043
FXUS62 KCHS 271814
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
214 PM EDT MON OCT 27 2025
SYNOPSIS
LOW PRESSURE WILL MOVE AWAY FROM OUR REGION TONIGHT. WEAK HIGH
PRESSURE WILL BRIEFLY PREVAIL LATE TUESDAY INTO EARLY
WEDNESDAY, FOLLOWED BY A COLD FRONT WEDNESDAY NIGHT. HIGH
PRESSURE RETURNS THURSDAY AND PERSISTS INTO THE WEEKEND.
NEAR TERM /THROUGH TONIGHT/
AS A CLOSED UPPER-LVL LOW MEANDER OVER THE MISSISSIPPI VALLEY AND A
WEDGE OF HIGH PRESSURE CONTINUES TO PUSH DOWN THROUGH THE CAROLINAS
AND GEORGIA, A COASTAL LOW PRESSURE WILL CONTINUE TO DEVELOP OVER
THE NEARSHORE WATERS. THIS PATTERN WILL SUPPORT A PROLONGED PERIOD
OF LOW-LVL ISENTROPIC ASCENT AND COLD AIR DAMMING CONDITIONS. MODEL
GUIDANCE CONTINUES TO SUGGEST THAT SHOWERS WILL LIKELY INCREASE IN
COVERAGE ACROSS SE GA AND THE SC LOWCOUNTRY THROUGHOUT THE DAY.
THUS, EXPECT LIGHT TO MODERATE RAIN SHOULD CONTINUE ACROSS THE
REGION THROUGH THE AFTERNOON. AS THE COASTAL LOW TRACKS
NORTHEASTWARD OFF THE COASTLINE THIS EVENING, EXPECT RAINFALL TO
BECOME MORE MODERATE, WITH POSSIBLE EMBEDDED ISOLATED THUNDERSTORMS
WITHIN SOME BANDS. EXPECT 0.5 TO 1.0 INCHES INLAND WITH 1.5 TO 2.0
INCHES ACROSS THE COASTAL COUNTIES THROUGH TOMORROW MORNING. THESE
BREEZY NORTHEAST WINDS SHOULD PERSIST THROUGHOUT THE DAY, ALONG WITH
CLOUDY AND COOL CONDITIONS. DUE TO THE LACK OF SUNLIGHT,
TEMPERATURES WILL STRUGGLE TO REACH INTO THE MID TO UPPER 60S THIS
AFTERNOON. AS FOR TONIGHT, TEMPERATURES WILL DROP INTO THE LOW TO
MID 50S INLAND AND THEN MID TO UPPER 50S ALONG THE COASTLINE.
SHORT TERM /TUESDAY THROUGH THURSDAY/
TUESDAY: WEAK MID-LEVEL TROUGHING OVER THE SOUTHEAST U.S. IN THE
MORNING WILL DISSIPATE IN THE AFTERNOON. THEN, LARGE SCALE TROUGHING
WILL APPROACH FROM THE CENTRAL U.S. IN THE EVENING AND OVERNIGHT. A
STORM SYSTEM WITH ITS ASSOCIATED LOW PRESSURE WILL BE OFFSHORE EARLY
IN THE MORNING AND QUICKLY MOVING AWAY. THIS WILL ALLOW WEAK HIGH
PRESSURE TO BRIEFLY PREVAIL OVER OUR REGION LATER IN THE DAY AND
DURING THE OVERNIGHT HOURS. MOISTURE WILL TREND LOWER AS TIME
PROGRESSES, WITH PWATS BELOW 1" LATE IN THE DAY AND OVERNIGHT. QPF
SHOULD BE 0.5" OR LESS DURING THE DAY, WITH THE HIGHEST AMOUNTS
ACROSS THE CHARLESTON TRI-COUNTY AND THE LOWEST AMOUNTS NEAR THE
ALTAMAHA RIVER. N TO NE SURFACE WINDS ALONG WITH ABUNDANT CLOUD
COVER WILL KEEP HIGH TEMPERATURES BELOW NORMAL. HIGHS WILL GENERALLY
BE IN THE UPPER 50S TO 60S, WHILE LOWS WILL RANGE FROM THE MID 40S
FAR INLAND TO THE MID 50S AT AND NEAR THE BEACHES.
