247
FXUS62 KCHS 230643
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
243 AM EDT TUE JUN 23 2026
WHAT HAS CHANGED
ALL KEY MESSAGES AND SECTIONS WERE UPDATED.
KEY MESSAGES
- 1) BREEZY CONDITIONS WITH SUMMER-LIKE TEMPERATURES TODAY
ACROSS THE SOUTH CAROLINA LOWCOUNTRY AND SOUTHEAST GEORGIA.
RECORD LOW MAXIMUM RECORDS WILL BE CHALLENGED THIS MORNING.
- 2) ABOVE-NORMAL TEMPERATURES AND BELOW-NORMAL RAIN CHANCES
ARE EXPECTED THROUGH THE UPCOMING WEEKEND. TEMPERATURES COULD
APPROACH THE TRIPLE DIGITS THIS WEEKEND.
DISCUSSION
KEY MESSAGE 1: BREEZY CONDITIONS WITH SUMMER-LIKE TEMPERATURES
TODAY ACROSS THE SOUTH CAROLINA LOWCOUNTRY AND SOUTHEAST GEORGIA.
RECORD LOW MAXIMUM RECORDS WILL BE CHALLENGED THIS MORNING.
THIS MORNING: REGIONAL VAD WIND PROFILES SHOW A MODEST LOW-
LEVEL JET (LLJ) IS STRENGTHENING ACROSS THE AREA EARLY THIS
MORNING AS THE REGION REMAINS PINNED BETWEEN HIGH PRESSURE
CENTERED WELL OFFSHORE AND AN APPROACHING COLD FRONT. NEAR TERM
GUIDANCE SHOWS THE INTENSITY OF THE LLJ PEAKING NEAR TO JUST
AFTER DAYBREAK WHICH WILL HELP KEEP THE ATMOSPHERE VERY WELL
MIXED THROUGH THE DIURNAL MINIMUM AS THE LOW-LEVEL WIND FIELD
STARTS TO INCREASE. LOW TEMPERATURES ARE ON TRACK TO BOTTOM OUT
IN THE MID 70S WEST OF THE I-95 CORRIDOR WITH UPPER 70S/LOWER
80S EAST OF THERE TO THE BEACHES INCLUDING DOWNTOWN CHARLESTON.
THE RECORD HIGH MINIMUMS AT ALL THREE CLIMATE SITES WILL BE
CHALLENGED. SEE THE CLIMATE SECTION BELOW FOR MORE DETAILS.
PATCHY UPSTREAM CONVECTION OVER WESTERN GEORGIA SHOULD DISSIPATE
PRIOR TO REACHING THIS FAR TO THE EAST.
TODAY AND TONIGHT: BREEZY WEST WINDS (15-25 MPH WITH GUSTS TO 30
MPH) AND HOT CONDITIONS WILL PREVAIL AS THE COMBINATION OF
INCREASING LOW-LEVEL WARM AIR ADVECTION, A MODEST WESTERLY FLOW
ALOFT AND BROAD SUBSIDENCE AHEAD OF AN APPROACHING COLD FRONT
HELP TO PUSH HIGHS IN THE LOWER-MID 90S FOR MANY LOCALES THIS
AFTERNOON. THE WESTERLY FLOW ALOFT WILL HELP PIN THE SEA BREEZE
ALONG OR EVEN JUST OFFSHORE OF THE BEACHES THROUGH THE DAY. THIS
SHOULD ALLOW VERY WARM TEMPERATURES TO REACH ALL THE WAY TO THE
BEACHES WITH UPPER 80S/LOWER 90S POSSIBLE. A BLEND OF THE
VARIOUS HIGH RESOLUTION DATA SETS ALSO SUGGESTS A POCKET OF MID
90S COULD EVEN INFILTRATE MUCH OF THE CHARLESTON PENINSULA--
SOMETHING THAT IS NOT OBSERVED BUT JUST A FEW TIMES A YEAR WITH
THE SEA BREEZE HOLDING TO THE EAST. THE RECORD HIGHS AT THE
CLIMATE SITES ARE IN THE 100-102 RANGE AND LOOK SAFE. THE
WESTERLY FLOW AND BUILDING SUBSIDENCE/MID-LEVEL DRYING ALOFT
WILL HELP MIX OUT DEWPOINTS INTO THE UPPER 60/LOWER 70S DURING
PEAK HEATING, BUT SOME MID 70S ARE LIKELY TO LINGER ACROSS PARTS
OF LONG, MCINTOSH AND COASTAL LIBERTY COUNTIES BEFORE THE
IMPACTS OF DRYING ALOFT REACH THAT FAR SOUTH. SO, WHILE HEAT
INDICES ARE POISED TO PEAK IN THE MID-UPPER 90S INLAND WITH
98-102 ACROSS MUCH OF THE COASTAL CORRIDOR, VALUES AS HIGH AS
105-107 COULD OCCUR FOR A FEW HOURS IN AREAS SUCH AS DARIEN,
TOWNSEND, EULONIA, HALFMOON LANDING AND SHELLMAN BLUFF. WHILE
SOME ISOLATED SPOTS COULD REACH AS HIGH 108-109 AT TIMES, THE
SITUATION JUST LOOKS TOO MARGINAL FOR A HEAT ADVISORY AT THIS
TIME.
