362
FXUS62 KGSP 231856
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
256 PM EDT THU JUL 23 2026
WHAT HAS CHANGED
NO SIGNIFICANT FORECAST CHANGES FOR THIS UPDATE.
KEY MESSAGES
1. THE THREAT FOR HEAVY RAINFALL AND ISOLATED FLASH FLOODING
PEAKS THIS AFTERNOON/EVENING, BUT SOME LEVEL OF LOCALLY EXCESSIVE
RAINFALL POTENTIAL CONTINUES THROUGH SATURDAY. A FLOOD WATCH FOR
FLASH FLOODING REMAINS IN EFFECT THROUGH THE AFTERNOON FOR MUCH
OF WESTERN NC.
2. A RETURN TO TYPICAL MID-SUMMER WEATHER BEGINS SUNDAY AND
CONTINUES THROUGH AT LEAST THURSDAY, WITH HOT TEMPERATURES AND
MOSTLY ISOLATED DIURNAL CONVECTION EXPECTED.
DISCUSSION
KEY MESSAGE 1: THE THREAT FOR HEAVY RAINFALL AND ISOLATED FLASH
FLOODING PEAKS THIS AFTERNOON/EVENING, BUT SOME LEVEL OF LOCALLY
EXCESSIVE RAINFALL POTENTIAL CONTINUES THROUGH SATURDAY. A FLOOD
WATCH FOR FLASH FLOODING REMAINS IN EFFECT THROUGH THE AFTERNOON FOR
MUCH OF WESTERN NC.
OUTFLOW-REINFORCED FRONTAL BOUNDARY IS CURRENTLY LOCATED NEAR THE
NC/SC BORDER AND WILL CONTINUE TO MOVE VERY SLOWLY SSW THROUGH
THE AFTERNOON/EVENING. MODERATE-TO-HEAVY RAIN SHOWERS AND ISOLATED
THUNDERSTORMS CONTINUE TO TRAIN ALONG/JUST NORTH OF THE BOUNDARY
ACROSS MAINLY THE SOUTHERN TIER OF NC COUNTIES AND NORTHERN TIER OF
SC COUNTIES. THIS TRAINING ACTIVITY WILL CONTINUE TO DRIFT TOWARD
THE SOUTHEAST THROUGH THE AFTERNOON, WITH RAINFALL RATES LIKELY
INCREASING AS THE BOUNDARY INTERACTS WITH MODERATELY UNSTABLE AIR
ACROSS THE UPSTATE. MEANWHILE, WITH THE WESTERN PART OF THE BOUNDARY
HUNG UP SOMEWHERE OVER THE BLUE RIDGE MOUNTAINS, DESTABILIZATION
HAS ALSO OCCURRED ACROSS THE TN VALLEY AND FAR WESTERN PORTIONS OF
THE SOUTHERN APPALACHIANS. CONVECTION IS EXPECTED TO INCREASE AND
COVERAGE AND INTENSITY THIS AFTERNOON ACROSS ALL BUT THE NORTHERN
NC FOOTHILLS AND NORTHWEST PIEDMONT, WITH A CONTINUED POTENTIAL
FOR HEAVY, AND LOCALLY EXCESSIVE RAINFALL. IN TERMS OF THE FLOOD
WATCH THAT COVERS MUCH OF WESTERN NC, A FEW COUNTIES ACROSS THE
FAR NORTH WERE REMOVED EARLIER. HOWEVER, IN LIGHT OF THE ABOVE
THINKING AND SIGNALS IN THE LATEST CONVECTION-ALLOWING GUIDANCE,
WE CURRENTLY SEE NO NEED TO MAKE FURTHER ADJUSTMENTS, AS EXCESSIVE
RAINFALL REMAINS POSSIBLE WITHIN THE WATCH AREA. LOCALIZED FLASH
FLOODING IS ALSO POSSIBLE SOUTH OF THE WATCH AREA...ESPECIALLY
ACROSS THE EASTERN HALF OF OUR SC COUNTIES. HOWEVER, IN LIGHT OF
TRENDS IN OBSERVATIONAL AND MODEL GUIDANCE, THE THREAT APPEARS TO
BE TOO LOCALIZED FOR WATCH CONSIDERATION.
WITH THE ATMOSPHERE ACROSS MUCH OF THE UPSTATE/NORTHEAST GA WEST OF
I-26 HAVING DESTABILIZED TO THE TUNE OF 2000+ J/KG OF SBCAPE, THERE
IS SOME POTENTIAL FOR AN ISOLATED SEVERE STORM OR TWO. MEANWHILE,
SURFACE ANALYSIS INDICATES A QUITE STABLE AIR MASS FILTERING INTO
THE NE CORNER OF THE AREA, WHERE TEMPS ARE CURRENTLY IN THE
MID/UPPER 60S. WITH 1020+ SURFACE HIGH SETTLING INTO THE NORTHEAST,
INVERTED SURFACE RIDGE WILL CONTINUE TO SHARPEN EAST OF THE
APPALACHIANS, AND THIS SHOULD ALLOW THE FRONT TO PICK UP A LITTLE
SPEED THIS EVENING INTO THE OVERNIGHT, WITH STABLE AIR EXPECTED TO
FILTER THROUGH THE REMAINDER OF THE CWA DURING THE OVERNIGHT. THIS
WILL RESULT IN DIMINISHING COVERAGE AND INTENSITY OF CONVECTION THIS
EVENING, AND ONLY SCATTERED, MOSTLY LIGHT SHOWERS ARE ANTICIPATED
DURING THE OVERNIGHT.
