649
FXUS62 KCAE 131821
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
221 PM EDT SAT JUN 13 2026
WHAT HAS CHANGED
AVIATION DISCUSSION UPDATED FOR 18Z TAFS.
KEY MESSAGES
- 1. ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND WILL INCREASE
THE RISK OF HEAT-RELATED ILLNESS.
- 2. THUNDERSTORM CHANCES ARE FORECAST TO INCREASE OVER THE
NEXT COUPLE OF DAYS, WITH UNSETTLED WEATHER POTENTIALLY
CONTINUING INTO NEXT WEEK.
DISCUSSION
KEY MESSAGE 1: ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND WILL
INCREASE THE RISK OF HEAT-RELATED ILLNESS.
ABOVE NORMAL TEMPERATURES WILL PERSIST ACROSS THE REGION TODAY
AND SUNDAY AS AN UPPER-LEVEL RIDGE REMAINS OVER THE SOUTHEAST.
THE RIDGE IS EXPECTED TO GRADUALLY WEAKEN OVER THE NEXT SEVERAL
DAYS AS TROUGHING ADVANCES EASTWARD. 850-MB TEMPERATURES ARE
FORECAST NEAR THE 90TH PERCENTILE THROUGH SUNDAY AHEAD OF AN
APPROACHING FRONT. HEAT INDICES THIS AFTERNOON ARE GENERALLY
SITTING AROUND 100-105F, WHILE VALUES ON SUNDAY ARE FORECAST TO
RANGE BETWEEN 100F-105F ONCE AGAIN. DESPITE THE HEAT, THE
AIRMASS IS NOT PARTICULARLY MOISTURE-RICH, ALLOWING DEWPOINTS TO
MIX OUT IN THE AFTERNOON. THIS SHOULD PREVENT WIDESPREAD HEAT
INDEX VALUES FROM EXCEEDING 108F (OUR HEAT ADVISORY CRITERIA).
ADDITIONALLY, INCREASING CHANCES FOR AFTERNOON/EVENING
CONVECTION BOTH TODAY AND SUNDAY DURING PEAK HEATING SHOULD HELP
LIMIT MAX TEMPS AND REDUCE THE DURATION OF THE MOST INTENSE
HEAT.
IT SHOULD BE NOTED THAT EXPERIMENTAL HEAT RISK IS HIGHLIGHTING
MAJOR TO LOCALIZED EXTREME HEAT IMPACTS ACROSS MOST OF THE FA
TODAY AND TOMORROW. THIS IS LIKELY DUE TO IT BEING EARLY IN THE
SUMMER WITH TEMPS A FEW DEGREES ABOVE NORMAL AND WARM OVERNIGHT
LOWS. EVEN THOUGH HEAT INDICES ARE EXPECTED TO STAY BELOW
ADVISORY CRITERIA, PLEASE BE SURE TO TAKE PROPER PRECAUTIONS. A
COOLING TREND IS EXPECTED TO DEVELOP EARLY NEXT WEEK AS THE
RIDGE BEGINS TO BREAK DOWN.
KEY MESSAGE 2: THUNDERSTORM CHANCES ARE FORECAST TO INCREASE
OVER THE NEXT COUPLE OF DAYS, WITH UNSETTLED WEATHER POTENTIALLY
CONTINUING INTO NEXT WEEK.
A WEAK BOUNDARY IS EXPECTED TO HANG OUT ACROSS THE AREA TODAY
AND SHOULD SERVE AS A FOCUS FOR CONVECTIVE DEVELOPMENT,
PARTICULARLY ACROSS THE CENTRAL AND EASTERN PORTIONS OF THE FA.
ADDITIONAL INTERACTIONS FROM THE SEA BREEZE MAY FURTHER ENHANCE
STORM DEVELOPMENT ACROSS THE COASTAL PLAIN THIS EVENING. THE
ENVIRONMENT APPEARS FAVORABLE FOR A FEW STRONG TO SEVERE
THUNDERSTORMS. FORECAST SOUNDINGS INDICATE >1000 J/KG OF MLCAPE,
INVERTED V SOUNDINGS, AND DCAPE OF 1000-1200 J/KG. WHILE STORM
COVERAGE IS EXPECTED TO REMAIN ISOLATED, ANY STORMS THAT DO
DEVELOP WILL HAVE THE POTENTIAL TO PRODUCE STRONG TO LOCALLY
DAMAGING WIND GUSTS.
FOR SUNDAY, THE ENVIRONMENT APPEARS SOMEWHAT MORE FAVORABLE FOR
ORGANIZED CONVECTION, WITH IMPROVED FORCING AND INCREASED
SHEAR. 0-6 KM BULK SHEAR VALUES OF 20-30 KT, COMBINED WITH
INCREASED INSTABILITY COULD SUPPORT A FEW STRONG THUNDERSTORMS.
STORM MODE IS EXPECTED TO CONSIST OF A FEW LINEAR SEGMENTS AND
MULTICELL CLUSTERS AHEAD OF THE FRONT, WITH DAMAGING WIND GUSTS
AS THE PRIMARY THREAT MAINLY IN THE LATE AFTERNOON AND INTO
THE EVENING HOURS. BEYOND THIS WEEKEND, PERSISTENTLY HIGH IVT
(90TH PERCENTILE PER NAEFS) SHOULD AID IN KEEPING THINGS
UNSETTLED EARLY AND MID WEEK. BY THE END END OF THIS UPCOMING
WEEK, IT APPEARS THAT ANOTHER FRONT MAY MAKE IT INTO THE AREA &
ANOTHER FOCUS FOR SHOWERS AND STORMS.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
OUTSIDE OF ISOLATED THUNDERSTORMS, VFR CONDITIONS LIKELY.
LIGHT WINDS FROM 5 TO 7 KNOTS OUT OF THE WEST THROUGH THE EARLY
EVENING. RIDGING WILL WORK TO GENERALLY INHIBIT CONVECTION
TODAY WITH JUST DIURNAL CUMULUS AND ISOLATED THUNDERSTORMS
EXPECTED. THEREFORE KEPT MENTION OF STORMS OUT OF MOST OF THE
TAFS. THAT SAID, COVERAGE SHOULD BE SLIGHTLY HIGHER TO THE EAST
AND ALONG THE COAST WITH ADDITIONAL FORCING FROM THE SEA BREEZE.
THEREFORE WE CONTINUED THE PROB30 GROUP FOR TSRA AT OGB FROM
20Z THROUGH 02Z. WINDS SHOULD SUBSIDE WITH SUNSET WITH ANOTHER
ROUND OF DEBRIS CLOUDS IN THE EVENING HELPING TO SUPPRESS FOG.
LOW LEVEL WINDS STRENGTHEN A BIT TONIGHT AND TOMORROW WHICH WILL
ALSO HINDER FOG DEVELOPMENT AND COULD ALLOW FOR SOME SW GUSTS
TO 18 KTS AFTER 15Z SUNDAY.
EXTENDED AVIATION OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY MOVING
INTO THE AREA FROM THE WEST AND MAY BRING STRONG WINDS. GREATER
RAIN CHANCES ARE EXPECTED EARLY NEXT WEEK ALONG WITH POSSIBLE
ASSOCIATED RESTRICTIONS.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...ND
AVIATION...CJR
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