THE PROSPECTS FOR DIURNAL CONVECTION DEVELOPING THIS AFTERNOON
IS POOR. DRYING MID-LEVELS AND SUBSIDENCE ALOFT AHEAD OF THE
COLD FRONT WILL KEEP THE ATMOSPHERE FAIRLY WELL CAPPED. THE ONLY
EXCEPTION IS OVER THE COUNTIES BORDERING THE ALTAMAHA RIVER
WHERE THE IMPACTS OF MID-LEVEL DRYING WILL NOT ARRIVE UNTIL
LATER IN THE AFTERNOON/EARLY EVENING. FORECAST SOUNDINGS AT
KJES AND KLHW SUGGEST THE CAP WILL MIX OUT BY MID-AFTERNOON, BUT
JUST BARELY. 20-30% POPS WERE HIGHLIGHTED ACROSS THE FAR SOUTH
CLOSER TO THE ALTAMAHA RIVER WITH POPS <10% ELSEWHERE. ANY
CONVECTION THAT IS ABLE TO DEVELOP WILL QUICKLY DISSIPATE JUST
AFTER SUNSET WITH RAIN-FREE CONDITIONS PREVAILING OVERNIGHT.
LAKE WINDS: DEEP MIXING WILL SUPPORT WINDS 15-20 KT WITH
FREQUENT GUSTS TO 25 KT OVER LAKE MOULTRIE TODAY WITH WAVES 1-2
FT. A LAKE WIND ADVISORY IS IN EFFECT FROM 8 AM UNTIL 5 PM.
KEY MESSAGE 2: ABOVE-NORMAL TEMPERATURES AND BELOW-NORMAL RAIN
CHANCES ARE EXPECTED THROUGH THE UPCOMING WEEKEND. TEMPERATURES
COULD APPROACH THE TRIPLE DIGITS THIS WEEKEND.
A WEAK COLD FRONT WILL PUSH OFFSHORE WEDNESDAY AS ATLANTIC HIGH
PRESSURE EXTENDS WESTWARD ACROSS THE FORECAST AREA. ALOFT,
BROAD TROUGHING WILL TRANSITION TO A BUILDING RIDGE AND
INCREASING SUBSIDENCE, LIMITING CONVECTION THROUGH THE WEEKEND.
ADDITIONALLY, RELATIVELY DRY LOW AND MID-LEVEL AIR WILL PERSIST
THROUGH MOST OF THE WEEK, FURTHER SUPPRESSING CONVECTION, WITH
NO MORE THAN ISOLATED SHOWER OR THUNDERSTORM ACTIVITY EXPECTED.
DESPITE NEAR-NORMAL TEMPERATURES FORECAST WEDNESDAY WITH THE
RECENT PASSAGE OF A WEAK COLD FRONT, A GRADUAL WARMING TREND IS
FORECAST THROUGH THE REMAINDER OF THE WEEK AND INTO THE WEEKEND.
HIGH TEMPERATURES ARE EXPECTED TO REACH THE MID TO UPPER 90S
FRIDAY, WITH UPPER 90S BECOMING COMMON ACROSS MUCH OF THE AREA
SATURDAY AND SUNDAY. A FEW LOCATIONS COULD EVEN EXCEED 100
DEGREES THIS WEEKEND. COMBINED WITH DEW POINTS IN THE 70S, HEAT
INDEX VALUES COULD REACH 108-112F, ESPECIALLY ACROSS THE COASTAL
COUNTIES. ADDITIONALLY, BEING THAT CONVECTION IS FORECAST TO BE
ISOLATED, WE DO NOT EXPECT MUCH RELIEF FROM SHOWERS. WHILE
CONFIDENCE IN THE MAGNITUDE OF THE HEAT REMAINS LIMITED GIVEN
THE FORECAST RANGE, THE COMBINATION OF EXTREME HEAT, HIGH
HUMIDITY, AND LIMITED COOLING COULD NECESSITATE HEAT ADVISORIES
WHERE HEAT INDICES MEET OR EXCEED OUR LOCAL CRITERIA OF 108F
DEGREES. FORECAST TRENDS WILL CONTINUE TO BE MONITORED OVER THE
COMING DAYS.
