437
FXUS62 KGSP 300252
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1052 PM EDT SAT MAR 29 2025
SYNOPSIS
MOISTURE RETURNS AND BRINGS ABOVE NORMAL TEMPERATURES TO THE REGION.
SHOWER AND THUNDERSTORM CHANCES INCREASE SUNDAY INTO MONDAY AS A
COLD FRONT CROSSES THE AREA. DRY HIGH PRESSURE RETURNS TUESDAY,
FOLLOWED BY AN UNSETTLED PATTERN MID-WEEK.
NEAR TERM /THROUGH SUNDAY NIGHT/
AS OF 10:05 PM EDT SATURDAY: PRETTY MUCH ALL OF THE SHOWER ACTIVITY
HAS FIZZLED OUT ACROSS OUR CWA OVER THE PAST FEW HRS. THIS ACTIVITY
HAS BEEN DEVELOPING AHEAD OF A WEAK H5 SHORTWAVE, BUT THAT FEATURE
IS NOW LIFTING NE OF OUR AREA. I EXPECT THE LULL IN SHOWER ACTIVITY
TO PERSIST WELL INTO THE OVERNIGHT, WITH MORE SHOWERS FOR THE MORNING
HRS. LOW TEMPS SHOULD BE SEASONALLY MILD WITH THE PERSISTENT CLOUD
COVER, WITH LOWS ON THE ORDER OF 10 TO 15 DEGREES ABOVE NORMAL.
OTHERWISE, A SLY FLOW REGIME HAS BEEN ESTABLISHED BETWEEN A LARGE
SFC HIGH PARKED WELL OFF THE CAROLINA COAST AND AN APPROACHING COLD
FRONT. THIS WILL CONTINUE TO ALLOW A GRADUAL INCREASE IN MOISTURE
THRU THE OVERNIGHT AND SUNDAY. OVER THE NC MTNS, WE CAN EXPECT MORE
SHOWERS TO DEVELOP BY THE PRE-DAWN HRS ON SUNDAY AS LOW-LEVEL ISEN-
TROPIC UPGLIDE IS SUFFICIENT ENOUGH TO SUPPORT PRECIP. OUTSIDE OF
THE MTNS, MORNING PRECIP LOOKS LESS LIKELY. THE CONVECTIVE PRECIP
POTENTIAL IMPROVES AS THE DAY WEARS ON, AND MOISTURE GETS PROGRE-
SSIVELY DEEPER AND THE ISENTROPIC LIFT MORE EFFICIENT. FORTUNATELY,
IT STILL APPEARS THAT THE HIGHER QPF AMOUNTS ARE GENERALLY MORE
LIKELY OVER AREAS WHERE WILDFIRES HAVE BEEN BURNING. THE MOST RECENT
CAMS STILL SHOW DECENT PRECIP COVERAGE MAKING WEST-TO-EAST PROGRESS
THRU THE DAY. IN ADDITION, SOME OF THE NEAR-TERM GUIDANCE CONTINUES
TO DEVELOP AREAS OF SFC-BASED CAPE GREATER THAN 500 J/KG DURING THE
AFTERNOON/EARLY EVENING, SO SOME THUNDERSTORMS WILL BE POSSIBLE OVER
MUCH OF OUR FCST AREA. OTHERWISE, TEMPERATURES WILL REMAIN ABOUT 4 TO
8 DEGREES ABOVE CLIMATOLOGY ON SUNDAY.
SHORT TERM /MONDAY THROUGH TUESDAY/
KEY MESSAGES:
1) SHOWERS AND THUNDERSTORM CHANCES INCREASE SUNDAY NIGHT THROUGH
MONDAY.
2) STRONG TO SEVERE THUNDERSTORMS POSSIBLE MONDAY WITH A COLD FRONT
MOVING INTO THE AREA.
3) DRY WEATHER RETURNS TUESDAY WITH RAIN CHANCES INCREASING BY
MIDWEEK.
