822
FXUS62 KCAE 211744
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
144 PM EDT TUE JUL 21 2026
WHAT HAS CHANGED
REMOVED A KEY MESSAGE TO FOCUS MORE ON THE APPROACHING FRONT.
GUIDANCE CONTINUES TO TREND TOWARD A SLOWER FRONTAL
PROGRESSION.
KEY MESSAGES
- 1. A SLOW-MOVING FRONT WILL APPROACH LATE TOMORROW INTO
THURSDAY, BRINGING SCATTERED TO WIDESPREAD RAIN/STORM CHANCES.
ACTIVE WEATHER PERSISTS INTO THE LATE WEEK.
DISCUSSION
KEY MESSAGE 1: A SLOW-MOVING FRONT WILL APPROACH LATE TOMORROW
INTO THURSDAY, BRINGING SCATTERED TO WIDESPREAD RAIN/STORM
CHANCES. ACTIVE WEATHER PERSISTS INTO THE LATE WEEK.
SLIGHTLY DRIER AIR HAS FILTERED INTO THE AREA TODAY WITH LOWER
PWATS AND DEWPOINTS MIXING OUT INTO THE UPPER 60S TO LOWER 70S.
AS A RESULT, FORCING REMAINS LIMITED WITH AFTERNOON
TEMPERATURES CLIMBING INTO THE MID-90S. CAM GUIDANCE CONTINUES
TO INDICATE LIMITED COVERAGE, WITH A MODEST CAP IN PLACE AND
HIGH LFCS SUPPRESSING STORM DEVELOPMENT. THAT SAID, CANNOT
COMPLETELY RULE OUT ISOLATED PULSE SHOWERS/T-STORMS THIS
EVENING.
A WEAK FRONT WILL SETTLE TOWARD THE AREA ON WEDNESDAY, BRINGING
INCREASING LOW-LEVEL CONVERGENCE AND IMPROVED LARGE-SCALE
FORCING. HOWEVER, GUIDANCE CONTINUES TO TREND TOWARD A SLOWER
FRONTAL PROGRESSION, RESULTING IN A SLIGHTLY WARMER FORECAST
WITH ONLY ISOLATED TO SCATTERED CONVECTION EXPECTED DURING THE
LATE AFTERNOON. RAIN AND THUNDERSTORM COVERAGE SHOULD INCREASE
WEDNESDAY NIGHT INTO THURSDAY AS THE FRONT MOVES IN. THE PRIMARY
UNCERTAINTY REMAINS THE LATER TIMING, WHICH WOULD REDUCE THE
OVERLAP BETWEEN THE STRONGEST FORCING AND PEAK INSTABILITY. IF
TRENDS CONTINUE, THE SEVERE THREAT MAY CONTINUE TO DIMINISH.
AS THE FRONT STALLS OUT ON THURSDAY, ANOTHER ROUND OF STRONGER
CONVECTION MAY DEVELOP. REGARDLESS, THE GREATER CONCERN APPEARS
TO BE THE POTENTIAL FOR HEAVY RAINFALL FROM LATE WEDNESDAY
THROUGH THURSDAY. PWATS EXCEEDING 2" AND RELATIVELY SKINNY CAPE
PROFILES WILL FAVOR EFFICIENT RAINFALL RATES, WHILE THE STALLED
BOUNDARY COULD SUPPORT TRAINING CONVECTION. THE ECMWF REMAINS
THE MOST AGGRESSIVE SOLUTION, WITH THE OVERALL ENVIRONMENT
SUPPORTING A HEAVY RAINFALL SETUP. THAT SAID, IT REMAINS
UNCOMMON FOR A FRONT TO PUSH THIS FAR SOUTH IN LATE JULY, SO
CONTINUED DOWNTRENDS ARE ANTICIPATED BUT THIS WILL BE MONITORED.
THE BOUNDARY IS EXPECTED TO LINGER ACROSS MUCH OF THE AREA
THROUGH FRIDAY, AS ANOTHER SHORTWAVE APPROACHES MAINTAINING
SCATTERED TO WIDESPREAD SHOWER AND THUNDERSTORM CHANCES.
FORECAST CONFIDENCE DECREASES INTO THE WEEKEND, BUT THE OVERALL
PATTERN REMAINS FAVORABLE FOR UNSETTLED WEATHER.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
VFR CONDITIONS LIKELY THROUGH THE 24 HR TAF PERIOD.
WITH DRIER AIR OVER THE REGION TODAY, CONVECTIVE COVERAGE WILL
BE LOW ENOUGH TO LIMIT THE CHANCE OF SHOWERS OR STORMS AT ANY OF
THE TAF SITES. EXPECT BREEZY SW WINDS TODAY WITH GUSTS AROUND
20 KTS. GUSTS SHOULD SUBSIDE AROUND 03Z BUT WINDS WILL STAY UP
AROUND 5 TO 10 KTS OVERNIGHT AS A FRONT SLOWLY APPROACHES THE
SOUTHEAST. THE FRONT WILL REMAIN TO OUR NORTH THROUGH THE END
OF THE TAF PERIOD. SW WINDS WILL PICK UP ONCE AGAIN WEDNESDAY
MORNING WITH GUSTS AROUND 20 KTS. A FEW PATCHES OF MVFR CEILINGS
MAY BE AROUND ON WEDNESDAY MORNING BUT VFR CONDITIONS REMAIN
THE MOST LIKELY SCENARIO. MUCH OF THE CONVECTIVE ACTIVITY
ASSOCIATED WITH THE FRONT SHOULD REMAIN NORTH OF THE TAF SITES
THROUGH THE END OF THE TAF PERIOD.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS FROM SHOWERS AND
THUNDERSTORMS LIKELY BEGINNING WEDNESDAY NIGHT THROUGH LATE THIS
WEEK.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...ND
AVIATION...CJR
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