803
FXUS62 KCHS 290630
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
230 AM EDT SUN JUN 29 2025
SYNOPSIS
HIGH PRESSURE WILL EXTEND ACROSS THE REGION THROUGH EARLY NEXT
WEEK. A COLD FRONT WILL THEN APPROACH THE AREA AROUND THE
MIDDLE OF NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
THE SYNOPTIC PATTERN TODAY WILL BE DOMINATED BY HIGH PRESSURE,
BOTH ALOFT AND AT THE SURFACE. GIVEN A LACK OF LARGE SCALE
FORCING, AFTERNOON SHOWERS AND THUNDERSTORMS WILL FOCUS ALONG
THE INLAND PROGRESSING SEA BREEZE AND ANY OUTFLOW BOUNDARIES
THAT ARE LINGERING AROUND. HOWEVER, 00Z CAMS ARE NOT VERY
SUPPORTIVE OF SIGNIFICANT COVERAGE GIVEN SOME DRIER AIR ALOFT.
THE FORECAST FEATURES POPS THIS AFTERNOON GENERALLY IN THE
30-40% RANGE, WITH SOME 50% ACROSS FAR SOUTHEASTERN GA. MOST
SHOWER/THUNDERSTORM ACTIVITY WILL WANE WITH NIGHTFALL, ALTHOUGH
SOME SHOWER ACTIVITY MAY PERSIST ALONG REMNANT BOUNDARIES INTO
THE OVERNIGHT HOURS. THE TEMPERATURE FORECAST TODAY WAS A
COMBINATION OF PERSISTENCE AND THE NBM, YIELDING HIGHS IN THE
LOW 90S AND OVERNIGHT LOWS IN THE 70S, WARMEST ALONG THE DIRECT
COASTLINE AND DOWNTOWN CHARLESTON.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
MONDAY: AN UPPER LEVEL LOW WILL BE RETROGRADING TO THE WEST WITH
SURFACE HIGH PRESSURE REMAINING ANCHORED NEAR BERMUDA. PWATS EACH
DAY ARE FORECAST TO BE BETWEEN 1.75" AND 2.00", OR NEAR CLIMATOLOGY
FOR THIS TIME OF YEAR PER THE ENSEMBLE SITUATIONAL AWARENESS BOARD,
WITH PLENTIFUL INSTABILITY EACH AFTERNOON (~1500 J/KG OF MU CAPE).
BESIDES THE UPPER LEVEL LOW, FORCING REMAINS RATHER WEAK EACH
AFTERNOON WHICH WOULD FAVOR THUNDERSTORMS FORMING ALONG THE SEA
BREEZE AND OTHER BOUNDARY COLLISIONS. EACH AFTERNOON WILL GENERALLY
FEATURE A 40% TO 60% CHANCE OF SHOWERS AND THUNDERSTORMS WITH HIGHS
IN THE LOWER 90S.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
NEXT WEEK WILL GENERALLY FAVOR AN INCREASING CHANCE OF SHOWERS AND
THUNDERSTORMS WEDNESDAY AND THURSDAY WITH A RETURN TO MORE DIURNAL
CONVECTION AND CLIMATOLOGICAL RAIN CHANCES FRIDAY AND SATURDAY.
TEMPERATURES ARE ALSO FORECAST TO BE NEAR NORMAL THROUGH THE PERIOD
THANKS TO THE INCREASED RAIN CHANCES.
WEDNESDAY/ THURSDAY: ENSEMBLE GUIDANCE IS IN FAIRLY GOOD AGREEMENT
THAT AN UPPER LEVEL DISTURBANCE WILL CROSS NEW ENGLAND WITH TRAILING
VORTICITY ALL THE WAY TOWARDS FL. AS THIS OCCURS, A WEAK COLD FRONT
WILL APPROACH THE REGION FROM THE NORTHWEST THURSDAY. ENSEMBLE
GUIDANCE IS IN FAIRLY GOOD AGREEMENT THAT WIDESPREAD SHOWERS AND
THUNDERSTORMS POSSIBLE WEDNESDAY AND THURSDAY. OVERALL, ABOUT 70% OF
ENSEMBLE GUIDANCE FAVORS THIS SOLUTIONS. THE LATEST RUN OF THE NBM
SHOWS ABOUT A 20% OF THE REGION RECEIVING AT LEAST AN INCH OF
RAINFALL IN A 24 HR PERIOD WEDNESDAY OR THURSDAY. EXPECT HIGHS IN
THE UPPER 80S (OR SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR).
