500
FXUS62 KGSP 281816
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
216 PM EDT FRI MAR 28 2025
SYNOPSIS
HIGH PRESSURE DRIFTS FURTHER EAST, ALLOWING MOISTURE AND ABOVE
NORMAL TEMPERATURES TO RETURN ACROSS THE REGION. SHOWER AND
THUNDERSTORM CHANCES INCREASE SUNDAY INTO MONDAY AS A COLD FRONT
CROSSES THE AREA. DRY HIGH PRESSURE RETURNS TUESDAY, FOLLOWED BY
ANOTHER APPROACHING FRONT MID-WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 138 PM: THE FORECAST CONTINUED TO MOVE ALONG AS EXPECTED, WITH
NO CHANGES SUGGESTED BY SATELLITE/OBS TRENDS. TEMP/DEWPT WERE BOTH
MORE OR LESS BEHAVING. REGULAR UPDATE WILL FOLLOW MOMENTARILY...
OTHERWISE...A RELATIVELY STRONG AND WELL DEFINED SFC HIGH WILL
PERSIST OFF THE SOUTH ATLANTIC COAST TODAY. AN ELEVATED WARM
FRONT NORTH OF THE REGION IS RESPONSIBLE FOR THE PATCHY HIGH-BASED
CLOUD COVER NOW OVER THE NC PIEDMONT. A FEW SIMILAR PATCHES MAY BE
REENTER FROM THE WEST THIS MORNING, BUT THE FRONT AND MOISTURE WILL
ADVECT OUT AS MID TO UPPER LEVEL RIDGE AXIS DRIFTS EASTWARD AND
OVER THE CWA. THUS, THESE CLOUDS WILL BE SHORT-LIVED AND MOSTLY
SUNNY SKIES ARE EXPECTED, ALTHOUGH SOME WISPY CIRRUS STILL WILL
STREAM IN. WITH A MILDER START VICE THURSDAY, AND THICKNESSES
BEING HIGHER UNDER THE RIDGE, MAX TEMPS WILL BE AROUND 10 DEGREES
WARMER TODAY, HITTING 80 IN SOME PIEDMONT LOCATIONS. LOW LEVEL WINDS
WILL CONTINUE TO BE SOUTHWESTERLY, HELPING TO BUOY DEWPOINTS. THAT
SAID, MODIFYING PROG SOUNDINGS TO REFLECT WARMER TEMPERATURES THAN
THE RAW MODEL VALUES SUGGESTS DEEPER MIXING WILL OCCUR THAN WHAT
SAID MODELS DEPICT, TAPPING INTO A DRY SUBSIDENT LAYER ABOVE THE
PBL. RH SHOULD EASILY FALL BELOW 30 PERCENT, AND GUSTS OF 20-25
MPH WILL OCCUR ON RIDGETOPS AND PARTS OF THE PIEDMONT. RED FLAG
WARNING REMAINS IN EFFECT FOR A PORTION OF THE MOUNTAINS/FOOTHILLS;
AN INCREASED FIRE DANGER STATEMENT WILL BE ISSUED FOR THE REST OF
OUR ZONES. IT IS WORTH NOTING THAT A FEW CAMS FEATURE SLIGHT CAPE
DEVELOPING ATOP THE DEEP PBL, ON THE UPSTREAM SIDE OF THE RIDGE
(OUR WESTERN MOUNTAINS) WHICH LEADS TO SREF POPS OF UP TO AROUND 20%
IN THAT AREA. HOWEVER, THE SREF "RUNS HOT" WITH POPS, AND FORCING
WILL BE SO WEAK AND THE PBL SO DEEP/DRY IN THAT SCENARIO THAT NO
MENTION OF POP APPEARS NECESSARY IN THE OFFICIAL FCST.
FLOW AROUND THE RIDGE WILL CONTINUE TONIGHT WITH LARGELY S TO SW
WINDS AT 925-850 MB. INITIALLY MOSTLY CLEAR SKIES WILL ALLOW FOR
SOME DEGREE OF DECOUPLING, SO MIXING WILL WEAKEN. MOISTURE RETURN
WILL CONTINUE IN THAT LAYER, AND MECHANICAL LIFT PROBABLY WILL
RESULT IN CLOUD COVER ALONG THE SOUTH-FACING BLUE RIDGE ESCARPMENT
(MOUNTAINS ALONG THE SOUTHERN BORDER OF NC). STILL PROBABLY TOO
SHALLOW FOR PRECIP, BUT THIS WILL RESULT IN EXPANDING LOW CLOUD
COVER IN THAT AREA. CIRRUS INCREASE OTHERWISE. ALONG WITH LIGHT
SW WINDS, THE CLOUDS LEAD TO MIN TEMPS WILL BE AROUND 10 ABOVE
NORMAL SATURDAY MORNING.
