417  
FXUS62 KCHS 172127  
AFDCHS  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON SC  
527 PM EDT THU SEP 17 2026  
   
WHAT HAS CHANGED
 
 
THE AVIATION SECTION WAS UPDATED FOR THE 18/00Z TAFS. THE RIP  
CURRENT SUBSECTION WAS REMOVED WITH A LOW RISK EXPECTED ALL  
BEACHES FOR FRIDAY.  
 

 
   
KEY MESSAGES
 
 
- 1) WARMING TEMPERATURES AND MOSTLY DRY CONDITIONS THROUGH  
FRIDAY. RAIN CHANCES WILL THEN GRADUALLY INCREASE THIS  
WEEKEND AND ESPECIALLY BY EARLY NEXT WEEK.  
 

 
   
DISCUSSION
 
 
KEY MESSAGE 1: WARMING TEMPERATURES AND MOSTLY DRY CONDITIONS  
THROUGH FRIDAY. RAIN CHANCES WILL THEN GRADUALLY INCREASE THIS  
WEEKEND AND ESPECIALLY BY EARLY NEXT WEEK.  
 
THROUGH TONIGHT: THE FORECAST AREA WILL REMAIN UNDER THE  
INFLUENCE OF DRY HIGH PRESSURE THROUGH THE OVERNIGHT. WITHIN THE  
NORTHEAST LOW-LEVEL FLOW, THERE WILL BE OCCASIONAL SHOWER  
DEVELOPMENT ACROSS THE COASTAL WATERS THAT COULD MAKE A RUN FOR  
THE SOUTHEAST GA COAST. BUT, MOST OF THIS ACTIVITY WILL DIMINISH  
BEFORE REACHING THE COAST AND REMAIN OVER THE MARINE AREA.  
 
FRIDAY AND SATURDAY: FOR FRIDAY, MODEL GUIDANCE DEPICTS AND  
UPSTREAM SURFACE TROUGH THAT WILL HELP TO KICK OFF AFTERNOON  
CONVECTION NORTH OF THE FORECAST AREA. THIS CONVECTION COULD  
MAKE A RUN FOR THE AREA FROM THE NORTH IN THE EVENING.  
OTHERWISE, MOST OF THE AREA SHOULD REMAIN DRY WITH TEMPERATURES  
WARMING SOLIDLY INTO THE LOW 90S. SATURDAY SHOULD BRING BETTER  
THUNDERSTORM CHANCES WITH ISOLATED TO SCATTERED COVERAGE IN THE  
AFTERNOON AND EVENING. ANOTHER ROUND OF HIGHS IN THE LOW 90S IS  
EXPECTED, ALONG WITH DEWPOINTS REBOUNDING INTO THE 70S FOR MUCH  
OF THE AREA. CERTAINLY NOT EXPECTING ANY HEAT ADVISORY  
CONDITIONS, BUT HEAT INDICES BACK INTO THE 100-105 DEGREE RANGE  
ARE LIKELY.  
 
SUNDAY THROUGH EARLY NEXT WEEK: THE OVERALL PATTERN WILL CHANGE  
AS THE SOUTHEAST SITS WITHIN A TROUGH AND A CLOSED UPPER LOW  
ACROSS THE FLORIDA PENINSULA AND THE EASTERN GULF. THE AIRMASS  
WILL BECOME INCREASINGLY MOIST, WITH PRECIPITABLE WATER VALUES  
PROGGED TO RISE TO NEAR 2 INCHES AT TIMES. WHEN COMBINED WITH A  
FRONT EXPECTED TO PUSH INTO THE AREA FROM THE NORTH, THE SETUP  
WILL FAVOR UNSETTLED CONDITIONS AND INCREASED RAIN CHANCES  
THROUGH THE EARLY TO MIDDLE OF PART OF THE WEEK. GIVEN THE HIGH  
PRECIPITABLE WATER AIRMASS AND THE PRESENCE OF ROUNDS OF  
CONVECTION, THERE WILL BE AT LEAST A LOW END THREAT FOR SOME  
LOCALLY HEAVY RAINFALL.  
 

 
   
AVIATION /20Z THURSDAY THROUGH TUESDAY/
 
 
18/00Z TAFS:  
KCHS/KJZI/KSAV: VFR THROUGH 19/00Z. SOME BRIEF, SHALLOW GROUND  
FOG COULD DEVELOP JUST BEFORE DAYBREAK, BUT NO IMPACTS ARE  
EXPECTED.  
 
EXTENDED AVIATION OUTLOOK: RAIN CHANCES ARE EXPECTED TO  
INCREASE LATE THIS WEEKEND AND INTO EARLY NEXT WEEK WHICH COULD  
RESULT IN PERIODIC FLIGHT RESTRICTIONS.  
 

 
   
MARINE
 
 
TONIGHT: THE GRADIENT WILL RELAX AND ALLOW WINDS TO STEADILY  
DIMINISH. WIND SPEEDS WILL BEGIN THE EVENING AROUND 15 KNOTS OR  
SO, BECOMING 5-10 KNOTS LATE. SEAS WILL DIMINISH IN RESPONSE,  
BECOMING MOSTLY 2-3 FEET EXCEPT UP TO 4 FEET IN THE GEORGIA  
OFFSHORE WATERS.  
 
FRIDAY THROUGH TUESDAY: WINDS AND SEAS ARE EXPECTED TO REMAIN  
WELL BELOW SMALL CRAFT ADVISORY THRESHOLDS THROUGH THE PERIOD.  
WINDS WILL BE 10 KNOTS OR LESS FOR MUCH OF THIS PERIOD, WITH  
SEAS GENERALLY IN THE 2-3 FT RANGE. THE MAIN FORECAST CONCERN  
WILL BE INCREASING COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS  
THE LOCAL WATERS, ESPECIALLY EARLY NEXT WEEK.  
 

 
   
CHS WATCHES/WARNINGS/ADVISORIES
 
 
GA...NONE.  
SC...NONE.  
MARINE...NONE.  
 

 
 

 
 
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