681
FXUS62 KGSP 241054
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
654 AM EDT FRI JUL 24 2026
WHAT HAS CHANGED
UPDATED FOR 12Z AVIATION PACKAGE.
SIMILAR THINKING FOR ISOLATED EXCESSIVE RAINFALL POTENTIAL TODAY,
DIMINISHING SATURDAY.
REVISED DETAILS ABOUT POSSIBLE CONVECTIVE COMPLEXES MAKING A RUN
AT THE AREA MONDAY OR TUESDAY NIGHTS.
KEY MESSAGES
1. POTENTIAL FOR AT LEAST LOCALIZED EXCESSIVE RAINFALL CONTINUES
THROUGH SATURDAY.
2. A RETURN TO TYPICAL MID-SUMMER WEATHER BEGINS SUNDAY AND
CONTINUES THROUGH TUESDAY, WITH HOT TEMPERATURES AND AT LEAST
ISOLATED DIURNAL CONVECTION EXPECTED. ANOTHER COLD FRONT MAY
REACH THE AREA IN THE MIDDLE OF NEXT WEEK.
DISCUSSION
KEY MESSAGE 1: POTENTIAL FOR AT LEAST LOCALIZED EXCESSIVE RAINFALL
CONTINUES THROUGH SATURDAY.
A STATIONARY FRONT WILL REMAIN SOUTH OF THE FORECAST AREA THROUGH
SATURDAY, WITH AT LEAST WEAK SOUTHERLY UPGLIDE CONTINUING ATOP
IT. THIS FRONT IS SITUATED NEAR THE BASE OF A BROAD TROUGH EXTENDING
ACROSS THE NORTHEASTERN QUADRANT OF THE CONUS. PWATS IN THE FRONTAL
ZONE WILL REMAIN AT OR ABOVE 2 INCHES THROUGH TODAY ALONG WITH AT
LEAST A FEW HUNDRED JOULES OF MUCAPE FOR PARCELS ELEVATED ABOVE THE
FRONTAL INVERSION. A FEW MODERATE-INTENSITY SHOWERS ARE POSSIBLE
NEARER THE FRONT THIS MORNING, MAINLY OVER THE SAVANNAH VALLEY
AND ADJACENT PARTS OF THE UPSTATE; OTHERWISE PRECIP THIS MORNING
WILL MAINLY BE JUST DRIZZLE OR SPRINKLES. OUR AREA WILL NOT HAVE
THE DEGREE OF INSTABILITY TODAY THAT WAS SEEN ON THURSDAY OWING TO
EXTENSIVE STRATUS, AND FOR AT LEAST PART OF THE DAY WE WILL BE IN A
RELATIVE LULL IN UPPER FORCING BETWEEN EMBEDDED SHORTWAVES. HENCE
DIURNAL CONVECTIVE COVERAGE IS EXPECTED TO BE A BIT LESS THAN
THURSDAY, WITH THE HEAVY RAIN CONCERN GREATEST IN THOSE AREAS
NEAREST THE FRONT--IN OUR SOUTHERN CWA. CAM RESPONSE IS RATHER
MUTED/NOISY-LOOKING DURING THE DAY. HOWEVER, STEERING FLOW ALOFT
WILL REMAIN WESTERLY, QUASI-PARALLEL TO THE FRONT, AND THIS SUGGESTS
ANY CONVECTION THAT DOES FIRE WILL BE CAPABLE OF EXCEPTIONALLY
HIGH RAINFALL RATES. WPC MAINTAINS A SLIGHT RISK OVER THE SOUTHERN
HALF OF THE CWA. BY LATE AFTERNOON SOME MORE WEAK VORT MAXES WILL
APPROACH FROM THE WEST AND IN TURN SOME CAMS SUGGEST CONVECTIVE
DEVELOPMENT MAINLY DURING THE EVENING. THE EXCESSIVE RAIN THREAT
WILL BE SOMEWHAT MITIGATED BY THE BEST COVERAGE TODAY APPEARING
IN OUR SOUTH WHICH GENERALLY SAW THE LEAST RAIN ON THURSDAY. THAT
IS A REASON WHY NO FLOOD WATCH IS IN EFFECT FOR TODAY.
THE AFOREMENTIONED WEAK VORT LOBES PROMOTE A DEEPENING OF THE
UPPER TROUGH SUCH THAT THE 500MB PATTERN IS MORE AMPLIFIED FOR
SATURDAY. SOME DRYING DOES OCCUR ALOFT WHICH WILL SHIFT THE BAND
OF FRONTAL MOISTURE STILL FURTHER SOUTH. WEAK DOWNSLOPE FLOW IN
LOW LEVELS MAY HELP SCOUR OUT CLOUDS PARTICULARLY IN THE NW CWA
AND IN TURN CONVECTION SHOULD REFLECT A SOMEWHAT MORE DIURNAL TREND.
