437
FXUS62 KCHS 181747
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1247 PM EST TUE NOV 18 2025
SYNOPSIS
DRY HIGH PRESSURE IS EXPECTED TO PREVAIL ACROSS THE AREA
THROUGH THE WEEK. A COLD FRONT IS EXPECTED TO MOVE THROUGH THIS
WEEKEND.
NEAR TERM /THROUGH TONIGHT/
THE MID-LEVELS WILL CONSIST OF A SHORTWAVE PASSING TO OUR NORTH THIS
EVENING AND OVERNIGHT. THOUGH, ZONAL FLOW SHOULD PREVAIL OVERHEAD
THROUGH THIS EVENING, THEN TRANSITION TO WNW FLOW AFTER MIDNIGHT. AT
THE SURFACE, WEAK COASTAL TROUGH AXIS REMAINS OFF THE COAST THIS
AFTERNOON, PUSHING INLAND QUICKLY THIS EVENING IN RESPONSE TO HIGH
PRESSURE SLIDING OFF THE MID-ATLANTIC COAST. SEVERAL HOURS OF WEAK
ONSHORE FLOW OVERNIGHT WILL RESULT IN MODEST MOISTURE POOLING ALONG
THE COAST. WHILE SOME LOW LEVEL CLOUDS LIKELY LINGER, THERE WILL BE
ENOUGH BREAKS TO PROMOTE EFFICIENT RADIATIONAL COOLING, AND PATCHY
TO AREAS OF FOG ARE EXPECTED ALONG THE COAST, WITH PATCHY, LIGHT FOG
POSSIBLE ELSEWHERE. THERE IS A 30-40% CHANGE ALONG MUCH OF THE HWY
70 CORRIDOR NEAR AND SOUTH OF CHARLESTON FOR AT LEAST PATCHY DENSE
FOG OVERNIGHT, AND A DENSE FOG ADVISORY MAY BE NEEDED, INCLUDING FOR
LOCATIONS AROUND THE SAVANNAH METRO, BY DAYBREAK WEDNESDAY.
SHORT TERM /WEDNESDAY THROUGH FRIDAY/
WEDNESDAY: ALOFT, A SHORTWAVE SITUATED ACROSS THE BLUEGRASS STATE
WILL SLOWLY WEAKEN AS IT APPROACHES THE MID-ATLANTIC COASTLINE AND A
STRONG UPPER-LVL RIDGE WILL BUILD IN LOCALLY FROM FROM THE WEST.
SIMULTANEOUSLY, AN ASSOCIATED FRONT WILL MOVE IN TANDEM WITH THE
SHORTWAVE, BUT IT IS EXPECTED TO REMAIN NORTH OF THE REGION. AT THE
SURFACE, HIGH PRESSURE WILL BE PRESENT ACROSS THE SOUTHEAST WITH
DEEP LAYER SUBSIDENCE USHERING US INTO A PERIOD OF WELL ABOVE NORMAL
TEMPS.
850 MB TEMPS REACH 1.5 TO 2 STANDARD DEVIATIONS ABOVE NORMAL BY
WEDNESDAY AFTERNOON, BRINGING HIGHS 10-15 DEG ABOVE NORMAL, IN THE
UPPER 70S TO LOWER 80S (AWAY FROM THE BEACHES, WHERE A SEA BREEZE IS
LIKELY). SUCH VALUES WOULD STILL BE SEVERAL DEGREES BELOW
RECORDS, BUT NOTABLY WARM FOR MID NOVEMBER NONETHELESS.
