418
FXUS62 KCHS 171836
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
236 PM EDT THU SEP 17 2026
WHAT HAS CHANGED
ALL SECTIONS HAVE BEEN UPDATED.
KEY MESSAGES
- 1) WARMING TEMPERATURES AND MOSTLY DRY CONDITIONS THROUGH
TOMORROW. 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 TOMORROW. 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 /18Z THURSDAY THROUGH TUESDAY/
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT KCHS, KJZI, AND KSAV
THROUGH 18Z FRIDAY. THERE ARE SOME SUBTLE HINTS IN MODEL
GUIDANCE THAT THERE COULD BE SHALLOW GROUND FOG AROUND SUNRISE
FRIDAY. FOR NOW WE HAVE NOT INCLUDED AN EXPLICIT MENTION IN THE
TAF'S, BUT THIS COULD NEED TO BE RECONSIDERED WITH FUTURE
ISSUANCES.
EXTENDED AVIATION OUTLOOK: MOSTLY VFR. 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 3 FEET EXCEPT UP TO 4 FEET IN THE OUTER GA
WATERS LATE.
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.
RIP CURRENTS: A MODERATE RISK OF RIP CURRENTS REMAINS IN EFFECT
THROUGH 8PM THIS EVENING FOR THE SOUTHEAST GA COAST.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
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