375
FXUS62 KGSP 271052
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
652 AM EDT MON OCT 27 2025
SYNOPSIS
A COLD AIR WEDGE PATTERN WILL PERSIST OVER THE WESTERN CAROLINAS
AND NORTHEAST GEORGIA INTO WEDNESDAY BRINGING MUCH NEEDED RAINFALL
AND COLDER TEMPERATURES. CONDITIONS GRADUALLY DRY OUT BY LATE WEEK
WITH TEMPERATURES REMAINING BELOW NORMAL THROUGH THE WEEKEND.
NEAR TERM /THROUGH TONIGHT/
AS OF 630 AM MON: HIGH PRESSURE EXTENDS DOWN THE EAST COAST
FROM ONTARIO/QUEBEC IN CAD CONFIGURATION; CAD WILL DOMINATE THE
FORECAST EARLY THIS WEEK. UPPER LOW NOW CENTERED NEAR THE MOUTH OF
THE OHIO RIVER WILL WOBBLE GRADUALLY EAST ACROSS TN TODAY. UPPER
DIVERGENCE DOWNSTREAM OF THE LOW IS PROVIDING DYNAMIC ENHANCEMENT
TO ONGOING WARM UPGLIDE THIS MORNING. CURRENT BAND OF RAIN WEST
OF I-26 CORRIDOR WILL SHIFT NE ACROSS THE REST OF THE AREA BY
9-10 AM. WHILE THE MOIST UPGLIDE WILL WEAKEN SLIGHTLY THEREAFTER
AND PRECIP MAY BECOME MORE SHOWERY FOR A TIME, FORCING WILL BE
REPLENISHED LATER IN THE DAY. THAT OCCURS AS WAA AND MOISTURE
FLUX DEEPEN/RESTRENGTHEN AS FLOW BACKS AT 700 MB, AND INSTABILITY
FROM ATOP THE WEDGE INVERSION ALSO BECOMES NONZERO. THE BETTER
SHORT-TERM PRECIP RATES IN THE WESTERN HALF OF THE AREA, AND IN
THE SOUTHERN BLUE RIDGE ESCARPMENT NEAR THE SOUTHWEST BORDER OF
NC, LOOK TO BE IN THE MORNING. WITH THE BETTER RATES SHIFTING TO
THE EAST-FACING ESCARPMENT AND EASTERN CWA IN GENERAL BY THE END
OF THE DAY. PWATS WILL CERTAINLY BE HIGH FOR THIS TIME OF YEAR
ALTHOUGH A RELATIVELY MANAGEABLE 1.5 TO 2 SD ABOVE CLIMO PER
ENSEMBLES. MOST PIEDMONT AREAS WILL SEE TOTALS OF 1 TO 2 INCHES
BY DAYBREAK TUESDAY WITH 2 TO 3 MORE LIKELY ALONG THE ESCARPMENT,
THOUGH ISOLATED TOTALS TO 4" COULD OCCUR. IN LIGHT OF THE RECENT
DRY WEATHER AND MOST GUIDANCE KEEPING 6-HOURLY TOTALS BELOW 2"
ALONG THE ESCARPMENT, FLOOD THREAT LOOKS TO BE MITIGATED IN THE
NEAR TERM. A RUMBLE OF THUNDER CAN'T BE RULED OUT IN THE SC/GA
LAKELANDS OWING TO STRONGER ELEVATED INSTABILITY.
TEMPS HAVE BEEN BASED ON A SHORT-TERM GUIDANCE BLEND WHICH TYPICALLY
DOES PRETTY WELL IN CAD EVENTS AND CAN ACCOUNT FOR NONDIURNAL
TRENDS. MOST AREAS LOOK TO HAVE LESS THAN 5 DEGREES OF VARIATION
FROM DAYBREAK TO PEAK HEATING. BY TONIGHT, WITH UPPER LOW REACHING
THE APPALACHIANS AND A COASTAL LOW WRAPPING UP OFF THE NC/SC COAST,
LOW-LEVEL FLOW BACKS AND SOME SHALLOW CAA IS EXPECTED TO BRING
TEMPS A BIT COOLER THAN THIS MORNING--MAINLY IN THE MID TO UPPER
40S IN THE PIEDMONT AND LOWER 40S IN THE MTN VALLEYS (MID-UPPER
30S AT HIGHER ELEVATIONS).
