371
FXUS62 KGSP 250545
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1245 AM EST TUE NOV 25 2025
SYNOPSIS
A COLD FRONT MOVES INTO THE AREA TODAY AND TO OUR EAST ON WEDNESDAY,
PRODUCING WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS. MUCH COLDER
TEMPERATURES ARRIVE BEHIND THE FRONT AND CONTINUE INTO THE WEEKEND.
FORECAST CONFIDENCE IS VERY LOW BEYOND SATURDAY AS ANOTHER COLD
FRONT MAY AFFECT THE WEATHER SUNDAY OR MONDAY.
NEAR TERM /THROUGH TONIGHT/
AS OF 1105 PM MONDAY: BENIGN WEATHER WILL GIVE WAY TO A MORE ACTIVE
PATTERN TODAY AND TONIGHT AS A SERIES OF TROUGHS IMPACT THE AREA. A
LEAD SOUTHERN STREAM SHORTWAVE TROUGH IS CURRENTLY LIFTING ACROSS
THE LOWER MISSISSIPPI VALLEY AND WILL SLIDE ACROSS THE SOUTHERN
APPALACHIANS THIS MORNING. FOLLOWING RIGHT BEHIND IT IS A SHARP
NORTHERN STREAM TROUGH THAT'S PROGGED TO DEEPEN AND TAKE ON A
NEGATIVE TILT AS IT DROPS ACROSS THE CENTRAL PLAINS AND INTO THE
MIDWEST LATE THIS AFTERNOON INTO TONIGHT. THIS WILL BRING SEVERAL
ROUNDS OF WEATHER TO THE REGION WITH THE PRIMARY FOCUS BEING ON THE
POTENTIAL FOR A FEW ISOLATED INSTANCES OF SEVERE CONVECTION. LOW-
LEVEL MASS RESPONSE HAS RESULTED IN A ROBUST LOW-LEVEL JET
TRANSLATING ACROSS THE LOWER MISSISSIPPI VALLEY THROUGH THE
OVERNIGHT HOURS WHICH IN TURN IS HELPING TO DRAW A BUOYANT WARM
SECTOR INLAND FROM THE GULF. SURFACE-BASED CAPE EXTENDS AS FAR NORTH
AS THE I-20 CORRIDOR ACROSS LOUISIANA INTO MISSISSIPPI WITH A BAND
OF DEEP CONVECTION EXTENDING FROM THE LOUISIANA COAST TO NORTHERN
MISSISSIPPI.
WITH TIME, THIS ACTIVITY WILL SHIFT EAST OVERNIGHT BUT PROGRESS WILL
BE SLOW OWING TO THE POSITIVE TILT OF THE LEAD TROUGH AND BOUNDARY
PARALLEL FLOW. GUIDANCE HAS SLOWED THE ARRIVAL OF ANY DEEPER
CONVECTION ACROSS THE MOUNTAINS TO AFTER DAYBREAK, WHICH MAKES SENSE
GIVEN LATEST UPSTREAM TIMING. AHEAD OF THE CONVECTIVE BAND, WARM
ADVECTION IN CONJUNCTION WITH ISENTROPIC ASCENT MAY HELP ISOLATED TO
SCATTERED SHOWERS BLOSSOM ACROSS THE UPSTATE NORTH OF I-85 AND THE
SOUTHERN BLUE RIDGE ESCARPMENT. EVENTUALLY, WHAT'S LEFT OF THE
CONVECTIVE BAND IS FORECAST TO PUSH INTO THE MOUNTAINS AND NORTHEAST
GEORGIA CLOSER TO MID MORNING. BY THIS POINT, THE CONVECTION WILL
LIKELY HAVE OUTPACED THE WARM SECTOR WITH SURFACE-BASED CAPE
CONFINED TO ALONG AND SOUTH OF I-20 ACROSS ALABAMA AND FAR WESTERN
GEORGIA. THUS, THIS INITIAL ROUND OF CONVECTION IS EXPECTED TO BE
ELEVATED ABOVE A SURFACE STABLE LAYER EXTENDING UP TO ~850MB PER
FORECAST SOUNDINGS. THIS WILL BE A SAVING GRACE AS SHEAR PROFILES
ARE RATHER CONCERNING WITH LONG CYCLONICALLY CURVED HODOGRAPHS AND
ROBUST SRH. HOWEVER, DESPITE CONVECTION BEING ELEVATED, A FEW STRONG
WIND GUSTS COULD OCCUR AT THE SURFACE DUE TO DYNAMIC LIFTING AND
DROPPING OF THE STABLE LAYER BY THE CONVECTION LINE.
