183
FXUS62 KCHS 121157
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
657 AM EST WED NOV 12 2025
SYNOPSIS
DRY HIGH PRESSURE WILL REMAIN THE PRIMARY FEATURE ACROSS THE
AREA THROUGH THE WEEKEND.
NEAR TERM /THROUGH TONIGHT/
TODAY: A ZONAL FLOW WILL BE IN PLACE ACROSS THE SOUTHEAST
UNITED STATES, SUPPORTING A DRY WEST-NORTHWEST FLOW ACROSS THE
REGION ALOFT. AT THE SFC, HIGH PRESSURE WILL REMAIN THE DOMINANT
WEATHER FEATURE ACROSS THE LOCAL AREA, BECOMING CENTERED ACROSS
FLORIDA AND THE EASTERN GULF BY THE AFTERNOON. THE PATTERN WILL
SUPPORT A BREEZY WEST-SOUTHWEST SFC WIND LOCALLY AND NOTICEABLY
WARMER TEMPS THAN THE PREVIOUS DAY UNDER SUNNY SKIES. IN GENERAL,
HIGH TEMPS SHOULD PEAK IN THE MID-UPPER 60S (WARMEST ACROSS
SOUTHEAST GEORGIA INLAND). WIND GUSTS COULD TOP OUT NEAR 20 MPH
ACROSS SOME SPOTS DURING PEAK HEATING HOURS LATE MORNING INTO LATE
AFTERNOON.
TONIGHT: LITTLE CHANGE OCCURS IN THE OVERALL PATTERN WITH A ZONAL
FLOW ALOFT AND SFC HIGH PRESSURE CENTERED TO THE SOUTHWEST ACROSS
THE GULF AND FLORIDA. HOWEVER, LATEST GUIDANCE INDICATES THE
PRESSURE GRADIENT TO BECOME CONSIDERABLY WEAKER ACROSS THE LOCAL
AREA DURING THE NIGHT, ESPECIALLY DURING THE SECOND HALF OF THE
NIGHT. THIS SHOULD SUPPORT ANOTHER STRONG CASE FOR RADIATIONAL
COOLING UNDER CLEAR SKIES ONCE SFC WINDS WEAKEN LATE EVENING, BUT
OVERNIGHT LOWS ARE EXPECTED TO REMAIN WARMER THAN THE PREVIOUS
NIGHT. IN GENERAL, LOW TEMPS SHOULD RANGE IN THE UPPER 30S/LOWER 40S
INLAND TO MID-UPPER 40S CLOSER TO THE COAST.
SHORT TERM /THURSDAY THROUGH SATURDAY/
SURFACE HIGH PRESSURE FOR THE END OF THE WEEK INTO THE EARLY WEEKEND
WILL RESULT IN RATHER PLEASANT FALL CONDITIONS. HIGHS ON THURSDAY
FROM THE UPPER 60S TO LOWER 70S WILL RISE TO BECOME LOWER TO MID 70S
ACROSS THE REGION BY SATURDAY, WITH WINDS REMAINING LIGHT THROUGHOUT
THE PERIOD. EACH NIGHT WILL SEE NEAR-IDEAL RADIATIONAL COOLING
SET UP, RESULTING IN OVERNIGHT LOWS DROPPING TO MEET SURFACE
DEWPOINT TEMPERATURES IN THE UPPER 30S INLAND TO UPPER 40S ALONG
THE COAST. WITH PRECIPITABLE WATER VALUES REMAINING NEAR HALF
AN INCH, A DRY FORECAST IS EXPECTED.
LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/
QUIET WITH DRY CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE REST
THE WEEKEND AS MOSTLY ZONAL FLOW OCCURS ALOFT, THOUGH SOME PERIODS
OF WEAK RIDGING AND TROUGHING WILL BE OCCURRING INTO THE MIDDLE
OF THE WEEK. TEMPERATURES WILL CONTINUE THE WARMING TREND ON
SUNDAY WITH WELL ABOVE NORMAL TEMPERATURES EXPECTED IN THE MID
TO UPPER 70S, WITH SOME GUIDANCE HINTING A QUICK COLD FRONT
MOVING THROUGH THE AREA ON OVERNIGHT INTO MONDAY, BUT THAT WILL
BE DETERMINED THE STRENGTH OF THE UPPER LEVEL TROUGH FROM THE
SURFACE LOW PRESSURE MOVING INTO THE NORTHEAST. FOR NOW, MONDAY
IS ONLY LOOKING LIKE A SLIGHT COOL-DOWN FROM SUNDAY WITH
TEMPERATURES IN THE LOWER TO MID 70S, WITH SIMILAR TEMPERATURES
INTO THE MIDDLE OF THE WEEK.
