811
FXUS62 KCHS 281133
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
633 AM EST FRI NOV 28 2025
SYNOPSIS
HIGH PRESSURE WILL PREVAIL THROUGH THE WEEKEND. A LOW PRESSURE
SYSTEM COULD IMPACT THE AREA EARLY NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
TODAY: THE BASE OF THE LONGWAVE EAST COAST TROUGH WILL SWING BY
TO THE NORTH EARLY THIS MORNING WITH MID-LEVEL HEIGHTS PROGGED
TO SLOWLY RISE THROUGH THE DAY AND INTO TONIGHT. THE FLOW WILL
TRANSITION TO A MORE ZONAL-TYPE CONFIGURATION THROUGH THE PERIOD
WITH CANADIAN HIGH PRESSURE EXPECTED TO BUILD INTO THE CENTRAL
APPALACHIANS BY DAYBREAK SATURDAY. COOL AND VERY DRY CONDITIONS
WILL PERSIST AS A MODIFIED CONTINENTAL POLAR (CP) AIRMASS
MAINTAINS ITS INFLUENCE ON THE REGION. COLD 850 HPA TEMPERATURES
OF +1 TO -2C WILL KEEP DAYTIME TEMPERATURES RATHER CHILLY, BUT
ONGOING DOWNSLOPE TRAJECTORIES OFF THE SOUTHERN APPALACHIANS
WILL HELP BOOST HIGHS A BIT COMPARED TO WHAT FULL INSOLATION
LOW-LEVEL THICKNESS SCHEMES WOULD SUGGEST. HIGHS LOOK TO PEAK IN
THE LOWER-MID 50S WITH LOWER-MID 50S AT THE BEACHES WHICH IS
ABOUT 10-15 DEGREES BELOW NORMAL FOR LATE NOVEMBER.
TONIGHT: HIGH PRESSURE WILL PERSIST THROUGH TONIGHT. HIGH CLOUDS
ASSOCIATED WITH BOTH THE POLAR AND SUBTROPICAL JETS WILL SPREAD
EAST ACROSS THE AREA OVERNIGHT. ALTHOUGH THE BOUNDARY LAYER
COULD DECOUPLE THIS EVENING, ESPECIALLY INLAND, INFLUENCES FROM
THE INCREASING CLOUD CANOPY WILL LIKELY CURTAIL THE DEGREE OF
RADIATIONAL COOLING. THE PRESSURE GRADIENT WILL ALSO BEGIN TO
TIGHTEN LATE AS THE POSITION OF THE HIGH TO THE NORTH BEGINS TO
INITIATE THE DEVELOPMENT OF A COASTAL TROUGH JUST OFFSHORE. IT
WILL STILL BE RATHER CHILLY WITH LOWS EXPECTED TO DROP INTO THE
UPPER 20S INLAND TO THE MID-UPPER 40S AT THE BEACHES. AS WINDS
BEGIN TO NUDGE HIGHER CLOSER TO DAYBREAK, WIND CHILL VALUES
COULD DROP INTO THE MID 20S INLAND WITH MID 30S AT THE BEACHES.
THIS IS JUST ABOVE COLD WEATHER ADVISORY CRITERIA.
SHORT TERM /SATURDAY THROUGH MONDAY/
SURFACE HIGH PRESSURE NORTH OF THE AREA WILL KEEP CONDITIONS
COOL AND DRY THROUGHOUT THE DAY, WITH HIGH TEMPERATURES A TOUCH
WARMER IN THE UPPER 40S TO UPPER 50S, POSSIBLE LOWER 60S ACROSS
FAR SOUTHEASTERN GEORGIA. OVERNIGHT INTO SUNDAY, LOWS ARE AGAIN
EXPECTED TO DIP INTO THE MID 30S FAR INLAND TO THE MID/UPPER 40S
ALONG THE COAST. PER THE ENSEMBLE SITUATIONAL AWARENESS TABLES,
THESE TEMPERATURES ARE IN THE BOTTOM 10TH PERCENTILE OF
CLIMATOLOGY, THUS NOT EXPECTING ANY RECORDS TO BE BROKEN. AS A
WEAK STATIONARY FRONT DEVELOPS OFF THE SOUTHEAST GEORGIA COAST
BY THE EVENING HOURS, MAY SEE SOME WEAK AND LIGHT SHOWERS
DEVELOP NEAR/ONSHORE, BUT FOR NOW THE NBM KEEPS THE FORECAST DRY
ON LAND.
FOR SUNDAY, THE AFOREMENTIONED STATIONARY FRONT MIXES OUT AS
ONSHORE FLOW RETURNS AHEAD OF AN APPROACHING COLD FRONT. 850MB
TEMPERATURES REACH BACK UP INTO THE UPPER SINGLE DIGITS EXPECT,
SO EXPECTING A MUCH WARMER DAY WITH HIGHS BACK UP INTO THE MID
TO UPPER 60S ACROSS SOUTHEASTERN SOUTH CAROLINA AND UPPER 60S TO
MID 70S ACROSS SOUTHEASTERN GEORGIA. ISENTROPIC LIFT MAY AGAIN
RESULT IN SOME WEAK SHOWERS DEVELOPING DURING THE AFTERNOON
HOURS, BUT THE BETTER CHANCES ARRIVE DURING THE EVENING AS THE
COLD FRONT SLIPS THROUGH THE AREA ALONG WITH SOME SCATTERED AND
WEAK SHORTWAVES.