CLOSE CONSIDERATION WAS GIVEN TO P-TYPE WITH NUMEROUS OBS SITES
IN THE NORTHERN MOUNTAINS HOVERING IN THE MID 30S AS OF THIS
WRITING, AND LIKELY FALLING BACK INTO THE MID 30S TONIGHT WITH
ONGOING PRECIP. PROG SOUNDINGS, BACKED UP BY ACARS SOUNDINGS FROM
CLT, SUGGEST SATURATION HAS ALREADY OCCURRED UP TO ABOUT 700
MB OVER THE MOUNTAINS, AND WITH WAA STRENGTHENING ONLY RAIN IS
EXPECTED. TEMPERATURES ON THE HIGHEST RIDGETOPS ARE WARMER THAN
THE VALLEYS ALTHOUGH THE NOSE OF THE INVERSION REMAINS ABOVE THE
SURFACE. GIVEN THE SATURATION, VERY LITTLE COOLING IS EXPECTED
THIS MORNING. THE WARM NOSE DOES REMAIN STRONG TONIGHT AND IS
SHOWN TO BE SATURATED BENEATH, BUT THE LOWER LEVEL CAA MAY BRING
TEMPS TO FREEZING JUST ABOVE THE SURFACE. WE OFTEN GET A FEW SLEET
REPORTS IN HIGHER ELEVATIONS IN THIS KIND OF SETUP DESPITE PROFILES
OBJECTIVELY LOOKING UNSUPPORTIVE OF ANYTHING BUT COLD RAIN. IF
SLEET OCCURS IT SHOULD BE JUST A NOVELTY WITH MINIMAL PUBLIC IMPACT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/
AS OF 1:35 AM EDT MONDAY: THE SHORT-TERM FORECAST PICKS UP AT 12Z
ON TUESDAY WITH A SPLIT UPPER FLOW PATTERN STILL IN PLACE OVER THE
CONUS AND A SOUTHERN STREAM UPPER LOW/SHORTWAVE PHASING INTO ANOMA-
LOUSLY LOW HEIGHTS OVER THE MID-ATLANTIC. BY EARLY WEDNESDAY, THE
SPLIT UPPER FLOW IS EXPECTED TO BE PHASING, RESULTING IN A VERY
LARGE UPPER LOW BEGINNING TO DEVELOP JUST TO OUR WEST. THE LOW
WILL MIGRATE EASTWARD AND IS EXPECTED TO BE CENTERED OVER OUR
AREA BY THE END OF THE PERIOD EARLY THURSDAY. AT THE SFC, A COLD-
AIR WEDGE WILL STILL BE IN PLACE OVER THE WESTERN CAROLINAS AS THE
PERIOD BEGINS EARLY TUESDAY. AS TUESDAY WEARS ON, THE WEDGE MAY
WEAKEN A BIT, HOWEVER THE MOIST UPGLIDE UP AND OVER THE WEDGE IS
EXPECTED TO DIMINISH MORE SUBSTANTIALLY. LATE TUES INTO WED, THE
MODELS DEVELOP ANOTHER SFC LOW ALONG AN ELONGATED BAROCLINIC ZONE
THAT STRETCHES ACROSS THE CENTRAL PLAINS. THIS LOW IS EXPECTED TO
LIFT A MOIST WARM FRONT OVER OUR CWA EARLY WEDNESDAY BRINGING MORE
SHOWERS TO OUR AREA. THE SFC LOW WILL BEGIN TO LIFT NORTH OF OUR
AREA AS THE PERIOD IS ENDING EARLY THURSDAY. OVERALL, WE'RE STILL
EXPECTING A LULL IN PRECIP ON TUESDAY WITH POPS RAMPING BACK UP
EARLY WEDNESDAY. I MAINTAIN LIKELY TO CATEGORICAL POPS OVER MOST
OF OUR CWA THRU 00Z THURSDAY. AFTER THAT, PRECIP CHANCES BEGIN TO
TAPER OFF FROM THE SOUTH. WITH REGARDS TO PRECIP AMOUNTS, FCST QPF
HAS BEEN TRENDING HIGHER WEDNESDAY INTO EARLY THURSDAY WITH THE
MORE FAVORED UPSLOPE AREAS NOW EXPECTED TO GET ANOTHER 2 TO 3".