WEDNESDAY: THE MID-LEVELS WILL CONSIST OF A STRONG LONGWAVE TROUGH
OVER THE MS RIVER VALLEY IN THE MORNING. IT'LL MOVE TO THE EAST,
GENERALLY STRETCHING FROM THE GREAT LAKES REGION INTO THE DEEP SOUTH
OVERNIGHT. AT THE SURFACE, A STORM SYSTEM AND IT'S ASSOCIATED COLD
FRONT WILL BE APPROACHING FROM THE WEST AND NORTHWEST DURING THE
DAY. THE COLD FRONT WILL QUICKLY MOVE THROUGH OUR AREA DURING THE
EVENING HOURS, THEN ZOOM OFFSHORE OVERNIGHT. THE NBM HAS SLIGHT
CHANCE TO CHANCE POPS DURING THE DAY, INCREASING TO CHANCE IN THE
EVENING. THEY WILL TREND LOWER AFTER THE FRONTAL PASSAGE OVERNIGHT.
N TO NE SURFACE WINDS IN THE MORNING ALONG WITH ABUNDANT CLOUD COVER
WILL KEEP HIGH TEMPERATURES BELOW NORMAL. HIGHS WILL GENERALLY BE IN
THE MID 60S TO MAYBE LOWER 70S NEAR THE ALTAMAHA RIVER. LOWS WILL
RANGE FROM THE MID 40S FAR INLAND TO THE MID 50S AT AND NEAR THE
BEACHES.
THURSDAY: THE LONGWAVE MID-LEVEL TROUGH WILL MOVE OVER THE EAST
COAST. THE COLD FRONT WILL BE OFFSHORE IN THE MORNING AND QUICKLY
MOVING AWAY, WHILE THE PARENT LOW WILL BE MOVING TOWARDS NEW
ENGLAND. HIGH PRESSURE WILL BE BUILDING IN FROM SOUTHERN PLAINS,
WITH ITS PERIPHERY STRETCHING INTO OUR REGION. THE HIGH WILL BRING
OUR AREA DRY CONDITIONS WITH GRADUALLY CLEARING SKIES. WINDS COULD
BE BREEZY FROM THE WEST. HIGHS WILL BE IN THE 60S.
LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/
HIGH PRESSURE WILL PREVAIL INTO THE WEEKEND, BRINGING DRY
CONDITIONS. TEMPERATURES WILL BE SEVERAL DEGREES BELOW NORMAL.
FRIDAY NIGHT IS FORECASTED TO BE THE COLDEST OF THE PERIOD AND FROST
CANNOT BE RULED OUT FAR INLAND.
AVIATION /18Z MONDAY THROUGH SATURDAY/
18Z TAFS: LOW-LVL MVFR CEILINGS WITH TEMPO IFR CEILINGS WILL
CONTINUE OVER THROUGH THE AFTERNOON AS THE SURFACE HIGH PRESSURE
CONTINUES TO WEDGE ACROSS THE REGION AND THIS AREA OF LOW PRESSURE
DEVELOPS OFFSHORE. THIS PATTERN SHOULD SUPPORT A PROLONGED PERIOD OF
LOW-LVL ISENTROPIC LIFT. FOR KCHS/KJZI, EXPECT IFR VISIBILITIES AND
CEILINGS BY 20Z AND CONTINUING INTO TUESDAY MORNING. AS FOR KSAV,
IFR VISIBILITIES AND CEILINGS BEGIN A LITTLE LATER AT 02Z AND ALSO
CONTINUE INTO TUESDAY MORNING. THERE IS A MENTION OF -RA AND BR
AT ALL TERMINALS THROUGH THE TAF PERIOD. NORTHEASTERLY WINDS
SHOULD PERSIST THROUGH THE OVERNIGHT WITH SPEEDS AROUND 10 TO 15
KTS AND GUSTS UP TO 20 TO 25 KTS (ESP. FOR KCHS/KJZI).
