750
FXUS62 KCHS 131825
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
225 PM EDT SUN SEP 13 2026
WHAT HAS CHANGED
ALL SECTIONS UPDATED.
KEY MESSAGES
- 1) LIMITED RAIN CHANCES TODAY AND MONDAY, WITH RECORD CHALLENGING
HIGH TEMPERATURES FORECAST MONDAY.
- 2) COOLER AND DRIER CONDITIONS EXPECTED TUESDAY THROUGH MID
WEEK.
- 3) MINOR COASTAL FLOODING POSSIBLE WITH THE TUESDAY MIDDAY
HIGH TIDE ALONG THE CHARLESTON AND COLLETON COUNTY COASTS.
DISCUSSION
KEY MESSAGE 1: LIMITED RAIN CHANCES TODAY AND MONDAY, WITH
RECORD CHALLENGING HIGH TEMPERATURES FORECAST MONDAY.
DESPITE A PWAT OF 2.31 INCHES WITH THIS MORNING'S 12Z KCHS RAOB
SOUNDING, CONDITIONS ARE FORECAST TO DRY OUT INTO THE AFTERNOON
HOURS AS A SHORTWAVE TROUGH ADVANCES TOWARDS THE LOCAL FORECAST
AREA. THIS SHORTWAVE CAN BE EASILY SEEN ON THE GOES MID-LEVEL WATER
VAPOR IMAGERY, AS OF 17Z ROUGHLY LOCATED JUST TO THE WEST OF
JENKINS/SCREVEN/ALLENDALE COUNTIES. THE KCLX RADAR HAS BEGUN TO
DETECT ISOLATED SHOWERS OVER SOUTHEASTERN GA. THESE SHOWERS ARE
FORMING JUST AHEAD OF THE SHORTWAVE, LIKELY INITIATING WITH THE
ASSISTANCE OF THE SEA BREEZE. MOST MODEL GUIDANCE FROM THIS MORNING
PAINT A RATHER BENIGN PICTURE OF ISOLATED CONVECTION THIS AFTERNOON
AND ANY SHOWERS/STORMS DIMINISHING WITH NIGHTFALL. A SIMILAR SET-UP
IS FORECAST ON MONDAY, WITH THE SHORTWAVE TROUGH PUSHING THROUGH THE
REGION OVERNIGHT. WITH THE ARRIVAL OF THE SHORTWAVE PWATS ARE
FORECAST TO DROP EVEN LOWER, WITH SOME GUIDANCE SHOWING VALUES AS
LOW AS 1.5 INCHES. THE BIGGER STORY WITH MONDAY'S FORECAST WILL BE
THE HOT TEMPERATURES.
HIGH PRESSURE WILL BUILD INTO THE FORECAST AREA ON MONDAY ALOFT,
CENTERED OVER THE DEEP SOUTH. AT THE SURFACE HIGH PRESSURE WILL
BRIEFLY BUILD INTO THE REGION AHEAD OF AN APPROACHING FRONT.
GUIDANCE POINTS TO HIGH TEMPERATURES REACHING INTO THE UPPER 90S
ACROSS MOST OF THE FORECAST AREA. THE 850MB TEMPERATURES ARE
FORECAST TO REACH AS HIGH AS 18-20C, WHICH WOULD POINT TO HIGH
TEMPERATURES IN THE MID 90S. SURFACE WINDS ARE FORECAST TO SHIFT TO
THE NW ON MONDAY. THIS DIRECTION TYPICALLY LEADS TO SOME DOWNSLOPING
INFLUENCES AND DRIER/WARMER CONDITIONS OVER THE LOCAL FORECAST AREA.
THESE TEMPERATURES COULD POTENTIALLY BE RECORD BREAKING AT THE LOCAL
CLIMATE SITES. SEE THE CLIMATE SECTION FOR MORE DETAILS.
KEY MESSAGE 2: COOLER AND DRIER CONDITIONS EXPECTED TUESDAY THROUGH
MID WEEK.
A BACKDOOR COLD FRONT WILL DROP THROUGH THE AREA MONDAY NIGHT,
FOLLOWED BY SEASONALLY STRONG HIGH PRESSURE RIDGING SOUTH INTO THE
CAROLINAS AND GEORGIA FOR MIDWEEK. THIS WILL BRING TEMPERATURES DOWN
TO MORE TYPICAL SEPTEMBER LEVELS, WITH HIGHS LARGELY IN THE 85-90
RANGE. LOWS ARE EXPECTED TO FALL WELL INTO THE 60S OVER MOST INLAND
LOCATIONS.
