187
FXUS62 KGSP 302322
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
722 PM EDT WED JUL 30 2025
SYNOPSIS
THE HEAT WAVE CONTINUES TO GRADUALLY WEAKEN THROUGH FRIDAY AS THE
UPPER PATTERN SLOWLY SHIFTS AND BRINGS A COLD FRONT DOWN FROM THE
NORTH. THE FRONT SHOULD MOVE ACROSS THE AREA FRIDAY AND FRIDAY
NIGHT, BRINGING SOME MUCH-NEEDED RELIEF FROM THE HEAT IN THE FORM
OF BELOW NORMAL TEMPERATURES THIS WEEKEND INTO EARLY NEXT WEEK.
NEAR TERM /THROUGH THURSDAY/
AS OF 155 PM EDT WEDNESDAY: RIDGETOP CONVECTION AND GARDEN VARIETY
ACTIVITY DEVELOPING ELSEWHERE SHOULD GRADUALLY GROW IN COVERAGE
OVER THE NEXT FEW HOURS. 2000-3000 J/KG OF SBCAPE, 600-1000 J/KG
OF DCAPE, AND VERY LITTLE DEEP LAYER SHEAR SUGGEST STORM MODE
THROUGH THIS AFTERNOON WILL SUPPORT PULSE CONVECTION CARRIED BY
OUTFLOW BOUNDARIES. PWAT VALUES OF 1.75"-2.00+" INDICATE THAT A
LOCALIZED HYDRO THREAT WILL BE POSSIBLE THANKS TO HEAVY RAINFALL
RATES AND SLOW MOVING STORMS. A FEW STRONG TO SEVERE STORMS CAN'T
BE RULED OUT, WITH WET MICROBURSTS BEING THE PRIMARY THREAT. CAMS
ARE IN DECENT AGREEMENT WITH DWINDLING CONVECTIVE COVERAGE SHORTLY
AFTER SUNSET, WITH ONLY ISOLATED SHOWERS AND THUNDERSTORMS THROUGH
MIDNIGHT OR SO. DEWPOINTS REMAIN ELEVATED IN THE LOW 70S, BUT
ENOUGH MIXING IN THE BOUNDARY LAYER AND MORNING CLOUD COVER HAS
KEPT TEMPERATURES IN CHECK, WITH MOST LOCATIONS ONLY IN THE UPPER
80S TO LOW 90S OUTSIDE OF THE MOUNTAINS, WHICH HAS ALLOWED FOR
HEAT INDICES TO REMAIN BELOW ADVISORY CRITERIA.
LEFTOVER CLOUD DEBRIS WILL BE PRESENT THROUGH THE EARLY OVERNIGHT
HOURS AND GROUND FOG MAY DEVELOP WHERE CLOUD COVER CLEARS QUICKER
THAN EXPECTED AND WHERE HEAVY RAINFALL OCCURRED. MOUNTAIN VALLEY FOG
AND LOW STRATUS IS EXPECTED AGAIN, WHILE BOUNDARY LAYERS STRUGGLE
TO FULLY DECOUPLE OVERNIGHT WITH WIDER DEWPOINT DEPRESSIONS. IN
THIS CASE, NOT EXPECTING WIDESPREAD COVERAGE IN LOW STRATUS AND
FOG BY DAYBREAK THURSDAY COMPARED TO THIS MORNING. OVERNIGHT LOWS
WILL REMAIN IN THE LOW TO MID 70S. WEAKNESS IN THE FLOW ALOFT WILL
BE EVIDENT AS AN UPPER TROUGH OVER THE NORTHEASTERN CONUS SLOWLY
DIGS SOUTH INTO THE REGION. THE SUBTROPICAL RIDGE THAT HAS PLASTERED
THE AREA WITH EXTREME HEAT WILL BE WELL WEST OF THE AREA BY THE END
OF THE FORECAST PERIOD. ANOTHER AREA TO WATCH IS THE FORMATION OF
A WEAK ANTICYCLONE ALOFT OVER FLORIDA. BETWEEN THE RIDGE OVER THE
SOUTHERN HIGH PLAINS AND ANTICYCLONE OVER FLORIDA, MOIST SOUTH TO
SOUTHWESTERLY FLOW WILL FILTER INTO THE REGION AND SET THE STAGE
FOR ANOTHER DIURNALLY DRIVEN CONVECTIVE DAY FOR THURSDAY.
