582
FXUS62 KCHS 091759
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1259 PM EST SUN NOV 9 2025
...NEAR RECORD COLD AND A WIDESPREAD FREEZE MONDAY NIGHT WITH
WIND CHILLS DROPPING INTO THE UPPER TEENS TO MID 20S -- FREEZE
WARNING ISSUED...
SYNOPSIS
A STRONG COLD FRONT WILL MOVE THROUGH TONIGHT, BRINGING MUCH
COLDER CONDITIONS TO THE AREA THIS WEEK. HIGH PRESSURE WILL
BUILD INTO THE REGION THROUGH THE REMAINDER OF THE WEEK.
NEAR TERM /THROUGH TONIGHT/
THIS AFTERNOON: THE OVERALL FORECAST THINKING HAS NOT CHANGED
SINCE THE UPDATE THIS MORNING. NEAR TERM GUIDANCE COUPLED WITH
THE 09/12Z HREF CONTINUES TO SHOW A MORE CONSOLIDATED SIGNAL
FOR A LOCAL ENHANCEMENT OF SHOWERS/TSTMS ACROSS THE COASTAL
CORRIDOR FROM LATE THIS AFTERNOON INTO THIS EVENING AHEAD OF THE
STRONG COLD FRONT. MODEL CROSS SECTIONS SHOW A CORRIDOR OF
STRONG UVVS BETWEEN 850-500 HPA DURING THIS TIME, LIKELY IN
RESPONSE TO THE APPROACH OF 700 HPA SHORTWAVE AND ASSOCIATED
SPEED MAX OVER THE MIDLANDS. ALTHOUGH INSTABILITY LOOKS ONLY
MARGINALLY FAVORABLE GIVEN THE TIME OF DAY, THE LACK OF
INSTABILITY COULD BE OVERCOME BY INCREASING QUASI-GEOSTROPIC
FORCING AHEAD OF THE SHORTWAVE. POPS WERE INCREASED FURTHER TO
60% ACROSS THE COASTAL CORRIDOR TO HELP TREND THE FORECAST, BUT
THIS IS STILL SOMEWHAT LOWER THAN SOME GUIDANCE WOULD SUGGEST.
FURTHER ADJUSTMENTS MAY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT.
STRONG WIND FIELDS AND LOWER TEMPERATURES ALOFT SUGGEST THERE
WILL BE A RISK FOR LARGE HAIL AND DAMAGING WINDS, BUT THE
ABSENCE OF STRONG INSTABILITY SUGGESTS THE SEVERE WEATHER RISK
WILL LIKELY REMAIN SOMEWHAT ISOLATED. HOWEVER, WIND FIELDS ARE
SUPPORTIVE OF SUPERCELLS, ESPECIALLY IF LOCALIZED CORRIDORS OF
HIGHER INSTABILITY CAN BE REALIZED. THE SEVERE WEATHER RISK
LOOKS HIGHEST BETWEEN 5-10PM.
OVERNIGHT: THE SURFACE COLD FRONT IS POISED TO PUSH OFFSHORE BY
MID-EVENING WITH THE ONSET OF STRONGER POST-FRONTAL COLD AIR
ADVECTION OCCURRING WITH THE PASSAGE OF THE 850 HPA FRONT A FEW
HOURS AFTER THAT. THE BULK OF THE SHOWER/TSTM ACTIVITY WILL
PUSH OFFSHORE WITH THE SURFACE FRONT, BUT A BROKEN LINE OF
SHOWERS COULD SWING THROUGH ALONG THE 850 HPA FRONT ITSELF. NEAR
TERM POPS WERE ADJUSTED SLIGHTLY TO BETTER REFLECT THIS IDEA.