KEY MESSAGE 2: A RETURN TO TYPICAL MID-SUMMER WEATHER BEGINS SUNDAY
AND CONTINUES THROUGH TUESDAY, WITH HOT TEMPERATURES AND AT LEAST
ISOLATED DIURNAL CONVECTION EXPECTED. ANOTHER COLD FRONT MAY REACH
THE AREA IN THE MIDDLE OF NEXT WEEK.
WITH NORTHWEST FLOW CONTINUING ALOFT SATURDAY NIGHT INTO SUNDAY,
DRYING CONTINUES AND THE FRONTAL ZONE SHOULD CONTINUE TO PROGRESS
SOUTHWARD. THE UPPER PATTERN CONTINUES TO AMPLIFY WITH A BROAD
596+ DM ANTICYCLONE REMAINING OVER THE ROCKIES/PLAINS WITH HEIGHTS
ACTUALLY FALLING OVER THE NORTHEAST COAST. TEMPERATURES TREND WARMER
SUNDAY-TUESDAY, A LITTLE ABOVE NORMAL, AS THE RIDGE BUILDS TO OUR
WEST AND AS SW FLOW IS RE-ESTABLISHED. DIURNAL CONVECTION SHOULD BE
POSSIBLE OVER THE MOUNTAINS EACH DAY WHICH COULD PROPAGATE INTO THE
FOOTHILLS/PIEDMONT. ESPECIALLY HOT AND HUMID CONDITIONS WILL DEVELOP
IN THE MIDWEST WITH A NW-SE ORIENTED THERMAL GRADIENT SUGGESTED BY
THE UPPER PATTERN. MODELS DIFFER IN THE TIMING OF THE SHORTWAVES
ROUNDING THE RIDGE AND DIVING INTO THE TROUGH BUT IT WOULD APPEAR WE
HAVE AT LEAST A CHANCE OF AN MCS REACHING THE NC MOUNTAINS BETWEEN
MONDAY NIGHT THROUGH EARLY WEDNESDAY. SHEAR APPEARS FAVORABLE BUT
THE DEGREE OF INSTABILITY EAST OF THE MOUNTAINS MAY BE A LIMITING
FACTOR. AN UPPER LOW COULD FORM WITHIN THE TROUGH BY THE MIDDLE
OF NEXT WEEK, WHICH COULD BRING A COLD FRONT TO THE AREA AND/OR
CLOUDS/PRECIP; THESE POSSIBILITIES SEEM TO ACCOUNT FOR MODEL BLEND
TEMPS TRENDING COOLER WED-THU.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
AT KCLT AND ELSEWHERE: WIDESPREAD IFR STRATUS, WITH A FEW HOLES OF
ONLY MVFR, ACROSS THE TERMINAL AREA EARLY THIS MORNING NORTH OF A
STALLED FRONT. A FEW PATCHES OF -DZ OR -SHRA WILL OCCUR; HEAVIER
PRECIP MAY LEAD TO IMPROVEMENT THOUGH IF/WHERE -DZ FORMS CIGS COULD
FALL TO LIFR. SLIGHT IMPROVEMENT IN CIGS/VSBY IS EXPECTED AS WINDS
WEAKEN DIURNALLY OVER THE FRONT, THOUGH PREDOMINANTLY IFR CIGS
SHOULD PREVAIL THROUGH THE DAY. SHRA ARE EXPECTED TO REDEVELOP
DURING AFTERNOON, PERHAPS WITH A FEW EMBEDDED TSRA NEAR KAVL AND
KAND. PROB30S ARE RETAINED AT ALL SITES, WITH IFR VSBY LIKELY IN
MODERATE TO HEAVY RAIN. MAINLY BREEZY NE WINDS TODAY EXCEPT SE AT
KAVL. RESTRICTIONS SHOULD WORSEN WITH IFR TO LIFR SETTING BACK IN
FRIDAY NIGHT AFTER THE AFTN/EVENING ACTIVITY DIMINISHES, WINDS GO
NEARLY CALM, AND SOME -DZ MAY RETURN. DEVELOPMENT OF DRIER NW WINDS
ALOFT SHOULD LEAD TO GRADUAL IMPROVEMENT THRU SATURDAY MORNING.
OUTLOOK: CONVECTION WILL REDEVELOP DIURNALLY SATURDAY AFTERNOON. AS
THE FRONT FINALLY SETTLES FURTHER SOUTH, SOME DRYING IS IN ORDER FOR
SUNDAY AND MONDAY, SO CONVECTION AND RESTRICTIONS LOOK LESS LIKELY.
LOW STRATUS AND/OR FOG WILL BE POSSIBLE EACH MORNING IN MOUNTAIN
VALLEYS AND ANY LOCATIONS WHICH RECEIVE HEAVY RAINFALL BY DAY.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
JCW
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