861
FXUS62 KGSP 261057
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
657 AM EDT SUN OCT 26 2025
SYNOPSIS
DRY AND COOL HIGH PRESSURE WILL LINGER OVER THE AREA TODAY. A
COLD AIR WEDGE PATTERN WILL SET UP OVER THE WESTERN CAROLINAS
TONIGHT INTO EARLY NEXT WEEK BRINGING MUCH NEEDED RAINFALL AND
COLDER TEMPERATURES. ANOTHER LOW PRESSURE SYSTEM WILL IMPACT
OUR AREA DURING THE MIDDLE OF NEXT WEEK. CONDITIONS GRADUALLY
DRY OUT BY LATE NEXT WEEK WITH TEMPERATURES REMAINING BELOW
NORMAL.
NEAR TERM /THROUGH TONIGHT/
AS OF 630 AM SUNDAY: FCST GENERALLY ON TRACK. LOBE OF DRY
CANADIAN SFC HIGH EXTENDING SOUTHWARD ON THE EAST SIDE OF THE
APPALACHIANS. THICK AREA OF ALTO/CIRRUS CLOUDS WILL BE SEEN IN
DIFFLUENT FLOW DOWNSTREAM OF UPPER LOW IN THE EASTERN PLAINS. SOME
BREAKS EVIDENT ON NOCTURNAL SATELLITE IMAGERY TO OUR WEST SO SOME
SUNSHINE MAY BE SEEN EARLY IN THE DAY, BUT ANOTHER BAND OF UPPER
DIVERGENCE AND DPVA AHEAD OF THE LOW SHOULD BRING IN MORE CIRRUS
BY AFTERNOON. A WARM FRONT LOOKS TO ACTIVATE FROM AR/MO TO THE
GA/SC LOWCOUNTRY ATOP THE SFC AIRMASS. THAT SHOULD INTRODUCE LOWER
ALTITUDE CLOUD COVER FROM THE SOUTH BY MIDDAY, SPREADING GRADUALLY
NORTHWARD THRU TONIGHT. LIGHT PRECIP BECOMES POSSIBLE BY AROUND 5
PM IN SW NC AND THE UPPER SAVANNAH VALLEY; COULDN'T RULE OUT SOME
VIRGA EARLIER THAN THAT. DEVELOPMENT OF PRECIP SHOULD STRENGTHEN
WHAT PROBABLY ALREADY CAN BE CLASSIFIED AS WEAK CAD, SO IF VIRGA
AND/OR RAIN MOVE IN FASTER THAN CURRENTLY ANTICIPATED TEMPS MAY
END UP A LITTLE COOLER THAN FORECAST.
WHILE SOME WARM UPGLIDE SHOULD CONTINUE THROUGH THE EVENING, THE
AFOREMENTIONED (SECOND) BAND OF DYNAMIC FORCING WILL ADVECT OUT
AND PRECIP COULD PROVE VERY LIGHT AND/OR INTERMITTENT UNTIL THE
WEE HOURS MONDAY MORNING WHEN 850-700MB FLOW IS SHOWN TO INCREASE
AND SOME INTERLEAVED DRY LAYERS SATURATE. SLIGHT MUCAPE DEVELOPS
AS INVERSION BECOMES MORE PRONOUNCED, WHICH SHOULD ALSO ENHANCE
PRECIP RATES. EASTERLY FLOW ALONG THE ESCARPMENT WILL BE A FACTOR
FOR LOCAL ENHANCEMENT TOO. EVEN IN LIGHT OF ALL THIS, THE WETTEST
GUIDANCE MEMBERS PRODUCE LESS THAN AN INCH TOTAL THRU 12Z MON. ALL
PRECIP SHOULD BE LIQUID: DESPITE SOME MIDDLE MOUNTAIN ELEVATIONS
REMAINING IN THE MID TO UPPER 30S AFTER PRECIP ONSET, STRONG WARM
NOSE SUGGESTS NO ICE NUCLEI BELOW THE NOSE FOR SNOW/SLEET. THE
RIDGETOPS LIKELY WILL BE ABOVE THE INVERSION AND THUS TOO WARM.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
AS OF 1:40 AM EDT SUNDAY: THE SHORT-TERM FCST PICKS UP AT 12Z ON
MONDAY WITH A SPLIT UPPER FLOW PATTERN STILL IN PLACE OVER THE
CONUS AND A SOUTHERN STREAM UPPER LOW MIGRATING EASTWARD OVER THE
MID-MS VALLEY. THIS LOW IS EXPECTED TO PHASE INTO ANOMALOUSLY LOW
HEIGHTS OVER THE MID-ATLANTIC BY EARLY TUESDAY. BY THE END OF THE
PERIOD EARLY WEDNESDAY, THE SPLIT UPPER FLOW IS EXPECTED TO BE
PHASING RESULTING IN A VERY LARGE UPPER LOW BEGINNING TO DEVELOP
OVER THE EASTERN/SE CONUS. AT THE SFC, A COLD-AIR WEDGE WILL BE
IN PLACE OVER THE WESTERN CAROLINAS AS THE PERIOD BEGINS EARLY
MONDAY. THE RESULTING MOIST ISENTROPIC UPGLIDE WILL PRODUCE NUMER-
OUS SHOWERS ACROSS OUR CWA ON MONDAY AND INTO TUESDAY. AS TUESDAY
WEARS ON, THE WEDGE WILL LIKELY WEAKEN SOMEWHAT AND THE MOIST
UPGLIDE UP AND OVER THE WEDGE IS EXPECTED TO DIMINISH. BY THE
END OF THE PERIOD EARLY WEDNESDAY, 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 AREA AS THE PERIOD IS ENDING EARLY WEDNESDAY.
