507
FXUS62 KCHS 190004
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
704 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 /TONIGHT/
THE MID-LEVELS WILL CONSIST OF A SHORTWAVE PASSING TO OUR NORTH
THIS EVENING AND OVERNIGHT, BUT ZONAL FLOW SHOULD PREVAIL
OVERHEAD THROUGH THIS EVENING, THEN TRANSITION TO WNW FLOW AFTER
MIDNIGHT. AT THE SURFACE, A WEAK COASTAL SHOULD PUSH 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 SHOULD
BE ENOUGH BREAKS TO PROMOTE EFFICIENT RADIATIONAL COOLING, AND
PATCHY/AREAS OF FOG ALONG THE COAST, WHILE PATCHY, LIGHT FOG IS
A POSSIBILITY ELSEWHERE. THERE IS A 30-40% CHANCE ALONG MUCH OF
THE HIGHWAY 17 CORRIDOR NEAR AND SOUTH OF CHARLESTON FOR AT
LEAST PATCHY DENSE FOG OVERNIGHT, AND A DENSE FOG ADVISORY OR
SPECIAL WEATHER STATEMENT COULD EVENTUALLY BE NEEDED, INCLUDING
FOR LOCATIONS AROUND THE SAVANNAH METRO AROUND 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 /00Z WEDNESDAY THROUGH SUNDAY/
VFR CONDITIONS WILL PREVAIL AT CHS/JZI/SAV TERMINALS THROUGH 00Z
THURSDAY. HOWEVER, A WEAK COASTAL TROUGH WILL SHIFT ONSHORE
OVERNIGHT WITH GREATER LOW-LVL MOISTURE CONTENT AND POSSIBLY
LEAD TO INCREASING LOW CLOUDS AND/OR FOG WITHIN A FEW HOURS OF
DAYBREAK WEDNESDAY MORNING. GUIDANCE SUGGESTS THE POTENTIAL FOR
REDUCED VSBYS MOST LIKELY TO OCCUR AT SAV, WHERE TEMPO MVFR
CONDITIONS REMAIN BETWEEN 10-13Z WEDNESDAY. THESE CONDITIONS
COULD EVENTUALLY BE REQUIRED AT CHS/JZI FOR THE SAME TIMEFRAME,
BUT GUIDANCE SUGGESTS VFR CONDITIONS THROUGH THE NIGHT, AND
THEREFORE HAVE BEEN LEFT VFR FOR THE NEXT 24-HR PERIOD.
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 LATE WEEK 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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