GUSTY NORTHWEST WINDS WILL PREVAIL THROUGH THE DAYBREAK OWING TO
STRONG COLD AIR ADVECTION. 850 HPA TEMPERATURES WILL DROP FROM
+10 TO +12C TO 0 TO +5C BY DAYBREAK MONDAY AS SKIES STEADILY
CLEAR. LOWS WILL RANGE FROM THE UPPER 30S ACROSS FAR INTERIOR
SOUTHEAST GEORGIA TO MID-UPPER 40S ACROSS CHARLESTON COUNTY AND
ALONG THE IMMEDIATE GEORGIA AND FAR LOWER SOUTH CAROLINA COAST.
LAKE WINDS: WINDS ON LAKE MOULTRIE ARE EXPECTED TO INCREASE TO
15-20 KT OVERNIGHT WITH THE ONSET OF STRONG COLD AIR ADVECTION
BEHIND A COLD FRONT. GUSTS COULD APPROACH 25 KT AT TIMES, BUT
DURATIONS ARE UNCERTAIN. NBM/HREF WIND GUST PROBABILITIES FOR
GUSTS 25 KT OR GREATER ARE QUITE LOW, SO A LAKE WIND ADVISORY
WAS NOT ISSUED FOR THE OVERNIGHT PERIOD. TRENDS WILL BE
CAREFULLY MONITORED.
SHORT TERM /MONDAY THROUGH WEDNESDAY/
A STRONG COLD AIR ADVECTION REGIME WILL SET UP ON MONDAY AS
HIGH PRESSURE BUILDS IN AT THE SURFACE BEHIND THE DEPARTING COLD
FRONT AND AN ANOMALOUSLY DEEP MID-LEVEL TROUGH DOMINATES ALOFT.
MONDAY'S HIGH TEMPERATURES ARE FORECAST TO ONLY REACH INTO THE
LOW TO MID 50S, WHICH DESPITE PLENTIFUL SUNSHINE, WILL LIKELY
FEEL A TAD COOLER DUE TO THE GUSTY NW WINDS. GUSTY NW WINDS ARE
FORECAST TO DEVELOP ACROSS THE REGION MONDAY AFTERNOON,
GENERALLY IN THE 20 TO 25 MPH RANGE. A LAKE WIND ADVISORY HAS
BEEN ISSUED FOR LAKE MOULTRIE FROM MONDAY AFTERNOON INTO EARLY
TUESDAY MORNING. THE MAIN FORECAST HIGHLIGHT WILL BE MONDAY
NIGHT AS TEMPERATURES PLUMMET INTO THE LOW 20S INLAND, WITH
FREEZING TEMPERATURES LIKELY ALMOST TO THE BEACHES. THESE LOW
TEMPERATURES WILL CHALLENGE THE RECORD LOW TEMPERATURES AT ALL
THREE CLIMATE SITES - SEE CLIMATE SECTION FOR MORE DETAILS. A
FREEZE WARNING HAS BEEN ISSUED FOR THE ENTIRE FORECAST AREA AS
CONFIDENCE REMAINS HIGH IN A WIDESPREAD FREEZE OCCURRING MONDAY
NIGHT. ADDITIONALLY, BREEZY CONDITIONS OVERNIGHT AND INTO
TUESDAY MORNING WILL YIELD WIND CHILL VALUES IN THE UPPER TEENS
TO AROUND 20, ESPECIALLY ACROSS INLAND ZONES. A COLD WEATHER
ADVISORY MAY BE REQUIRED FOR A PORTION OF THE FORECAST AREA,
MAINLY WEST OF I-95.
NOT MUCH CHANGE IN THE SYNOPTIC SET UP ON TUESDAY, WITH CAA
STILL DOMINATING DUE TO THE ANOMALOUSLY DEEP MID-LEVEL TROUGH.
HIGH TEMPERATURES ON TUESDAY WILL LIKELY STRUGGLE TO GET OUT OF
THE LOW 50S, WITH SOME LOCATIONS MAYBE NOT MAKING IT OUT OF THE
40S. THE GUSTY NW WINDS SEEN ON MONDAY WILL DIMINISH TO ONLY
AROUND 15 MPH TUESDAY AFTERNOON. ANOTHER CHILLY NIGHT IS
EXPECTED TUESDAY NIGHT, AS WINDS CONTINUE TO DIMINISH AND SKIES
REMAIN CLEAR. A VERY NICE RADIATIONAL COOLING SET UP IS
FORECAST, YIELDING LOW TEMPERATURES IN THE UPPER 20S INLAND AND
UPPER 30S TO NEAR 40 ALONG THE COASTLINE.
