101
FXUS62 KGSP 291807
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
207 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 TONIGHT/
AS OF 150 PM: PLENTY OF CLOUDINESS SEEN ON SATELLITE IMAGERY THIS
AFTERNOON, MAINLY OVER THE MTNS AND FOOTHILLS, WHICH ALONG WITH THE
HIGHER RH, MAKES THE SITUATION IN THE NEAR TERM SEEM A LITTLE LESS
DIRE. OUTSIDE THE MTNS, ENOUGH THIN SPOTS WERE APPARENT THAT SOME
CU CLOUD STREETS HAD DEVELOPED, SHOWING THE LOW LEVEL SW RETURN
FLOW NICELY. SEEING SEVERAL SHOWERS ON RADAR OVER NORTHEAST GA,
JUST OUTSIDE THE FCST AREA, STREAMING UP TOWARD THE SMOKIES, SO
SCORE ANOTHER ONE FOR THE CAMS. DON'T EXPECT MORE THAN A HUNDREDTH
OR TWO OF AN INCH, AT MOST. TEMP/DEWPT TRENDS WERE RUNNING OKAY,
BUT OBS WERE A FEW DEGREES UNDER THE FCST WHERE THE CLOUD COVER
WAS THICKER. NO BIG CHANGES IN THAT REGARD.
REGULAR DISCUSSION WILL FOLLOW SHORTLY.
OTHERWISE...STRONG WESTERN ATLANTIC HIGH PRESSURE CONTINUES TO
NOSE INTO THE SOUTHEAST CONUS. DEEP SHORTWAVE CENTERED OVER THE
ARKLATEX IS ASSOCIATED WITH PLENTIFUL HIGH ALTITUDE MOISTURE AND
WILL PROVIDE SOME DPVA AS IT TRACKS NORTHEAST INTO KY/TN TODAY,
ALTHOUGH DAMPENING. FORCING WITH THE SHORTWAVE LOOKS TO ARRIVE
LATER IN THE DAY WHEN SOME OF THE LOW-LEVEL MOISTURE WILL HAVE HAD
A CHANCE TO MIX OUT. THERE IS SOME PROGGED SBCAPE BUT THE VERY
DRY MIDLEVEL AIR SEEN ABOVE THE PBL APPEARS TO BE TOO MUCH OF A
LIMITING FACTOR FOR UPDRAFTS. THE BETTER THERMODYNAMICS WILL BE
WEST OF OUR MOUNTAINS IN TN. LIKEWISE, THE SOUTHERLY FLOW SHOULD
CARRY ANY CELLS DEVELOPING IN THE SMOKIES INTO TN IF THEY CAN
SURVIVE THAT LONG. INCREASED THICKNESSES ARE LIKELY TO BE OFFSET
BY CLOUD COVER TODAY; MAX TEMPS END UP ABOUT THE SAME AS FRIDAY
IN OUR EAST, AND A COUPLE DEGREES COOLER IN THE CLOUDIER WEST HALF.
SYNOPTIC SCALE WARM FRONT APPEARS TO LIFT NORTH INTO THE CWA
TONIGHT IN CONJUNCTION WITH STRENGTHENING LOW PRESSURE IN THE
MIDWEST. LOW-LEVEL FLOW WILL TURN A BIT MORE SOUTHWESTERLY, BUT
MECHANICAL LIFT STILL SHOULD BE PRESENT ALONG THE ESCARPMENT
AND ALSO IN THE SW-FACING RIDGES. MIDLEVEL MOISTURE INCREASES
AND SATURATION SHOULD OCCUR THRU A MUCH DEEPER LAYER, MAINLY
AFTER MIDNIGHT. CAM RESPONSE DOES REMAIN MAINLY ALONG THE
TERRAIN. POPS INCREASE FIRST IN THAT AREA AND THEN EXPAND INTO
THE LOWER ELEVATIONS IN THE SAVANNAH VALLEY, WESTERN UPSTATE,
AND EASTERN NC FOOTHILLS CLOSER TO DAWN SUNDAY. WIDESPREAD LOW
CLOUDS ARE LIKELY TO DEVELOP BY SUNDAY MORNING ALSO. MIN TEMPS
10-15 ABOVE NORMAL UNDER THESE CONDITIONS; HIGH-MIN RECORDS STILL
ARE UNLIKELY TO BE THREATENED.