CONVECTION WILL QUICKLY WEAKEN THROUGH THE MORNING AS THE REMNANT
LINE PUSHES ACROSS THE MOUNTAINS AND WESTERN UPSTATE. A FEW EMBEDDED
LIGHTNING STRIKES WITH SOME DEGREE OF ELEVATED INSTABILITY WILL BE
POSSIBLE, BUT ANY ISOLATED STRONG STORMS SHOULD HAVE SINCE WEAKENED.
THIS WILL MAKE FOR A RATHER COMPLICATED TEMPERATURE FORECAST,
HOWEVER, WITH PLENTIFUL RAIN COOLED AIR ALONG AND NORTH OF I-85
WHERE DEWPOINTS IN THE 40S AND LOW WETBULB TEMPERATURES WILL HELP TO
LOCK IN A RATHER SHARP TEMPERATURE GRADIENT. HIGHS ACROSS PORTIONS
OF THE MOUNTAINS, AND ESPECIALLY THE ADJACENT FOOTHILLS, WILL LIKELY
REMAIN IN THE MID 50S. SOUTH OF I-85 ON THE OTHER HAND WILL SEE
WARMER HIGHS AGAIN IN THE UPPER 60S TO LOW 70S. AT LEAST SCATTERED
SHOWERS WILL LIKELY CONTINUE THROUGH THE AFTERNOON BEFORE COVERAGE
STARTS TO RAMP BACK UP LATE AFTERNOON INTO THE EVENING. THE
PREVIOUSLY MENTIONED STRENGTHENING NORTHERN STREAM TROUGH WILL BRING
RENEWED HEIGHT FALLS ACROSS THE REGION ALONG WITH STRENGTHENING WIND
FIELDS. THE RIGHT ENTRANCE REGION OF A ROBUST UPPER JET IS PROGGED
TO TRANSLATE ACROSS THE SOUTHERN APPALACHIANS THROUGH THE EVENING
AND INTO THE OVERNIGHT. MASS RESPONSE TO A DEEPENING SURFACE CYCLONE
OVER THE GREAT LAKES WILL ALSO HELP TO ADVECT UPPER 50S TO LOW 60S
DEWPOINTS BACK INTO THE AREA, ESPECIALLY ALONG AND SOUTH OF I-85.