AS OF 150 PM SATURDAY: PICKING UP SUNDAY NIGHT, ONGOING SCATTERED
SHOWERS ARE POSSIBLE AHEAD OF A COLD FRONT CONTINUES ITS TREK TOWARD
THE CWA. AN AREA OF LOW PRESSURE OVER THE CENTRAL CONUS LIFTS NE AND
PROVIDES THE NEXT FORCING MECHANISM FOR STRONG TO POTENTIALLY SEVERE
WEATHER. STRONG SOUTHERLY SURFACE FLOW ADVECTS MOISTURE INTO THE
AREA AND BY SUNDAY NIGHT, INCREASING DEWPOINTS AND PRIMING THE
REGION FOR THUNDERSTORM CHANCES ON MONDAY. CURRENT GUIDANCE
INCREASES PWATS INTO THE 1-1.5 INCH RANGE AND BRINGS A DECENT SWATH
OF DPVA THROUGH WITH THE FRONT. BY MONDAY, THE COLD FRONT IS STILL
ON TRACK TO PUSH INTO THE CWA, BRINGING A RISK FOR SHOWERS AND
THUNDERSTORMS. HOWEVER, LATEST GUIDANCE HAS SLOWED THE FROPA A BIT
AND ARE NOT IN COMPLETE AGREEMENT WITH TIMING, BUT STILL HAVE THE
LINE MOVING THROUGH MONDAY MORNING INTO THE AFTERNOON. SHOULD THE
FRONT TAKE ITS TIME AND MOVE IN TOO EARLY, THIS COULD INHIBIT SEVERE
POTENTIAL WITH INSTABILITY BECOMING MORE ROBUST AND AVAILABLE
FURTHER TO THE EAST. GUIDANCE FROM NBM/GFS SHOWS A FEW HUNDRED
JOULES OF SBCAPE AND MODEST SHEAR OF 40-50KTS. MODELED SOUNDINGS IN
THE NC PIEDMONT DO SHOW A BIT OF CURVATURE AND 0-1KM SRH IN THE 100-
150 RANGE, SUGGESTING THAT THERE IS A NONZERO CHANCE FOR AN
ENVIRONMENT THAT COULD SUPPORT TORNADO DEVELOPMENT. AT THIS POINT,
THE STORM PREDICTION CENTER HAS HIGHLIGHTED THE AREA FOR POTENTIAL
SEVERE WEATHER, BUT THERE IS STILL UNCERTAINTY THIS FAR OUT. AS
HIGHLIGHTED YESTERDAY, A POSSIBLE LIMITATION TO THE SEVERE POTENTIAL
HERE, OTHER THAN THE EARLIER TIMING OF THE FRONT ARRIVAL, IS IF
SEVERE WEATHER DEVELOPS FURTHER SOUTH. THIS COULD INHIBIT MOISTURE
TRANSPORT AND DISRUPT THE NECESSARY INGREDIENTS FOR STRONGER
CONVECTION, LEAVING MORE SHOWERY STORMS BEHIND. ADDITIONALLY, QPF
RESPONSE CONTINUES TO BE LESS THAN IMPRESSIVE OVER THE SHORT PERIOD,
WHICH DOESN'T CONTRIBUTE MUCH IN THE WAY OF RELIEF FOR THE ONGOING
WILDFIRES. STORM TOTALS FROM SUNDAY THROUGH MONDAY NIGHT HAVE
ANYWHERE FROM 0.5 TO 1.5 INCHES, WITH THE STRONGEST SIGNAL ACROSS
THE FAR WESTERN NC MOUNTAINS AND NE GEORGIA COUNTIES. TRENDS ARE NOT
LOOKING BETTER AT THIS POINT, BUT WHERE RAIN IS NEEDED THE MOST IS
AT LEAST WHERE THE RAIN IS EXPECTED TO FALL. AFTER THE FROPA, HIGH
PRESSURE RETURNS AND SHUNTS RAIN CHANCES ON TUESDAY. TEMPERATURES
WILL REMAIN A TICK ABOVE NORMAL.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
KEY MESSAGES
1) UNSETTLED PATTERN WITH SOME RAIN CHANCES THROUGH THE BEGINNING OF
NEXT WEEKEND.
2) TEMPERATURES WARM TO WELL ABOVE NORMAL THROUGH THE PERIOD.
