441
FXUS62 KCHS 190724
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
224 AM EST FRI DEC 19 2025
SYNOPSIS
A COLD FRONT WILL SHIFT ACROSS THE AREA EARLY TODAY, RESULTING
IN AN INFLUX OF DRIER AIR AND BREEZY WINDS. HIGH PRESSURE WILL
THEN PREVAIL OVER THE WEEKEND, WITH ANOTHER COLD FRONT FORECAST
TO IMPACT THE AREA MONDAY.
NEAR TERM /THROUGH TONIGHT/
PRIOR TO DAYBREAK: WARM AND MOIST AIR RESIDES ACROSS SOUTHEAST SOUTH
CAROLINA AND SOUTHEAST GEORGIA WELL AHEAD OF A COLD FRONT CURRENTLY
EXTENDING ACROSS CENTRAL GEORGIA. FEW SHOWERS CONTINUE TONIGHT,
MAINLY ALONG COASTAL AREAS AND OFFSHORE WHILE H5 VORT ENERGY
TRAVERSES ALOFT AND LOW-LVL WIND FIELDS STRENGTHEN LOCALLY. ACTIVITY
WILL CONTINUE TO SHIFT OFFSHORE DURING THE NEXT 1-2 HOURS, LEAVING
MOST AREAS DRY FOR A FEW HOURS UNTIL THE COLD FRONT BEGINS TRACKING
ACROSS THE LOCAL AREA FROM WEST TO EAST APPROACHING DAYBREAK. LATEST
RADAR IMAGERY INDICATES AN ENHANCED LINE OF CONVECTION WITH THE
FRONT UPSTREAM, BUT EXPECT THIS LINE TO WEAKEN CONSIDERABLY WHILE
APPROACHING FROM THE WEST DUE TO WEAK INSTABILITY. HOWEVER, STRONG
SHEAR AND MID-LVL LAPSE RATES IN THE 7-7.5 C/KM RANGE SHOULD HELP
MAINTAIN A BROKEN LINE OF LIGHT TO MODERATE SHOWERS ACROSS INLAND
ZONES AS FROPA BEGINS JUST PRIOR TO SUNRISE. OVERNIGHT LOWS REMAIN
MILD GIVEN COLD FROPA ARRIVAL TIME, GENERALLY IN THE MID-UPPER 50S
ACROSS MOST AREAS.
LAKE WIND: STRONG LOW-LVL WIND FIELDS RESIDE ACROSS THE REGION
CURRENTLY, BUT LOW-LVL MIXING IS NOT FAVORABLE IN A WARM AIR
ADVECTION REGIME ACROSS COOLER LAKE WATERS AHEAD OF A COLD FRONT.
THERE IS STILL SOME RISK FOR WESTERLY SFC WINDS TO STRENGTHEN AS A
COLD FRONT NEARS AND PASSES ACROSS THE AREA LATE, WITH GUSTS TO
AROUND 20 KT LIKELY, BUT POSSIBLY UP TO 25 KT FOR A FEW HOURS.
TRENDS WILL CONTINUE TO BE MONITORED FOR THE POTENTIAL OF A LAKE
WIND ADVISORY LATE NIGHT/EARLY MORNING.
TODAY: A SFC COLD FRONT WILL TRACK ACROSS THE REGION EARLY, LIKELY
EXITING THE REGION OFFSHORE SHORTLY AFTER DAYBREAK. A POTENT MID-LVL
TROUGH WILL FOLLOW TO FRONT, PIVOTING ACROSS THE SOUTHEAST AND MID-
ATLANTIC STATES DURING MID-LATE MORNING HOURS, PLACING THE LOCAL
AREA ALONG ITS SOUTHERN EDGE. THIS SHOULD SUPPORT A RATHER DIFFUSE
LINE OF SHOWERS ACROSS INLAND AREAS EARLY MORNING, WHICH ERODE
QUICKLY WHILE TRACKING NORTHEAST ACROSS SOUTHEAST SOUTH CAROLINA DUE
TO CONSIDERABLY DRIER AIR ARRIVING BEHIND THE SFC FRONT. HOWEVER,
BREEZY SOUTHWEST/WEST WINDS (20-25 MPH) ARE EXPECTED DURING MORNING
INTO EARLY AFTERNOON HOURS WHILE COLD AIR ADVECTION OCCURS ACROSS
THE REGION. AFTERNOON HIGHS SHOULD STILL WARM INTO THE MID-UPPER 60S
(WARMEST ACROSS THE COASTAL CORRIDOR) AS A NORTHWEST DOWNSLOPE WIND
DEVELOPS OFF THE SFC AND SKIES BECOME CLEAR DURING PEAK DIURNAL
HEATING HOURS. HIGH PRESSURE WILL SETTLE INTO THE REGION BY LATE
DAY, RESULTING IN DIMINISHING WINDS AND COOLER TEMPS LATE AFTERNOON.