WITH THE UPPER TROUGH SLOWLY DIGGING SOUTH TOWARDS THE AREA, AN
ATTENDANT FRONTAL BOUNDARY WILL ALSO BE KNOCKING ON THE BACKDOOR TO
THE NORTHWEST. WITH THE ADDED FORCING FROM THE FRONTAL BOUNDARY TO
GO ALONG WITH AN ENVIRONMENT THAT'S VERY SIMILAR TO THE PAST FEW
DAYS WITH 2000-3000 J/KG OF SBCAPE, 600-1000 J/KG OF DCAPE, AND
VERY LITTLE DEEP LAYER SHEAR, EXPECT CONVECTIVE COVERAGE TO BECOME
MORE WIDESPREAD DURING PEAK HEATING THURSDAY. RIDGETOP INITIATION
IS EVIDENT TO GO ALONG WITH INITIATION SOLELY FROM THE ADDED FORCING
FOR ASCENT ACROSS THE MOUNTAINS AND WILL SHIFT SOUTH AND EAST LATER
INTO THE AFTERNOON. A FEW INDUCED COLD POOLS MAY DEVELOP, WHICH
WOULD HELP TO SLIGHTLY ELEVATE THE SEVERE POTENTIAL. NOT OUTLOOKED
AT THE MOMENT FROM SPC, BUT CAN'T RULE OUT A SMALL MARGINAL RISK
DUE TO THIS POTENTIAL. INCREASED COMPRESSIONAL WARMING AHEAD OF THE
BOUNDARY AND DEWPOINTS CONTINUING TO HOVER IN THE LOW TO MID 70S,
WOULDN'T BE SURPRISED IF A FEW LOCATIONS OUTSIDE OF THE MOUNTAINS
FLIRT WITH HEAT ADVISORY CRITERIA INDICES ON THURSDAY. AFTERNOON
HIGHS ON THURSDAY WILL BE IN THE LOW TO MID 90S.
SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/
AS OF 1252 PM EDT WEDNESDAY...THE MORNING GUIDANCE BLEND CONTINUES
TO TREND WARMER FOR FRIDAY AS A FRONTAL ZONE DROPS DOWN FROM THE
NORTH. ON THE ONE HAND, THE FRONTAL BOUNDARY WILL BE THE FOCUS FOR
WIDESPREAD/NUMEROUS MAINLY AFTERNOON/EVENING SHOWERS AND STORMS,
WITH PLENTY OF CLOUDS, BOTH OF WHICH WOULD TEND TO CUT DOWN ON
THE POTENTIAL FOR HIGH TEMPS GETTING UP INTO THE LOW/MID 90S. ON
THE OTHER HAND, THERE WON'T REALLY BE MUCH OF AN AIR MASS CHANGE
ON FRIDAY AND WE SHOULD GET YET ANOTHER WARM START TO THE DAY,
SO WE COULD EASILY REACH THE 90S EAST OF THE MTNS BEFORE ALL
THE CONVECTION REALLY GETS GOING. THERE'S AN OUTSIDE SHOT AT
REACHING HEAT ADVISORY CRITERIA IN A FEW SPOTS, BUT FOR NOW WE
ARE LIMITING THE APPARENT TEMPS BELOW 105. AS PER USUAL, THE SHEAR
WILL BE RELATIVELY WEAK BUT THERE SHOULD BE ENOUGH SFC-BASED CAPE
AND DCAPE TO SUPPORT A FEW WET MICROBURST PRODUCERS. CONFIDENCE
IS RUNNING HIGH THAT FRIDAY WILL BE THE END OF OUR LONG STREAK
IN THE 90S. THE TRANSITION SHOULD OCCUR FRIDAY NIGHT INTO EARLY
SATURDAY AS THE MID/UPPER TROF IN THE EAST CONTINUES TO SLOWLY
AMPLIFY OVER THE EAST COAST AND THE SFC HIGH OVER THE GREAT LAKES
STARTS TO WEDGE DOWN EAST OF THE MTNS, PUSHING THE FRONTAL ZONE
SOUTH OF THE FCST AREA. WE STILL EXPECT SATURDAY TO FEEL A WHOLE
LOT DIFFERENT AND COOLER AS HIGH PRESSURE TAKES UP RESIDENCE TO
OUR NORTH AND SUPPORTS A WEAK SUMMERTIME WEDGE SCENARIO. EASTERLY
FLOW AND WEAK UPGLIDE SHOULD KEEP CLOUDS AROUND WELL INTO THE
DAY WITH SOME LOW LEVEL FORCING TO ACCOUNT FOR SHOWER ACTIVITY,
ESPECIALLY OVER THE MTNS DOWN THROUGH THE SAVANNAH R BASIN. HIGH
TEMPS ARE PROJECTED TO BE ON THE ORDER OF TEN DEGREES BELOW NORMAL,
BUT THIS COULD GO A CATEGORY EITHER WAY.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/