THE MID-LEVEL TROUGH WILL PUSH OFF THE EASTERN SEABOARD
OVERNIGHT TUESDAY INTO WEDNESDAY, TRANSITIONING INTO A ZONAL
FLOW ALOFT ON WEDNESDAY. AT THE SURFACE THE CENTER OF HIGH
PRESSURE WILL BE OVER THE SOUTHEASTERN STATES. TEMPERATURES WILL
REACH BACK UP INTO THE MID 60S, THOUGH STILL A TICK BELOW
NOVEMBER NORMALS. A RAIN FREE FORECAST HAS BEEN MAINTAINED AS
HIGH PRESSURE DOMINATES.
LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/
ZONAL FLOW WILL DOMINATE ALOFT MID-WEEK, WITH BROAD RIDGING
DEVELOPING LATE WEEK. AT THE SURFACE HIGH PRESSURE WILL PREVAIL,
YIELDING A DRY FORECAST THROUGH THE PERIOD. TEMPERATURES WILL
RETURN TO NEAR NORMAL ON THURSDAY AND ARE FORECAST TO REMAIN
NEAR NORMAL INTO THE WEEKEND.
AVIATION /15Z SUNDAY THROUGH THURSDAY/
09/18Z TAF DISCUSSION:
KCHS/KJZI/KSAV: THE RISK FOR TSTM IMPACTS WILL INCREASE BY LATE
AFTERNOON AND CONTINUE THROUGH MID-EVENING BEFORE A COLD FRONT
SHIFTS OFFSHORE. RISK LOOKS GREATEST 00-03Z AT KCHS AND KJZI AND
23-02Z AT KSAV. SOME SHOWERS WILL LIKELY LINGER AFTER THIS UNTIL
FROPA BY LATE EVENING/VERY EARLY MONDAY MORNING. GUSTY NORTHWEST
WINDS WILL PREVAIL AFTER FROPA AND PERSIST INTO 18Z MONDAY.
EXTENDED AVIATION OUTLOOK: GUSTY NW WINDS 20 TO 25 KT ARE FORECAST
MONDAY AFTERNOON INTO MONDAY EVENING. OTHERWISE, PREVAILING
VFR.
MARINE
TONIGHT: SOUTHWEST WINDS WILL TURN WEST AND EVENTUALLY NORTHWEST
LATER THIS EVENING AND OVERNIGHT A STRONG COLD FRONT PUSHES
THROUGH THE COASTAL WATERS. WINDS ARE EXPECTED TO SURGE TO 20-25
KT BEHIND THE FRONT WITH 15-20 KT IN THE CHARLESTON HARBOR AS
COLD AIR ADVECTION INTENSIFIES. SMALL CRAFT ADVISORIES HAVE BEEN
EXTENDED NORTH IN THE SOUTH SANTEE-EDISTO BEACH NEARSHORE LEG
AND ARE NOW IN EFFECT FOR ALL AREAS OVERNIGHT WITH THE EXCEPTION
OF CHARLESTON HARBOR. GUSTS COULD GET CLOSE TO 25 KT IN THE
CHARLESTON HARBOR AFTER MIDNIGHT, ESPECIALLY NEAR THE HARBOR
ENTRANCE WHERE THE FETCH WILL BE THE LONGEST, BUT IT IS UNCLEAR
IF DURATIONS WILL BE ENOUGH TO SUPPORT A SMALL CRAFT ADVISORY.
SEAS WILL BUILD TO 3-4 FT NEARSHORE WATERS AWAY FROM THE
BEACHES TO 4-6 FT OVER THE GEORGIA OFFSHORE WATERS.