TONIGHT: QUIET WEATHER CONDITIONS ARE EXPECTED WITH DRY HIGH
PRESSURE BECOMING CENTERED ACROSS THE SOUTHEAST. WEST WINDS WILL
BECOME NOTICEABLY WEAKER, EVENTUALLY BECOMING LIGHT/CALM BY LATE
EVENING AND THEREFORE SETTING UP A STRONG RADIATIONAL COOLING NIGHT
UNDER CLEAR SKIES. OVERNIGHT LOWS WILL BE CONSIDERABLY COLDER THAN
THE PREVIOUS NIGHT, DIPPING INTO THE LOWER 30S WELL INLAND TO MID-
UPPER 30S ALONG/EAST OF I-95. LOCATIONS SHOULD STAY IN THE LOW-MID
40S NEAR THE BEACHES.
SHORT TERM /SATURDAY THROUGH MONDAY/
SFC HIGH PRESSURE BUILDS ACROSS THE REGION SATURDAY IN THE WAKE OF
FROPA, ALLOWING DRY CONDITIONS TO PREVAIL. WINDS LOOK TO REMAIN
LIGHT DURING THIS TIME, WITH DIRECTION SHIFTING MORE SOUTHEASTERLY
THROUGH THE AFTERNOON AS THE AFOREMENTIONED HIGH DRIFTS INTO THE MID-
ATLANTIC. OUTSIDE OF THIS, EXPECT DEWPOINTS TO RISE A BIT AS A SEA-
BREEZE PUSHES INLAND, WITH HIGHS RISING INTO THE LOWER 60S UNDER
SUNNY SKIES.
UPPER LEVEL FLOW REMAINS QUASI-ZONAL HEADING INTO SUNDAY AS A
SHORTWAVE STRENGTHENS SOUTH OF THE JAMES BAY AREA. MEANWHILE, AT THE
SFC, MODELS SHOW AN ADVANCING COLD FRONT PROGGED TO PUSH EASTWARD
ACROSS THE APPALACHIAN MOUNTAINS, AND INTO OUR AREA BY MONDAY. THAT
BEING SAID, OVERALL MOISTURE REMAINS QUITE MEAGER, KEEPING THE
FORECAST DRY. IN REGARD TO TEMPERATURES, HAVE AFTERNOON HIGHS
WARMING INTO THE MID TO UPPER 60S SUNDAY PRIOR TO FROPA, WITH
TEMPERATURES THEN DIPPING BACK INTO THE 50S TO LOWER 60S MONDAY IN
ITS WAKE.
LONG TERM /MONDAY NIGHT THROUGH THURSDAY/
QUIET CONDITIONS CONTINUE THROUGHOUT THE EXTENDED PERIOD AS SFC HIGH
PRESSURE STRENGTHENS OVERHEAD. BOTH DETERMINISTIC AND ENSEMBLE
GUIDANCE ALSO REMAIN IN GOOD AGREEMENT THAT STRONG UPPER LEVEL
RIDGING WILL DEVELOP ACROSS THE CENTRAL CONUS DURING THIS TIME,
ALLOWING UNSEASONABLY WARM TEMPERATURES TO PREVAIL. CURRENTLY HAVE
HIGHS IN THE 60S TUESDAY WARMING INTO THE 70S BY CHRISTMAS
EVE/CHRISTMAS DAY. LOWS WILL ALSO REMAIN QUITE MILD, AS TEMPERATURES
ONLY FALL INTO THE MID TO UPPER 40S.