SHORT TERM /SATURDAY THROUGH MONDAY/
KEY MESSAGES:
1) SHOWERS AND THUNDERSTORM CHANCE INCREASE SATURDAY NIGHT THROUGH
MONDAY.
2) STRONG TO SEVERE THUNDERSTORMS POSSIBLE MONDAY WITH A COLD FRONT
MOVING INTO THE AREA.
AS OF 155 PM FRIDAY: PICKING UP ON SATURDAY NIGHT, A STRONG AREA OF
SURFACE HIGH PRESSURE SITUATED OVER THE ATLANTIC STARTS TO SLIDE
EASTWARD, INCREASING MOISTURE OVER THE SOUTHEAST. MEANWHILE, AN AREA
OF LOW PRESSURE STARTS TO DEVELOP OVER THE CENTRAL CONUS AND LIFTS
NE BY SUNDAY, INCREASING RAIN CHANCES ACROSS THE AREA. S/SW WINDS
HELP TO INCREASE THE MOISTURE RETURN AS GUIDANCE HAS PWATS
INCREASING TO THE 1-1.5 INCH RANGE. POPS START TO RAMP UP SATURDAY
NIGHT AND BY SUNDAY, CHANCE POPS EXPECTED AHEAD OF THE COLD FRONT.
BY MONDAY, A COLD FRONT FROM THE SURFACE LOW TO THE NORTH IS
EXPECTED TO PUSH INTO THE CWA, BRINGING A RISK FOR SHOWERS AND
THUNDERSTORMS IN THE AFTERNOON/EVENING TIME RANGE. GUIDANCE AT THIS
POINT REMAINS MURKY ON HOW THE INGREDIENTS WILL PLAY OUT. AS OF NOW,
THE FRONT TIMING COULD PLAY A KEY ROLE IN THUNDERSTORM/SEVERE
CHANCES. MONDAY AFTERNOON, GUIDANCE FROM NBM/GFS SHOWS A FEW HUNDRED
JOULES OF SBCAPE AND MODEST SHEAR OF 40-50KTS. AT THIS POINT, THE
STORM PREDICTION CENTER HAS HIGHLIGHTED THE AREA FOR POTENTIAL
SEVERE WEATHER, BUT THERE IS STILL UNCERTAINTY THIS FAR OUT. ONE
POSSIBLE LIMITATION COULD BE THE CHANCE FOR SEVERE WEATHER TO THE
SOUTH, INHIBITING ENOUGH INSTABILITY AND MOISTURE TO BE IN PLACE
ACROSS THE CWA AT THE TIME OF THE FROPA. AGAIN, THIS COULD CHANGE
BUT IT'S ONE LIMITATION WITH CURRENT GUIDANCE. ADDITIONALLY,
RAINFALL OVER THE SHORT PERIOD DOESN'T LOOK HEAVY ENOUGH TO SUPPRESS
ONGOING WILDFIRES. THERE'S A PROBABILITY OF 40-50% OF HALF AN INCH
OR MORE ACROSS THE WESTERN ZONES ON MONDAY. WHERE RAIN IS NEEDED THE
MOST IS AT LEAST WHERE THE RAIN IS EXPECTED TO FALL, BUT THERE IS
STILL UNCERTAINTY TO TOTALS THIS FAR OUT. TEMPERATURES AT IF NOT A
TICK ABOVE NORMAL.
LONG TERM /MONDAY NIGHT THROUGH THURSDAY/
KEY MESSAGES
1) DRY WEATHER RETURNS TUESDAY WITH RAIN CHANCES INCREASING BY MID
WEEK.
2) TEMPERATURES REMAIN ABOVE NORMAL THROUGH THE PERIOD.
AS OF 200 PM FRIDAY: BY MONDAY NIGHT, THE REMNANT COLD FRONT SHOULD
BE EXITING THE CWA AND LEAVING DRIER AIR TO FILTER IN ONCE AGAIN
BEHIND IT. THE GENERAL SYNOPTIC FLOW TURNS MORE BROAD AND SW THROUGH
THE END OF THE PERIOD, INCREASING MOISTURE ACROSS THE SOUTHEAST.
LONG RANGE GUIDANCE FROM THE GFS/EURO HINT AT ANOTHER POSSIBLE
FRONTAL PASSAGE BY MID-WEEK, INCREASING RAIN CHANCE PROBS.