THE UPTICK IN FORCING IN CONCERT WITH THE ARRIVAL OF AN ESTABLISHED
WARM SECTOR WILL PROMOTE THE DEVELOPMENT OF A SECOND ROUND OF DEEP
CONVECTION THIS EVENING INTO TONIGHT. SEVERAL ROUNDS OF STORMS MAY
LIFT ACROSS THE AREA DURING THIS PERIOD WITH THE BULK OF THIS
ACTIVITY FOCUSED ALONG THE WARM FRONT IN THE VICINITY OF I-85. 100-
250 J/KG OF SURFACE-BASED CAPE MAY BE REALIZED DESPITE NOCTURNAL
TIMING WITH AROUND 60KTS OF DEEP-LAYER VERTICAL WIND SHEAR. LOW-
LEVEL SHEAR WON'T BE AS IMPRESSIVE BY THIS TIME AS FLOW WILL HAVE
VEERED TO OUT OF THE SOUTHWEST WITH NOTABLY LESS LOW-LEVEL CURVATURE
IN THE HODOGRAPHS. THUS, A COUPLE STRONG TO MARGINALLY SEVERE STORMS
CANNOT BE RULED OUT WITH MAINLY A THREAT FOR LOCALLY GUSTY/DAMAGING
WINDS. IF A STORM CAN FAVORABLY INTERACT WITH NEARBY BOUNDARIES AN
ISOLATED TORNADO CANNOT BE COMPLETELY DISCOUNTED, BUT CONFIDENCE IS
MUCH LOWER. FLOODING IS NOT EXPECTED TO BE AN ISSUE OWING TO DRY
ANTECEDENT CONDITIONS AND PROGRESSIVE NATURE OF ANY STORMS.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
AS OF 1210 AM EST TUESDAY: ANY LINGERING PRECIP WEDNESDAY MORNING
SHOULD TAPER OFF QUICKLY AS THE COLD FRONT MOVES EAST OF THE AREA
AND A DRY AND COLD AIR MASS BEGINS MOVING IN. THAT SAID, THE COLD
AIR WILL BE DELAYED UNTIL WED NITE. WITH CLEARING SKIES AND SLOW AIR
MASS ARRIVAL, HIGHS WILL BE 10 TO 15 DEGREES ABOVE NORMAL WITH
BREEZY CONDITIONS. THE COLD AIR ARRIVES IN EARNEST WED NITE. LOWS
WILL BE UP TO 5 DEGREES BELOW NORMAL. COOLING CONTINUES ON
THANKSGIVING DAY INTO THE NIGHT. HIGHS WILL BE 5 TO 10 DEGREES BELOW
NORMAL WITH LOWS AROUND 10 DEGREES BELOW NORMAL. BREEZY TO WINDY
CONDITIONS CONTINUE ACROSS THE MOUNTAINS THROUGH THE PERIOD WITH
BREEZY CONDITIONS ELSEWHERE DURING THE DAY. CAN'T RULE OUT THE NEED
FOR A WIND ADVISORY FOR PORTIONS OF THE MOUNTAINS.
LONG TERM /FRIDAY THROUGH MONDAY/
AS OF 1240 AM EST TUESDAY: THE COLD AND DRY AIR MASS REMAINS OVER
THE AREA THROUGH AT LEAST SATURDAY. BREEZY TO WINDY CONDITIONS WILL
CONTINUE FRIDAY WITH WINDS ABATING FRIDAY NIGHT INTO SATURDAY AS THE
CENTER OF SURFACE HIGH PRESSURE MOVES INTO THEN EAST OF THE AREA.
HIGHS FRIDAY 10 TO 15 DEGREES BELOW NORMAL AND AROUND 10 BELOW
NORMAL SATURDAY. LOWS FRIDAY NIGHT 10 TO 15 DEGREES BELOW NORMAL.
THE MAIN CONCERN, BESIDE THE COLD TEMPS, DURING THIS PERIOD IS THE
LOW RELATIVE HUMIDITY AND BREEZY WINDS. WINDS DO DROP OFF BELOW RED
FLAG CRITERIA FRIDAY EVEN THOUGH THEY DO REMAIN BREEZY AND WILL BE
LIGHT ON SATURDAY. RH DROPS BELOW 25% ACROSS MUCH OF THE AREA FRIDAY
BUT RECOVERS SLIGHTLY FOR SATURDAY. FOR NOW, IT LOOKS LIKE RED FLAG
WOULD NOT BE MET, BUT IT BEARS MONITORING.
FORECAST CONFIDENCE DROPS SIGNIFICANTLY FOR THE REST OF THE PERIOD.
