080
FXUS62 KCHS 260021
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
821 PM EDT SAT OCT 25 2025
SYNOPSIS
HIGH PRESSURE WILL PREVAIL THROUGH THE WEEKEND. AN UPPER
DISTURBANCE AND COMPLEX SURFACE FRONTAL SYSTEM WILL IMPACT THE
AREA LATE SUNDAY THROUGH MONDAY NIGHT. A STRONG COLD FRONT
COULD MOVE THROUGH DURING THE MIDDLE OF NEXT WEEK BEFORE HIGH
PRESSURE RETURNS LATE WEEK INTO NEXT WEEKEND.
NEAR TERM /UNTIL 6 AM SUNDAY MORNING/
THIS EVENING: OVERALL, ANOTHER QUIET NIGHT IS EXPECTED. SURFACE
ANALYSIS SHOWS THAT EXPANSIVE HIGH PRESSURE WILL REMAIN IN
CONTROL ACROSS THE EASTERN US, WITH A SHARPENING COASTAL TROUGH
JUST OFF THE SC/GA COAST. SATELLITE IMAGERY SHOWS A NICE
RESERVOIR OF STRATOCUMULUS OFFSHORE ON THE EAST SIDE OF THE
COASTAL TROUGH, WITH PLENTIFUL DRY AIR WEST OF THE TROUGH AXIS
WHERE PRECIPITABLE WATER VALUES ARE DOWN AROUND HALF AN INCH.
MODEL GUIDANCE DOES FAVOR THE COASTAL TROUGH PUSHING CLOSER TO
THE COAST THROUGH THE NIGHT, WITH POTENTIALLY EVEN A BIT OF
SHOWER ACTIVITY ALONG IT. HOWEVER, CURRENT THINKING IS THAT THE
DRY AIR WILL WIN OUT AND KEEP THE FORECAST DRY FOR THE COAST
THROUGH SUNRISE. THE PRESSURE GRADIENT SHOULD BE TIGHT ENOUGH TO
MAINTAIN 5-10 MPH OF NORTHEAST WIND THROUGH THE NIGHT,
ESPECIALLY ALONG THE COAST. THIS COMBINED WITH MORE CLOUD COVER
SHOULD PREVENT IDEAL RADIATIONAL COOLING CONDITIONS AND KEEP
TEMPERATURES WARMER. LOWS COULD STILL DIP INTO THE UPPER 40S
INLAND, BUT SHOULD HOVER MORE IN THE UPPER 50S AND EVEN LOW 60S
ALONG THE IMMEDIATE COAST.
SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/
SUNDAY: AS THIS CLOSED UPPER-LVL LOW SITUATED OVER THE SOUTHERN
PLAINS TRAVELS EASTWARD TOWARDS THE REGION, IT WILL SLOWLY
BECOME ABSORBED INTO THE BACKGROUND WESTERLY FLOW THROUGHOUT THE
DAY. AHEAD OF THIS SYSTEM, MOISTURE WILL ADVECT BACK INTO THE
REGION AS THIS LOW TRAVELS ALONGSIDE A STALLED FRONTAL BOUNDARY.
EXPECT CLOUDS TO ALSO FILL INTO THE REGION THROUGH THE MORNING,
ALONG WITH A CHANCE FOR SOME SPRINKLES IN THE AFTERNOON AS
AFOREMENTIONED STALLED FRONT TRIES LIFT NORTHWARDS ACROSS THE
REGION AS A WARM FRONT. IT'S UNLIKELY THERE WILL BE MEASURABLE
RAINFALL IN THE AFTERNOON AS THE MID-LVLS REMAIN FAIRLY DRY.