SURFACE HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH
THROUGHOUT THE DAY ON MONDAY, WITH THE PREVIOUS FRONT BEING
PUSHED OFF TO OUR SOUTH ACROSS NORTHERN FLORIDA. THIS WILL DROP
AFTERNOON TEMPERATURES BACK DOWN INTO THE MID 50S TO MID 60S,
WARMEST ACROSS SOUTHEAST GEORGIA. WITH ISENTROPIC LIFT
CONTINUING ALOFT AND SCATTERED SHORTWAVES OUT AHEAD OF AN
APPROACHING TROUGH MOVING ACROSS THE AREA, LOW CHANCES (20-30%)
FOR SCATTERED SHOWERS CONTINUE THROUGHOUT THE DAY.
LONG TERM /MONDAY NIGHT THROUGH THURSDAY/
AS THE AFOREMENTIONED TROUGH CONTINUES TO MOVE TOWARDS THE
AREA, A SURFACE LOW WILL BE MOVING TOWARDS THE AREA ACROSS THE
GULF WHICH WILL BE INCREASING RAINFALL CHANCES INTO TUESDAY.
TIMING OF THE HEAVIEST RAINFALL IS A LITTLE UNCERTAIN, BUT
CURRENTLY LOOKS MOST LIKELY DURING THE DAYTIME HOURS ON TUESDAY
AS THE SURFACE LOW TRAVERSES THE REGION. DESPITE PRECIPITABLE
WATER VALUES APPROACHING THE 90TH PERCENTILE OF CLIMATOLOGY NEAR
1.5 INCHES, RAINFALL AMOUNTS LOOK TO REMAIN IN THE 0.5-1.0 INCH
RANGE, HIGHEST ACROSS SOUTHEAST SOUTH CAROLINA.
CHANCES FOR RAINFALL DWINDLE INTO THE OVERNIGHT HOURS, WITH
SURFACE HIGH PRESSURE BUILDING INTO THE REGION BEHIND THE COLD
FRONT. WITH STRONG ZONAL FLOW ALOFT, THE SURFACE HIGH PRESSURE
MOVES OFFSHORE FAIRLY QUICKLY, BRINGING TEMPERATURES BACK TO
NEAR NORMAL.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
28/12Z TAF DISCUSSION:
KCHS/KJZI/KSAV: VFR THROUGH 29/06Z.
EXTENDED AVIATION OUTLOOK: VFR CONDITIONS ARE EXPECTED THROUGH
SATURDAY. FLIGHT RESTRICTIONS ARE POSSIBLE AT ALL TERMINALS DUE
TO SHOWERS AND LOW CLOUDS ASSOCIATED WITH A PASSING FRONT SUNDAY
AFTERNOON/EVENING, REMAINING POSSIBLE THROUGH TUESDAY.
MARINE
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS THE WATERS AS
DAYBREAK APPROACHES. WINDS ARE 41008 ARE STILL ELEVATED ENOUGH
THAT AN EXTENSION OF THE SMALL CRAFT ADVISORY FOR THE GEORGIA
OFFSHORE WATERS IS WARRANTED. THE ADVISORY HAS BEEN EXTENDED
UNTIL 10 AM, ALTHOUGH THIS MAY BE BE A BIT TOO LONG. THE
ADVISORY FOR THE GEORGIA NEARSHORE WATERS WILL BE ALLOWED TO
EXPIRE AT 7 AM.
THROUGH TONIGHT: NORTH WINDS WILL GRADUALLY DIMINISH ACROSS THE
WATERS TODAY THEN VEER TO THE NORTHEAST TONIGHT AS HIGH
PRESSURE MOVES INTO THE CENTRAL APPALACHIANS. SPEEDS WILL SETTLE
INTO THE 10-15 KT RANGE THIS AFTERNOON AND EVENING, THEN BEGIN
TO INCREASE BACK INTO THE 15-20 KT RANGE EARLY SATURDAY IN
RESPONSE TO A TIGHTENING PRESSURE GRADIENT AND THE DEVELOPMENT
OF A WEAK COASTAL TROUGH OFFSHORE. SEAS WILL SUBSIDE TO 2-4 FT
THIS AFTERNOON AND PERSIST INTO THE OVERNIGHT HOURS.
SATURDAY THROUGH TUESDAY: SURFACE HIGH PRESSURE TO THE NORTH
WILL KEEP THE SURFACE PRESSURE GRADIENT ELEVATED THROUGHOUT
SATURDAY, RESULTING IN SEMI-BREEZY NORTHEASTERLY WINDS. WINDS
LOOK TO REMAIN BELOW ADVISORY CRITERIA AT NEAR 20 KNOTS, BUT
SOMETHING TO KEEP AN EYE ON. MAY SEE SOME WEAK SHOWERS OR EVEN
AN ISOLATED THUNDERSTORM DEVELOP BY THE AFTERNOON ESPECIALLY
WELL OFFSHORE (40+NM OUT), WITH CHANCES FOR PERIODIC RAINFALL
CONTINUING THROUGHOUT THE DAY ON SUNDAY. WINDS WEAKEN ON SUNDAY,
BUT WILL BE INCREASING THROUGHOUT THE DAY ON MONDAY AS A COLD
FRONT APPROACHES THE AREA FROM THE WEST WITH RAINFALL CHANCES
SIMILARLY INCREASING THROUGHOUT THE DAY. A SURFACE LOW PRESSURE
IS EXPECTED TO TRAVERSE THE REGION ON TUESDAY, CONTINUING
CHANCES FOR SHOWERS AND SOME THUNDERSTORMS, WITH WINDS REMAINING
ELEVATED. WINDS CURRENTLY LOOK SUB-ADVISORY, BUT SEAS DO BEGIN
TO APPROACH/EXCEED 6 FEET ON TUESDAY.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR
AMZ374.
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