184
FXUS62 KGSP 291031
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
631 AM EDT FRI MAY 29 2026
WHAT HAS CHANGED
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
1. THE POTENTIAL FOR ISOLATED HEAVY RAINFALL AND FLASH FLOODING
RETURNS TONIGHT INTO SATURDAY, AS A FRONT MOVES BACK INTO THE
AREA. ONE LAST ROUND OF CONVECTION IS ANTICIPATED MONDAY BEFORE
THE FRONT FINALLY CLEARS THE REGION. TEMPERATURES TREND BELOW
NORMAL FOR THE WEEKEND.
2. DRY AND COOLER THAN NORMAL WEATHER IS EXPECTED TUESDAY THROUGH
AT LEAST THURSDAY.
DISCUSSION
KEY MESSAGE 1: THE POTENTIAL FOR ISOLATED HEAVY RAINFALL AND FLASH
FLOODING RETURNS TONIGHT INTO SATURDAY, AS A FRONT MOVES BACK
INTO THE AREA. ONE LAST ROUND OF CONVECTION IS ANTICIPATED MONDAY
BEFORE THE FRONT FINALLY CLEARS THE REGION. TEMPERATURES TREND
BELOW NORMAL FOR THE WEEKEND.
A BRIEF PERIOD OF NE LOW LEVEL FLOW WILL CONTINUE TO ADVECT SLIGHTLY
DRIER AND COOLER AIR INTO THE FORECAST AREA THROUGH TODAY, AND MAX
TEMPS ARE FORECAST TO BE AROUND 5 DEGREES COOLER THAN THURSDAY...OR
RIGHT AROUND NORMAL. MUCH OF THE FORECAST AREA IS EXPECTED TO BE
RELATIVELY STABLE TODAY, AND POPS THROUGH 00Z ARE PRIMARILY CONFINED
TO THE SOUTHERN AND WESTERN PERIPHERY OF THE CWA...CLOSER TO THE OLD
FRONTAL BOUNDARY THAT HAS BEEN MEANDERING ACROSS THE REGION FOR DAYS.
OTHERWISE, AN UPPER LOW WILL REMAIN CENTERED NEAR NEW ENGLAND
THROUGH MUCH OF THE WEEKEND, WITH A TROUGH EXTENDING SOUTHWARD NEAR
THE EAST COAST. AN UPSTREAM, HIGH-AMPLITUDE RIDGE EXTENDING FROM
THE DEEP SOUTH INTO THE CANADIAN PRAIRIE IS FORECAST TO WEAKEN
OVER THE SOUTHEAST TODAY, AS A SHORT WAVE TROUGH EJECTS FROM THE
SOUTHERN PLAINS INTO THE TN VALLEY BY TONIGHT. THIS WILL ALLOW THE
FRONTAL BOUNDARY TO NUDGE NORTHEAST BACK INTO THE WESTERN PART OF
THE CWA TONIGHT, WITH THE BOUNDARY AND INCREASING SYNOPTIC FORCING
ALLOWING FOR DEVELOPMENT OF AT LEAST SCATTERED CONVECTION ACROSS
ROUGHLY THE WESTERN HALF OF THE AREA. PRECIPITABLE WATER VALUES RE-
SURGING TO AROUND 1.75", COMBINED WITH MEAN CLOUD-BEARING WINDS
ROUGHLY PARALLEL TO THE BOUNDARY SUGGESTS THE POSSIBILITY OF
TRAINING OF HEAVY RAIN-PRODUCING CELLS. ADDITIONALLY, SHEAR
PARAMETERS SHOULD BE ADEQUATE FOR ORGANIZATION OF CONVECTION INTO
SMALL CLUSTERS, WITH POTENTIAL FOR BACK-BUILDING CLUSTERS ADDING TO
THE LOCALLY HEAVY RAINFALL POTENTIAL. THE THREAT FOR FLASH FLOODING
STILL LOOKS TOO LOCALIZED TO JUSTIFY WATCH CONSIDERATION, ESPECIALLY
SINCE INSTABILITY WILL BE WEAK GIVEN THE TIME OF DAY. NEVERTHELESS,
A FLASH FLOOD EVENT OR TWO IS VERY MUCH IN THE REALM OF POSSIBILITY
TONIGHT/EARLY SATURDAY.
CONVECTION SHOULD INCREASE IN COVERAGE (OR REDEVELOP) ACROSS AT
LEAST THE SW HALF OF THE CWA AS THE ATMOSPHERE DESTABILIZES SATURDAY
AFTERNOON. DEPENDING UPON HOW MUCH INSTABILITY IS REALIZED (WHICH
WILL DEPEND LARGELY ON THE COVERAGE OF CONVECTION AND/OR EXTENT
OF CONVECTIVE DEBRIS CLOUDINESS SAT MORNING), SHEAR PARAMETERS
ARE EXPECTED TO BE ADEQUATE FOR A LOW-END SEVERE STORM THREAT,
ALONG WITH THE CONTINUED POTENTIAL FOR ISOLATED FLASH FLOODING
SAT AFTERNOON/EVENING.
