280
FXUS62 KGSP 281434
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1034 AM EDT TUE OCT 28 2025
SYNOPSIS
A COLD AIR WEDGE PATTERN WILL PERSIST OVER THE WESTERN CAROLINAS
AND NORTHEAST GEORGIA KEEPING TEMPERATURES CHILLY THROUGH
WEDNESDAY. OCCASIONAL SHOWERS ARE EXPECTED TODAY WITH WIDESPREAD
MODERATE TO HEAVY RAIN ON WEDNESDAY. CONDITIONS GRADUALLY DRY OUT
BY LATE WEEK WITH TEMPERATURES TRENDING WARMER FOR THE WEEKEND,
ALTHOUGH STILL BELOW NORMAL.
NEAR TERM /THROUGH TONIGHT/
AS OF 1030 AM EDT TUESDAY: CAD FIRMLY ENTRENCHED ACROSS THE AREA
THIS MORNING. ALTHOUGH AREAS OF MODERATE RAIN ARE DIMINISHING AS
ISENTROPIC LIFT WEAKENS, THE LIFT IS STILL STRONG ENOUGH FOR AREAS
OF LIGHT RAIN AND DRIZZLE TO CONTINUE THROUGH THE DAY INTO THE
OVERNIGHT. GUSTY NE WINDS WILL CONTINUE FOR ALL BUT THE MORE
SHELTERED MOUNTAIN VALLEYS INTO TONIGHT AS WELL. WITH THE PRECIP AND
CLOUDS, TEMPS ARE NOT RISING AS FAST, SO HAVE LOWERED HIGHS TO
MATCH, WITH THE WARMEST LOCATIONS THE LITTLE TN VALLEY AND LOWER
FRENCH BROAD VALLEY NEAR THE TN BORDER AS IS USUAL IN A CAD PATTERN.
LOWS TONIGHT WILL BE NEAR NORMAL. HAVE REMOVED ANY SPURIOUS WINTRY
PRECIP FROM THE MT. MITCHELL AREA DUE TO BAD FORECAST TEMP DATA.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
AS OF 1215 AM TUE: CAD EXPECTED TO CONTINUE THROUGH THE DAY WEDNESDAY
WITH CANADIAN SFC HIGH REMAINING IN DAMMING CONFIGURATION. PROG
SOUNDINGS FEATURE A SATURATED SFC-BASED LAYER EXTENDING THROUGH THE
INVERSION. HENCE THICK CLOUD COVER SHOULD PERSIST AND GUSTY NE WINDS
RETURN EAST OF THE MOUNTAINS. STACKED LOW PRESSURE WILL MOVE ACROSS
TN DURING THE DAY THEN SWING NORTHWARD ALONG THE APPALACHIANS BY
EARLY THURSDAY. ISENTROPIC LIFT WILL STRENGTHEN IN ADVANCE OF THE LOW
AS 925-850MB WINDS PICK UP. THAT ALONE IS LIKELY TO GENERATE PRECIP
IN THE FOOTHILLS ALONG THE ESCARPMENT AND THE NW NC PIEDMONT IF NOT
MORE OF THE CWA. HIGH ELEVATIONS WILL SEE GUSTS OF 30-40 MPH AS JET
MOVES OVER THE MOUNTAINS WED MORNING. DESPITE THE ONGOING WAA, THE
WARM NOSE WILL BE ABOVE THE HIGHEST RIDGETOPS AND WITH TEMPS HOVERING
JUST ABOVE FREEZING SOME WINTRY MIX COULD OCCUR E.G. AT MOUNT
MITCHELL. MODELS ALSO ARE IN DECENT AGREEMENT ON A SLUG OF UPPER
DIVERGENCE MOVING OVER THE MOUNTAINS WED AFTERNOON IMMEDIATELY AHEAD
OF THE LOW, WITH ASSOCIATED FRONTOGENETIC FORCING. THIS LEADS TO AN
UPTICK IN PRECIP RATES WHICH SHOULD TRACK WITH THE LOW, THUS SHIFTING
ACROSS THE MOUNTAINS AND THEN GENERALLY NORTHWARD ACROSS THE I-40
CORRIDOR EAST OF THE MOUNTAINS. MOST OF THE CWA ENDS UP WITH
CATEGORICAL POPS BETWEEN 18Z WED AND 06Z THU. MOST MODELS DEPICT
925MB FLOW VEERING BY AFTERNOON, AND TEMPS RISING A FEW DEGREES
