449
FXUS62 KGSP 280608
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
208 AM EDT WED MAY 28 2025
SYNOPSIS
COOL HIGH PRESSURE WILL MOVE OFF THE EAST COAST TONIGHT AND
WEDNESDAY RESULTING IN WARMER TEMPERATURES WEDNESDAY. LOW
PRESSURE MOVES ALONG A FRONT TOWARD OUR REGION CROSSING
OUR AREA THURSDAY NIGHT AND FRIDAY WITH MORE RAIN. A SLOW
MOVING WEAK COLD FRONT WILL DRIFT TOWARD THE CAROLINA COAST BY
FRIDAY NIGHT. DRIER WEATHER MOVES OVER OUR AREA FOR THE
WEEKEND AND INTO NEXT WEEK.
NEAR TERM /THROUGH TODAY/
AS OF 12:35 AM EDT WEDNESDAY: THE BROAD ARC OF SHOWERS HAS MOVED
EAST OF OUR CWA OVER THE PAST HR OR SO. ANOTHER BAND OF SCT SHOWERS
IS CURRENTLY MAKING ITS WAY OVER EASTERN/CENTRAL TN AND WILL GRA-
DUALLY APPROACH OUR WESTERN ZONES OVER THE NEXT FEW HRS. MOST OF
THE LATEST CAM GUIDANCE HAS THIS ACTIVITY DIMINISHING AS IT NEARS
OUR CWA, BUT WE WILL LIKELY GET SOME ADDITIONAL LIGHT SHOWERS FROM
IT AS INCREASINGLY SHALLOW UPGLIDE WILL PERSIST INTO THE MORNING
WITH THE WEDGE NOT EXPECTED TO ERODE UNTIL MID TO LATE MORNING.
OTHERWISE, SFC HIGH PRESSURE WILL SLIDE OFF THE EAST COAST, WHILE
A WEAK LOW PRESSURE SYSTEM DEVELOPS NEAR THE TIDEWATER AREA. MEAN-
WHILE, 850 MB FLOW VEERS TO WESTERLY AND HELPS SCOUR OUT THE CAD
WEDGE. SO A PRONOUNCED REBOUND IN TEMPS WITH SCATTERING OUT OF THE
LOW CLOUDS IS EXPECTED ACROSS THE ENTIRE AREA. THERE WILL BE SOME
SFC-BASED CAPE PRESENT, BUT CONVECTION IS EXPECTED TO LACK A GOOD
TRIGGER. ISOLATED TO WIDELY SCATTERED SHOWERS AND ISOLATED THUNDER-
STORMS IS EXPECTED LATE AFTN INTO EARLY EVENING, HIGHEST IN THE
MOUNTAINS. HIGHS WILL BE BACK INTO THE UPPER 70S TO LOWER 80S IN
THE LOWER VALLEYS AND PIEDMONT.
SHORT TERM /TONIGHT THROUGH FRIDAY/
KEY MESSAGES:
1) SHOWER CHANCES INCREASE THURSDAY
2) SHOWERS AND THUNDERSTORMS POSSIBLE FRIDAY WITH A COLD FRONT
3) TEMPERATURES REBOUND TO NORMAL
AS OF 140 PM TUESDAY: PICKING UP WEDNESDAY NIGHT, THE PATTERN
BECOMES MORE UNSETTLED THROUGH THE SHORT TERM. SYNOPTICALLY, BROAD
SW FLOW OVER THE SOUTHEAST TO START WITH EMBEDDED SHORTWAVES MOVING
THROUGH INTO THURSDAY NIGHT. THIS ADDITIONAL UPPER FORCING SUPPORT
INCREASES RAIN CHANCES ACROSS THE CWA. CAPPING POPS AT CHANCE (45-
60%). CURRENT GUIDANCE SHOWS MINIMAL INSTABILITY DURING THE
AFTERNOON HOURS, KEEPING THUNDERSTORM CHANCES LOW. CANNOT RULE OUT A
RUMBLE OF THUNDER. FOR FRIDAY, THE PATTERN REMAINS UNSETTLED AS
GUIDANCE SHOWS A TROUGH AND UPPER LOW SWINGING SOUTHWARD, BRINGING A
COLD FRONT ACROSS THE CWA. AT THIS TIME, THE FROPA LOOKS TO SWEEP
THROUGH FRIDAY, REACHING EAST OF THE MOUNTAINS AROUND PEAK HEATING.
CURRENT MODELS ARE NOT AS EXCITED WITH RELATIVELY MODERATE BULK
SHEAR OF 25-30KTS AND A FEW HUNDRED JOULES OF SBCAPE. MODELED
SOUNDINGS FROM THE GFS, FOR WHAT IT'S WORTH, SHOW A PROFILE THAT
COULD SUPPORT A FEW STRONG THUNDERSTORMS, BUT SEVERE IS LIMITED AT
THIS TIME. HOWEVER, DEPENDING ON WHERE THIS FRONT PASSES THROUGH AND
WHEN IT OCCURS WILL PLAY A ROLE IN HOW THESE STORMS EVOLVE.