THE CHANCE FOR RAINFALL SHOULD BE PRETTY LIMITED DURING THIS TIME
PERIOD AS PWATS ARE FORECAST TO EVENTUALLY DROP BELOW 1 INCH (WHICH
IS 10-15TH PERCENTILE OF CLIMO). THE EXCEPTION WOULD BE ON TUESDAY
ACROSS PORTIONS OF SOUTHEAST GEORGIA WHERE LOW LEVEL CONVERGENCE
INTERSECTS SOME LINGERING DEEP MOISTURE BEFORE THE DRIER AIR REALLY
ARRIVES. OTHERWISE, IT LOOKS TO BE A PLEASANT COUPLE OF DAYS.
NORTHEAST WINDS COULD GET A BIT GUSTY ALONG THE COAST.
KEY MESSAGE 3: MINOR COASTAL FLOODING POSSIBLE WITH THE TUESDAY
MIDDAY HIGH TIDE ALONG THE CHARLESTON AND COLLETON COUNTY
COASTS.
MINOR COASTAL FLOODING IS POSSIBLE WITH THE TUESDAY MIDDAY HIGH TIDE
ALONG THE CHARLESTON AND COLLETON COUNTY COASTS. STRENGTHENING
NORTHEAST WINDS ARE EXPECTED ON TUESDAY WHICH WILL INCREASE TIDAL
DEPARTURES. THE TIDE WOULD NEED ~1 FT DEPARTURE TO REACH MINOR
FLOODING THRESHOLDS OF 7 FT MLLW IN THE CHARLESTON HARBOR. MOST
GUIDANCE INDICATES THIS COULD BE ACHIEVED, WITH TIDE LEVELS POSSIBLY
FALLING SOMEWHERE IN THE 7.0-7.2 FT MLLW RANGE. A COASTAL FLOOD
ADVISORY COULD BE NEEDED. NO ISSUES EXPECTED FURTHER SOUTH ALONG THE
LOWER SC AND SOUTHEAST GA COASTS.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
DRY CONDITIONS ARE FORECAST THROUGH THE 18Z TAF AT KCHS/KJZI WHILE
SOME VCTS ARE POSSIBLE AT KSAV THROUGH THE AFTERNOON. CONFIDENCE IS
TOO LOW TO INCLUDE RESTRICTIONS AT KSAV DUE TO SHOWERS/STORMS, SO
HAVE VCTS FROM 18 TO 23Z. SKIES ARE FORECAST TO GO SKC MONDAY
MORNING WITH WINDS TIPPING AROUND TO THE NW.
EXTENDED AVIATION OUTLOOK: VFR. GUSTY WINDS ARE POSSIBLE TUESDAY
THROUGH THURSDAY AFTERNOONS.
MARINE
THROUGH TONIGHT: WEAK TROUGHING ACROSS INLAND LOCATIONS HAVE SHIFTED
WINDS TO THE SSW. AS THE TROUGHING WEAKENS WINDS WILL TIP TO THE W
OVERNIGHT, GENERALLY IN THE 10 TO 15 KNOT RANGE. SEAS WILL AVERAGE 2
TO 3 FT.
MONDAY THROUGH THURSDAY: NO MARINE CONCERNS ON MONDAY. WINDS AND
SEAS WILL INCREASE TUESDAY AS HIGH PRESSURE RIDGES SOUTH INTO THE
REGION, WITH CONDITIONS REMAINING ELEVATED INTO THURSDAY. WIND GUSTS
ARE EXPECTED TO PEAK IN THE 25-30 KNOT RANGE WHILE SEAS BUILD TO 5-7
FEET. THERE IS A LOW-END CHANCE SOME GUSTS REACH NEAR GALE FORCE
LATER TUESDAY AND AGAIN LATER WEDNESDAY, PARTICULARLY OVER THE GA
WATERS. HOWEVER, IT LOOKS MARGINAL AND SHORT-LIVED WITH NBM
INDICATING PROBABILITIES FOR GUSTS OVER 34 KNOTS ARE LESS THAN 30%.
WILL CONTINUE TO MONITOR. PRESSURE GRADIENT SHOULD BEGIN TO EASE ON
THURSDAY, WITH CONDITIONS LIKELY FALLING BELOW ADVISORY LEVELS
FRIDAY.
RIP CURRENTS: GUSTY NORTHEAST WINDS AND INCREASING SEAS TUESDAY INTO
MIDWEEK WILL LEAD TO AN ELEVATED RISK OF RIP CURRENTS. LATEST RIP
CURRENT FORECAST FOR TUESDAY INDICATES A MODERATE RISK FOR SC
BEACHES AND A HIGH RISK FOR GA.
CLIMATE
RECORD HIGH TEMPERATURES
SEPTEMBER 14:
KCHS: 94/1991
KCXM: 94/1938
KSAV: 96/1991
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
CPM/ETM
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