525
FXUS62 KCAE 081800
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
200 PM EDT TUE JUL 8 2025
SYNOPSIS
TEMPERATURES REMAIN ABOVE NORMAL TODAY BEFORE COOLING SOME
TOMORROW AND THURSDAY WITH DIURNALLY DRIVEN SHOWERS AND
THUNDERSTORMS AS A UPPER TROUGH APPROACHES. A COUPLE STRONGER
STORMS AND HEAVY RAINFALL COULD BE POSSIBLE WEDNESDAY AND
THURSDAY. TEMPERATURES SLOWLY RISE IN THE LATE WEEK AND INTO
THIS WEEKEND WITH TYPICAL SUMMERTIME SHOWERS/STORMS.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGE(S):
- HOT WITH SCATTERED THUNDERSTORMS EXPECTED THIS AFTERNOON; SOME
ISOLATED DAMAGING WINDS POSSIBLE.
VERY HOT AND UNSETTLED CONDITIONS EXPECTED THIS AFTERNOON, AS
SCATTERED SHOWERS AND THUNDERSTORMS HAVE ALREADY DEVELOPED ACROSS
THE AREA. FOR AREAS THAT ARE STILL DRY, TEMPERATURES HAVE REACHED
THE MID 90S WITH DEWPOINTS IN THE LOW 70S, LEADING TO HEAT INDICES
IN THE LOW 100'S. THAT SAID, TEMPERATURES HAVE DECREASED QUICKLY FOR
LOCATIONS THAT HAVE ALREADY GOTTEN RAINED ON, WITH TEMPERATURES A
FULL 10 DEGREES COOLER IN THE LOW TO MID 80S. LOW LEVEL LAPSE RATES
REMAIN STEEP, BUT MID LEVEL LAPSE RATES ARE QUITE WEAK WHICH HAS
INHIBITED MUCH VERTICAL DEVELOPMENT. THE RESULT IS STORMS THAT ARE
QUICKLY DROPPING THEIR CORES AND PRODUCING WEAK OUTFLOW BOUNDARIES.
HOWEVER, ATMOSPHERIC MOISTURE LEVELS REMAIN HIGH WITH PW VALUES
RANGING FROM 1.7" TO 2.2". IN COMBINATION WITH WEAK STEERING FLOW
AND THEREFORE SLOW (IF ANY) STORM MOTIONS, WE'LL CONTINUE TO KEEP A
CLOSE EYE ON RAIN RATES/RAINFALL AMOUNTS AND THE POTENTIAL FOR
STRONGER DOWNBURST WINDS MAINLY DUE TO PRECIP LOADING. CAM
DEPICTIONS OF ONGOING CONVECTION HAVE BEEN DOING QUITE WELL, SHOWING
THE MAIN AREA OF DEVELOPMENT ALONG THE I-20 CORRIDOR, WHICH
COINCIDENTALLY LINES UP WELL WITH THE 1.9" PW DELINEATION VIA
SATELLITE ESTIMATES. CANNOT TOTALLY RULE OUT SOME ISOLATED STRONG TO
DAMAGING WIND GUSTS, BUT OVERALL THE SEVERE THREAT STILL LOOKS LOW
TODAY. CONVECTION SHOULD DECREASE QUICKLY WITH THE LOSS OF HEATING
AROUND SUNSET, AND THE OVERNIGHT PERIOD SHOULD BE MILD WITH
TEMPERATURES IN THE 70S.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
KEY MESSAGE(S):
- A BIT COOLER WEDNESDAY AND THURSDAY WITH INCREASED CLOUD
COVER.
- SCATTERED TO WIDESPREAD SHOWERS/STORMS EACH AFTERNOON AND
EVENING WHERE COUPLE STRONG TO MARGINALLY SEVERE STORMS CANNOT
BE RULED OUT.
- HIGH PWATS EACH DAY COMBINED WITH WEAK STEERING FLOW SUGGEST
AN ISOLATED FLASH FLOOD POTENTIAL WITH CONVECTION.
WEDNESDAY AND THURSDAY LOOK TO BE FAIRLY SIMILAR DAYS, THOUGH
WEDNESDAY IS PERHAPS A BIT MORE INTERESTING. A UPPER TROUGH
MOVING INTO THE REGION IS EXPECTED TO DOMINATE EACH DAY AS
RIDGING BECOMES INCREASINGLY SUPPRESSED BY THIS AND INCREASING
SOUTHWESTERLY FLOW YIELDS PWAT'S THAT APPROACH 2.1-2.2", PERHAPS
A BIT LOWER INTO THURSDAY. AT THE SURFACE, SOME LEE TROUGHING
IS EXPECTED AND EVIDENT IN MOST CAM'S BY ENHANCED CONVERGENCE
TOWARD THE NORTHERN FA AND INTO THE UPSTATE. WHILE FORCING IS
GENERALLY ON THE WEAKER SIDE EACH DAY, MODERATE TO STRONG
INSTABILITY IS DEPICTED WITH THE HREF MEAN SBCAPE APPROACHING
2500 TO 2800 J/KG WEDNESDAY AFTERNOON, AND FORECASTING SOUNDINGS
SHOWING AROUND 1500 TO 2000 J/KG ON THURSDAY. THIS SHOULD ALLOW
SCATTERED TO WIDESPREAD SHOWERS AND PULSE TO A COUPLE MESSY
CLUSTERS OF STORMS TO FORM IN THE CONVERGENT ZONE AND ALSO ALONG
THE INLAND PUSHING SEA-BREEZE DURING THE AFTERNOON AND INTO THE
EVENING EACH DAY. STRONG INVERTED V PROFILES BRING MODERATE TO
STRONG DCAPE AND WHEN COMBINED WITH NEARLY SATURATED PROFILES
ALOFT, WEAK DEEP LAYER, AND WEAK STEERING FLOW, PRECIPITATION
LOADING COULD LEAD TO SOLID DOWNBURSTS IN THE STRONGEST STORMS
AND THUS DAMAGING WIND GUSTS WOULD BE THE PRIMARY THREAT IN ANY
MARGINALLY SEVERE STORM. DUE TO THIS, THE SPC HAS MAINTAINED A
MARGINAL RISK (LEVEL 1 OUT OF 5) EACH DAY ACROSS THE FA, WITH A
SLIGHT RISK (LEVEL 2 OUT OF 5) THAT CLIPS THE FAR NW CWA ON
WEDNESDAY. THIS SEEMS REASONABLE, ESPECIALLY FOR WEDNESDAY WHERE
THE GREATER INSTABILITY WILL BE.
