739
FXUS62 KGSP 240002
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
702 PM EST SUN NOV 23 2025
SYNOPSIS
DRY BUT MILD HIGH PRESSURE REMAINS OVER THE AREA THROUGH
TOMORROW. A MOIST COLD FRONT CROSSES THE AREA TUESDAY INTO
WEDNESDAY, PRODUCING WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS.
MUCH COLDER TEMPERATURES ARRIVE BEHIND IT.
NEAR TERM /THROUGH MONDAY/
AS OF 200 PM SUNDAY:
KEY MESSAGE 1: DRY WEATHER HIGH PRESSURE CENTERED OVER THE MID
MISSISSIPPI VALLEY THIS AFTERNOON WILL CONTINUE TO BUILD EASTWARD
THROUGH TONIGHT AND MONDAY. A WEAK COLD FRONT WILL SLIDE ACROSS
OR JUST NORTH OF THE AREA THIS EVENING, BUT WITH LITTLE AVAILABLE
MOISTURE, NO PRECIPITATION IS EXPECTED. THE HIGH WILL MOVE FROM THE
OHIO VALLEY THIS EVENING TO THE CENTRAL APPALACHIANS OVERNIGHT,
REACHING THE MID ATLANTIC STATES MONDAY MORNING AND THE COAST BY
LATE IN THE DAY. THIS PATTERN WILL MAINTAIN QUIET AND DRY CONDITIONS
ACROSS THE REGION THROUGH MONDAY. CONFIDENCE: HIGH.
KEY MESSAGE 2: INCREASING CLOUDS MONDAY THE LOW-LEVEL RIDGE
AXIS WILL SHIFT EAST OF THE AREA ON MONDAY, ALLOWING SOUTHERLY
RETURN FLOW TO DEVELOP ON ITS BACKSIDE. THIS WILL INITIATE WEAK
ISENTROPIC LIFT, FAVORING THE FORMATION OF STRATOCUMULUS DURING THE
DAY. UNCERTAINTY REMAINS IN BOTH THE TIMING AND AREAL COVERAGE OF
THIS CLOUD DEVELOPMENT, WITH ENSEMBLES SHOWING INCREASING SPREAD
(NBM 25TH–75TH PERCENTILE RANGE OF 40 TO 50 PERCENT) FROM LATE
MORNING THROUGH AFTERNOON. THE MOST LIKELY SCENARIO SUPPORTS
CLOUDS DEVELOPING FIRST ACROSS THE WESTERN ZONES (WEST OF I-26)
AND GRADUALLY EXPANDING EAST TOWARD THE I-77 CORRIDOR BY LATE
AFTERNOON. FORECAST TRENDS LEAN SLIGHTLY MORE PESSIMISTIC ON CLOUD
COVER, BLENDING TOWARD THE NBM 75TH PERCENTILE, WITH UPSLOPE FLOW
ENHANCING CLOUDS ACROSS THE GA/SC FOOTHILLS AND ADJACENT MOUNTAINS.
CONFIDENCE: MODERATE DUE TO TIMING AND COVERAGE UNCERTAINTY.
KEY MESSAGE 3: MILD TEMPERATURES WITH GRADUAL COOLING THE CURRENT
WARM SPELL WILL PERSIST THROUGH THIS AFTERNOON BEFORE MODERATING
SLIGHTLY BEHIND TONIGHT’S WEAK COLD FRONT. HIGHS TODAY WILL RANGE
FROM THE LOWER TO MID 70S ACROSS THE PIEDMONT, AROUND 10 TO 15
DEGREES ABOVE NORMAL AND MORE TYPICAL OF MID TO LATE OCTOBER. COOLER
AIR WILL FILTER IN OVERNIGHT, LEADING TO HIGHS ON MONDAY MAINLY
IN THE MID TO UPPER 60S, STILL 5 TO 10 DEGREES ABOVE NORMAL.
NBM ENSEMBLE SPREAD REMAINS SMALL FOR HIGHS BOTH TODAY AND MONDAY
(LESS THAN 4 DEGREES BETWEEN THE 25TH AND 75TH PERCENTILES),
INDICATING HIGH CONFIDENCE. FOR LOWS TONIGHT, A MODEST 4
TO 7 DEGREE SPREAD APPEARS ACROSS THE NC/SC FOOTHILLS AND
NC PIEDMONT. PROBABILITIES OF TEMPERATURES FALLING BELOW 37
DEGREES REMAIN ONLY 10 TO 15 PERCENT IN THESE AREAS, AND THE
REFS INDICATES PROBABILITIES OF TEMPERATURES BELOW 38 DEGREES
WITH WINDS UNDER 4 MPH (WITHIN A 10 KM RADIUS) AROUND 20 TO 35
PERCENT. FROST DEVELOPMENT IS THEREFORE UNLIKELY, AND ANY OCCURRENCE
WOULD HAVE MINIMAL IMPACT GIVEN THE END OF THE GROWING SEASON.