AVIATION /06Z TUESDAY THROUGH SATURDAY/
23/06Z TAF DISCUSSION:
KCHS/KJZI/KSAV: VFR THROUGH THE ENTIRE TAF PERIOD. WESTERLY
WINDS WILL INCREASE CLOSER TO DAYBREAK AND BECOME GUSTY. GUSTS
SHOULD PEAK IN THE 24-28 KT RANGE FROM MID-MORNING THROUGH LATE
AFTERNOON. CONDITIONS COULD GET CLOSE TO LOW-LEVEL WIND SHEAR
(LLWS) CRITERIA THROUGH ABOUT 10Z AS THE LOW-LEVEL JET
INTENSIFIES. THE SITUATION LOOKS A BIT MARGINAL, SO ANY MENTION
OF LLWS WAS WITHHELD AT THIS TIME. IF WINDS ON REGIONAL RADAR
VAD WIND PROFILES INCREASE MORE THAN EXPECTED, THEN AMENDMENTS
TO INCLUDE LLWS MAY BE ISSUED.
EXTENDED AVIATION OUTLOOK: NO HIGH CONFIDENCE CONCERNS.
MARINE
THROUGH TONIGHT: A MODEST NOCTURNAL SURGE IS ONGOING ACROSS THE
WATERS EARLY THIS MORNING WITH THE HIGHEST WINDS (15-20 KT WITH
FREQUENT GUSTS 25-28 KT) BEING OBSERVED OFF THE CHARLESTON
COUNTY COAST. WINDS WILL HOLDING STEADY IF NOT INCREASE A TAD
MORE THROUGH DAYBREAK AS THE LOW-LEVEL JET PEAKS. WINDS MAY
DIMINISH SOME THIS MORNING, BUT WILL THEN PICK BACK UP THIS
AFTERNOON REACHING 20-25 KT WITH GUSTS TO 30 KT OVER THE SOUTH
SANTEE-EDISTO BEACH NEARSHORE AND OFFSHORE LEGS WITH 15-20 KT
WITH GUSTS TO 25 KT ACROSS CHARLESTON HARBOR AND THE EDISTO
BEACH-SAVANNAH NEARSHORE AND OFFSHORE LEGS. SMALL CRAFT
ADVISORIES ARE POSTED FOR THESE AREAS. WINDS OVER THE SAVANNAH-
ALTAMAHA RIVER NEARSHORE AND OFFSHORE LEGS LOOK TO REMAIN BELOW
FREQUENT 25 KT GUSTS, BUT IT MAY BE CLOSE FOR THE NORTHERN
PORTIONS OF THE OFFSHORE LEG. WINDS WILL BEGIN TO DIMINISH LATE
THIS AFTERNOON AND DIMINISH FURTHER OVERNIGHT AS THE LOW-LEVEL
JET PROPAGATES EAST AND A WEAK COLD FRONT DROP SOUTH THROUGH THE
WATERS. SEAS 2-4 FT NEARSHORE, 3-5 FT OFFSHORE WILL BUILD TO
3-5 FT, EXCEPT 4-6 FT OVER THE SOUTH SANTEE-EDISTO BEACH
NEARSHORE AND OFFSHORE LEGS LATE THIS AFTERNOON/EVENING BEFORE
DIMINISHING OVERNIGHT.
WEDNESDAY THROUGH SUNDAY: FAVORABLE MARINE CONDITIONS ARE
EXPECTED ACROSS THE LOCAL WATERS THROUGH THE WEEKEND. A WEAK
FRONT LOCATED OFFSHORE WEDNESDAY WILL DISSIPATE BY THURSDAY AS
ATLANTIC HIGH PRESSURE EXTENDS WESTWARD OVER THE REGION. EXPECT
AN INCREASE IN WINDS ALONG THE COAST DURING THE AFTERNOON AND
EVENING PERIODS ASSOCIATED WITH THE DAILY SEA BREEZE
CIRCULATION. OTHERWISE, NO MARINE HAZARDS ARE ANTICIPATED
THROUGH THE FORECAST PERIOD.
RIP CURRENTS: BREEZY SOUTHWEST WINDS ALONG THE CHARLESTON
COUNTY BEACHES WILL SUPPORT A MODERATE RISK FOR RIP CURRENTS
THROUGH THIS EVENING. CONDITIONS LOOK TO REMAIN IN THE LOW RISK
CATEGORY FOR ALL REMAINING BEACHES.
CLIMATE
RECORD HIGH TEMPERATURES:
JUNE 28:
KCHS: 99/1998
KSAV: 100/1998
RECORD HIGH MINIMUM TEMPERATURES:
JUNE 23:
KCHS: 78/2024
KCXM: 82/1998
KSAV: 77/2017
JUNE 27:
KCHS: 77/2015
KSAV: 79/1952
JUNE 28:
KCHS: 78/2013
KCXM: 81/1998
KSAV: 80/1880
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...LAKE WIND ADVISORY FROM 8 AM THIS MORNING TO 5 PM EDT THIS
AFTERNOON FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 5 PM EDT THIS
AFTERNOON FOR AMZ340-362.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ360.
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