THURSDAY AND FRIDAY: A STRONG UPPER-LVL RIDGE WITH NEARLY 590 DM
WILL BE PRESENT OVER THE GULF ON THURSDAY AND FRIDAY, AS A SURFACE
LOW DEVELOPS ACROSS THE CENTRAL CONUS. EXPECT TEMPERATURES TO REMAIN
WELL ABOVE NORMAL WITH A RAIN-FREE FORECAST. HIGH TEMPERATURES
THURSDAY AND FRIDAY WILL REACH NEAR RECORD HIGHS (SEE CLIMATE
SECTION), WITH LOW 80S ACROSS THE SC LOWCOUNTRY TO THE LOW TO MID
80S ACROSS SE GA.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/
EXPECT UPPER-LVL RIDGING TO BECOME SUPPRESSED AS A PROGRESSIVE
SHORTWAVE APPROACHES THE REGION ON SATURDAY, AND AN ASSOCIATED COLD
FRONT PASSES THROUGH THE AREA ON SATURDAY NIGHT. PRIMARY SOURCE OF
UNCERTAINTY REMAINS THE MAGNITUDE OF THE SHORTWAVE TO OUR NORTH. THE
MOST LIKELY SCENARIO AT THIS POINT IS THAT THE MAJORITY OF THE
FORCING ASSOCIATED WITH THE FRONT PASSES NORTH OF THE AREA, BUT IT
IS ENOUGH TO KEEP CONDITIONAL INSTABILITY IN PLACE LOCALLY, AND THE
COLD FRONT BRINGS MAINLY LIGHT PRECIP TO THE AREA SATURDAY. THE LESS
LIKELY SCENARIO IS THAT THE STRONGER RIDGING TO OUR SOUTH BUILDS
NORTHWARD STRONG ENOUGH TO KEEP THE COLD FRONTAL PASSAGE COMPLETELY
DRY. REGARDLESS, QPF IS TOO MODEST TO MAKE MUCH OF A DENT IN THE
MODERATE TO SEVERE DROUGHT THAT IS CURRENTLY IN PLACE ACROSS INLAND
PORTIONS OF THE AREA.
BROAD HIGH PRESSURE THEN BUILDS IN GRADUALLY FROM THE NORTH BEHIND
THE FRONT MONDAY, PERSISTING THROUGH EARLY NEXT WEEK.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
18Z TAFS: VFR PREVAILS THROUGH THIS EVENING, WITH SCATTERED CLOUD
COVERAGE ALONG THE GA AND SE SC COAST EXPECTED TO PERSIST WITH 4KFT
BASES. THEN, THIS EVENING, A THE COASTAL TROUGH PUSHES INLAND
QUICKLY AS HIGH PRESSURE MOVES OFF THE COAST, ALLOWING FOR INCREASED
LL MOISTURE ADVECTION ALONG THE COAST. THERE ARE EXPECTED TO REMAIN
ENOUGH BREAKS IN THE CLOUDS TO ALLOW FOR EFFICIENT RADIATIONAL
COOLING, A PATCH FOG IS EXPECTED TO DEVELOP MAINLY ALONG THE HWY 17
CORRIDOR NEAR AND SOUTH OF CHARLESTON. AS SUCH, HAVE INTRODUCED
TEMPO MVFR FOG WITHIN SEVERAL HOURS OF SUNRISE WEDNESDAY. FOG WILL
DISSIPATE GRADUALLY AFTER SUNRISE GIVEN THE LACK OF GRADIENT.
EXTENDED AVIATION FORECAST: PREVAILING VFR. A COLD FRONT COULD BRING
AT LEAST BRIEF FLIGHT RESTRICTIONS SATURDAY, BUT THE PRECIPITATION
AND WIND CHARACTERISTICS OF THE FRONT REMAIN UNCERTAIN.
MARINE
BENIGN MARINE CONDITIONS PERSIST THROUGH THE END OF THE WORKWEEK
WITH MAINLY LIGHT WINDS AND 1-2 FT SEAS. WITH WARM CONDITIONS OVER
LAND, A SEA BREEZE IS LIKELY EACH AFTERNOON THROUGH FRIDAY, BRINGING
LOCALLY GUSTY WINDS NEAR THE COAST EACH AFTERNOON.
A COLD FRONT COULD IMPACT THE AREA SATURDAY, BUT SIGNIFICANT
UNCERTAINTY REMAINS WITH RESPECT TO THE STRENGTH OF THE FRONT AND
THE WIND AND PRECIP CHARACTERISTICS ASSOCIATED WITH IT. STAY TUNED
TO SUBSEQUENT FORECASTS AS THE POTENTIAL FOR HAZARDOUS MARINE
CONDITIONS SATURDAY INTO SUNDAY WILL BE REFINED IN THE COMING
DAYS.
CLIMATE
RECORD HIGH TEMPERATURES:
NOVEMBER 19:
KCHS: 83/1942
KCXM: 82/1958
KSAV: 85/1942
NOVEMBER 20:
KCHS: 82/1942
KCXM: 78/1900
KSAV: 83/1942
NOVEMBER 21:
KCHS: 83/1973
KCXM: 80/1942
KSAV: 82/2011
NOVEMBER 22:
KCHS: 83/1942
KCXM: 79/1997
KSAV: 82/1997
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
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