OUTSIDE OF ANY SEVERE RISK, ANOTHER CONCERN IS THE ISOLATED
FLASH FLOODING RISK, WHERE WPC HAS A MARGINAL RISK (LEVEL 1 OUT
OF 4) FOR EXCESSIVE RAINFALL OVER THE WHOLE CWA WEDNESDAY AND A
SLIGHT RISK THAT CLIPS THE NORTHERN FA (LEVEL 2 OUT OF 4).
ANOTHER MARGINAL RISK IS SEEN MAINLY ACROSS THE PEE DEE REGION
ON THURSDAY. HREF MEMBERS ON WEDNESDAY GENERALLY DEPICT A BATCH
A SHOWERS/STORMS FORMING TOWARD THE NORTHERN FA ALONG A
CONVERGENT ZONE, AS WELL AS ALONG THE INLAND PUSHING SEA-BREEZE.
INTERACTIONS WITH THE OUTFLOW FROM STORMS TO THE NORTH AND
STORMS ALONG THE SEA BREEZE COUPLED WITH WEAK STEERING FLOW AND
HIGH PWAT'S, BRING THE RISK FOR AREAS OF LOCALLY HEAVY RAINFALL
AND FLASH FLOODING EACH DAY, ESPECIALLY ALONG AREAS OF
INTERACTING STORMS/BOUNDARIES.
LONG TERM /FRIDAY THROUGH TUESDAY/
KEY MESSAGE(S):
- NEAR AVERAGE TEMPERATURES FRIDAY WITH GRADUAL WARMING TREND
INTO THE EARLY WEEK WITH HOT/MUGGY CONDITIONS POSSIBLE.
- MORE TYPICAL ISOLATED TO SCATTERED CONVECTION EXPECTED DURING
THE EXTENDED.
THE EC ENSEMBLE AND GEFS GENERALLY SHOW THIS UPPER TROUGH
STARTING TO MOVE OUT ON FRIDAY, WITH WEAK RIDGING STARTING TO
BUILD BACK IN, BEFORE FULLY BUILDING IN FOR THE WEEKEND AND INTO
EARLY NEXT WEEK. THIS BRINGS TEMPERATURES BACK NEAR NORMAL
FRIDAY AND SLIGHTLY ABOVE NORMAL THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK. HOT AND MUGGY CONDITIONS ARE POSSIBLE OVER THE
WEEKEND AS PWAT'S REMAIN SEASONABLY HIGH. IN TERMS OF
SHOWER/STORM CHANCES, COVERAGE SHOULD BE GREATEST ON FRIDAY AS
RIDGING STILL REMAINS SOMEWHAT SUPPRESSED BEFORE RETURNING TO
TYPICAL ISOLATED TO SCATTERED CHANCES OVER THE WEEKEND AND INTO
EARLY NEXT WEEK.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
VFR CONDITIONS THROUGH EARLY AFTERNOON, WITH SCATTERED CONVECTION
LIKELY IN THE MID AFTERNOON-EVENING ALONG WITH POSSIBLE RESTRICTIONS.
VFR WILL DOMINATE THE FORECAST PERIOD WITH FEW-SCT CUMULUS FIELD
AROUND 4K-6KFT MSL THIS AFTERNOON. ISOLD-SCT -SHRA/-TSRA SHOULD
THEN DEVELOP AT ALL TAF SITES, PARTICULARLY AFTER 08/18Z WITH
THE POTENTIAL FOR GUSTY WINDS TO AROUND 25 KTS. THERE MAY ALSO
BE SOME BRIEF CIG/VSBY RESTRICTIONS WITH THE STRONGER TSRA.
OTHERWISE, SFC WINDS MAINLY SLY LESS THAN 10 KTS WITH CONVECTION
DIMINISHING AFTER 09/00Z. SOME OVERNIGHT FOG AND STRATUS ARE
POSSIBLE DEPENDING ON RAINFALL TOTALS AND COVERAGE AS WINDS
BECOME LIGHT AND VARIABLE. VERY SIMILAR CONDITIONS EXPECTED TO
DEVELOP ON WEDNESDAY, THOUGH PRECIPITATION COVERAGE MAY BE
GREATER.
EXTENDED AVIATION OUTLOOK...THERE IS THE POSSIBILITY OF
DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS THIS WEEK WITH THE
POTENTIAL FOR PERIODIC RESTRICTIONS.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
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