385
FXUS62 KGSP 041917
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
317 PM EDT SUN MAY 4 2025
SYNOPSIS
DRIER WEATHER IS EXPECTED THROUGH TUESDAY WITH TEMPERATURES REMAINING
BELOW NORMAL FOR EARLY MAY. ANOTHER UNSETTLED PATTERN WILL LIKELY DEVELOP
BY MID-WEEK, WITH INCREASED CHANCES FOR RAIN THROUGH THE END OF THE WEEK.
NEAR TERM /THROUGH MONDAY/
AS OF 213 PM EDT SUNDAY: SHAPING UP TO BE A LOVELY AFTERNOON ACROSS
THE FCST AREA, WITH A MORE TEMPERATE AND DRIER AIR MASS MOVING IN
BEHIND A DEPARTED COLD FRONT. SOME MORE CONGESTED CLOUDS ARE NOTED
ACROSS THE MTNS AND A FEW SHOWERS ARE MOVING NORTHEAST UP THE
GREAT VALLEY OF TN, DEVELOPING IN THE COLDER AIR ALOFT COURTESY
OF THE MID/UPPER LOW OVER THE CUMBERLAND PLATEAU REGION. ONLY A
FEW MINOR CHANGES WERE MADE TO THE MTN PRECIP PROBS AND DEWPT/TEMP
TRENDS BECAUSE OF FROPA.
FOR THE NEXT 24 HOURS WE WILL REMAIN UNDER THE CYCLONIC FLOW AROUND
THE UPPER LOW SPINNING OVER THE NORTHERN CUMBERLAND PLATEAU AND
OHIO VALLEY REGIONS. WE SHOULD BE IN THE DRY SLOT FOR THE MOST
PART OVERNIGHT, WITH DRIER AIR HAVING MOVED IN, WHICH SHOULD KEEP
MOST OF THE FOG CHANCES AT BAY. HOWEVER, THE SITUATION IS ALMOST
FALL-LIKE WITH THE UPPER LOW NEARBY, SO SOME THICKER FOG IN THE
LITTLE TN RIVER VALLEY WOULD NOT BE A SURPRISE. LOW TEMPS WILL BE
ON THE ORDER OF FIVE DEGREES UNDER NORMAL. MONDAY LOOKS, ON THE
WHOLE, SIMILAR TO TODAY WITH SCATTERED CLOUDS DEVELOPING ACROSS
THE REGION AND HIGH TEMPS 3-5 DEGREES COOLER THAN USUAL. MIGHT BE
A LITTLE BIT BETTER COVERAGE OF SHOWER ACTIVITY AS VORT CENTERS
ROTATE AROUND THE UPPER LOW AND PROVIDE A BIT OF SUPPORT, SO PRECIP
CHANCES ARE MORE EXPANSIVE, BUT STILL CONFINED TO THE MOUNTAINS. A
RUMBLE OF THUNDER IS ALSO POSSIBLE OVER MAINLY THE NRN MOUNTAINS.
SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/
AS OF 2:45 PM EDT SUNDAY, KEY MESSAGES:
1. TUESDAY IS STILL LOOKING MOSTLY DRY WITH NEAR-NORMAL TEMPERATURES.
3. WIDESPREAD PRECIPITATION CHANCES INCREASE ON WEDNESDAY WITH TEMPER-
ATURES TRENDING BELOW NORMAL UNDER INCREASING CLOUD COVER.