MONDAY THROUGH THURSDAY: IN THE WAKE OF A STRONG COLD FRONT
GUSTY NW WINDS WILL DEVELOP ACROSS THE MARINE ZONES AS HIGH
PRESSURE BUILDS INTO THE REGION. A GALE WATCH IS IN EFFECT FOR
ALL WATERS OUTSIDE OF THE CHARLESTON HARBOR, WHERE A SMALL CRAFT
ADVISORY IS IN PLACE. WIND GUSTS AROUND 35 KNOTS ARE FORECAST
MONDAY AFTERNOON INTO EARLY TUESDAY MORNING (25 KNOTS IN THE
CHARLESTON HARBOR). SEAS ARE FORECAST TO BUILD, PEAKING MONDAY
NIGHT AROUND 4 TO 6 FT IN THE NEARSHORE WATERS AND 7 TO 9 FT IN
THE 20 TO 60 NM OFFSHORE GA WATERS. THE CENTER OF HIGH PRESSURE
MEANDERS CLOSER TO THE LOCAL WATERS MID-WEEK, WITH WINDS
DIMINISHING TO 10 TO 15 KNOTS ON TUESDAY AND SEAS AVERAGING 1 TO
3 FT. THE REMAINDER OF THE PERIOD IS FORECAST TO REMAIN BELOW
SMALL CRAFT ADVISORY CRITERIA.
FIRE WEATHER
SOME FIRE WEATHER CONCERNS EXIST FOR BOTH MONDAY AND TUESDAY AS RH
VALUES DROP TO AROUND 30% ON MONDAY AND 25% ON TUESDAY.
ADDITIONALLY, NW WIND GUSTS ON MONDAY ARE FORECAST TO BE AROUND 20
TO 25 MPH, WITH GUSTS TO AROUND 15 MPH ON TUESDAY. SOME BENEFICIAL
RAINFALL IS POSSIBLE SUNDAY AFTERNOON WHICH WOULD HELP ALLEVIATE SOME
CONCERNS. AT THIS TIME, PARTNERS INDICATE FUELS ARE NOT DRY
ENOUGH FOR AN ELEVATED FIRE DANGER AT THIS TIME.
CLIMATE
MONDAY NIGHT'S FREEZE WILL NOT BE THE EARLIEST ON RECORD FOR ALL
THREE CLIMATE SITES. BELOW ARE THE RECORDS FOR INFORMATIONAL
PURPOSES.
KCHS: OCTOBER 25, 1937
KCXM: NOVEMBER 3, 1954
KSAV: OCTOBER 27, 1962
UPCOMING RECORD LOW TEMPERATURES:
NOVEMBER 11 (TUESDAY):
KCHS: 29/1943
KCXM: 32/1913
KSAV: 31/1968
NOVEMBER 12 (WEDNESDAY):
KCHS: 27/1943
KCXM: 33/1894
KSAV: 30/2011
UPCOMING RECORD LOW MAXIMUM TEMPERATURES:
NOVEMBER 10 (MONDAY):
KCHS: 46/1991
KCXM: 47/1991
KSAV: 49/1968
NOVEMBER 11 (TUESDAY):
KCHS: 54/1968
KCXM: 46/1913
KSAV: 49/1913
CHS WATCHES/WARNINGS/ADVISORIES
GA...FREEZE WARNING FROM 9 PM MONDAY TO 9 AM EST TUESDAY FOR GAZ087-
088-099>101-114>119-137>141.
SC...FREEZE WARNING FROM 9 PM MONDAY TO 9 AM EST TUESDAY FOR SCZ040-
042>045-047>052.
LAKE WIND ADVISORY FROM 5 PM MONDAY TO 4 AM EST TUESDAY FOR
SCZ045.
MARINE...SMALL CRAFT ADVISORY FROM 3 PM MONDAY TO 7 AM EST TUESDAY FOR
AMZ330.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 4 PM EST MONDAY
FOR AMZ350-352-354.
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
AMZ350-352-354-374.
SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 4 PM EST MONDAY
FOR AMZ374.
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