398
FXUS62 KCAE 121822
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
222 PM EDT FRI JUN 12 2026
WHAT HAS CHANGED
LOWERED TEMPERATURES A BIT FOR TOMORROW AFTERNOON. AVIATION
DISCUSSION UPDATED FOR 18Z TAFS.
KEY MESSAGES
- 1. ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND WILL INCREASE
THE RISK OF HEAT-RELATED ILLNESS.
- 2. ISOLATED THUNDERSTORMS TODAY; RAIN CHANCES INCREASE OVER
THE WEEKEND INTO EARLY NEXT WEEK.
DISCUSSION
KEY MESSAGE 1: ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND WILL
INCREASE THE RISK OF HEAT-RELATED ILLNESS.
CONDITIONS ARE EXPECTED TO CONTINUE TO BE QUITE HOT THROUGH THE
WEEKEND WITH THE AXIS OF THE RIDGE OVERHEAD PEAKING, BRINGING
THE HOTTEST TEMPERATURES SO FAR THIS YEAR. 90TH+ PERCENTILE
UPPER RIDGING AND MOIST LOW LEVEL SOUTH-SOUTHWEST FLOW OVER THE
STATE WILL PERSIST INTO THE WEEKEND. HIGH TEMPERATURES WILL
CONTINUE TO BE IN THE MID TO UPPER 90S TODAY THROUGH SUNDAY WITH
DEWPOINTS IN THE MID 60S TO LOW 70S IN THE AFTERNOON. THIS IS
EXPECTED TO LEAD TO HEAT INDEX VALUES PEAKING IN THE LOW 100S
WITH SOME VALUES IN THE 105-108F RANGE POSSIBLE. GIVEN THIS WILL
BE SOME OF THE HOTTEST TEMPERATURES AND HEAT INDICES SO FAR IN
2026, THERE IS CURRENTLY A HEAT ADVISORY IN EFFECT FOR THE
NORTHERN AND EASTERN MIDLANDS, WHERE MOST OF THE HOTTEST HEAT
INDICES ARE OCCURRING THIS AFTERNOON. ALTHOUGH THERE IS STILL
LOW CONFIDENCE WE WILL EXCEED CRITERIA (HI OF 108F-112F), THESE
EARLY SEASON HEAT WAVES TEND TO CONTRIBUTE TO A HIGHER RISK FOR
HEAT-RELATED ILLNESS, SO WE ARE MESSAGING EXTREME CAUTION.
ADDITIONALLY, THE EXPERIMENTAL HEAT RISK CATEGORY OF MAJOR (3
OUT OF 4) WILL BE IN PLACE FOR THE ENTIRE FORECAST AREA TODAY,
WITH EVEN SOME EXTREME (4 OUT OF 4) AREAS STARTING TO SHOW UP
OVER THE WEEKEND PARTICULARLY IN COLUMBIA AND AUGUSTA.
SATURDAY IS STILL EXPECTED TO BE JUST AS WARM AS TODAY, WITH THE
POTENTIAL FOR HEAT ADVISORIES ONCE AGAIN. HOWEVER, WE HAVE
DECIDED TO HOLD OFF AT THIS TIME SINCE THERE IS A HIGHER CHANCE
FOR CONVECTION DURING PEAK HEATING HOURS WHICH COULD LIMIT THE
POTENTIAL FOR EXCEEDING EXTENDED OR LARGE COVERAGE.
TEMPERATURES SUNDAY ARE FORECAST TO BE A FEW DEGREES LOWER AHEAD
OF AN APPROACHING FRONTAL ZONE AS THE RIDGE ATTEMPTS TO HOLD
ACROSS THE SOUTHEAST. CONDITIONS WILL BE MONITORED BUT
WIDESPREAD HEAD ADVISORY CRITERIA REMAIN LESS LIKELY AT THIS
TIME. A COOLING TREND IS EXPECTED TO DEVELOP INTO THE NEW WORK
WEEK AS THE INFLUENCE OF THE RIDGE WEAKENS.
KEY MESSAGE 2: ISOLATED THUNDERSTORMS TODAY; RAIN CHANCES INCREASE
OVER THE WEEKEND INTO EARLY NEXT WEEK.