THIS WILL BE IN ADDITION TO THE PRECIP FROM EARLIER IN THE WEEK.
NONETHELESS, THE OVERALL FLOODING THREAT STILL APPEARS LOW AT THIS
TIME, HOWEVER THE POTENTIAL FOR LOCALIZED FLOODING OVER THE MORE
FAVORED ZONES IS INCREASING. AS FOR TEMPERATURES, HIGHS HAVE BEEN
TRENDING A BIT COOLER FOR BOTH TUES AND WED AND WILL LIKELY STRUGGLE
TO WARM ABOVE THE LOW TO MID 50S ACROSS MOST OF OUR FCST AREA. WINDS
HAVE ALSO TRENDED A BIT STRONGER FOR TUES, WITH GUSTS IN THE 20 TO
30 MPH RANGE FOR MOST OF THE DAY.
LONG TERM /THURSDAY THROUGH SUNDAY/
AS OF 1:45 AM EDT MONDAY: THE EXTENDED FCST PICKS UP AT 12Z ON
THURSDAY WITH A VERY LARGE UPPER LOW CENTERED OVER OUR AREA WITH
UPPER RIDGING WELL TO OUR WEST. ON FRIDAY, THE UPPER LOW IS EX-
PECTED TO LIFT NORTHWARD AND APPEARS TO REMAIN CLOSED INTO THE
WEEKEND. HEIGHTS WILL LIKELY RECOVER SOMEWHAT FRIDAY INTO EARLY
SATURDAY, HOWEVER MOST OF THE LONG-RANGE GUIDANCE HAS THE BACK-
SIDE OF THE LOW AMPLIFYING AGAIN JUST TO OUR WEST LATE SATURDAY
INTO SUNDAY. THE RESULTING UPPER TROF WILL THEN TRANSLATE OVER
OUR AREA BY THE END OF THE PERIOD, LATE SUNDAY INTO MONDAY.
AT THE SFC, A ROBUST LOW WILL BE LIFTING NORTH OF THE CAROLINAS
AS THE PERIOD BEGINS EARLY THURS. IN ITS WAKE, DRY HIGH PRESSURE
SPREADS OVER OUR REGION FROM THE WEST AND LINGERS THRU SATURDAY.
ON SUNDAY, THE LONG-RANGE GUIDANCE APPEARS TO MOVE SOME SORT OF
MOIST, TRAILING COLD FRONT OVER OUR AREA FROM THE WEST, BUT THE
TIMING AND IMPACTS TO OUR SENSIBLE WX REMAIN UNCLEAR AT THIS TIME.
OVERALL, PRECIP CHANCES TAPER OFF FROM SOUTH TO NORTH ACROSS OUR
FCST AREA ON THURSDAY, WITH NO SUBSTANTIAL QPF EXPECTED AFTER
ROUGHLY 12Z THURSDAY. FRIDAY AND SATURDAY ARE STILL EXPECTED TO
BE MOSTLY DRY. THE UNSEASONABLY COOL TEMPERATURES ARE EXPECTED TO
CONTINUE THRU THE PERIOD, WITH HIGH TEMPS GRADUALLY WARMING AS
THE PERIOD WEARS ON, HOWEVER LOW TEMPS TREND COLDER THRU SATURDAY
MORNING UNDER DIMINISHING CLOUD COVER.
