781
FXUS62 KCAE 050041
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
841 PM EDT FRI SEP 4 2026
WHAT HAS CHANGED
THE HEAT ADVISORY FOR LANCASTER AND CHESTERFIELD COUNTIES TODAY
WAS ALLOWED TO EXPIRE. ANOTHER HEAT ADVISORY FOR THE WHOLE CWA
REMAINS IN EFFECT FROM 11AM TO 8PM SATURDAY. AVIATION DISCUSSION
UPDATED FOR 00Z TAF ISSUANCE.
KEY MESSAGES
- 1. HEAT INDEX VALUES UP TO 110 SATURDAY ELEVATING THE RISK OF
HEAT RELATED ILLNESSES.
- 2. SEVERE STORMS POSSIBLE SATURDAY AFTERNOON OR EVENING.
- 3. HEAT ADVISORY FOR LANCASTER AND CHESTERFIELD COUNTIES HAS
EXPIRED.
DISCUSSION
KEY MESSAGE 1. HEAT INDEX VALUES UP TO 110 SATURDAY ELEVATING
THE RISK OF HEAT RELATED ILLNESSES.
THE CENTER OF THE UPPER RIDGE SHIFTS WEST ON SATURDAY. WEAK
DOWNSLOPE WINDS AND INCREASING MOISTURE AHEAD OF A COLD FRONT
WILL PUSH AFTERNOON TEMPERATURES INTO THE UPPER 90S TO NEAR 100
DEGREES AND HEAT INDEX VALUES TO NEAR 110. THERE WILL ALSO BE A
GREATER VULNERABILITY TO HEAT RELATED ILLNESS DUE THE UPTICK IN
OUTDOOR ACTIVITIES THIS SATURDAY. A HEAT ADVISORY HAS BEEN
ISSUES FOR THE ENTIRE FORECAST AREA.
THERE IS SOME POTENTIAL FOR THUNDERSTORMS, ESPECIALLY IN THE
NORTHERN FA LATE SATURDAY AFTERNOON AND EVENING. BUT WE BELIEVE
THAT THE LATER TIMING OF THE STORMS WILL STILL ALLOW HEAT INDEX
VALUES TO EXCEED ADVISORY THRESHOLDS THROUGH THE BULK OF THE
AFTERNOON.
KEY MESSAGE 2. SEVERE STORMS POSSIBLE SATURDAY AFTERNOON OR
EVENING.
AS RIDGING SHIFTS WEST, WE WILL SEE SHORTWAVE ENERGY DIG INTO
THE MID ATLANTIC STATES ON SATURDAY AFTERNOON AND EVENING. A
COLD FRONT WELL TO OUR NORTH WILL BE THE FOCUS FOR CONVECTIVE
INITIATION. AS STORMS DEVELOP AND MOVE SOUTH AND EAST DURING THE
DAY THEY WILL ENCOUNTER VERY STEEP LAPSE RATES WHICH WOULD SUPPORT
DAMAGING WINDS IN SOME OF THE STRONGER STORMS. THE OVERALL
LIMITING FACTORS FOR SEVERE WEATHER INTO SC WILL BE THE LIMITED
MOISTURE AVAILABLE AND THE FACT THAT THE STRONGER DYNAMICS
SHOULD REMAIN TO OUR NORTH. WITH PWAT VALUES ONLY 1.6 TO 1.8
INCHES WE MAY ONLY SEE SCATTERED THUNDERSTORMS THAT DO NOT
DEVELOP INTO AN MCS. HOWEVER, EVEN IF THE STRONGER STORMS DO
REMAIN TO OUR NORTH, AN OUTFLOW BOUNDARY COULD STILL PUSH INTO
THE NORTHERN FA IN THE EVENING. THIS COULD SPARK AT LEAST
SCATTERED CONVECTION THROUGH THE EVENING AND OVERNIGHT AS IT
PROGRESSES SOUTHWARD THROUGH THE FORECAST AREA.