AVIATION /06Z FRIDAY THROUGH TUESDAY/
PERIODS OF IFR/MVFR CIGS ARE LIKELY ALONG WITH A FEW SHOWERS
POSSIBLE AT CHS/JZI/SAV EARLY THIS MORNING. HOWEVER, THE MAIN
CONCERN IS LOWER CIGS THROUGH ABOUT 12Z FRIDAY. SOUTHWEST SFC WINDS
ARE EXPECTED TO BECOME BREEZY DURING THE NEXT HOUR, GENERALLY
IMPROVING IFR CIGS TO MVFR LATER TONIGHT, BEFORE ABRUPTLY GOING VFR
ONCE FROPA OCCURS AROUND 12Z. VFR CONDITIONS WILL THEN PREVAIL
THROUGH 06Z SATURDAY, BUT GUSTY WEST/NORTHWEST WINDS (15-22 KT) WILL
REMAIN LATE MORNING INTO EARLY AFTERNOON HOURS, BEFORE GOING LIGHT
AFTER SUNSET.
EXTENDED AVIATION OUTLOOK: VFR EXPECTED TO PREVAIL OVER THE
WEEKEND, WITH PERIODS OF MVFR POSSIBLE MONDAY MORNING IN THE
WAKE OF FROPA.
MARINE
PRIOR TO DAYBREAK: LOW-LVL WIND FIELDS WILL STRENGTHEN ACROSS LOCAL
WATERS TONIGHT, EVENTUALLY LEADING TO AN INCREASE IN SFC WINDS
UPWARDS TO THE 20-30 KT RANGE AND SEAS THAT BUILD UP TO 6-9 FT
(STRONGEST/LARGEST) ACROSS OFFSHORE GEORGIA WATERS AND NEARSHORE
SOUTH CAROLINA WATERS OFF THE CHARLESTON COUNTY COAST.) SMALL CRAFT
ADVISORIES CONTINUE FOR ALL WATERS GIVEN THE EXPECTED TREND.
ADDITIONALLY, LATEST WEB CAMS AND SFC OBS INDICATE IMPROVEMENT
ACROSS COASTAL WATERS IN REGARDS TO SEA FOG. EXPECT THIS TREND TO
CONTINUE AS WINDS STRENGTHEN THROUGH THE NIGHT, WITH THE BULK OF SEA
FOG CONCERNS ENDING BY AROUND 3 AM.
TODAY AND TONIGHT: A COLD FRONT WILL SHIFT ACROSS LOCAL WATERS EARLY
WITH COLD AIR ADVECTION IN ITS WAKE SUPPORTING GUSTY WINDS THROUGH
LATE MORNING/EARLY AFTERNOON HOURS. SMALL CRAFT ADVISORIES WILL
REMAIN IN EFFECT ACROSS ALL WATERS, BUT WILL START TO COME DOWN AT
VARIOUS TIMES DURING THE DAY, STARTING WITH THE CHARLESTON HARBOR
LATE MORNING, THEN SOUTHERN NEARSHORE SOUTH CAROLINA AND NEARSHORE
GEORGIA WATERS EARLY AFTERNOON. HIGHER SEAS (6-7 FT) WILL LINGER
DURING AFTERNOON HOURS ACROSS OUTER GEORGIA WATERS AND NEARSHORE
WATERS OFF THE CHARLESTON COUNTY COAST, SO SMALL CRAFT ADVISORIES
WILL REMAIN IN EFFECT UNTIL 7 PM FOR THESE AREAS. CONDITIONS
CONTINUE TO IMPROVE OVERNIGHT WITH HIGH PRESSURE BECOMING CENTERED
ACROSS THE REGION. IN GENERAL, NORTHWEST WINDS WILL REMAIN AROUND 10-
15 KT OR LESS WITH SEAS IN THE 2-4 FT AFTER MIDNIGHT.
SATURDAY AND SUNDAY: SEAS 2 TO 4 FT WITH WINDS GUSTING UP TO 15 KT
AT TIMES. NO ADVISORIES OR WARNINGS ARE EXPECTED.
MONDAY: A COLD FRONT WILL CROSS THE WATERS IN THE EARLY MORNING
HOURS FROM THE NORTHEAST WITH WINDS GUSTING 25 TO 30 KT AT TIMES.
SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR ALL ZONES (THE ONE
EXCEPTION BEING THE HARBOR).
TUESDAY: NORTHEAST WINDS TURNING FROM THE SOUTHEAST AROUND 10 KT
WITH SEAS 4 TO 7 FT RELAXING TO 3 TO 6 FT.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ330.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ350-
374.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR AMZ352-
354.
NEAR TERM...DPB
SHORT TERM...SST
LONG TERM...SST
AVIATION...DPB/SST
MARINE...DPB/SST
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