806
FXUS62 KCAE 131810
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
210 PM EDT THU AUG 13 2026
WHAT HAS CHANGED
DANGEROUS HEAT EXPECTED TODAY AND FRIDAY WITH DAYTIME HIGHS IN
THE UPPER 90S TO AROUND 100 AND HEAT INDEX VALUES BETWEEN 105
AND 110. THE HEAT ADVISORY HAS BEEN EXTENDED AND IS NOW IN
EFFECT THROUGH 8PM FRIDAY. AVIATION DISCUSSION UPDATED FOR 18Z
TAFS.
KEY MESSAGES
- 1. HEAT INDICES BETWEEN 105-110F EXPECTED TODAY AND FRIDAY.
- 2. ISOLATED STORMS TODAY, RAIN CHANCES PICK BACK UP THIS
WEEKEND AND EARLY NEXT WEEK.
DISCUSSION
- 1. HEAT INDICES BETWEEN 105-110F EXPECTED TODAY AND FRIDAY.
WEAK DOWNSLOPE FLOW WILL HELP PUSH TEMPERATURES INTO THE UPPER
90S FOR MOST LOCATIONS TODAY. WITH DEWPOINTS IN THE LOW TO MID
70S THIS AFTERNOON, HEAT INDEX VALUES SHOULD EXCEED 105. THERE
IS A QUESTION OF WHETHER CONVECTION WILL PUT AN EARLY STOP TO
DAYTIME HEATING BUT EVEN SO WITH ONLY ISOLATED COVERAGE
EXPECTED WE SHOULD STILL SEE AT LEAST POCKETS OF DANGEROUS HEAT
AND HUMIDITY. RIDGING IS MORE DIRECTLY OVERHEAD ON FRIDAY WHICH
SHOULD HELP TO SUPPRESS CONVECTIVE DEVELOPMENT. MOS GUIDANCE
SHOWS TEMPS NEAR 100 AGAIN FRIDAY WITH SIMILAR DEWPOINTS TO THE
PREVIOUS DAY. THIS WILL LIKELY LEAD TO ANOTHER DAY OF DANGEROUS
HEAT WITH HEAT INDEX VALUES BETWEEN 105 AND 110.
INCREASED DIURNAL SHOWER/STORM CHANCES INTO THE WEEKEND AND
EARLY NEXT WEEK LIMIT CONFIDENCE IN THE NEED FOR ADDITIONAL HEAT
PRODUCTS, BUT EITHER WAY, ABOVE NORMAL TEMPERATURES ARE
EXPECTED TO CONTINUE INTO EARLY NEXT WEEK AS THE RIDGE LIKELY
DOES NOT BECOME MORE FLATTENED OUT UNTIL AROUND THE MID WEEK.
- 2. ISOLATED STORMS TODAY, RAIN CHANCES PICK BACK UP THIS
WEEKEND AND EARLY NEXT WEEK.
ANOTHER CHANCE FOR ISOLATED TO WIDELY SCATTERED CONVECTION WILL
EXIST THIS AFTERNOON. THERE IS A THREAT FOR DAMAGING DOWNBURST
WINDS WITH MLCAPE VALUES FROM 2000-3000 J/KG AND DCAPE VALUES
AROUND 1000 J/KG FROM THE SPC MESO PAGE. THIS ALONG WITH WEAK
SHORTWAVE ENERGY RIDING OVER TOP OF THE RIDGE TO OUR WEST COULD
SUPPORT SEVERE WEATHER THIS AFTERNOON AND INTO THE EVENING.
OUTFLOWS FROM THE HIGHER TERRAIN IN THE APPALACHIANS MAY TRIGGER
ADDITIONAL CONVECTION INTO THE EVENING.
GLOBAL ENSEMBLES CONTINUE TO FAVOR RIDGING SLOWLY FLATTENING
INTO EARLY NEXT WEEK, WITH MORE CHANCES FOR SHORTWAVES AND/OR
WEAKENING MCSS TO NEAR THE FA IN A NORTHWEST FLOW REGIME.
PWATS WILL LIKELY REMAIN NEAR OR ABOVE 2 INCHES THROUGH THE
LATE WEEKEND INTO NEXT WEEK. THIS SYNOPTIC SETUP WILL FAVOR AT
LEAST ISOLATED TO WIDELY SCATTERED CONVECTION. THERE IS SOME
INDICATION IN GLOBAL MODELS THAT TROUGHING COULD DEVELOP OVER
PORTIONS OF THE EASTERN TOWARD THE MIDDLE OF THE WEEK SHIFTING
TO A WETTER PATTERN.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
VFR CONDITIONS LIKELY WITH SOME SCATTERED CONVECTION THURSDAY
AFTERNOON.
TYPICAL SUMMERTIME CUMULUS IS PRESENT OVERHEAD UNDER LIGHT WSW
WINDS. CONVECTION TO OUR WEST WILL CONTINUE TO MOVE ACROSS,
BRINGING A CHANCE FOR LATE AFTERNOON AND EVENING THUNDERSTORMS.
HI-RES GUIDANCE HAS STRUGGLED TO CAPTURE THE ACTIVITY, BUT
PROB30S ARE INCLUDED AT ALL TERMINALS GIVEN THE POTENTIAL WITH
DEVELOPMENT BETWEEN 20Z-01Z. THE HIGHEST COVERAGE IS EXPECTED
NEAR THE AGS AND DNL TERMINALS. GIVEN THE ENVIRONMENT IN PLACE,
HEAVY RAIN AND GUSTY WINDS COULD PRODUCE BRIEF RESTRICTIONS
WITH ANY STORMS.
STRATUS/FOG FRIDAY MORNING WILL DEPEND LARGELY ON RAINFALL
TOTALS TODAY, THOUGH CONFIDENCE IN WIDESPREAD RESTRICTIONS
REMAINS LOW. WINDS BECOME LIGHT AND VARIABLE TO CALM OVERNIGHT,
THE INCREASE AFTER SUNRISE OUT OF THE WEST.
EXTENDED AVIATION OUTLOOK...DIURNAL CHANCES FOR THUNDERSTORMS
CONTINUE EACH DAY THROUGH THE WEEKEND.
CAE WATCHES/WARNINGS/ADVISORIES
SC...HEAT ADVISORY UNTIL 8 PM EDT FRIDAY FOR SCZ016-018-020>022-
025>031-035-037-038-041-115-116-135>137.
GA...HEAT ADVISORY UNTIL 8 PM EDT FRIDAY FOR GAZ040-063>065-077.
DISCUSSION...DH/CJR
AVIATION...ND
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