801
FXUS62 KCHS 250555
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
155 AM EDT WED JUN 25 2025
SYNOPSIS
HIGH PRESSURE WILL LARGELY REMAIN ACROSS THE SOUTHEAST U.S. HOT
AND HUMID CONDITIONS ARE EXPECTED TO CONTINUE WITH RAIN CHANCES
INCREASING MID TO LATE WEEK AS SURFACE TROUGHING BEGINS TO FORM
OVER THE REGION AND A FEW UPPER DISTURBANCES PASS THROUGH.
NEAR TERM /UNTIL 6 AM THIS MORNING/
TONIGHT: THE REMAINDER OF THE NIGHT SHOULD REMAIN QUIET/DRY AS
SFC HIGH PRESSURE PREVAILS ACROSS THE LOCAL AREA AND THE REGION
REMAINS POSITIONED BETWEEN A BROAD MID-UPPER LVL LOW CENTERED
OFFSHORE AND A MID-LVL RIDGE CENTERED TO THE NORTH/NORTHWEST
INLAND. LOWS ARE EXPECTED TO REMAIN MILD, GENERALLY IN THE MID
70S INLAND TO UPPER 70S/AROUND 80 ALONG THE IMMEDIATE COAST.
SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/
WEDNESDAY: A STRONG UPPER LEVEL RIDGE OVER THE EASTERN CONUS
WILL CONTINUE TO HOLD WEDNESDAY, ALONG WITH THE SURFACE HIGH
OVER THE CENTRAL ATLANTIC. MODELS SHOW A STRONG SIGNAL THAT A
MCS WILL DEVELOP OVER SOUTHEASTERN NORTH CAROLINA IN THE
AFTERNOON AND MOVE SOUTHWEST TOWARD CENTRAL GEORGIA, WITH
CONVECTION POSSIBLY TRACKING OVER OUR INLAND COUNTIES IN THE
EVENING. IMPRESSIVE INSTABILITY VALUES ARE NOTED WITH MLCAPE
UPWARDS OF 2500 J/KG, MID-LVL LAPSE RATES PEAKING AROUND 8-9
DEGREES C/KM, AND DCAPE VALUES IN EXCESS OF 1200 J/KG, WHICH
CERTAINLY FUEL THE POSSIBILITY FOR STRONG TO SEVERE
THUNDERSTORMS TO DEVELOP. MODEL SOUNDINGS SHOW SLIGHTLY LESS
IMPRESSIVE VALUES CLOSER TO THE COAST, BUT AN UNSTABLE
ENVIRONMENT NONETHELESS. BULK SHEAR IS ON THE ORDER OF 15-20 KT,
WHICH COULD LEAD TO STORMS LACKING ORGANIZATION, HOWEVER
DEVELOPING STORMS WOULD HAVE DECENTLY STRONG UPDRAFTS AND
DOWNDRAFTS. THIS LEADS US TO THE MAIN THREAT WHICH WILL BE FOR
STRONG, DAMAGING WIND GUSTS, ALTHOUGH HAIL CANNOT BE RULED OUT.
WE KEPT POPS MAXED TO ONLY 30-40% WITH THE MAJORITY OF THE
UNCERTAINTY STEMMING FROM THE TIMING AND OVERALL EVOLUTION OF
THE MCS, WHICH MODELS TEND TO HAVE TROUBLE CAPTURING.
TEMPERATURES WILL ONCE AGAIN CLIMB TO THE MID TO UPPER 90S, WITH
A MAJORITY OF HEAT INDICES ACROSS THE CWA PEAKING AROUND
104-107 DEGREES. ALTHOUGH, A FEW SPOTS ACROSS THE CHARLESTON
TRI-COUNTY COULD REACH 108-109 DEGREES WHERE THE HIGHER DEW
POINTS POOL. LIMITING FACTORS INCLUDE THE POSSIBILITY FOR
CONVECTION TO ARRIVE AROUND THE TIME OF PEAK HEATING WHICH WOULD
DISRUPT TEMPERATURES, AND DEEP MIXING WHICH WOULD PROMOTE DEW
POINTS TO DROP INTO THE UPPER 60S. BECAUSE CONDITIONS ARE
MARGINAL WITH REGARDS TO MEETING HEAT ADVISORY CRITERIA (108F),
THERE ARE NO PLANS TO ISSUE ONE AT THIS TIME, BUT WE WILL
CONTINUE TO MONITOR. CONVECTION SHOULD COME TO AN END OVERNIGHT
WITH MIN TEMPERATURES REACHING THE LOW TO MID 70S.
