205
FXUS62 KGSP 111045
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
645 AM EDT SAT JUL 11 2026
WHAT HAS CHANGED
THE AVIATION DISCUSSION HAS BEEN UPDATED FOR THE 12Z TAFS ISSUANCE.
KEY MESSAGES
1. VERY ACTIVE CONVECTIVE WEATHER IS EXPECTED TO CONTINUE THROUGH
EARLY NEXT WEEK. ISOLATED SEVERE STORMS AND LOCALIZED FLASH
FLOODING WILL BE POSSIBLE EACH DAY THROUGH MONDAY. OTHERWISE,
A COOLING TREND IS EXPECTED, WITH WELL-BELOW NORMAL TEMPERATURES
FORECAST BY MONDAY.
2. A RETURN TO SEASONABLY HOT CONDITIONS AND TYPICAL COVERAGE OF
DIURNAL SHOWERS AND STORMS IS EXPECTED DURING THE LATTER HALF OF
NEXT WEEK.
DISCUSSION
KEY MESSAGE 1: VERY ACTIVE CONVECTIVE WEATHER IS EXPECTED TO CONTINUE
THROUGH EARLY NEXT WEEK. ISOLATED SEVERE STORMS AND LOCALIZED
FLASH FLOODING WILL BE POSSIBLE EACH DAY THROUGH MONDAY. OTHERWISE,
A COOLING TREND IS EXPECTED, WITH WELL-BELOW NORMAL TEMPERATURES
FORECAST BY MONDAY.
HOW CONVECTIVE TRENDS WILL EVOLVE THROUGHOUT THE DAY IS ABOUT AS
CLEAR AS MUD AT THIS JUNCTURE, AS IN ADDITION TO ONGOING ACTIVITY
ACROSS THE NC MOUNTAINS, THERE ARE MULTIPLE AREAS OF LOOSELY
ORGANIZED SHOWERS AND STORMS CURRENTLY STRETCHING FROM THE
CUMBERLAND PLATEAU IN TN/KY WESTERN OHIO VALLEY INTO THE MID-MISS
VALLEY. THESE AREAS OF CONVECTION WILL APPROACH THE SOUTHERN
APPALACHIANS AND VICINITY THROUGHOUT THE DAY...AS AN AREA OF HEIGHT
FALLS DIVES FROM THE CORN BELT EARLY THIS MORNING...TO THE TN VALLEY
TONIGHT. THE EXTENT OF ANY SEVERE STORM THREAT TODAY WILL DEPEND
LARGELY UPON HOW THIS UPSTREAM ACTIVITY EVOLVES THROUGH THE
MORNING...AND THE DEGREE (IF ANY) TO WHICH IT IS ABLE TO INHIBIT
DESTABILIZATION LATER TODAY. BASED UPON THE LATEST MESOANALYSIS,
CONVECTION IS GOING TO CONTINUE STRUGGLING TO MAKE SIGNIFICANT
INROADS INTO THE CWA THIS MORNING, AS MUCAPE FALLS OFF DRAMATICALLY
(< 500 J/KG) EAST OF THE BLUE RIDGE. WE THEREFORE SUSPECT THE
PIEDMONT AND FOOTHILLS SHOULD MODERATELY DESTABILIZE THIS AFTERNOON,
WITH MCV'S AND/OR OUTFLOWS/DIFFERENTIAL HEATING BOUNDARIES LEFT
BEHIND BY UPSTREAM CONVECTION PROVIDING THE LIFT TO INTERACT WITH
THIS INSTABILITY AND PRODUCE GOOD COVERAGE OF SHOWERS AND STORMS
ACROSS THE AREA THIS AFTERNOON INTO THE EVENING...WITH MULTIPLE
ROUNDS OF CONVECTION POSSIBLE AS ACTIVITY FARTHER UPSTREAM
APPROACHES THE AREA.