HOWEVER, ONE SCENARIO ADVERTISED IS THAT THE COLD FRONT STALLS
FURTHER NORTH WITH MOST OF THE CONVECTION FORMING IN THE MIDLANDS
AND UPSTATE OF SC WITH ANOTHER BATCH OF CONVECTION FORMING JUST
SOUTH OF THE PANHANDLE OF FL. THIS WOULD BE A DRIER SCENARIO FOR SC
AND GA AND IS CAPTURED BY ABOUT 30% OF THE ENSEMBLE SOLUTIONS.
FRIDAY/ SATURDAY: THE UPPER LEVEL DISTURBANCE WILL EJECT EAST OF THE
UNITED STATES. AS THIS OCCURS, A RETURN TO A MORE CLIMATOLOGICAL
SUMMER PATTERN IS FORECAST WITH A CHANCE OF SHOWERS AND
THUNDERSTORMS EACH AFTERNOON. EXPECT HIGHS IN THE LOW 90S.
AVIATION /06Z SUNDAY THROUGH THURSDAY/
GENERALLY VFR WILL PREVAIL ACROSS THE TERMINALS THROUGH THE 06Z
TAF PERIOD AT KCHS/KJZI/KSAV. THERE ARE A FEW SHOWERS POPPING UP
NEAR KJZI AS OF 2:30AM ALONG THE LAND BREEZE. A TEMPO GROUP HAS
BEEN ADDED TO THEIR TAF TO ACCOUNT FOR THIS. OTHERWISE, THE 06Z
TAF FOR ALL THREE SITES REMAINS PRECIPITATION FREE AS
THUNDERSTORM ACTIVITY THIS AFTERNOON IS FORECAST TO REMAIN WEST
OF THE TERMINALS. GUSTY WINDS (UP TO AROUND 20 KNOTS) ARE
POSSIBLE THIS AFTERNOON WITH THE INLAND PROGRESSING SEA BREEZE.
EXTENDED AVIATION OUTLOOK (MONDAY - THURSDAY): BRIEF FLIGHT
RESTRICTIONS ARE POSSIBLE MONDAY AND TUESDAY AFTERNOON DURING
CONVECTION. WEDNESDAY AND THURSDAY, MORE WIDESPREAD COVERAGE OF
SHOWERS AND THUNDERSTORMS ARE FORECAST AS A COLD FRONT APPROACHES
FROM THE NORTHWEST. THIS COULD PROVIDE MORE FREQUENT PERIODS OF
CEILING AND VISIBILITY RESTRICTIONS.
MARINE
TODAY: THE LOCAL MARINE ZONES WILL REMAIN UNDER THE INFLUENCE OF
HIGH PRESSURE TODAY, YIELDING SOUTHERLY WINDS GENERALLY 10 TO
15 KNOTS. THE AFTERNOON SEA BREEZE WILL CREATE GUSTY CONDITIONS
ALONG THE COASTLINE THIS AFTERNOON, WITH GUSTS AROUND 20 KNOTS.
SEAS ARE FORECAST TO AVERAGE 2 TO 3 FT.
TONIGHT: WINDS WILL DIMINISH SLIGHTLY WITH NIGHTFALL, WITH
GENERALLY SSW WINDS AROUND 10 KNOTS FORECAST. SEAS WILL REMAIN 2
TO 3 FT ACROSS THE WATERS.
MONDAY THROUGH THURSDAY: HIGH PRESSURE OVER THE ATLANTIC WILL
PREVAIL THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK, YIELDING
SOUTH/SOUTHWEST FLOW 10 TO 15 KNOTS. GUSTS ALONG THE COAST COULD
REACH 20 KNOTS EACH AFTERNOON IN ASSOCIATION WITH THE AFTERNOON SEA
BREEZE. SEAS SHOULD AVERAGE 2 TO 3 FT INITIALLY, THEN BUILD 3 TO 4
FT BY TUESDAY AND PERSIST THROUGH FRIDAY. SHOWERS AND THUNDERSTORMS
ARE FORECAST TO INCREASE IN COVERAGE WEDNESDAY AND THURSDAY OVER THE
WATERS AS A COLD FRONT APPROACHES FROM THE NORTHWEST. NO MARINE
HEADLINES ARE EXPECTED.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
NEAR TERM...CPM
SHORT TERM...HAINES
LONG TERM...HAINES
AVIATION...CPM/HAINES
MARINE...CPM/HAINES
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