679
FXUS62 KGSP 121831
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
231 PM EDT SUN JUL 12 2026
WHAT HAS CHANGED
RAIN CHANCES HAVE TRENDED DOWN ABOUT 10-15 PERCENT FROM THURSDAY
THROUGH SATURDAY.
UPDATED THE AVIATION DISCUSSION FOR THE 18Z TAFS.
KEY MESSAGES
1. VERY ACTIVE CONVECTIVE WEATHER IS EXPECTED TO CONTINUE
THROUGH AT LEAST MONDAY. ISOLATED SEVERE STORMS AND LOCALIZED
FLASH FLOODING WILL BE POSSIBLE TODAY THROUGH MONDAY. OTHERWISE, A
COOLING TREND IS EXPECTED, WITH WELL-BELOW NORMAL HIGH TEMPERATURES
FORECAST MONDAY AND TUESDAY.
2. A RETURN TO SEASONABLY HOT AND DRIER CONDITIONS IS EXPECTED
DURING THE LATTER HALF OF NEXT WEEK.
DISCUSSION
KEY MESSAGE 1: VERY ACTIVE CONVECTIVE WEATHER IS EXPECTED TO CONTINUE
THROUGH AT LEAST MONDAY. ISOLATED SEVERE STORMS AND LOCALIZED
FLASH FLOODING WILL BE POSSIBLE TODAY THROUGH MONDAY. OTHERWISE, A
COOLING TREND IS EXPECTED, WITH WELL-BELOW NORMAL HIGH TEMPERATURES
FORECAST MONDAY AND TUESDAY.
A 500 MB VORT MAX CAN BE SEEN DRIFTING OVER THE OH/TN VALLEYS TOWARD
THE SOUTHERN APPALACHIANS ON WV IMAGERY. THIS FEATURE WILL HELP
SUPPORT A COUPLE MORE ROUNDS OF CONVECTION ACROSS THE AREA. THE
FIRST WILL BE WITH DAYTIME HEATING, AS THE MOIST AIR MASS IN PLACE
HAS DESTABILIZED TO AROUND 2000-2500 J/KG. WITH THE APPROACHING
WAVE, BULK SHEAR WILL INCREASE SLIGHTLY, APPROACHING 25-30 KT,
WHICH IS DECENT FOR MID-JULY. THE CAMS SHOW HINTS OF MULTICELL
CLUSTERS AND EVEN SOME ROTATING UPDRAFTS, ESPECIALLY ACROSS THE
UPSTATE AND NE GA PIEDMONT WHERE MID CLOUDS HAVE CLEARED OUT THE
MOST. THE DAY 1 CONVECTIVE OUTLOOK HAS BEEN ADJUSTED WITH SLIGHT
RISK TRIMMED TO THE SOUTHERN THIRD OR SO OF THE CWFA. DAMAGING WIND
GUSTS WILL BE THE PRIMARY THREAT, BUT WITH A LITTLE MORE SHEAR,
LARGE HAIL UP TO QUARTER-SIZED WILL BE POSSIBLE.
TONIGHT, A WEAK BACKDOOR COLD FRONT WILL SLIDE SOUTH THRU THE AREA,
HELPING TRIGGER ADDITIONAL CONVECTION THRU THIS EVENING. THEN,
LOW-LEVEL FLOW TURNS OUT OF THE E/SE ON THE NORTH SIDE OF THE FRONT,
WITH UPSLOPE FORCING ENOUGH TO TRIGGER ANOTHER ROUND OF SHOWERS
LATE OVERNIGHT THRU EARLY MONDAY MORNING. THE 12Z CAMS ARE STILL
NOT IN GREAT AGREEMENT ON COVERAGE AND PLACEMENT, BUT SEEM TO FAVOR
THE NORTHERN NC ESCARPMENT AND ADJACENT FOOTHILLS. THE SIGNAL IS
STILL TOO SUBTLE TO WARRANT A FLASH FLOOD WATCH. NEVERTHELESS,
A SLIGHT RISK OF EXCESSIVE RAINFALL CONTINUES TONIGHT, WITH PWATS
AROUND 2" AND WARM CLOUD DEPTHS OVER 10 KFT.