CONFIDENCE IS LOW ON ANY ORGANIZED SYSTEM AT THIS POINT. OVERALL,
THE EXTENDED LOOKS TO BE MORE UNSETTLED WITH MORE MOISTURE AND
POSSIBLE RAINFALL. THIS COULD IMPROVE FIRE WEATHER CONCERNS BUT IT'S
STILL TOO EARLY TO DRAW CONCLUSIONS. TEMP WISE, EXPECT WELL-ABOVE
NORMAL TEMPERATURES AND A RETURN TO SPRING WEATHER ONCE AGAIN.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
AT KCLT AND ELSEWHERE: THE SMOKE PLUME FROM THE TABLE ROCK FIRE
COMPLEX WAS DRIFTING NNE PAST KAVL, AND COULD OCCASIONALLY BRING
A VIS RESTRICTION IN SMOKE THROUGH THE NEXT SEVERAL HOURS. OTHER
THAN THAT...PREVAILING VFR AT ALL TERMINALS THRU TONIGHT. MID-LEVEL
CLOUDS WILL INVADE AFTER MIDNIGHT. TOWARD DAYBREAK SATURDAY, THERE
IS SOME CONCERN ABOUT MOISTURE RETURN FROM THE S/SE DEVELOPING
A LOW CLOUD CEILING IN THE UPSLOPE AREAS ALONG THE BLUE RIDGE
ESCARPMENT. THE MODEL GUIDANCE IS OFTEN TOO QUICK IN DEVELOPING THE
LOW CLOUDS IN SUCH A DRY ENVIRONMENT, SO CONFIDENCE IS LOW. THUS,
A CEILING RESTRICTION WILL NOT BE INCLUDED AT THIS TIME, BUT IS
WITHIN THE REALM OF POSSIBILITIES. EITHER WAY, STRATOCU WILL BE
MORE PREVALENT ACROSS THE REGION BY AFTERNOON. SOME LOW-END GUSTS
ARE ALSO POSSIBLE IN THE AFTERNOON.
OUTLOOK: A FRONTAL SYSTEM WILL BRING INCREASING CHANCES FOR SHOWERS
AND THUNDERSTORMS, ALONG WITH OCCASIONAL RESTRICTIONS ON SUNDAY
AND ESPECIALLY MONDAY. DRYING IS EXPECTED FOR TUESDAY.
FIRE WEATHER
TEMPERATURES WARM ENOUGH TODAY (COMPARED TO THURSDAY) THAT ALTHOUGH
DEWPOINTS WILL BE HIGHER, RH STILL IS EXPECTED TO FALL BELOW 30
PERCENT ACROSS ALL BUT THE HIGHER ELEVATIONS OF THE BALSAMS AND
THE HIGH RANGES NORTHEAST OF THE FRENCH BROAD VALLEY. MOST LOWER
ELEVATIONS WILL SEE RH FALL TO 20-25%. BREEZY CONDITIONS CAN
BE EXPECTED DURING THE AFTERNOON WITH GUSTS OF 15-25 MPH, WITH
ISOLATED SPOTS SEEING A BRIEF GUST TO 30 MPH. AN IMPACT-BASED RED
FLAG WARNING REMAINS IN EFFECT FOR PORTIONS OF THE MOUNTAINS OF
WESTERN NORTH CAROLINA, UPSTATE OF SOUTH CAROLINA AND RABUN COUNTY
IN NORTHEAST GEORGIA. THE WINDS MAY NOT MEET OBJECTIVE CRITERIA FOR
AN INCREASED FIRE DANGER STATEMENT ELSEWHERE IN NC/SC, BUT IN LIGHT
OF THE EXCEPTIONALLY DRY FUELS, LOW RH, AND MARGINALLY CRITICAL
WINDS, STATEMENTS HAVE BEEN ISSUED FOR ALL ZONES IN THOSE STATES,
AND IN NE GA FOR THE USUAL 4 HRS OF RH BELOW 25%.
GSP WATCHES/WARNINGS/ADVISORIES
GA...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR GAZ010.
INCREASED FIRE DANGER UNTIL 8 PM EDT THIS EVENING FOR GAZ017-
018-026-028-029.
NC...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR NCZ048>053-
058-059-062>065-303-505>510.
INCREASED FIRE DANGER UNTIL 8 PM EDT THIS EVENING FOR NCZ033-
035>037-056-057-068>072-082-501>504.
SC...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR SCZ101>106-
108.
INCREASED FIRE DANGER UNTIL 8 PM EDT THIS EVENING FOR
SCZ008>014-019-107-109.
SYNOPSIS...CP
NEAR TERM...PM/WIMBERLEY
SHORT TERM...CP
LONG TERM...CP
AVIATION...PM
FIRE WEATHER...
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