HEADING INTO SUNDAY EVENING, PRECIPITATION CHANCES INCREASE
SIGNIFICANTLY FROM SOUTH TO NORTH ALONG THE COASTLINE AS THIS
AFOREMENTIONED LOW BEGINS TO RE- STRENGTHEN OFF OF THE
COASTLINE. EXPECT LIGHT TO MODERATE SHOWERS TO DEVELOP OVERNIGHT
AND CONTINUE INTO MONDAY. TEMPERATURES WILL TREND A BIT COOLER
ON SUNDAY AS INCREASING CLOUD COVER WILL INHIBIT SURFACE
HEATING. FORECAST NOTES HIGHS ONLY REACHING INTO THE LOW TO MID
70S, AND OVERNIGHT LOWS IN THE MID TO UPPER 50S ACROSS THE
INLAND COUNTIES WITH LOW 60S ALONG THE IMMEDIATE COASTLINE.
MONDAY AND TUESDAY: AT THE SURFACE, THIS AFOREMENTIONED LOW
WILL SHIFT OFFSHORE AND THEN RE-STRENGTHEN OFF THE SOUTHEAST
COASTLINE THROUGHOUT MONDAY MORNING. THERE STILL REMAINS SOME
UNCERTAINTY REGARDING THE EXACT POSITION OF THE LOW, HOWEVER
THERE IS INCREASING CONFIDENCE THAT WIDESPREAD LIGHT TO MODERATE
RAINFALL WILL PERSIST THROUGHOUT MONDAY AND INTO TUESDAY
MORNING. PREDICTED TOTAL RAINFALL AMOUNTS REMAIN AROUND 1-1.5
INCHES FOR MONDAY THROUGH TUESDAY MORNING. THERE IS POTENTIAL
FOR LOCALIZED HIGHER RAINFALL AMOUNTS, WITH THE PROB. FOR >2
INCHES IN 24 HOURS AROUND 30-40%. THIS PROB. COULD INCREASE IF
THE FUTURE MODEL CONSENSUS POSITIONS THE LOW DEVELOPING CLOSER
TO THE COASTLINE. IN ADDITION TO THE RAINFALL, NORTHEASTERLY
WINDS WILL CONTINUE TO INCREASE THROUGHOUT THE DAY ON MONDAY AS
THE LOCAL PRESSURE GRADIENT REMAINS PINCHED. EXPECT WINDS TO
SHIFT MORE NORTHERLY ON TUESDAY, BUT REMAIN ELEVATED AS THE
REGION REMAINS POSITIONED BETWEEN STRENGTHENING HIGH PRESSURE TO
THE NORTH AND THIS OFFSHORE DEVELOPING LOW. LUCKILY,
PRECIPITATION CHANCES WILL DECREASE TO 20-30% ON TUESDAY AS THIS
LOW SHIFTS NORTHEASTWARD UP THE COASTLINE. TEMPERATURES WILL
YET AGAIN TREND ON THE COOLER SIDE AS HIGHS WILL ONLY REACH INTO
THE MID TO UPPER 60S ON MONDAY, AND LOW TO MID 60S ON TUESDAY.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
A BIT OF UNCERTAINTY REMAINS IN THE FORECAST THROUGH THE
EXTENDED AS THIS UPPER-LVL CUT-OFF LOW EMERGES FROM THE CENTRAL
US THROUGH THE MID-WEEK. A STRONG, COLD FRONT COULD POTENTIALLY
PASS THROUGH THE REGION ON THURSDAY WITH ANOTHER ROUND OF
SHOWERS POSSIBLE ON WEDNESDAY AHEAD OF THE FRONT. BEHIND THE
FRONT, EXPECT A COOL, DRY AIRMASS TO BUILD IN FROM BEHIND AS
NORTH-NORTHWESTERLY FLOW TAKES CONTROL. EXPECT TEMPERATURES TO
RANGE FROM LOW TO MID 60S WITH SOME SPOTS IN SE GEORGIA REACHING
INTO THE UPPER 60S. THERE IS A SMALL CHANCE (<20%) OF FROST ON
FRIDAY AND SATURDAY MORNING AS LOWS DROP INTO THE UPPER 30S
ACROSS THE INLAND COUNTIES.