SHORT TERM /SUNDAY 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 FRIDAY/
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 /18Z SATURDAY THROUGH THURSDAY/
AT KCLT AND ELSEWHERE: JUST ABOUT THE MOST PESSIMISTIC FORECAST I'VE
ISSUED IN THE PAST MONTH OR SO. AFTER SOME LINGERING MVFR-LEVEL
BKN CEILING AROUND THE WESTERN UPSTATE OF SC, TERMINALS SHOULD BE
VFR FOR THE REST OF THE DAY AND WELL INTO THE OVERNIGHT, THOUGH
PROBABLY IN-AND-OUT OF A VFR-LEVEL BKN STRATOCU THAT HAS DEVELOPED
UNDERNEATH THE MID-LEVEL CLOUDS. SOME LIGHT SHOWER ACTIVITY WILL
REMAIN CONCENTRATED WEST OF THE TERMINALS. OCCASIONAL GUSTS IN THE
S TO SW WIND CAN BE EXPECTED UNTIL THE BOUNDARY LAYER DECOUPLES
IN THE EARLY EVENING. MEANWHILE, MOISTURE WILL CONTINUE TO SLOWLY
IMPROVE OVERNIGHT, ALLOWING SHOWER ACTIVITY TO DEVELOP AND MOVE
IN FROM THE WEST IN THE PRE-DAWN HOURS. MOST OF THE GUIDANCE HAS
THIS DEVELOPMENT, SO CONFIDENCE HAS GONE UP THAT RESTRICTIONS WILL
DEVELOP FROM WEST TO EAST AFTER 09Z SUNDAY, PREVAILING MVFR FOR THE
MOST PART. THERE ARE INDICATIONS IN THE GUIDANCE OF A PREVAILING
IFR STRATUS DECK IN THE MORNING, BUT CONFIDENCE IS TOO LOW TO BRING
THIS IN OUTSIDE OF A PROB30. EVENTUALLY, PRECIP COVERAGE BECOMES
HIGH ENOUGH TO WARRANT A PREVAILING MENTION ALONG WITH LOWERING
CEILING. THIS WILL TAKE AWHILE TO MAKE IT AS FAR EAST AS KCLT,
HOWEVER, PROBABLY NOT UNTIL AFTERNOON. WIND WILL STAY GENERALLY
S TO SSW, WITH GUSTS POSSIBLE AGAIN SUNDAY AFTERNOON. NOTE THAT
GUIDANCE DEVELOPS ENOUGH INSTABILITY TO SUPPORT A THUNDERSTORM
MENTION, BUT CONFIDENCE IS TOO LOW TO INCLUDE THIS DETAIL YET.
OUTLOOK: RESTRICTIONS AND PRECIP LINGER INTO SUNDAY NIGHT. A BRIEF
LULL, THEN SHRA/TSRA POSSIBLE MONDAY. DRYING IS EXPECTED FOR TUE,
LIKELY LASTING INTO WED.
FIRE WEATHER
ALTHOUGH MIXING THIS AFTERNOON WILL TAP INTO A DRY LAYER ABOVE THE
PBL AND DEWPOINTS THUS DIP DIURNALLY, SOUTHERLY FLOW IS PROVIDING
ENOUGH MOISTURE RETURN THIS MORNING THAT RH WILL REMAIN ABOVE 30% IN
ALL AREAS, AND PROBABLY CLOSER TO 50% IN THE HIGHER ELEVATION AREAS
WHERE WILDFIRES ARE ALREADY BEING FOUGHT. THAT SAID, PER
COORDINATION WITH NC STATE OFFICIALS, AN IMPACT-BASED FIRE DANGER
STATEMENT IS CURRENTLY IN PLACE FOR NC ON ACCOUNT OF THE CRITICALLY
DRY FUELS. WIND GUSTS OF 20-25 MPH, BRIEFLY UP TO 30 MPH, WILL BE
POSSIBLE AGAIN THIS AFTERNOON.
PRECIP ACTIVITY THROUGH THIS EVENING IS NOT LIKELY TO HAVE A
SIGNIFICANT IMPACT ON ONGOING WILDFIRES. HOWEVER, CHANCES INCREASE
TOWARD DAYBREAK SUNDAY, WITH THE FASTEST ACCUMULATION RATES LIKELY
TO OCCUR SUNDAY.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...INCREASED FIRE DANGER UNTIL 8 PM EDT THIS EVENING FOR NCZ033-
035>037-048>053-056>059-062>065-068>072-082-501>510.
SC...NONE.
SYNOPSIS...CP
NEAR TERM...PM/WIMBERLEY
SHORT TERM...CP
LONG TERM...CP
AVIATION...PM
FIRE WEATHER...
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