AS OF 136 PM EDT WEDNESDAY...OUR WEAK SUMMERTIME WEDGE SHOULD BE
ESTABLISHED ACROSS THE AREA BY SATURDAY NIGHT. THE OVERALL PATTERN
IN THE NORTHERN STREAM CHANGES ONLY SLOWLY SUNDAY THROUGH MONDAY
AS THE PARENT HIGH DRIFTS OFF THE COAST OF NEW ENGLAND AND THE
MARITIME PROVINCES BUT LEAVES BEHIND A REMNANT OVER THE MID-ATLANTIC
REGION. THE COOLER EASTERLY FLOW SHOULD KEEP TEMPS 5-10 DEGREES
BELOW NORMAL SUNDAY AND FIVE BELOW NORMAL MONDAY AS THE AIR MASS
SLOWLY MODIFIES. THE MODEL BLEND KEEPS A CHANCE OF PRECIP ACROSS
THE ENTIRE REGION BOTH DAYS BUT THIS IS ACCEPTED WITH A HEALTHY
DOSE OF SKEPTICISM. FCST SOUNDINGS FROM THE GFS, FOR EXAMPLE,
WOULD SUGGEST THAT MOST OF THE FCST AREA WOULD REMAIN PRECIP-FREE,
SO DON'T GET YOUR HOPES UP TOO MUCH FOR ADDITIONAL RAIN. THE
EXPECTATION IS THAT BY TUESDAY, THE REMNANT WEDGE WILL BE DRAINING
AWAY AND TEMPS WILL BE CLIMBING BACK UP TOWARD NORMAL. THERE IS MUCH
UNCERTAINTY REGARDING THE RETURN FLOW OF MOISTURE FROM THE SOUTH,
BUT MUCH OF THE GUIDANCE DIGS ANOTHER SHORT WAVE TO OUR IMMEDIATE
WEST BY THAT TIME. DEPENDING ON HOW QUICK THIS DEVELOPS, WE COULD
SEE A RESURGENCE IN CONFIDENCE OF SCATTERED/NUMEROUS SHOWERS AND
STORMS. BY WEDNESDAY, WE SHOULD BE BACK TO GOOD OLD NORMAL SUMMER
TEMPS AND PRECIP PROBS, WITH AN OUTSIDE CHANCE OF GETTING SOME
KIND OF ORGANIZED CONVECTION DROPPING IN FROM THE NORTHWEST.
AVIATION /00Z THURSDAY THROUGH MONDAY/
AT KCLT AND ELSEWHERE: VFR CONDITIONS TO START WITH A MIX OF
RESTRICTIONS OVERNIGHT. SCATTERED TSRA ARE AROUND THE AREA, BUT NOT
DIRECTLY OVER TERMINALS AT THIS TIME. WILL KEEP A VCTS FOR MOST
SITES, WITH A TEMPO THROUGH 02Z FOR KAND AS STORMS ARE APPROACHING.
OVERNIGHT, WINDS BECOME VRB TO CALM, INCREASING THE CHANCES FOR BR
IN LOCATIONS WHERE RAIN FELL THIS EVENING. KAVL ONCE AGAIN HAS THE
HIGHER CONFIDENCE, HENCE A TEMPO FOR 1/2SM FG FOR A FEW HOURS AROUND
DAYLIGHT. LOW STRATUS IS POSSIBLE AT THE OTHER TERMINALS WITH MVFR
AND A BRIEF IFR NOT OUT OF THE QUESTION. AFTER SUNRISE, WINDS GENTLY
COME UP AND BECOME MORE SW ACROSS THE AREA AND VSBY/CIGS SHOULD
IMPROVE. ANOTHER ROUND OF SCATTERED TSRA FOR THURSDAY AFTERNOON, SO
PROB30S AT ALL SITES ONCE AGAIN.
OUTLOOK: SCATTERED SHOWERS AND THUNDERSTORMS EACH AFTERNOON
THROUGH SATURDAY. LOW STRATUS AND/OR FOG IS POSSIBLE EACH MORNING,
ESPECIALLY IN THE MOUNTAIN VALLEYS.
CLIMATE
RECORDS FOR 07-30
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 93 1954 68 1936 72 2011 54 2014
1878 1897
1895
KCLT 101 2011 71 1981 77 1953 58 1914
1941
KGSP 101 1999 73 1981 77 2011 60 1914
1911
1884
RECORDS FOR 07-31
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 95 1999 65 1936 71 2011 53 1986
1914
KCLT 100 1999 69 1936 77 1941 56 1914
1931 1931
1915
KGSP 104 1999 71 2014 78 1999 56 1936
1931
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...PM
NEAR TERM...CAC
SHORT TERM...PM
LONG TERM...PM
AVIATION...CP
CLIMATE...
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