THE SHORT-TERM FCST PICKS UP AT 00Z ON TUESDAY WITH A CLOSED UPPER
LOW STILL CENTERED TO OUR NW OVER THE MID TO LOWER OH VALLEY. THE
LOW WILL EVENTUALLY OPEN BACK UP TO THE MEAN UPPER FLOW AND DISSIPATE
BY THE END OF THE PERIOD LATE WEDNESDAY. AT THE SAME TIME, WEAK UPPER
RIDGING TRIES TO BUILD OVER THE SE FROM THE GULF. AT THE SFC, WEAK
HIGH PRESSURE ON THE UPSTREAM SIDE OF A LARGER SFC LOW WILL SPREAD
OVER OUR AREA AS THE PERIOD BEGINS. THIS SHOULD LIMIT ANY CONVECTIVE
POTENTIAL ACROSS OUR AREA WITH ONLY A SLIGHT CHANCE OF PRECIPITATION
LINGERING OVER THE NORTHERN NC MTNS. WIDESPREAD PRECIP CHANCES RETURN
ON WEDNESDAY AS A WARM FRONT LIFTS OVER THE FCST AREA, BUT IT REMAINS
UNCLEAR HOW QUICKLY THIS FRONT WILL PROGRESS NORTHWARD. OTHERWISE,
TEMPERATURES WILL BE NEAR-NORMAL ON TUESDAY AND LIKELY BELOW NORMAL
BY WEDNESDAY UNDER INCREASING CLOUD COVER.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
AS OF 2:25 PM EDT SUNDAY, KEY MESSAGES:
1. WIDESPREAD PRECIP CHANCES RETURN BY WEDNESDAY AS A WARM FRONT
LIFTS OVER THE FCST AREA. PRECIPITATION CHANCES PERSIST EACH DAY
THRU THE WEEKEND.
2. FORECAST CONFIDENCE REMAINS RELATIVELY LOW FOR MOST OF THE
EXTENDED PERIOD DUE TO UNCERTAINTY REGARDING THE LOCATION OF
THE FRONT.
THE EXTENDED FCST PICKS UP AT 00Z ON THURSDAY WITH CONFLUENT UPPER
FLOW WITHIN WHAT'S LEFT OF A DECAYING OMEGA BLOCK KEEPING WEAK SFC
HIGH PRESSURE OVER THE WESTERN CAROLINAS. ON THURS, ROBUST CANADIAN
HIGH PRESSURE DIVES SOUTHWARD OVER THE GREAT LAKES AND TOWARDS OUR
AREA. THIS HIGH WILL PUSH A BACKDOOR COLD FRONT SOUTHWARD AND TOWARDS
OUR CWA. AT THE SAME TIME, ANOTHER SFC LOW TRIES TO SPIN UP ALONG THE
ASSOCIATED BAROCLINIC ZONE BY EARLY FRI. IT'S NOT CLEAR HOW LONG THIS
LOW MAY LINGER OVER OUR REGION, BUT IT COULD KEEP PRECIP CHANCES OVER
OUR AREA THRU MUCH OF THE WEEKEND. WITH THE POOR RUN-TO-RUN CONSISTENCY
CONTINUING AMONG THE LONG-RANGE MODELS, I KEPT A RELATIVELY LONG STRETCH
OF CHANCE POPS FOR MUCH OF THE PERIOD. IF THE SFC HIGH ENDS UP BEING
STRONGER AND ADVANCES FURTHER SOUTH BY THE WEEKEND, THINGS WILL LIKELY
BE DRIER. TEMPERATURES START OUT NEAR-NORMAL ON THURSDAY, BUT TREND
BELOW NORMAL FOR THE REST OF THE PERIOD.
AVIATION /19Z SUNDAY THROUGH FRIDAY/
AT KCLT AND ELSEWHERE: VFR AT ALL TERMINALS THROUGH THE PERIOD. FOR
THE AFTERNOON, A DRIER POST-FRONTAL AIR MASS HAS TAKEN OVER, WITH
COLDER AIR ALOFT ALLOWING FOR A NICE STRATOCU FIELD. TERMINALS WILL
BE IN-AND-OUT OF A SCT/BKN CLOUD DECK WITH A BASE BETWEEN 040-050,
SO ALL GET A TEMPO FOR BKN CEILING. WIND MAY OCCASIONALLY GUST
FROM THE SW DUE TO DEEP ENOUGH MIXING. THE GUSTS WILL DIMINISH
TOWARD SUNSET AND THE LOW CLOUDS WILL MELT AWAY WITH THE LOSS OF
HEATING. WIND WILL BE LIGHT WSW OVERNIGHT. ON MONDAY, EXPECT THE
SCATTERED STRATOCU TO RETURN WITH LATE MORNING HEATING.
OUTLOOK: VFR EXPECTED THROUGH THE FIRST PART OF THE
WEEK. RESTRICTIONS WILL RETURN FROM MID-WEEK ONWARD AS A FRONT
STALLS NEARBY.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...JPT
NEAR TERM...PM
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...PM
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