COMPARED TO TUESDAY NEARER THE WEDGE BOUNDARY, PARTICULARLY SPOTS SE
OF I-85 AND E OF I-77. HOWEVER, PROG SOUNDINGS SUGGEST A SLIGHT
INVERSION OR ISOTHERMAL LAYER WILL PERSIST WHICH SHOULD INHIBIT ANY
SFC BASED INSTABILITY. IN LIGHT OF THE DYNAMIC LIFT, 0-6KM BULK SHEAR
IN EXCESS OF 80 KT, AND 0-3KM SHEAR NEARING 50 KT, WE SHOULD HOPE THE
LACK OF INSTABILITY HOLDS TRUE. NOW THAT WE'VE HAD SOME RAIN, IT'S
SOMEWHAT MORE PLAUSIBLE THAT THIS SECOND ROUND OF QPF COULD CAUSE
HYDROLOGIC ISSUES. LOCALIZED TOTALS OF 3" OR MORE APPEAR POSSIBLE
MAINLY ALONG THE EAST-FACING ESCARPMENT (LAKE LURE, OLD FORT, JONAS
RIDGE, ETC.) OVER THE COURSE OF WED AND WED NIGHT, BUT STILL NOT
CONFIDENT SHORT-TERM RATES WOULD CAUSE FLASH FLOODING AS THOSE AREAS
WERE NOT HIT AS HARD WITH QPE AS THE SOUTHERN ESCARPMENT WAS ON
MONDAY.
TEMPS WILL REMAIN FAIRLY STEADY THROUGH WED EVENING BUT ONCE THE LOW
LIFTS OUT TO THE NORTH, A SHIFT TO NW WINDS WILL OCCUR AND INDUCE
LOW-LEVEL CAA, PROBABLY LEADING TO A FAIRLY RAPID DECLINE IN TEMPS
TOWARD DAYBREAK. PRECIP CHANCES DECLINE EAST OF THE MOUNTAINS BY THU
MORNING. CONTINUED CAA SHOULD ERODE THE WEDGE DURING THE DAY, BUT AS
USUAL COMING OUT OF A WEDGE MANY LOCATIONS TREND WARMER WITH HIGHS
BACK NEAR 60 OVER MOST OF THE PIEDMONT AND LOWER-MID 50S IN MOUNTAIN
VALLEYS. SOME MOISTURE WILL BANK ALONG THE MOUNTAIN SPINE IN
CONTINUING NW FLOW AND LINGER INTO THU NIGHT; POPS ACCORDINGLY
PERSIST NEAR THE TN BORDER. NEAR-SFC TEMP PROFILES MAY PERMIT A
CHANGE TO SNOW OR RIME ICING THU NIGHT IN THE HIGHEST ELEVATIONS.
WIND GUSTS AT THOSE ELEVATIONS MAY ALSO RISE TO NEAR ADVISORY
CRITERIA. TEMPS AND DEWPOINT DEPRESSIONS MAY BE SUPPORTIVE OF FROST
IN SOME VALLEYS IN THE SOUTHERN MOUNTAINS AND FOOTHILLS--RECALL THE
GROWING SEASON IS CONSIDERED TO HAVE ENDED IN THE TN BORDER ZONES.
HOWEVER, WINDS MAY BE TOO STRONG FOR GOOD SURFACE RADIATION.
LONG TERM /FRIDAY THROUGH MONDAY/
AS OF 115 AM TUE: QUASI-ZONAL UPPER FLOW NOTED ALOFT FRIDAY AND
SATURDAY ACROSS THE SOUTHERN US, WITH THE REGION BEING IN BETWEEN
TROUGHS, SO TO SPEAK. DRY WEATHER EXPECTED ACROSS THE CWA UNDER THE
ASSOCIATED WEAK DRY SFC HIGH. SOME CLOUD COVER MAY LINGER NEAR THE TN
BORDER ON UPSLOPE FLOW. TEMPERATURES MODERATE SLIGHTLY BUT REMAIN A
FEW DEGREES BELOW NORMAL FOR BOTH MAXES AND MINS. FROST APPEARS MORE
LIKELY FRIDAY NIGHT THAN THE PREVIOUS NIGHT GIVEN LIGHT WINDS AND
TEMPS IN THE MID 30S ACROSS THE FOOTHILLS AND SOME PIEDMONT LOCATIONS
NW OF I-85. NOV 1 IS THE NORMAL DATE WE STOP ISSUING FROST/FREEZE
PRODUCTS FOR ALL THE MOUNTAINS AND FOOTHILLS, BUT CAN'T RULE OUT
EVENTUALLY NEEDING ONE FOR PART OF THE PIEDMONT.