A CLASSIC SUMMERTIME CONVECTIVE PATTERN IS EXPECTED TO REMAIN IN
PLACE ACROSS THE REGION THROUGH THE WEEKEND, SUPPORTING DAILY
CHANCES FOR AFTERNOON AND EVENING CONVECTION. SURFACE HIGH
PRESSURE WILL REMAIN POSITIONED EAST OF THE FORECAST AREA,
WHILE UPPER-LEVEL RIDGING WILL GENERALLY LIMIT THE OVERALL
COVERAGE OF SHOWERS AND STORMS. EVEN WITH THE RIDGING ALOFT,
SLIGHTLY ABOVE NORMAL ATMOSPHERIC MOISTURE AND STRONG DAYTIME
HEATING WILL ALLOW CONDITIONS TO DESTABILIZE. EXPECT ISOLATED
TO SCATTERED COVERAGE EACH AFTERNOON WITH SOME ENHANCED
ACTIVITY CLOSER TO THE COAST AS INTERACTIONS FROM THE SEA BREEZE
MOVE INLAND. MUGGY CONDITIONS AND INTENSE HEATING TODAY WILL
ALLOW FOR FAIRLY STRONG INSTABILITY, WITH OVER 2000 J/KG OF
SBCAPE. HOWEVER, WEAK WIND SHEAR SHOULD PREVENT WIDESPREAD
ORGANIZED CONVECTION. INSTEAD, THE ENVIRONMENT WILL FAVOR A FEW
STRONG PULSE-TYPE THUNDERSTORMS CAPABLE OF PROTECTING LOCALIZED
DAMAGING DOWNBURST WINDS. SPC HAS ISSUED A MARGINAL RISK (1/5)
FOR SEVERE THUNDERSTORMS MAINLY NORTH OF A MCCORMICK- COLUMBIA-
SUMTER LINE, WITH A SLIGHT RISK (2/5) IN THE NORTHERNMOST
PORTION OF LANCASTER COUNTY INCLUDING THE CHARLOTTE METRO TODAY.
SIMILAR CONDITIONS ARE EXPECTED SATURDAY AHEAD OF AN APPROACHING
FRONTAL BOUNDARY. AS THE AFTERNOON SEABREEZE INTERACTS WITH
1500-2000 J/KG OF CAPE, ANOTHER ROUND OF MORE SCATTERED SHOWERS
AND THUNDERSTORMS IS POSSIBLE, RESEMBLING ACTIVITY OBSERVED THE
PREVIOUS DAYS. SIMILAR ACTIVITY IS EXPECTED SUNDAY AS A MORE
PRONOUNCED SHORTWAVE TOUGH MOVES INTO THE REGION.
MOISTURE TRANSPORT THEN INCREASES EARLY NEXT WEEK WITH NAEFS IVT
PERCENTILES OVER 90 PERCENT OF CLIMATOLOGY, AND REMAIN ELEVATED
THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. WITH THIS IN MIND, EXPECT
A MORE ACTIVE PATTERN WITH ABOVE NORMAL MOISTURE (AND SUBSEQUENTLY
LOWER TEMPERATURES GIVEN THE HIGHER RAIN CHANCES) TO KICK IN BY
MONDAY AND LAST FOR SEVERAL DAYS.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
VFR CONDITIONS CONTINUE THROUGH THIS TAF PERIOD.
SCT CUMULUS ARE DEVELOPING WITH 6-10 KT SOUTHWESTERLY TO
WESTERLY WINDS ACROSS THE AREA. THE REMAINDER OF THE AFTERNOON
SHOULD SEE THESE CONDITIONS CONTINUING WITH ISOLATED SHOWERS AND
STORMS POSSIBLE, BUT LIKE PREVIOUS DAYS, CONFIDENCE IN THESE
IMPACTING THE TERMINALS IS LOW. TONIGHT, WINDS BECOME LIGHT AND
VARIABLE AS FEW TO SCT CIRRUS PASS THROUGH THE REGION. AFTER
14-16Z SATURDAY, WINDS BECOME A BIT MORE WESTERLY TO
NORTHWESTERLY, BUT REMAIN LIGHT AS ANOTHER CUMULUS DECK
DEVELOPS. MORE AFTERNOON SHOWERS/STORMS ARE POSSIBLE JUST AFTER
THIS TAF PERIOD, WHERE COVERAGE MAY BE SLIGHTLY GREATER THAN HAS
BEEN SEEN RECENTLY.
EXTENDED AVIATION OUTLOOK...ISOLATED TO WIDELY SCATTERED
DIURNAL SHOWERS AND STORMS POSSIBLE LATER SATURDAY AND AGAIN ON
SUNDAY. GREATER RAIN CHANCES ARE EXPECTED EARLY NEXT WEEK.
CAE WATCHES/WARNINGS/ADVISORIES
SC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ016-022-029-
031-038-115-116.
GA...NONE.
DISCUSSION...ND
AVIATION...DH
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