THERE SHOULD BE A RELATIVE LULL IN SHOWER COVERAGE MID TO LATE
MONDAY MORNING, AS AN AREA OF LOW CLOUDS SPREADS OVER THE FORECAST
AREA AND PERSISTS UNTIL AROUND MIDDAY. A 1021-1023 MB SFC HIGH OVER
THE MID-ATLANTIC MAY BE STRONG ENOUGH COMBINED WITH LOW CLOUDS
AND SPOTTY PRECIP TO PRODUCE AN IN-SITU CAD. TEMPS WILL BE ABOUT
10-15 DEG BELOW NORMAL ACROSS MOST OF THE AREA AS A RESULT. THE
CLOUDS AND COOL TEMPS WILL LIMIT INSTABILITY. BUT GUIDANCE SHOWS
PRETTY SOLID COVERAGE OF DIURNAL POPS AGAIN MONDAY AFTN-EVE. A
DECENT AMOUNT OF ELEVATED CAPE SHOULD SUPPORT AT LEAST SCATTERED
TSTMS EMBEDDED WITHIN NUMEROUS TO WIDESPREAD SHOWERS. PWATS WILL
REMAIN AROUND 2"+, SO EXCESSIVE RAIN WILL STILL BE A CONCERN,
ALTHOUGH MUTED SLIGHTLY BY LESS AVAILABLE INSTABILITY.
RELATIVELY COOL/MOSTLY STABLE AND SHOWERY CONDITIONS CONTINUE INTO
TUESDAY...ALTHOUGH GUIDANCE SIGNALS ADVECTION OF DRIER AIR INTO
THE HEART OF THE FORECAST AREA FROM THE N AND NE. STILL CAN'T RULE
OUT SOME DEGREE OF A HEAVY RAINFALL THREAT AROUND THE SOUTHERN AND
WESTERN PERIPHERY OF THE CWA TUESDAY, BUT MUCH OF THE AREA MAY
WELL BE FREE OF CONVECTION TUE AFTERNOON. FORECAST MAXES REMAIN
AROUND 10 DEGREES BELOW NORMAL TUE.
KEY MESSAGE 2: A RETURN TO SEASONABLY HOT AND DRIER CONDITIONS IS
EXPECTED DURING THE LATTER HALF OF NEXT WEEK.
AN UPPER RIDGE WILL PERSIST ACROSS THE CENTRAL AND NORTHERN GREAT
PLAINS, WHILE A WEAK UPPER LOW WILL RETROGRADE ACROSS THE SOUTHEAST
TOWARD TX. UPPER RIDGING WILL GRADUALLY NOSE EAST/SOUTHEAST INTO
OUR REGION THRU THE END OF THE WEEK, RESULTING IN SEASONABLY HOT
CONDITIONS TO RETURN TO THE CWFA THURSDAY THRU NEXT WEEKEND. THE 12Z
GUIDANCE HAS TRENDED A LITTLE DRIER FOR THURSDAY AND FRIDAY, THEN
SOME INCREASE IN DIURNAL CONVECTION OVER THE WEEKEND. GENERALLY
ISOLATED TO WIDELY SCATTERED CONVECTION IN THE MOUNTAINS, WITH
VERY ISOLATED ACTIVITY IN THE PIEDMONT UNTIL SLIGHTLY HIGHER POPS
SATURDAY AND SUNDAY.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
AT KCLT AND ELSEWHERE: SCATTERED CONVECTION HAS STARTED TO FIRE
AS OF THE 18Z TAF ISSUANCE ACROSS THE UPSTATE AND COVERAGE SHOULD
CONTINUE TO INCREASE THRU THE REST OF THE AFTN HOURS. HENCE,
TEMPO FOR TS STILL LOOKS GOOD. THE NC SITES HAVE MORE MID AND
HIGH CLOUDS LINGERING FROM THIS MORNING, AND GUIDANCE DELAYS
REDEVELOPMENT OF CONVECTION SLIGHTLY; THEREFORE, TEMPOS WERE PUSHED
BACK AN HOUR OR TWO WITH THE 18Z TAFS. OTHERWISE, EXPECT LINGERING
SHOWERS AND ISOLATED THUNDERSTORMS THRU THE EVENING. A BACKDOOR
FRONT WILL SLIP IN FROM THE NE AND TOGGLE WINDS OUT OF THE NE OR
ENE, BUT SHOULD REMAIN LIGHT. MOIST EASTERLY FLOW WILL SUPPORT
EXPANSION OF MVFR TO IFR CIGS FORMING ACROSS THE AREA OVERNIGHT
THRU MONDAY MORNING. THE LOW CLOUDS MAY PERSIST INTO EARLY AFTN,
BEFORE BEGINNING TO LIFT TO MVFR. CONFIDENCE IS LOW TO MODERATE
ON HOW MUCH TS WILL BE ABLE TO FORM DUE TO THE WEDGE-LIKE AIR
MASS. BUT SCATTERED TO NUMEROUS SHRA ARE EXPECTED WITH ENOUGH
POTENTIAL FOR TSRA TO WARRANT A PROB30 AT KCLT LATE MONDAY AFTN.
OUTLOOK: GREATER THAN NORMAL COVERAGE OF SHRA/TSRA WILL CONTINUE
ACROSS OUR FCST AREA 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.
ARK
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