WHILE DEEP LAYER SHEAR IS FORECAST TO REMAIN WEAK, LOW LEVEL
SHEAR OF 15-20 KTS WILL CONTINUE TO SUPPORT SOME DEGREE OF COLD
POOL-CLUSTERING THAT WILL POSE SOME THREAT OF STRONG-TO-DAMAGING
DOWNBURSTS. THE THREAT FOR ISOLATED FLASH FLOODING WILL ALSO
PERSIST THROUGH THE DAYLIGHT HOURS, ESPECIALLY ACROSS THE FAR
WESTERN MOUNTAINS...THE AREA WHICH STANDS THE BEST CHANCE OF SEEING
MULTIPLE ROUNDS OF HEAVY RAIN SHOWERS AND STORMS. OTHERWISE, ONE
MORE DAY OF ABOVE NORMAL TEMPERATURES IS EXPECTED TODAY BEFORE
COOLER CONDITIONS EVOLVE EARLY NEXT WEEK. A FEW SPOTS ACROSS
THE SOUTHERN TIER OF FORECAST ZONES AND THE CHARLOTTE METRO AREA
COULD BRIEFLY SEE HEAT INDEX IN THE 101-103 RANGE THIS AFTERNOON,
BUT NOTHING WORTHY OF ANY HEAT HEADLINES.
CONVECTION-ALLOWING AND SHORT TERM MODEL GUIDANCE AGREE THAT A
RELATIVE LULL IN THE CONVECTIVE ACTIVITY WILL OCCUR TONIGHT, BEFORE
ANOTHER ROUND OF FAIRLY WIDESPREAD CONVECTION DEVELOPS SUNDAY...AS
AN UPPER LOW BEGINS TO CLOSE OFF OVER THE TN VALLEY. INCREASED
CLOUD COVER AND SLIGHTLY LOWER HEIGHTS ARE FORECAST TO YIELD ONE
OF THE FEW NEAR-NORMAL TEMPERATURE DAYS WE'VE SEEN OVER THE PAST
COUPLE OF WEEKS. THIS WILL RESULT IN SLIGHTLY LOWER INSTABILITY. IN
TERMS OF THE SEVERE WEATHER THREAT, THE LOWER BUOYANCY MAY BE
SOMEWHAT OFFSET BY A BRIEF INCREASE IN DEEP LAYER SHEAR SUNDAY
AFTERNOON...SO ANOTHER MARGINAL RISK IS APPROPRIATE.
BY LATE SUNDAY, A SLOW-MOVING BACK DOOR COLD FRONT IS EXPECTED
TO BEGIN MOVING INTO THE CWA FROM THE NE...ALTHOUGH UNCERTAINTY
ABOUT HOW FAR SW IT WILL PUSH REMAINS HIGH...OWING TO POTENTIAL
DEVELOPMENT OF WEAK LOW PRESSURE ACROSS THE REGION. IN ASSOCIATION
WITH THIS BOUNDARY, ESE UPSLOPE FLOW IS FORECAST TO DEVELOP
ACROSS AT LEAST THE NORTHERN PART OF THE AREA. ALL THIS AS THE
FLOW ALOFT WEAKENS WITHIN A COL REGION ON THE EAST SIDE OF THE
UPPER LOW. THESE FACTORS SPELL POTENTIAL FOR SLOW-MOVING AND/OR
TRAINING CELLS...WITHIN AN ENVIRONMENT CHARACTERIZED BY PWATS OF
AROUND 2 INCHES AND WARM CLOUD DEPTHS WELL OVER 10 KFT. THE FLASH
FLOOD THREAT THEREFORE MAY SEE A BIT OF AN UPTICK IN THE LATE SUNDAY
THROUGH MONDAY TIME FRAME...ALTHOUGH INSTABILITY WILL INCREASINGLY
BECOME A LIMITING FACTOR BY MONDAY, AS EXTENSIVE CLOUD COVER AND
NE FLOW HOLDS HIGH TEMPS WELL BELOW CLIMO.
KEY MESSAGE 2: A RETURN TO SEASONABLY HOT CONDITIONS AND TYPICAL
COVERAGE OF DIURNAL SHOWERS AND STORMS IS EXPECTED DURING THE LATTER
HALF OF NEXT WEEK.
WEAKLY CYCLONIC UPPER FLOW EARLY IN THE WEEK IS FORECAST TO GIVE WAY
TO RISING HEIGHTS AND THE RETURN OF RIDGING ALOFT BY THE MIDDLE OF
NEXT WEEK, AS AN ANTICYCLONE CENTERED OVER THE NORTHERN GREAT
PLAINS/ UPPER MISS VALLEY GETS SQUEEZED FROM THE SOUTH AND BROADENS.