CONFIDENCE: HIGH IN TEMPERATURE TRENDS, MODERATE IN LOW TEMPERATURE
DISTRIBUTION.
SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/
AS OF 1023 AM EST SUNDAY...
KEY MESSAGES:
1) A COLD FRONT ARRIVES ON TUESDAY, WITH AT LEAST SCATTERED
SHOWERS EXPECTED THROUGH THE DAY TUESDAY AND CONTINUING THROUGH
MOST OF WEDNESDAY.
2) EMBEDDED THUNDER IS EXPECTED WITH THIS SYSTEM, MAINLY OVER THE
EASTERN PIEDMONT AND UPSTATE. SEVERE RISK IS LIMITED BUT NONZERO,
WITH THE MAIN THREAT BEING DAMAGING STRAIGHT-LINE WINDS.
DEEP LAYER SW FLOW WILL BE IN PLACE OVER THE CAROLINAS BY MONDAY
NIGHT, WITH OUR REGION SANDWICHED BETWEEN POTENT RIDGING OVER
THE WESTERN ATLANTIC AND AN AMPLIFYING LONGWAVE TROUGH ACROSS
THE WEST/CENTRAL CONUS. A COLD FRONT POSITIONED OUT OVER THE
TENNESSEE VALLEY WILL STRUGGLE TO MAKE MUCH EASTWARD PROGRESS
OVERNIGHT A DEAMPLIFYING SHORTWAVE MORE OR LESS MERGES WITH
THE MEAN FLOW, LEAVING THE UPPER FLOW BASICALLY PARALLEL TO THE
FRONT. IN THE LOW-LEVELS, A ~1025BM SURFACE HIGH WILL PUSH OFF
THE MID-ATLANTIC COAST, MAINTAINING A CAD-LIKE REGIME THROUGH
THE OVERNIGHT HOURS...FEATURING ALL THE HALLMARKS OF A SOLID
WEDGE...WITH LOW-LEVEL WAA AND MOIST UPGLIDE...A STRONG INVERSION
BELOW 950MB...AND A WEAK INVERTED RIDGE EAST OF THE APPALACHAINS.
GIVEN THIS, ALTHOUGH MENTIONABLE POPS AREN'T WARRANTED FOR MOST OF
THE CWA UNTIL DAYBREAK, SOME PATCHY LIGHT DRIZZLE CAN'T BE RULED
OUT ACROSS MUCH OF THE AREA BEFORE DAWN, PARTICULARLY ACROSS THE
SAVANNAH RIVER VALLEY WHERE A FEW MODELS ARE KEYING ON A SURGE IN
MOIST ISENTROPIC ASCENT AFTER MIDNIGHT.
EITHER WAY, THE FRONT WILL FINALLY PUSH INTO THE AREA AFTER
DAYBREAK, SPURRING WIDESPREAD SHOWERS AND A CATEGORICAL POP ACROSS
THE WESTERN 2/3 OF THE CWA. DESPITE SOME TIMING DIFFERENCES IN
ENSEMBLE SOLUTIONS STILL, THE GENERAL TREND IN THE LAST 2 MODEL
CYCLES OR SO IS TOWARD A SLOWER FROPA, WITH THE FRONT STALLING
ACROSS THE AREA WELL INTO TUESDAY NIGHT. NO SURFACE-BASED
INSTABILITY LOOKS TO DEVELOP ON TUESDAY, BUT BY WEDNESDAY, WITH
THE FRONT STILL DRAPED ACROSS THE LOW TERRAIN, MODEL CONSENSUS IS
THAT A TONGUE OF 100-300 J/KG SBCAPE WILL DEVELOP, MAINLY ALONG AND
SOUTH OF I-85. THE LATEST LREF CYCLE SUPPORTS A 40-50% CHANCE OF
AT LEAST 300 J/KG ACROSS OUR SOUTHEASTERNMOST TIER OF COUNTIES.
GIVEN THIS, IT'S IMPORTANT TO CONSIDER WIND PROFILES...WHICH
FEATURE SOME 40-50KTS OF BULK SHEAR BUT GENERALLY UNIDIRECTIONAL
HODOGRAPHS. SO, A TORNADIC HSLC EVENT CONTINUES TO LOOK UNLIKELY,
BUT THE CHANCES ARE INCREASING FOR AT LEAST ISOLATED SEVERE
STORMS TO PRODUCE DAMAGING WIND WEDNESDAY AFTERNOON AND EVENING.