CURRENTLY, SPC HAS HIGHLIGHTED AN AREA JUST ON THE EASTERN FRINGE OF
THE CWA, SO WILL CONTINUE TO MONITOR AS THINGS WILL CHANGE. POPS
REMAIN HIGH (70-80%) RANGE AS THERE IS DECENT WIDESPREAD QPF
RESPONSE WITH THIS SYSTEM. TEMPERATURES SHOULD REBOUND CLOSER TO
NORMAL.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
KEY MESSAGES
1) RAIN CHANCES INCREASE SUNDAY ACROSS THE NC MOUNTAINS
2) HIGH PRESSURE BUILDS IN TO START THE WEEK AND MOSTLY DRY
CONDITIONS RETURN
3) TEMPERATURES GRADUALLY WARM THROUGH THE PERIOD
AS OF 200 PM TUESDAY: BY FRIDAY NIGHT, THE UPPER LOW BEGINS TO LIFT
NE, DRAGGING THE REMNANT COLD FRONT OUT OF THE AREA. BEHIND THE
FRONT, MUCH DRIER AIR FILTERS IN AS NW FLOW BRINGS IN THE LESS MUGGY
AIR INTO THE REGION. THROUGH THE WEEKEND, THE TROUGH REMAINS
STEADILY OVERHEAD AS A RIDGE BUILDS IN OUT WEST. THIS SHOULD HELP TO
KEEP RAIN CHANCES DOWN ON SATURDAY FOR A PORTION OF THE CWA.
GUIDANCE AT THIS TIME SETS UP A PERSISTENT NW FLOW OVER THE NC
MOUNTAINS, WITH LINGERING SURFACE MOISTURE. CANNOT RULE OUT A FEW
LIGHT SHOWERS BUT POPS REMAIN AT SLIGHT CHANCE (15-30%) AT BEST.
LOOKING AHEAD INTO SUNDAY, LONG RANGE GUIDANCE FROM THE GFS/EURO
WANT TO SEND A VORTICITY LOBE SCREAMING DOWN THE WESTERN SIDE OF THE
TROUGH. THIS MEANS BRINGING A HICCUP IN THE UPPER FLOW AND
ADDITIONAL FORCING, THAT COULD CONTRIBUTE TO INCREASING PRECIP
CHANCES. THIS IS STILL 5-6 DAYS OUT, SO WON'T LOCK ANYTHING IN AT
THIS TIME. HOWEVER, SHOWER CHANCES INCREASE SLIGHTLY, MOSTLY OVER
THE MOUNTAINS (30-40%). LOOKING EVEN FURTHER INTO THE FORECAST, THE
SYNOPTIC PATTERN STARTS TO TURN DRIER AS A QUASI-OMEGA BLOCKING
PATTERN ATTEMPTS TO EMERGE AT THE BEGINNING OF NEXT WEEK. THIS TIME,
THE RIDGE AXIS LOOKS TO PUSH FURTHER EASTWARD AND BRING MUCH DRIER
WEATHER FOR THE AREA AS WHOLE, BUT TYPICAL DIURNALLY DRIVEN POP UP
SHOWERS EMERGE. ALL IN ALL, THE EXTENDED LOOKS TO HAVE A MIX OF
MOSTLY DRY WEATHER AND A FEW SHOWERS. TEMPERATURES LOOK TO GRADUALLY
INCREASE THROUGHOUT THE PERIOD AND REMAIN AT OR JUST ABOVE NORMAL BY
THE END OF THE PERIOD.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
AT KCLT AND ELSEWHERE: A COOL-AIR DAMMING WEDGE REMAINS IN PLACE
ACROSS THE REGION. OUR FCST AREA IS CURRENTLY BETWEEN TWO BROAD
BANDS OF PRECIP, ONE TO OUR EAST AND ONE TO OUR WEST. THE BAND TO
OUR WEST WILL LIKELY IMPACT SOME OF OUR TERMINALS OVER THE NEXT
FEW HRS, SO I HAVE TEMPOS FOR -RA AT MOST TERMINALS. OTHERWISE,
EXPECT CIGS TO REMAIN IFR THRU MUCH OF THE MORNING WITH VISBY
BEING MORE UNCERTAIN. AT PRESENT, MOST TERMINALS ARE REPORTING
VFR VISBY, BUT THIS WILL LIKELY FLUCTUATE THRU THE MORNING DEPEN-
DING ON WHO GETS SHOWERS AND HOW LONG THEY LINGER. THE CAD EROSION
PROCESS IS EXPECTED TO BEGIN BY MID TO LATE MORNING AS WINDS VEER
AND THE LOW-LEVEL UPGLIDE DIMINISHES. EXPECT CIGS TO LIFT TO MVFR
BY LATE MORNING AT MOST TERMINALS, AND THEN VFR BY THE EARLY TO MID
AFTERNOON. IN ADDITION, THE LATEST NEAR-TERM GUIDANCE CONTINUES TO
GENERATE SCT SHOWERS ACROSS OUR AREA THIS EVENING, WITH THUNDER
LOOKING MORE LIKELY OVER THE MTNS. THUS, I INCLUDED PROB30S FOR
SHRA AT ALL OUR TAF SITES (EXCEPT KAVL), BEGINNING AROUND 20 TO
22Z. AT KAVL, I HAVE A PROB30 FOR TSRA FROM 18 TO 24Z TODAY.
OTHERWISE, WINDS WILL REMAIN LIGHT AND FROM THE N TO NE THRU
AT LEAST MID-MORNING. THEY WILL VEER AROUND TO SW BY THE AFTN.
OUTLOOK: SHOWER AND THUNDERSTORM CHANCES AND ASSOCIATED RESTRICTIONS
CONTINUE THRU THE REMAINDER OF THE WORK WEEK WITH DRIER CONDITIONS
EXPECTED BY THE START OF THE WEEKEND.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...DEO
NEAR TERM...JPT/WIMBERLEY
SHORT TERM...CP
LONG TERM...CP
AVIATION...JPT
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