AVIATION /00Z SUNDAY THROUGH THURSDAY/
OVERALL, VFR CONDITIONS ARE EXPECTED TO PREVAIL AT KCHS, KJZI,
AND KSAV THROUGH 00Z MONDAY. WE DO EXPECT TO SEE LOW-LEVEL CLOUD
COVERAGE INCREASE LATER IN THE TAF PERIOD, WITH EVEN SOME LOW
END POTENTIAL FOR MVFR CEILINGS NEAR THE END OF THE DAY AT KSAV.
NORTHEAST WINDS WILL AGAIN BE ELEVATED AND BREEZY AT TIMES, WITH
GUSTS INTO THE 15-20 KNOT RANGE.
EXTENDED AVIATION FORECAST: WIDESPREAD RAINFALL IS EXPECTED
MONDAY, BRINGING THE POTENTIAL FOR ADDITIONAL FLIGHT
RESTRICTIONS. THE FORECAST BECOMES LESS CERTAIN AS WE MOVE INTO
MID-WEEK, WITH ADDITIONAL AND PROLONGED FLIGHT RESTRICTIONS IN
SUB-VFR CEILINGS REMAINING POSSIBLE.
MARINE
TONIGHT: HIGH PRESSURE CENTERED ACROSS THE MID-ATLANTIC STATES
AND A WEAK INVERTED TROUGH NEAR THE GULF STREAM WILL PLACE A
RATHER ENHANCED PRESSURE GRADIENT ALONG WITH A 1000 MB
GEOSTROPHIC WIND AROUND 30 KT ACROSS LOCAL WATERS THROUGHOUT THE
DAY AND NIGHT. THE PATTERN SHOULD SUPPORT EAST-NORTHEAST WINDS
BETWEEN 15-20 KT WITH GUSTS TO AROUND 25 KT FOR LOCAL WATERS
OUTSIDE THE CHARLESTON HARBOR THIS AFTERNOON WITH A SLIGHT
UPTICK IN WIND SPEEDS OVERNIGHT. SEAS WILL ALSO BUILD FROM 3-5
FT TO 4-6 FT LATE DAY AND OVERNIGHT. SMALL CRAFT ADVISORIES WILL
REMAIN IN EFFECT FOR ALL WATERS OUTSIDE THE CHARLESTON HARBOR
THROUGH THE NIGHT.
SUNDAY THROUGH WEDNESDAY: BREEZY NORTHEASTERLY WINDS WILL
PERSIST THROUGH AT LEAST THE MIDDLE OF THE WEEK AS THIS LOW
TRIES TO DEVELOP OFF THE IMMEDIATE COASTLINE OVERNIGHT ON SUNDAY
INTO MONDAY MORNING. THEREFORE, SMALL CRAFT ADVISORIES HAVE
BEEN ISSUED FOR ALL MARINE ZONES UNTIL FURTHER NOTICE. WIND
SPEEDS WILL GENERALLY RANGE FROM 20 TO 25 KT WITH GUSTS UP TO 30
KT POSSIBLE. ADDITIONALLY, SEAS WILL RANGE FROM 5 TO 8 FT AS A
POWERFUL SWELL FROM TC MELISSA BEGINS TO BUILD INTO THE LOCAL
WATERS.
RIP CURRENTS: THERE IS A MODERATE RISK FOR RIP CURRENTS FOR
SOUTH CAROLINA BEACHES AND A HIGH RISK OF RIP CURRENTS FOR THE
GEORGIA BEACHES ON SUNDAY. IT'S LIKELY THERE WILL BE AN ENHANCED
RISK ON MONDAY INTO NEXT WEEK DUE A COMBINATION OF INCREASING
WINDS AND SEAS.
CHS WATCHES/WARNINGS/ADVISORIES
GA...HIGH RISK FOR RIP CURRENTS FROM 8 AM EDT SUNDAY THROUGH SUNDAY
EVENING FOR GAZ117-119-139-141.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR AMZ350-352-
354-374.
NEAR TERM...BSH
SHORT TERM...DENNIS
LONG TERM...DENNIS
AVIATION...BSH/DENNIS
MARINE...DENNIS/DPB
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