AVIATION /12Z WEDNESDAY THROUGH SUNDAY/
VFR CONDITIONS WILL PREVAIL AT CHS/JZI/SAV TERMINALS THROUGH 12Z
THURSDAY, BUT LLWS HAS BEEN INCLUDED AT CHS/JZI TERMINALS
THROUGH 1330Z TODAY BASED ON MEASURED 35 KT WESTERLY WINDS AT
2K FT FROM THIS MORNING'S 12Z FLIGHT. GUSTY SOUTHWEST SFC WINDS
WILL THEN PREVAIL AT ALL TERMINALS LATE MORNING AND AFTERNOON
WITH SPEEDS TOPPING OUT AROUND 20 KT.
EXTENDED AVIATION OUTLOOK: VFR CONDITIONS EXPECTED TO PREVAIL.
MARINE
TODAY AND TONIGHT: HIGH PRESSURE WILL DOMINATE THE WEATHER
PATTERN THROUGH THE PERIOD, REMAINING CENTERED ACROSS FLORIDA
AND THE EASTERN GULF. LATEST GUIDANCE SUGGESTS THE PRESSURE
GRADIENT TO STRENGTHEN LATE MORNING AND AFTERNOON WITH A 1000 MB
GEOSTROPHIC WIND IN THE 30-35 KT RANGE EXTENDING ACROSS
NORTHERN SOUTH CAROLINA WATERS FOR SEVERAL HOURS. COLD AIR
ADVECTION WILL PROMOTE LOW-LVL MIXING WITH A SOUTHWEST WIND
GUSTING UPWARDS TO 20-25 KT ACROSS LOCAL WATERS (HIGHEST OFF THE
CHARLESTON COUNTY COAST). A SMALL CRAFT ADVISORY HAS BEEN
ISSUED FOR NORTHERN SOUTH CAROLINA WATERS LATE MORNING INTO
EVENING HOURS AS A RESULT. SEAS WILL ALSO BUILD THROUGHOUT THE
DAY, GENERALLY TO 2-4 FT ACROSS MOST WATERS, BUT SEAS UP TO 5 FT
ARE POSSIBLE ACROSS NORTHERN SOUTH CAROLINA WATERS THIS
AFTERNOON INTO EARLY EVENING. THE PRESSURE GRADIENT WILL THEN
NOTICEABLY WEAKEN DURING OVERNIGHT HOURS AND WINDS WILL TIP MORE
WEST-NORTHWEST LATE EVENING, SUPPORTING WINDS IN THE 15-20 KT
RANGE AND SEAS THAT SLOWLY SUBSIDE 1-2 FT AFTER MIDNIGHT.
THURSDAY THROUGH MONDAY: SURFACE HIGH PRESSURE THROUGH SATURDAY WILL
RESULT IN TRANQUIL SEAS, WITH WINDS NOT HIGHER THAN 10-15 KNOTS.
SUNDAY WILL SEE A SURGE IN WINDS MOSTLY IN THE 15-25 KNOT RANGE,
CURRENTLY HIGHEST IN THE NEARSHORE WATERS FROM SOUTH SANTEE, SC TO
SAVANNAH, GA FROM 0-20NM OUT, WITH SEAS PEAKING AS HIGH AS 3-6 FEET.
SMALL CRAFT ADVISORIES MAY BE NEEDED. CONDITIONS IMPROVE OVERNIGHT
INTO MONDAY AS WINDS TURN WESTERLY.
FIRE WEATHER
RELATIVE HUMIDITY VALUES SHOULD APPROACH 25-30% AWAY FROM THE COAST
LATE MORNING AND AFTERNOON WHILE SOUTHWEST WIND GUSTS AROUND 15 MPH
BECOME COMMON. NEAR CRITICAL RELATIVE HUMIDITY VALUES ARE MOST
FAVORABLE ACROSS SOUTHEAST GEORGIA AWAY FROM THE COAST LATE MORNING
INTO EARLY AFTERNOON, BUT LOWEST VALUES SHOULD BE LIMITED TO A FEW
HOURS DURATION DUE TO INCREASING MOISTURE LEVELS ACROSS THE AREA BY
MID AFTERNOON. AT THIS TIME A FIRE DANGER STATEMENT IS NOT NEEDED,
BUT CONDITIONS WILL BE MONITORED THROUGHOUT THE DAY FOR ANY
NECESSARY UPDATES.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR AMZ350.
NEAR TERM...DPB
SHORT TERM...APT
LONG TERM...APT
AVIATION...APT/DPB
MARINE...APT/DPB
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