ALTHOUGH SURFACE-BASED STABLE AIR IS EXPECTED ACROSS MUCH OF THE
AREA ON FRIDAY, SOME ELEVATED INSTABILITY IS EXPECTED ACROSS MUCH
OF THE SOUTHWEST HALF...WHILE SOME RIPPLES ALOFT ARE EXPECTED
TO PASS OVER THE AREA THROUGHOUT THE DAY. SCATTERED SHOWERS AND
SOME STORMS ARE EXPECTED TO REDEVELOP BY AFTERNOON, WITH LIKELY
POPS ADVERTISED ACROSS MUCH OF THIS AREA. WHILE THE POTENTIAL FOR
ISOLATED EXCESSIVE RAINFALL WILL BE LOWER, A MARGINAL RISK WILL
EXIST...WITH PERHAPS A SLIGHTLY HIGHER RISK ACROSS THE SOUTHWEST
FRINGE, WHERE THE HIGHEST MUCAPE IS EXPECTED. SLIGHTLY MORE
UNSTABLE CONDITIONS ARE POSSIBLE SATURDAY, ALBEIT WITH GENERALLY
LOWER MOISTURE CONTENT. NEVERTHELESS, SCATTERED SHOWERS AND SOME
TS ARE AGAIN EXPECTED DURING THE AFTERNOON, WITH A CONTINUED LOW
END HEAVY RAINFALL THREAT.
FORECAST HIGH TEMPS ARE AROUND 10 DEGREES BELOW CLIMO ACROSS
MUCH OF THE CWA FRIDAY, EXCEPT FOR WARMER CONDITIONS ACROSS THE
SOUTHWEST FRINGE. SATURDAY WILL BE WARMER, BUT STILL BELOW NORMAL
ACROSS MOST OF THE AREA.
KEY MESSAGE 2: A RETURN TO TYPICAL MID-SUMMER WEATHER BEGINS
SUNDAY AND CONTINUES THROUGH AT LEAST THURSDAY, WITH HOT
TEMPERATURES AND MOSTLY ISOLATED DIURNAL CONVECTION EXPECTED.
A DRIER AND HOTTER PATTERN IS FORECAST TO EVOLVE BY THE END OF THE
WEEKEND, AS THE AXIS OF A LONG WAVE TROUGH PUSHES JUST OFF THE EAST
COAST, WITH RISING HEIGHTS EXPECTED ACROSS OUR AREA THROUGH MUCH OF
THE WEEK AS A RIDGE BUILDS STRONGLY ACROSS THE ROCKIES AND GREAT
PLAINS. TEMPERATURES WARM TO NORMAL BY MONDAY, AND PERHAPS A LITTLE
ABOVE CLIMO BY MID-WEEK. A RETURN TO A DIURNAL CONVECTIVE CYCLE IS
EXPECTED, WITH SAID CYCLE CURRENTLY EXPECTED TO BE RELATIVELY
INACTIVE, AS (AT MOST) ISOLATED ACTIVITY IS FORECAST EACH
AFTERNOON/EVENING.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
AT KCLT AND ELSEWHERE: VERY MESSY AVIATION WEATHER WILL OCCUR OVER
THIS FORECAST PERIOD, AS AN E=>W ORIENTED COLD FRONT CONTINUES TO
DRIFT SLOWLY SOUTH ACROSS THE TERMINAL FORECAST AREA THROUGH THE
AFTERNOON/EVENING. WITH MOST TAF SITES (EXCEPT KHKY) BEING NEAR OR
SOUTH OF THE BOUNDARY, WIDESPREAD SHOWERS AND AT LEAST SCATTERED
TS ARE EXPECTED NEAR THE UPSTATE SC TERMINALS AND KCLT/KAVL THIS
AFTERNOON, WITH TEMPOS FOR TSRA AND CATEGORICAL -SHRA (OR VCSH)
WARRANTED AT THESE SITES. IFR/LOW MVFR CIGS WILL PERSIST NORTH OF
THE BOUNDARY, WHILE 1-2SM VISBY WILL OCCUR WITH HEAVIER BURSTS
OF RAIN/TSRA. AD THE FRONT CONTINUES TO SAG SOUTH THIS EVENING,
CIGS SHOULD LOWER TO LOW MVFR OR IFR AT ALL SITES BY LATE EVENING
OR SO. SHOWER/TS CHANCES WILL LINGER WELL INTO THE EVENING, BUT
WITH DIMINISHING COVERAGE AND INTENSITY. NEVERTHELESS, SPOTTY
SHOWERS WILL LIKELY LINGER INTO THE OVERNIGHT, ESPECIALLY ACROSS
THE SOUTHERN HALF OF THE AREA. OTHERWISE, CIGS MAY LOWER TO LIFR
OVERNIGHT, WHILE REDUCED VISBY IN BR WILL BECOME MORE LIKELY AS
WELL. CIGS WILL BE SLOW TO IMPROVE DURING THE DAYLIGHT HOURS FRIDAY,
WHILE COVERAGE OF SHOWERS AND PERHAPS SOME STORMS IS EXPECTED TO
BEGIN FLARING UP BY EARLY AFTERNOON.
OUTLOOK: RESTRICTIONS CONTINUE THROUGH SATURDAY AS SHOWERS
AND THUNDERSTORMS REMAIN. MUCH LOWER CHANCES OF CONVECTION AND
ASSOCIATED RESTRICTIONS SUNDAY AND MONDAY. LOW STRATUS AND/OR FOG
ARE POSSIBLE EACH MORNING IN THE MOUNTAIN VALLEYS AND LOCATIONS
WHICH RECEIVE HEAVY RAINFALL.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NCZ036-037-048>053-
056>059-062>065-068>072-503>510.
SC...NONE.
JDL
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