AS OF 200 PM SATURDAY: BY TUESDAY NIGHT, SURFACE HIGH PRESSURE
EXPANDS SOUTHWARD FROM CANADA AND SUPPRESSES RAIN CHANCES ONCE
AGAIN. THE GENERAL SYNOPTIC FLOW TURNS MORE QUASI-ZONAL INTO MID
WEEK BEFORE A TROUGH BUILDS IN ACROSS THE ROCKIES AND BRINGS MID-
LEVEL FLOW OUT OF THE SW. MEANWHILE, AN AREA OF HIGH PRESSURE BEGINS
TO BUILD AGAIN OVER THE ATLANTIC AND AMPLIFY WESTWARD BY THE END OF
THE WEEK. WEDGED BETWEEN THESE TWO PATTERNS IS THE SOUTHEAST,
PRIMING THE AREA FOR CONSISTENT MOISTURE FETCH AS SURFACE WINDS
REMAIN S/SW. LONG RANGE GUIDANCE FROM THE GFS/EURO HINT AT ANOTHER
POSSIBLE FRONTAL PASSAGE BY MID-WEEK, HOWEVER THE HIGH PRESSURE
COULD SHUNT IT OFF TO THE NORTH. DEPENDING ON HOW FAR THE HIGH
AMPLIFIES, WHICH BOTH THE GFS/EURO HAVE MUCH FURTHER WEST THAN
PREVIOUS RUNS, COULD SHUNT SOME OF THE POTENTIAL FOR RAINFALL.
EITHER WAY, THE EXTENDED PERIOD LOOKS UNSETTLED AND WETTER THAN WHAT
HAS BEEN SEEN IN RECENT WEEKS. THERE REMAINS A LOT OF UNCERTAINTY
INTO HOW THESE AIR MASSES WILL INTERACT AND WHAT AMOUNTS OF
PRECIPITATION COULD FALL ACROSS THE CWA. ADDITIONALLY, THE AREA
COULD SEE TEMPERATURES IN THE 80S TOWARD THE END OF THE FORECAST
PERIOD DEPENDING ON THE STRENGTH OF THE BUILDING RIDGE. OVERALL,
EXPECT WELL-ABOVE NORMAL TEMPERATURES AND A DECREASE IN CRITICAL
FIRE WEATHER CONDITIONS.
AVIATION /03Z SUNDAY THROUGH THURSDAY/
AT KCLT AND ELSEWHERE: WE'RE STILL SEEING SOME LIGHT SHOWER ACTI-
VITY AROUND KAVL THIS EVENING, BUT IT'S DOUBTFUL THAT THEY WILL
SEE ANY RESTRICTIONS FROM IT. OTHERWISE, DEEPER MOISTURE WILL
CONTINUE TO GRADUALLY INCREASE TONIGHT/OVERNIGHT, ALLOWING SCT
SHOWER ACTIVITY TO DEVELOP AND MOVE IN FROM THE WEST DURING THE
MORNING. STILL EXPECT CIG RESTRICTIONS TO DEVELOP FROM WEST TO
EAST BEGINNING AROUND 09Z OVER OUR FCST AREA WITH PREVAILING MVFR
FOR MOST SITES. THERE'S A DECENT CHANCE THAT SOME SITES WILL SEE
IFR CIGS BY MID TO LATE MORNING, BUT I WAS ONLY CONFIDENT ENOUGH
TO INCLUDE THIS AT KAVL AND KAND. I HAVE PROB30S FOR SHRA BEGINNING
BY LATE MORNING FOR MOST SITES, WITH PREVAILING SHRA FOR THE AFTN/
EARLY EVENING, WITH PRECIP TAKING A BIT LONGER TO REACH KCLT AND
KHKY. I ALSO INCLUDED A PROB30 FOR TSRA FOR THE UPSTATE TERMINALS
BEGINNING AROUND 19Z, AS THEY APPEAR TO HAVE SOME AMOUNT OF SFC-
BASED INSTABILITY PRESENT. WINDS SHOULD REMAIN GENERALLY S TO SSW
THRU THE TAF PERIOD, WITH LOW-END GUSTS POSSIBLE AGAIN SUNDAY AFTN.
OUTLOOK: SHRA/TSRA AND ASSOCIATED RESTRICTIONS POSSIBLE ON MONDAY.
DRYING IS EXPECTED ON TUESDAY WITH MORE PRECIP POSSIBLE BY LATE WEEK.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...CP
NEAR TERM...JPT
SHORT TERM...CP
LONG TERM...CP
AVIATION...JPT
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