OVERALL, WE ARE STILL EXPECTING A LULL IN PRECIP ON TUESDAY
WITH POPS BEGINNING TO RAMP BACK UP AS THE PERIOD ENDS EARLY
WEDNESDAY. WITH REGARDS TO PRECIP AMOUNTS, WE'RE CURRENTLY
FORECASTING ROUGHLY 1 TO 2 INCHES OVER MOST OF OUR CWA FROM
LATE SUNDAY THRU TUESDAY. ALTHOUGH LOCALIZED HIGHER AMOUNTS
ARE CERTAINLY POSSIBLE, ESPECIALLY OVER THE FAVORED UPSLOPE
ZONES, THE FLOODING THREAT STILL APPEARS MINIMAL AT THIS TIME.
ON MONDAY AND TUESDAY, HIGHS WILL STRUGGLE TO WARM ABOVE THE
LOW TO MID 50S ACROSS MOST OF OUR FCST AREA WITH THE WEDGE IN
PLACE. WE CAN ALSO EXPECT SOME LOW-END GUSTS BOTH DAYS AS THE
PRESSURE GRADIENT REMAINS FAIRLY TIGHT.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
AS OF 1:20 AM EDT SUNDAY: THE EXTENDED FCST PICKS UP AT 12Z ON
WEDNESDAY WITH A VERY LARGE UPPER LOW BEGINNING TO DEVELOP OVER
THE EASTERN/SE CONUS. THE LATEST OPERATIONAL MODELS APPEAR TO
BE COMING INTO BETTER AGREEMENT WITH THIS SCENARIO AND GENERALLY
HAVE THE UPPER LOW LINGER OVER OUR REGION THRU AT LEAST THURSDAY.
ON FRIDAY, THE LOW IS EXPECTED TO LIFT NORTHWARD AND APPEARS TO
REMAIN CLOSED INTO THE WEEKEND. HEIGHTS WILL LIKELY RECOVER SOME-
WHAT ON SATURDAY, HOWEVER MOST OF THE LONG-RANGE GUIDANCE HAS
THE BACKSIDE OF THE LOW AMPLIFY AGAIN JUST TO OUR WEST BY THE
END OF THE PERIOD LATE SATURDAY INTO SUNDAY. AT THE SFC, A ROBUST
LOW WILL DEVELOP ALONG AN ELONGATED BAROCLINIC ZONE THAT STRETCHES
ACROSS THE CENTRAL PLAINS BY THE START OF THE PERIOD EARLY WED.
OVER THE NEXT 24 HRS OR SO, THIS LOW IS EXPECTED TO MOVE OVER OUR
AREA AND THEN LIFT NORTH LATE THURSDAY INTO FRIDAY. IN ITS WAKE,
DRY HIGH PRESSURE SPREADS OVER OUR REGION FROM THE WEST AND LIN-
GERS THRU SATURDAY. OVERALL, THE BEST CHANCES FOR MORE WIDESPREAD
PRECIP STILL APPEAR TO BE ON WEDNESDAY, HOWEVER WE MAINTAIN HIGH-
END SOLID CHANCE TO LIKELY POPS OVER MOST OF OUR FCST AREA THRU
THURSDAY MORNING. 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 SUNDAY THROUGH THURSDAY/
AT KCLT AND ELSEWHERE: WIDESPREAD CIGS ABOVE FL120 THIS MORNING
WITH SCT LOWER CLOUDS AT 100-120. SOME BREAKS POSSIBLE EARLY IN THE
DAY BEFORE A REINFORCING DECK ARRIVES LATER. IN DEVELOPING COLD-AIR
DAMMING REGIME, EXCEPT FOR KAVL WINDS WILL PREVAIL LIGHT NE EARLY
THIS MORNING BECOMING LARGELY 7-10 KT FOR THE MIDDAY/AFTERNOON
AND GUSTS OF 15-20 KT POSSIBLE THEN AND OVERNIGHT TONIGHT. KAVL
INSTEAD WILL REMAIN SE. LOWER VFR CIGS DEVELOP FROM SOUTH TO
NORTH BEGINNING LATE MORNING, WITH PRECIP CHANCES FOLLOWING BY
EVENING. ON ACCOUNT OF DRY AIR AT THE SURFACE PRECIP LIKELY WILL
BE OF LITTLE IMPACT INITIALLY, BUT AS MOISTENING OCCURS AT LOWER
LEVELS, SOME CIG/VSBY RESTRICTIONS WILL DEVELOP. EXCEPT AT KAVL,
ANY RESTRICTIONS ARE NOT LIKELY UNTIL AFTER MIDNIGHT TONIGHT,
WITH LOW MVFR ACROSS MUCH OF THE AREA AFTER DAYBREAK MON. IFR
CAN'T BE RULED OUT, BUT LAMP OFTEN OVERDOES ONSET OF RESTRICTIONS
WHEN WEAKLY FORCED PRECIP OCCURS IN AN ESTABLISHED DRY CAD REGIME,
SO HAVE KEPT THE TAFS SLIGHTLY MORE OPTIMISTIC (LESS RESTRICTIVE)
THAN LAMP.
OUTLOOK: WIDESPREAD PRECIP AND RESTRICTIONS MONDAY, WITH A GOOD
CHANCE OF THOSE LINGERING THROUGH DAYBREAK TUESDAY. CONFIDENCE
LOW HOW MUCH IMPROVEMENT IN CONDITIONS WILL OCCUR TUESDAY, BUT
PERIODIC PRECIP/RESTRICTIONS PROBABLY RETURN IN SOME FASHION FOR
WED AND THU. DRIER WEATHER RETURNS TO END THE WEEK.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...JPT
NEAR TERM...JCW
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...JCW
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