129
FXUS62 KCAE 031045
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
645 AM EDT THU SEP 3 2026
WHAT HAS CHANGED
CONFIDENCE INCREASING THAT HOT/HUMID CONDITIONS WILL PERSIST
INTO SATURDAY. AVIATION DISCUSSION UPDATED FOR 12Z TAF
ISSUANCE.
KEY MESSAGES
- 1. POTENTIAL FOR HEAT INDICES ABOVE 105F SATURDAY ALONG WITH
CHANCE FOR STRONGER CONVECTION. ISOLATED TO SCATTERED STORM
CHANCES PERSIST INTO EARLY NEXT WEEK WITH NEAR NORMAL
TEMPERATURES.
- 2. MOSTLY DRY CONDITIONS TODAY AND FRIDAY WITH HEAT INDICES
NEAR 105F.
DISCUSSION
KEY MESSAGE 1. POTENTIAL FOR HEAT INDICES ABOVE 105F SATURDAY
ALONG WITH CHANCE FOR STRONGER CONVECTION. ISOLATED TO SCATTERED
STORM CHANCES PERSIST INTO EARLY NEXT WEEK WITH NEAR NORMAL
TEMPERATURES.
THE MAIN CHANGE WITH THIS FORECAST PACKAGE IS INCREASING
CONFIDENCE IN A SLOWER MOVING FRONT AND THUS HOTTER TEMPERATURES
ON SATURDAY. THE UPPER RIDGE WILL SLOWLY RETROGRADE AS THE
PREVIOUSLY ADVERTISED TROUGH DIGS INTO THE EASTERN US, BUT 850MB
TEMPERATURES ARE EXPECTED TO REMAIN NEAR THE NAEFS 99.5TH
PERCENTILE OR EVEN APPROACH CLIMATOLOGICAL MAX VALUES. THIS IS
BRINGING LOWER IQR RANGES IN BOTH NBM AND LREF CLUSTER GUIDANCE
FOR MAXIMUM TEMPERATURES WITH INCREASING CONFIDENCE IN THE
PERSISTENCE OF MAX TEMPERATURES IN THE UPPER 90S. WITH
SEASONABLE MOISTURE IN PLACE, HEAT INDICES BETWEEN 105-108F SEEM
REASONABLE AND THUS THE NEED FOR A HEAT ADVISORY WILL CONTINUE
TO BE EVALUATED. GLOBAL MODELS AND LREF CLUSTER ANALYSIS ARE
ALSO PICKING UP ON A SHORTWAVE MOVING ACROSS PORTIONS OF
SOUTHERN VA INTO NC ALONG WITH THE SURFACE FRONT. THIS IS
EXPECTED TO YIELD CONVECTION HERE AND WITH THE CWA IN A
NORTHWEST FLOW REGIME WITH THE INCREASING TROUGHING, THERE IS
THE POTENTIAL FOR THIS CONVECTION TO MOVE INTO THE CWA DURING
THE LATE AFTERNOON INTO THE EVENING HOURS. WITH ENHANCED
KINEMATICS AND STRONG INSTABILITY, CANNOT RULE OUT STRONGER
CONVECTION, BUT AS IS TYPICAL WITH NORTHWEST FLOW REGIMES,
CONFIDENCE IN CONVECTIVE EVOLUTION AND LONGEVITY IS A BIT LOW AT
THIS TIME. OVERALL, HEAT SAFETY PRECAUTIONS SHOULD BE TAKEN ON
SATURDAY WITH ANY OUTDOOR ACTIVITIES AND STAY TUNED FOR ANY
CHANGES IN TIMING OR INTENSITY OF POTENTIAL CONVECTION LATER IN
THE DAY.
THE END OF THE WEEKEND INTO NEXT WEEK IS EXPECTED TO YIELD NEAR
NORMAL TEMPERATURES WITH CONTINUING AT LEAST ISOLATED CHANCES
FOR DIURNAL CONVECTION. THIS COMES AS THE FRONT SLOWLY CLEARS
THE AREA AND TROUGHING PERSISTS BEFORE THE RIDGE IS EXPECTED TO
SLOWLY SLIDE BACK IN DURING THE MID WEEK.
KEY MESSAGE 2. MOSTLY DRY CONDITIONS TODAY AND FRIDAY WITH HEAT
INDICES NEAR 105F.
THE FORECAST REMAINS ON TRACK OVER THE COMING 48 HOURS AS THE
ROBUST UPPER RIDGE SLIDES OVERHEAD TODAY INTO FRIDAY. THERE
REMAINS SOLID DETERMINISTIC AND ENSEMBLE AGREEMENT THAT AS THIS
RIDGE SHIFTS IN, TEMPERATURES SHOULD TOP OUT IN THE UPPER 90S
EACH AFTERNOON WITH MINIMAL DIURNAL CONVECTION DUE TO SUBSIDENCE
FROM THE RIDGE. WITH PWAT'S REMAINING NEAR 1.90", SURFACE
DEWPOINTS SHOULD STICK TOWARD THE UPPER 60S TO LOWER 70S EACH
AFTERNOON, BRINGING WIDESPREAD HEAT INDICES BETWEEN 100-105F
EACH DAY. IT IS POSSIBLE A FEW LOCATIONS BRIEFLY TOUCH OR NEAR
HEAT ADVISORY CRITERIA TODAY AND FRIDAY, BUT VALUES ARE NOT
EXPECTED TO BE WIDESPREAD ENOUGH TO WARRANT A HEAT ADVISORY AT
THIS TIME. THIS WILL CONTINUE TO BE EVALUATED THROUGH THE DAY
TODAY. EITHER WAY, HEAT SAFETY PRECAUTIONS SHOULD BE TAKEN AS WE
NEAR THE END OF THE WEEK.
AVIATION /12Z THURSDAY THROUGH MONDAY/
LOW IMPACT MORNING FOG AND STRATUS POSSIBLE IN THE EASTERN AND
SOUTHERN MIDLANDS, OTHERWISE CALM AND VFR.
CALM WEATHER EXPECTED THROUGH THE TAF PERIOD WITH SOME SUNRISE
MIFG AND BRIEF RESTRICTIONS POSSIBLE, BUT LOW CONFIDENCE. OGB
MAY BRIEFLY DIP TO MVFR THROUGH 13Z. OTHERWISE, A HOT TYPICAL
SUMMER DAY EXPECTED WITH CU FIELD DEVELOPING BY LATE MORNING AND
GENERALLY SOUTHEASTERLY WINDS EXPECTED INTO THE AFTERNOON;
SUSTAINED 5-7 KNOTS WITH GUSTS TO AROUND 10 KNOTS. LIKE
WEDNESDAY, A ROGUE SHOWER- STORM OR TWO IS POSSIBLE, BUT
CONFIDENCE IS FAR TOO LOW FOR EVEN A PROB30 MENTION.
EXTENDED AVIATION OUTLOOK...CHANCES FOR RESTRICTIONS AND
THUNDERSTORMS INCREASE THIS WEEKEND AS A COLD FRONT APPROACHES.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...DH
AVIATION...42
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page