A SURFACE HIGH BUILDING BEHIND A SHORT WAVE DIGGING THROUGH THE MEAN
TROUGH ACROSS THE NORTHEAST AND MID-ATLANTIC LATE SATURDAY WILL
STRENGTHEN LOW LEVEL NE FLOW ACROSS OUR AREA SATURDAY NIGHT/EARLY
SUNDAY, PUSHING THE FRONTAL ZONE BACK SOUTHWEST OF THE CWA IN
BACKDOOR FASHION. RESULTANT ADVECTION OF COOLER AND DRIER AIR
INTO THE CWA (SUNDAY MAX TEMPS 10 OR MORE DEGREES BELOW CLIMO) IS
EXPECTED TO RESULT IN ANOTHER PAUSE IN CONVECTIVE ACTIVITY. A MORE
SUBSTANTIAL SHORT WAVE TROUGH/UPPER LOW DIGGING INTO THE NORTHEAST
SUNDAY NIGHT/EARLY MONDAY WILL SWEEP A COLD FRONT THROUGH THE REGION
MONDAY, BRINGING ONE FINAL ROUND OF (MOSTLY) SCATTERED CONVECTION
BEFORE COOLER/DRIER/STABLE AIR WITH MORE STAYING POWER ARRIVES FOR
THE REMAINDER OF NEXT WEEK.
KEY MESSAGE 2: DRY AND COOLER THAN NORMAL WEATHER IS EXPECTED TUESDAY
THROUGH AT LEAST THURSDAY.
AN UPPER LOW IS FORECAST TO BE ESTABLISHED OFF THE MID-ATLANTIC
COAST BY MID-WEEK, WITH AN ANOMALOUSLY LOW HEIGHTS FORECAST TO COVER
MUCH OF THE EASTERN SEABOARD UNTIL LATER IN THE WEEK. THIS IS
EXPECTED TO RESULT IN TEMPERATURES AROUND 5 DEGREES BELOW CLIMO FROM
TUESDAY THROUGH THE END OF THE PERIOD. THESE COOLER TEMPERATURES
ALONG WITH SURFACE DEWPOINTS GENERALLY IN THE 50S ARE EXPECTED TO
PRECLUDE THE POTENTIAL FOR ANY DIURNAL INSTABILITY/CONVECTION
TUESDAY THROUGH THURSDAY.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
AT KCLT AND ELSEWHERE: FOG/LOW STRATUS WILL REMAIN CONFINED TO
THE MOUNTAIN VALLEYS WEST OF KAVL THIS MORNING, WITH VFR FORECAST
THROUGH AT LEAST THIS EVENING AT THE TAF SITES. FEW/SCT CUMULUS OR
STRATOCU MAINLY IN THE 030-050 RANGE ARE POSSIBLE AT JUST ABOUT
ANY TIME, BUT ESPECIALLY DURING THE AFTERNOON. GENERALLY LIGHT
NE WINDS THIS MORNING STEADILY WEAKENING, POSSIBLY BECOMING LIGHT
SSW BY THIS EVENING.
A FRONTAL BOUNDARY WILL APPROACH FROM THE SOUTHWEST THIS EVENING,
RESULTING IN INCREASED COVERAGE OF SHOWERS AND SOME THUNDERSTORMS,
MAINLY AFTER MIDNIGHT AND MAINLY IN WESTERN AREAS. MOST TAF SITES
RECEIVE A PROB30 AT SOME POINT LATE TONIGHT/EARLY SATURDAY...MOSTLY
FOR SHRA, ALTHOUGH TSRA IS CARRIED AT KAND. CAN'T RULE OUT TS AT
THE OTHER SITES, BUT CHANCES ARE TOO LOW FOR A TAF MENTION. CIGS
WILL BEGIN TO LOWER FROM THE WEST OVERNIGHT AND MVFR CIGS ARE
FORECAST AT ALL SITES BY DAYBREAK EXCEPT KCLT AND KHKY (AND CAN'T
RULE IT OUT THERE EITHER.)
OUTLOOK: CHANCES FOR SHOWERS, THUNDERSTORMS, AND ASSOCIATED
RESTRICTIONS CONTINUE INTO SATURDAY, ESPECIALLY DURING THE
AFTERNOON. AREA. AFTER ANOTHER BRIEF DRYING PERIOD SUNDAY, CHANCES
FOR MAINLY DIURNAL CONVECTION RETURN MONDAY BEFORE A LONGER TERM
DRYING PATTERN BECOMES ESTABLISHED BEGINNING TUESDAY,
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
JDL
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page