PRIOR TO THIS PATTERN CHANGE, CONVECTIVE CHANCES REMAIN SOMEWHAT
ELEVATED TUESDAY, BUT BY WED...A MORE TYPICAL REGIME OF WIDELY
SCATTERED MOUNTAIN CONVECTION...WITH ISOLATED COVERAGE ELSEWHERE IS
EXPECTED...WITH THAT TREND GENERALLY FORECAST TO CONTINUE THROUGH
THE END OF THE WEEK. TEMPERATURES ARE FORECAST TO REMAIN SEVERAL
DEGREES BELOW CLIMO TUESDAY BEFORE WARMING TO NEAR-NORMAL WED...THE
N ENDING THE WEEK A COUPLE OF DEGREES ABOVE CLIMO.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
AT KCLT AND ELSEWHERE: AREAS OF WEAKENING SHOWERS AND ISOLATED
THUNDERSTORMS CONTINUE TO MOVE INTO WESTERN NORTH CAROLINA FROM
EAST TN THIS MORNING. MOST OF THESE HAVE BEEN DISSIPATING SHORTLY
AFTER MOVING AWAY FROM THE TN BORDER, BUT A FEW OF THESE MAY DRIFT
TOWARD KAVL EARLY IN THE FORECAST PERIOD. CHANCES FOR SHOWERS AND
POSSIBLY TS WILL INCREASE FROM THE WEST FROM LATE MORNING ON,
AND A TEMPO FOR TSRA IS INCLUDED AT KAVL BEGINNING AT 15Z. THE
CONVECTIVE POTENTIAL WILL INCREASE AT THE OTHER TAF SITES DURING THE
AFTERNOON, AND PROB30S FOR TSRA BEGIN AS EARLY AS 17Z AT KGSP/KGMU,
AND GENERALLY AFTER 18Z AT THE OTHER SITES. PROB30S ARE LIKELY
TO BE EVENTUALLY CONVERTED TO TEMPOS AT THE OTHER SITES, BUT THIS
WILL NEED TO WAIT UNTIL CONFIDENCE IN TIMING IMPROVES.
WINDS WILL REMAIN OUT OF THE WSW...INCREASING TO AROUND 10 KTS
AT MOST SITES BY EARLY AFTERNOON. THIS WILL CREATE A CROSSWIND
CONCERN AT KCLT. DIRECTIONS ARE EXPECTED TO PRIMARILY FAVOR S OF
DUE W, BUT PERIODS OF 270 AND EVEN 280 CAN BE EXPECTED. FOR THE
OVERNIGHT PERIOD, SOME CONVECTION-ALLOWING MODELS BRING NOCTURNAL
SHOWERS AND STORMS TO THE AREA...INCLUDING TO KCLT. THIS IS FAR
FROM CERTAIN AT THIS POINT, AND WE WILL CONTINUE TO HIGHLIGHT
THIS AFTERNOON/EVENING WITH THE GREATEST POTENTIAL. CONDITIONS
WILL BE MORE FAVORABLE FOR FOG AND/OR LOW STRATUS DEVELOPMENT
LATE TONIGHT/EARLY SUNDAY, BUT CONFIDENCE IS STILL GENERALLY
LOW...RESTRICTIONS WILL BE LIMITED TO MVFR AT THE TYPICAL LOCATIONS
(KAVL/KHKY) FOR THE TIME BEING...WITH THE POTENTIAL FOR LOW STRATUS
HINTED AT THE OTHER SITES WITH FEW/SCT IFR LAYERS.
OUTLOOK: GREATER THAN NORMAL COVERAGE OF SHRA/TSRA WILL CONTINUE
ACROSS OUR AREA SUNDAY INTO MONDAY AS MULTIPLE ROUNDS OF STORMS
ARE EXPECTED ACROSS THE REGION. DRIER CONDITIONS SHOULD DEVELOP
TUESDAY INTO WEDNESDAY. LOW STRATUS AND/OR FOG WILL BE POSSIBLE EACH
MORNING IN THE MTN VALLEYS AND IN LOCATIONS THAT SEE APPRECIABLE
RAINFALL THE PREVIOUS AFTERNOON/EVENING.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
JDL
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