WITH A SURFACE BOUNDARY OVER THE REGION ON SUNDAY WE CAN EXPECT
AT LEAST A CHANCE OF SHOWERS AND THUNDERSTORMS AS AN UPPER
LEVEL SHORTWAVE CROSSES INTO THE FORECAST AREA. WITH A DEEPER
TROUGH AND HIGHER ATMOSPHERIC MOISTURE WE WOULD EXPECT SCATTERED
TO NUMEROUS THUNDERSTORMS SUNDAY AFTERNOON AND EVENING. CLOUD
COVER COULD ULTIMATELY HINDER POTENTIAL INSTABILITY AND LOWERS
THE THREAT OF SEVERE WEATHER. THAT SAID A FEW STORMS MAY STILL
BECOME SEVERE, ESPECIALLY IF CLOUD COVER STARTS BREAKING EARLIER
THAN EXPECTED.
KEY MESSAGE 3. HEAT ADVISORY FOR LANCASTER AND CHESTERFIELD
COUNTIES HAS EXPIRED.
HEAT INDICES ARE GRADUALLY FALLING BELOW 100F IN THE ADVISORY
AREA AND THUS THE ADVISORY HAS BEEN ALLOWED TO EXPIRE. OVERNIGHT
LOWS TONIGHT SHOULD STICK NEAR THE MID 70S BEFORE ANOTHER VERY
HOT DAY IS EXPECTED SATURDAY AS DISCUSSED IN KEY MESSAGE #1.
AVIATION /00Z SATURDAY THROUGH WEDNESDAY/
MAINLY VFR CONDITIONS THROUGH THE TAF PERIOD, WITH SOME FOG AND
STRATUS POSSIBLE NEAR DAYBREAK.
SIMILAR CONDITIONS ARE EXPECTED THROUGH THE OVERNIGHT PERIOD
TONIGHT WITH MOSTLY VFR CONDITIONS AND DEVELOPING RESTRICTIONS
EARLY SATURDAY MORNING WITH LINGERING LOW LEVEL MOISTURE TRAPPED
BELOW SOME DRIER AIR ALOFT. GUIDANCE GENERALLY FAVORS
RESTRICTIONS AFFECTING THE SOUTHERN TERMINALS SO HAVE KEPT
CONDITIONS VFR AT CAE/CUB AND BROUGHT IN RESTRICTIONS ELSEWHERE,
ONCE AGAIN IN A TEMPO GROUP WITH OVERALL LIMITED CONFIDENCE IN
COVERAGE. RESTRICTIONS WILL LIKELY DISSIPATE SHORTLY AFTER
SUNRISE AND ARE NOT EXPECTED TO LINGER AS LONG AS THIS PAST
MORNING WITH MOISTURE A BIT MORE SHALLOW. A FRONT APPROACHES
THIS EVENING WHICH WILL LEAD TO ISOLATED STORMS DEVELOPING,
ALTHOUGH COVERAGE NEAR TERMINALS WILL LIKELY BE LIMITED SO HAVE
EXCLUDED ANY MENTION OF TSRA FROM THE TAFS WITH THIS ISSUANCE.
EXTENDED AVIATION OUTLOOK...CHANCES FOR RESTRICTIONS AND
THUNDERSTORMS INCREASE SUNDAY. DIURNAL STORM CHANCES CONTINUE
EARLY NEXT WEEK.
CAE WATCHES/WARNINGS/ADVISORIES
SC...HEAT ADVISORY FROM 11 AM TO 8 PM EDT SATURDAY FOR SCZ016-018-
020>022-025>031-035-037-038-041-115-116-135>137.
GA...HEAT ADVISORY FROM 11 AM TO 8 PM EDT SATURDAY FOR GAZ040-
063>065-077.
DISCUSSION...DH/CJR
AVIATION...96
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