QPF RESPONSE, MEANWHILE, HAS INCREASED SOMEWHAT OVER THE SAVANNAH
RIVER VALLEY, WHILE REMAINING MORE OR LESS UNCHANGED OVER THE
SMOKIES AND BALSAMS. THE THINKING REMAINS THAT DRY ANTECEDENT
CONDITIONS WILL PRECLUDE MUCH IF ANY HYDRO THREAT.
OTHERWISE...EXPECT HIGHS A LITTLE COOLER ON TUESDAY, NEAR- OR
ONLY SLIGHTLY-ABOVE NORMAL ACROSS THE FOOTHILLS AND PARTS OF THE
NC PIEDMONT WHICH WILL BE INSIDE THE COLD WEDGE...BUT STILL WELL
ABOVE NORMAL OVER MOST OF THE UPSTATE AND EASTERN PIEDMONT, WHICH
WILL BE OUTSIDE THE WEDGE. WIDESPREAD ABOVE-NORMAL TEMPERATURES
ARE THEN EXPECTED ON WEDNESDAY, BEFORE THE FRONT PICKS UP AND
BEGINS TO USHER IN COOLER AIR WEDNESDAY EVENING.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
AS OF 1103 AM EST SUNDAY...
KEY MESSAGES:
1) DRY AND COLD WEATHER PERSISTS THROUGH AT LEAST SATURDAY, WITH
CHILLY HIGHS AND FRIGID LOWS.
2) A COLD FRONT APPROACHES FROM THE WEST ON SUNDAY.
WEDNESDAY NIGHT WILL BE OUR COLDEST NIGHT IN A WHILE, AS STRONG
POSTFRONTAL CAA USHERS IN A MUCH COLDER AND DRIER AIR MASS.
LOWS WILL FALL INTO THE 30S ACROSS THE LOW TERRAIN...AND MAY DROP
INTO AT LEAST THE MID 20S, MAYBE COLDER, AT HIGHER ELEVATIONS.
CONTINENTAL HIGH PRESSURE WILL DOMINATE THE FORECAST THROUGH
AT LEAST SATURDAY, KEEPING HIGHS IN THE LOW 50S EACH AFTERNOON,
AND FRIGID LOWS IN THE LOW 30S OR 20S EACH NIGHT, EVEN AT LOWER
ELEVATIONS. BY SUNDAY, BROAD TROUGHING OVER THE WESTERN CONUS WILL
EJECT A SHORTWAVE INTO THE SOUTHERN GREAT PLAINS, SPURRING SURFACE
CYCLOGENESIS AND DRIVING ANOTHER COLD FRONT TOWARD OUR AREA.
IT LIKELY WON'T MAKE IT TO US BY THE END OF THE 7-DAY FORECAST
PERIOD SUNDAY EVENING, BUT BY ALL ACCOUNTS THE PATTERN LOOKS TO
BE AMPLIFYING BY THEN.
AVIATION /00Z MONDAY THROUGH FRIDAY/
AT KCLT AND ELSEWHERE: EXPECT DRY, VFR CONDITIONS TO PERSIST
AT ALL TERMINALS THRU THE 00Z TAF PERIOD. MOSTLY CLEAR SKIES
SHOULD PREVAIL WELL INTO MONDAY MORNING, WITH FEW TO SCT HIGH
CLOUDS MOVING OVER THE AREA BY THE AFTERNOON. BKN MID TO HIGH
CLOUDS WILL LIKELY REACH KCLT BY THE END OF THE PERIOD LATE
MONDAY NIGHT. OTHERWISE, WINDS WILL REMAIN LIGHT AND VRB TO
CALM THRU THE OVERNIGHT AND THEN FAVOR A LIGHT, NELY DIRECTION
BY LATE MORNING. THEY SHOULD GO S OF E BY THE EARLY AFTERNOON
AND STAY THAT WAY FOR THE REMAINDER OF THE TAF PERIOD. AT KAVL,
THE CURRENT NLY WINDS SHOULD GO LIGHT AND VRB LATER TONIGHT AND
EVENTUALLY PICK BACK UP FROM THE S TO SE TOMORROW AFTERNOON.
OUTLOOK: MTN VALLEY FOG AND LOW STRATUS WILL BE POSSIBLE EARLY
TUES. EXPECT NUMEROUS SHOWERS AND POSSIBLY A FEW THUNDERSTORMS
WITH ASSOCIATED RESTRICTIONS TUES INTO WED AS A MOIST COLD FRONT
MOVES THRU THE AREA. DRIER AND PREDOMINANTLY VFR CONDITIONS SHOULD
RETURN BY LATE WED AND LINGER THRU LATE WEEK.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...MPR
NEAR TERM...JK/JPT
SHORT TERM...MPR
LONG TERM...MPR
AVIATION...JPT
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