AVIATION /12Z MONDAY THROUGH FRIDAY/
AT KCLT AND ELSEWHERE: COLD-AIR DAMMING REGIME FOR THE 12Z TAF
PERIOD. WIDESPREAD LIGHT-MODERATE RA ALREADY OVER KAVL AND THE SC
SITES AS OF 1040Z WITH BAND TIMED TO REACH KCLT/KHKY BY 12Z AND
SPREAD NE FROM THERE. AREAS OF IFR CIGS HAVE DEVELOPED AHEAD OF
THE RAIN, AND WHILE RAIN WILL REINFORCE THE CAD REGIME CIGS MAY
LIFT FOR A TIME DURING RAIN, ALTHOUGH PERIODS OF MVFR TO IFR VSBY
MAY RESULT THEREIN. THIS IS HANDLED WITH TEMPOS. SOMEWHAT OF A
LULL IN PRECIP MAY OCCUR WITH -DZ AND/OR -SHRA BEGINNING 14-16Z
AND CONTINUING THRU EARLY AFTERNOON; ALL SITES SETTLE TO IFR IN
THAT TIMEFRAME AND REMAIN NO BETTER THAN IFR THRU THE END OF THEIR
PERIODS. HEAVIER SHOWERS LIKELY AT SOME POINT IN THE AFTERNOON OR
EARLY EVENING SO PROB30 GENERALLY USED TO HANDLE ASSOCIATED LOWER
CATEGORY. STEADIER MODERATE TO HEAVY PRECIP OVERNIGHT TONIGHT WITH
CIGS LARGELY FALLING TO LIFR FOR A TIME. SOME DEGREE OF MIDLEVEL
DRYING WILL OCCUR TONIGHT AND PRECIP RATES SHOULD TAPER FROM WEST
TO EAST AFTER MIDNIGHT. IFR CURRENTLY LOOKING LIKELY THRU END OF
THE PERIOD EVEN AT KCLT. BREEZY NE WINDS EXCEPT PRIMARILY SE AT
KAVL ONCE THEY PICK UP LATER THIS MORNING; GUSTS TO 15-25 KT MUCH
OF THE DAY. LLWS CONDITIONS LIKELY TO BE MET AT KAVL TONIGHT AS
WINDS STRENGTHEN ABOVE THE DAMMED BOUNDARY LAYER.
OUTLOOK: DECREASE IN PRECIP COVERAGE/INTENSITY FOR A TIME TUESDAY,
BUT RESTRICTIONS LIKELY WILL LINGER. PRECIP/RESTRICTIONS PROBABLY
WORSEN WEDNESDAY WITH NEXT PASSING STORM SYSTEM. DRIER WEATHER
MAY RETURN AS SOON AS THURSDAY MORNING EAST OF THE MOUNTAINS AND
SHOULD LAST INTO THE WEEKEND.
CLIMATE
RECORDS FOR 10-27
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 85 1939 37 1957 62 1939 23 1962
KCLT 86 1939 48 1957 71 2010 24 1962
1919
KGSP 86 1891 48 1957 69 2010 30 1962
RECORDS FOR 10-28
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 81 2023 41 1910 62 1984 23 1914
1940 1918
KCLT 87 1940 49 1976 67 1919 26 2001
KGSP 85 1991 51 1976 66 1919 27 1914
1903
RECORDS FOR 10-29
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 82 2020 32 1910 59 1984 21 1976
KCLT 83 2023 48 1925 67 1984 27 2001
2020 1910 1976
KGSP 84 2016 47 1925 66 1984 25 1976
1927
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...JPT
NEAR TERM...JCW
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...JCW
CLIMATE...GSP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page