EXTENDED AVIATION OUTLOOK: LOW CEILINGS ASSOCIATED WITH A WEDGE OF
HIGH PRESSURE COULD BRING FLIGHT RESTRICTIONS LATE TUESDAY AND
WEDNESDAY. SHOWERS ASSOCIATED WITH A COLD FRONT COULD BRING SOME
FLIGHT RESTRICTIONS WEDNESDAY NIGHT. VFR WILL RETURN ON
THURSDAY.
MARINE
THROUGH TONIGHT: BREEZY EAST-NORTHEASTERLY WINDS BETWEEN 15 TO 20
KTS WITH GUSTS UP TO 25 TO 30 KTS. AS THE COASTAL LOW FORMS AND
TRACKS NORTHEASTWARD OVER THE WATERS, EXPECT AN INCREASE OF ONSHORE
WINDS WITH RISING WINDSWELL. LIGHT TO MODERATE SHOWERS WILL CONTINUE
THROUGH THE AFTERNOON INTO THE OVERNIGHT, WITH THE CHANCE FOR SOME
ISOLATED THUNDERSTORMS AS WEAK ELEVATED INSTABILITY PERSISTS
OVER THE ATLANTIC. SEAS WILL RANGE FROM 6 TO 8 FT THIS
AFTERNOON, AND THEN INCREASE TO 6 TO 10 FT IN THE NEARSHORE
CHARLESTON WATERS, WHILE DECREASING 5 TO 7 FT IN THE NEARSHORE
AND OUTER GEORGIA WATERS BY THIS EVENING. SMALL CRAFT ADVISORIES
WILL REMAIN IN EFFECT FOR ALL MARINE ZONES THROUGHOUT THE
PERIOD.
TUESDAY THROUGH FRIDAY: LOW PRESSURE WILL BE MOVING AWAY FROM
OUR REGION ON TUESDAY. WEAK HIGH PRESSURE WILL BRIEFLY PREVAIL
LATE TUESDAY INTO EARLY WEDNESDAY. A COLD FRONT WILL QUICKLY
MOVE THROUGH WEDNESDAY NIGHT. HIGH PRESSURE RETURNS THURSDAY AND
PERSISTS INTO THE WEEKEND. ADDITIONALLY, TC MELISSA WILL BE
PASSING WELL OFFSHORE LATER THIS WEEK. THIS COMPLEX SYNOPTIC
PATTERN WILL BRING ELEVATED WINDS AND SEAS TO OUR COASTAL
WATERS, WHICH IS WHY THERE ARE SMALL CRAFT ADVISORIES IN EFFECT.
THEY WILL EXPIRE AT VARIOUS DAYS/TIMES THIS WEEK. SEE THE MWW
FOR MORE DETAILS.
RIP CURRENTS: THE COMBINATION OF GUSTY NE WINDS AND ELEVATED SWELL
WILL BRING A HIGH RISK OF RIP CURRENTS TO ALL OF OUR BEACHES THROUGH
TUESDAY AND A MODERATE RISK ON WEDNESDAY.
TIDES/COASTAL FLOODING
CHARLESTON TIDE GAGE: DUE TO INCREASING NORTHEASTERLY FLOW
THERE IS A RISK OF MINOR COASTAL FLOODING WITH THE LATE
MORNING/EARLY AFTERNOON HIGH TIDES THROUGH MID-WEEK. THE
CURRENT FORECAST FEATURES A FORECAST OF 6.8 FT MLLW FOR TUESDAY AND
TUESDAY, WITH 6.9 FT MLLW ON WEDNESDAY. COASTAL FLOOD ADVISORIES MAY
BE NEEDED.
CLIMATE
RECORD PRECIPITATION:
OCTOBER 27:
KCHS: 1.07/2006
KCXM: 1.49/1985
KSAV: 2.22/1888
CHS WATCHES/WARNINGS/ADVISORIES
GA...HIGH RISK FOR RIP CURRENTS THROUGH TUESDAY EVENING FOR GAZ117-119-
139-141.
SC...HIGH RISK FOR RIP CURRENTS THROUGH TUESDAY EVENING FOR SCZ048>051.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR AMZ330.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT FRIDAY FOR AMZ350.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR AMZ352-354.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT FRIDAY FOR AMZ374.
NEAR TERM...DENNIS
SHORT TERM...
LONG TERM...
AVIATION...DENNIS
MARINE...DENNIS
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