROUGH THE PERIOD BUT WITH SLIGHTLY MORE CLOUDS
2) BREEZY WINDS DEVELOP ON SUNDAY, MAINLY EAST OF THE MOUNTAINS
3) ABOVE NORMAL TEMPERATURES CONTINUE DESPITE SLIGHTLY COOLER
CONDITIONS RETURNING SUNDAY INTO TUESDAY
WEAK UPPER RIDGING REMAINS IN PLACE THROUGH AT LEAST MONDAY BEFORE
UPPER TROUGHING DEVELOPS TOWARDS THE END OF THE PERIOD. AT THE SFC,
A STRONGER AREA OF HIGH PRESSURE NOSES DOWN THE EASTERN US THIS
WEEKEND, LINGERING OVER THE REGION THROUGH MONDAY BEFORE GRADUALLY
WEAKENING TUESDAY. MEANWHILE, A BACKDOOR COLD FRONT APPROACHES OUT
OF THE NORTH SATURDAY BEFORE STALLING ACROSS THE FORECAST AREA
SUNDAY INTO MONDAY. THE FRONT SHOULD PUSH SOUTH OF THE AREA LATE
MONDAY INTO EARLY TUESDAY. THE LATEST NBM IS TRENDING DRIER THROUGH
THE PERIOD BUT GLOBAL MODELS REMAIN INCONSISTENT RUN TO RUN,
FLIPPING BACK AND FORTH BETWEEN WHETHER MOSTLY DRY CONDITIONS WILL
CONTINUE OR WHETHER RAIN CHANCES WILL RETURN. THUS, WENT WITH NBM
POPS FOR NOW AS CONFIDENCE ON CONVECTION RETURNING WITH THE SFC
RIDGE IN PLACE REMAINS LOW. HOPEFULLY GUIDANCE WILL COME INTO BETTER
AGREEMENT AS WE GET CLOSER TO THE WEEKEND. BREEZY WINDS WILL DEVELOP
SUNDAY AFTERNOON, MAINLY EAST OF THE MOUNTAIN, IN ASSOCIATION WITH
THE BACKDOOR COLD FRONT. THE FRONT WILL ALSO KEEP SOME PERIODIC
CLOUD COVER AROUND. WARM CONDITIONS RETURN SATURDAY BUT HIGHS WILL
NOT BE AS WARM AS FRIDAY. REGARDLESS, AFTERNOON TEMPS ON SATURDAY
SHOULD RUN ~6-8 DEGREES ABOVE NORMAL. COOLER HIGHS RETURN SUNDAY
INTO TUESDAY BUT AFTERNOON TEMPS SHOULD STILL END UP A FEW DEGREES
ABOVE NORMAL SUNDAY AND MONDAY, WITH TUESDAY'S HIGHS ENDING UP ~5
DEGREES ABOVE NORMAL. LOWS EACH NIGHT WILL REMAIN ~4-7 DEGREES ABOVE
NORMAL.
AVIATION /12Z WEDNESDAY THROUGH SUNDAY/
AT KCLT AND ELSEWHERE: MOUNTAIN VALLEY FOG WITH IFR TEMPO LIFR AT
KAVL WILL LIFT THROUGH MVFR TO VFR BY 15Z. ELSEWHERE, VFR STRATOCU
AND CIRRUS IN PLACE. EXPECT ALL AREAS TO SEE VFR STRATOCU AND CIRRUS
EXPECTED THROUGH THE REST OF THE DAY. ISOLATED SHOWERS ARE POSSIBLE
BUT CHANCE TOO LOW FOR THE TAFS. LIGHT W TO NW WIND DEVELOPS, LIGHT
NNW AT KAVL. SKIES CLEAR DURING THE EVENING WITH WINDS BECOMING CALM
TO LIGHT AND VARIABLE. MOUNTAIN VALLEY FOG EXPECTED ONCE AGAIN.
OUTLOOK: DRY CONDITIONS EXPECTED THROUGH SUNDAY. SOME MOUNTAIN
VALLEY FOG WILL REMAIN POSSIBLE EACH MORNING WHEREVER CLOUDS DO NOT
INHIBIT NOCTURNAL RADIATION.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...AR
NEAR TERM...RWH
SHORT TERM...AR
LONG TERM...AR
AVIATION...RWH
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