THE NEXT TROUGH, CONTAINING AN EMBEDDED SHORTWAVE ON AN ALBERTA
CLIPPER-LIKE TRACK, IS PROGGED TO IMPINGE ON THE CENTRAL/SOUTHERN
APPALACHIANS SATURDAY NIGHT OR SUNDAY MORNING. SMALL POPS RETURN TO
THE NW FLOW AREAS AT THAT TIME, MENTIONED AS SNOW IN HIGH ELEVATIONS
WITH FAVORABLE TEMPS. MODELS ARE IN REASONABLE AGREEMENT ON THE FRONT
SIDE OF THIS TROUGH, BUT DIVERGE ON THE BACK SIDE. THE 27/12Z ECMWF
AND 28/00Z GDPS MAINTAIN AN OPEN TROUGH BUT SUGGEST A TRAILING
EMBEDDED SHORTWAVE COULD BRING ANOTHER SHOT OF PRECIP TO PARTS OF THE
CWA, PRIMARILY THE MOUNTAINS, AT SOME POINT SUNDAY NIGHT THRU MONDAY
NIGHT. THE GFS ON THE OTHER HAND SHEARS OFF A WAVE NEAR THE GULF
COAST EARLY SUNDAY WHICH EVOLVES INTO A CUTOFF LOW WITH WET
WARM-FRONTAL PRECIP RIDING UP FROM THE SOUTH BY MONDAY. MOST MEMBERS
OF THE EPS/GEPS AND EVEN GEFS SHOW THE DRIER CLIPPER-LIKE SOLUTION.
POPS CURRENTLY SLIGHT-CHANCE ACROSS THE NW HALF OF THE CWA WITH
CHANCE VALUES CONFINED TO THE MOUNTAINS WEST OF THE BLUE RIDGE
ESCARPMENT. TEMPS REMAIN SLIGHTLY BELOW NORMAL THRU EARLY NEXT WEEK.
AVIATION /14Z TUESDAY THROUGH SATURDAY/
AT KCLT AND ELSEWHERE: EXPECT WIDESPREAD CIG RESTRICTIONS TO
CONTINUE THRU THE 12Z TAF PERIOD AT ALL TERMINALS. EXPECT PERIODS OF
LIGHT RAIN AND DRIZZLE THROUGH THE DAY AND INTO TONIGHT WITH MAINLY
VFR VSBY BUT SOME MVFR OR EVEN IFR IN THE BRIEFLY HEAVY RAINFALL.
AFTERNOON/EVENING AS CAD-INDUCED PRECIP DIMINISHES. I MAINTAIN
PROB30S AND/OR VCSH FOR ANY LINGERING RAIN THIS AFTERNOON/EVENING
WITH IFR CIGS NOW EXPECTED TO IMPROVE TO LOW-END MVFR AT MOST SITES
BY THE EARLY AFTERNOON. OTHERWISE, WINDS WILL REMAIN OUT OF THE NE
WITH PERSISTENT GUSTS IN THE 20 TO 30 MPH RANGE THRU TONIGHT. AT
KAVL, WINDS WILL FAVOR A N DIRECTION THRU TONIGHT AND THEN GO
SE OVERNIGHT WITH LOW-END GUSTS.
OUTLOOK: EXPECT MORE SCT TO WIDESPREAD SHOWERS AND ASSOCIATED RE-
STRICTIONS ON WEDNESDAY WITH THE PASSING OF THE NEXT LOW PRESSURE
SYSTEM. DRIER WEATHER SHOULD RETURN ON THURSDAY AND LINGER INTO THE
WEEKEND.
CLIMATE
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...JCW
NEAR TERM...RWH
SHORT TERM...JCW
LONG TERM...JCW
AVIATION...JPT/RWH
CLIMATE...
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