THE GFS CONTINUES TO SHOW A DRY FORECAST UNTIL MONDAY WHEN A SPLIT
FLOW BECOMES ACTIVE AND A COLD FRONT ASSOCIATED WITH THE NORTHERN
STREAM AND A GULF LOW ASSOCIATED WITH THE SOUTHERN STREAM MOVE INTO
THE AREA BRINGING RAIN TO THE AREA. THE GFS SHOWS A COLD RAIN WITH
TEMPERATURES WARMING ABOVE FREEZING BUT A WEAK COLD AIR DAMMING
PATTERN SETTING UP. THE CANADIAN AND ECMWF AREA FASTER WITH THIS
SYSTEM BRINGING PRECIP INTO THE AREA SATURDAY NIGHT AND SUNDAY.
SHOULD THIS OCCUR, THERE MAY BE ENOUGH COLD AIR ACROSS THE MOUNTAINS
FOR A WINTRY MIX TO DEVELOP. THE GFS ENSEMBLE MEAN IS SLIGHTLY
FASTER, BUT STILL SLOW ENOUGH TO PRECLUDE ANY WINTRY PRECIP. OTHER
ENSEMBLES TREND TOWARD THE FASTER GUIDANCE. GIVEN THE UNCERTAINTY,
KEPT PRECIP CHANCES SAT NITE IN THE SLIGHT CHANCE RANGE WITH ANY
WINTRY PRECIP LIMITED TO THE MOUNTAINS, SIMILAR TO THE MODEL BLEND.
PRECIP CHANCES INCREASE SUNDAY, BUT TEMPS WARM ENOUGH TO CHANCE
PRECIP TO ALL RAIN EXCEPT FOR THE HIGHEST ELEVATIONS. THE BLEND ALSO
KEEPS LIQUID RAIN CHANCE IN PLACE ON MONDAY, WHILE THE FASTER MODELS
SUGGEST DRYING BY THEN. OBVIOUSLY, THIS WILL BE MONITORED WITH
EVERYONE STAYING UP TO DATE WITH THE LATEST FORECASTS GIVEN THE BUSY
TRAVEL DAY SUNDAY.
AVIATION /06Z TUESDAY THROUGH SATURDAY/
AT KCLT AND ELSEWHERE: VFR CONDITIONS ARE ONGOING ACROSS THE AREA
AND WILL CONTINUE THROUGH MUCH OF THE OVERNIGHT AS MAINLY HIGH
CLOUDS STREAM ACROSS THE AREA. BY DAYBREAK AND THEREAFTER CONDITIONS
HEAD DOWNHILL AS A STORM SYSTEM APPROACHES THE AREA. THIS WILL BRING
INCREASING MOISTURE WITH THE DEVELOPMENT OF A DECK OF LOW STRATUS
AND SUBSEQUENT MVFR CEILINGS. A FEW INSTANCES OF IFR CEILINGS WILL
ALSO BE POSSIBLE. A BAND OF SHOWERS IS ALSO EXPECTED TO MOVE ACROSS
THE AREA MAINLY ALONG AND NORTH OF I-85 THROUGH THE MORNING WITH AT
LEAST SCATTERED SHOWERS LINGERING THROUGH THE AFTERNOON. ADDITIONAL
SHOWERS AND THUNDERSTORMS APPEAR LIKELY TO REDEVELOP DURING THE
EVENING AND OVERNIGHT HOURS. ANY OF THIS ACTIVITY WILL HAVE
ASSOCIATED VISIBILITY RESTRICTIONS FROM RAIN AND WILL CONTINUA
THROUGH THE END OF THE TAF PERIOD. CEILINGS WILL CONTINUE TO BE AN
ISSUE AS WELL WITH MVFR PERSISTING. WINDS WILL BE LIGHT AND VARIABLE
THROUGH THE PERIOD WITH FREQUENT WIND SHIFTS EXPECTED AS SHOWERS AND
STORMS MOVE THROUGH.
OUTLOOK: DRIER AND PREDOMINANTLY VFR CONDITIONS SHOULD RETURN BY
WEDNESDAY MORNING AND LINGER THROUGH LATE WEEK.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...RWH
NEAR TERM...TW
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...TW
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