THURSDAY AND FRIDAY: THE AFOREMENTIONED UPPER LEVEL RIDGE WILL
BEGIN TO WEAKEN SLIGHTLY AS IT MOVES TOWARD THE ATLANTIC.
REMNANT VORTICITY FROM AN MCS OVER THE DEEP SOUTH, IN ADDITION
TO A WEAK UPPER LOW ACROSS FLORIDA, COULD PROVIDE FORCING FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE
AFTERNOON/EVENING PERIOD BOTH THURSDAY AND FRIDAY. TEMPERATURES
WILL BECOME A BIT MORE MUTED WITH HIGHS IN THE UPPER 80S TO LOW
90S BOTH DAYS. OVERNIGHT LOWS THURSDAY WILL DIP INTO THE LOW TO
MID 70S, NEARING THE UPPER 70S ALONG THE IMMEDIATE COAST.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
WEAK SURFACE TROUGHING INLAND WILL BECOME MORE DOMINANT OVER
THE WEEKEND, ALONG WITH A MID LEVEL LOW OVER THE FL PENINSULA
AND RIDGING TO OUR NORTHEAST. THIS WILL LEAD TO DAILY RAIN
CHANCES THROUGH EARLY NEXT WEEK, ESPECIALLY ACROSS SOUTHEAST
GEORGIA. TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL FOR THIS
TIME OF THE YEAR.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
VFR CONDITIONS WILL PREVAIL AT CHS/JZI/SAV TERMINALS THROUGH 06Z
THURSDAY. HOWEVER, THERE IS SOME RISK FOR AN AFTERNOON SHOWER OR
THUNDERSTORM IMPACTING THE TERMINALS WITH A SEA BREEZE SHIFTING
INLAND, FOLLOWED BY ANOTHER RISK FOR SHOWERS/THUNDERSTORMS
DURING EVENING HOURS. AT THIS TIME, PROBABILITIES REMAIN TOO LOW
TO INCLUDE MENTION OF SHRA/TSRA AT THE TERMINALS THIS AFTERNOON,
AND THE BULK OF CONVECTION DURING EVENING HOURS APPEARS TO REMAIN
INLAND TO THE TERMINALS. FUTURE TAF ISSUANCES COULD NEED TO
INCLUDE MENTION OF THIS ACTIVITY.
EXTENDED AVIATION OUTLOOK: BRIEF FLIGHT RESTRICTIONS ARE
POSSIBLE IN THE AFTERNOON AND EVENING HOURS WITHIN SHOWERS AND
THUNDERSTORMS.
MARINE
TONIGHT: SOUTH-SOUTHWEST WINDS WILL GENERALLY REMAIN IN THE
10-15 KT RANGE FOR THE NEXT FEW HOURS, BUT SHOULD GRADUALLY
BECOME MORE SOUTHWESTERLY AND DIMINISH TO 10 KT OR LESS
APPROACHING DAYBREAK WHILE HIGH PRESSURE HOLDS IN PLACE THROUGH
THE NIGHT. SEAS ARE EXPECTED TO AVERAGE AROUND 2 FT THROUGH THE
PERIOD.
WEDNESDAY THROUGH SUNDAY: SOUTH TO SOUTHWEST WINDS COULD BECOME
A BIT GUSTY EACH AFTERNOON WITH GUSTS UP TO 15-20 KT AS THE
SEABREEZE DEVELOPS (GUSTS STRONGEST ACROSS THE IMMEDIATE COAST
AND CHARLESTON HARBOR). OTHERWISE, NO MARINE CONCERNS EXPECTED
THROUGH THE PERIOD.
TIDES/COASTAL FLOODING
ASTRONOMICAL TIDES WILL PEAK AROUND 6.5 FT MLLW AT CHARLESTON
WITH THE EVENING HIGH TIDE CYCLE WEDNESDAY NIGHT. AFTERNOON
WINDS WILL ONLY BE MARGINALLY SUPPORTIVE OF INCREASING TIDAL
DEPARTURES. THE WEDNESDAY EVENING HIGH TIDE WILL LIKELY PEAK
AROUND 6.8-6.9 FT MLLW, FALLING JUST SHORT OF COASTAL FLOOD
ADVISORY CRITERIA.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
NEAR TERM...DPB
SHORT TERM...BRS
LONG TERM...BRS
AVIATION...BRS/DPB
MARINE...BRS/DPB
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