North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

882
FXUS62 KCHS 250053
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
853 PM EDT Thu Sep 24 2026

.WHAT HAS CHANGED...
Updated Key Message 2 and Aviation Section.

&&

.KEY MESSAGES...
- 1) Cool weather will linger into the weekend. Near to slightly
  above normal temperatures return next week.

- 2) The coastal flood risk ramps up due to persistent
  northeast winds and high astronomical tides.

- 3) A High Risk of rip currents continues through this
  evening, followed by a Moderate Risk Friday. The rip current
  risk could remain elevated through the weekend.

&&

.DISCUSSION...
KEY MESSAGE 1: Cool weather will linger into the weekend. Near
to slightly above normal temperatures return next week.

An impressively strong CAD (for Early Fall) is ongoing across
the region this afternoon as low pressure strengthens offshore
of the North Carolina Outer Banks. The wedge appears to be
nearing full maturity with inland pressure rises starting to
wane. The combination of weak isentropic lift with a corridor of
strong UVVs head of an approaching shortwave rounding the base
of the powerful upper low centered over Eastern North Carolina
will support the development of additional isolated to scattered
showers across mainly the Charleston Tri-County into Colleton
County over the next few hours with a few patches of light
drizzle also possible. With low-level dry air still being
funneled south within the CAD, diabatic effects will have an
meaningful impact on temperatures for the remainder of the
afternoon across mainly parts of the Lowcountry. Temperature
falls into the lower-mid 60s were recently noted across parts
of Berkeley County where shower activity is the greatest and
shows the impact diabatic processes can have. The high temperature
forecast for the rest of today was lowered yet again per
ongoing short term trends with the largest adjustments made
north of the I-26 corridor. Some locations across the interior
portions of the Lowcountry into the Charleston Metro Area will
likely hold in the 60s for the rest of the day. The NBM
continues to perform poorly and is running a very warm bias
(~5-10 deg)-- typical in CAD events.

Shower activity will quickly wane by late afternoon/early
evening as the corridor of strongest forcing shifts offshore
with the passing shortwave. Skies are expected to clear
overnight as the developing nor`easter shifts farther to the
north offshore of the Mid-Atlantic States and even deeper drier
air to the north gradually erodes the low-level cloud deck from
the top-down. With the lack of a strong downslope component
expected off the Southern Appalachians, there are concerns
guidance is too quick in scouring out the low-level moisture
embedded in the CAD. The forecast will show improving sky cover
through the night, but not exactly to the degree the NBM is
forecasting. It will certainly be the coolest night so far since
last Spring with lows expected to drop into the mid-upper 50s
inland with lower 60s at the beaches.

The inland wedge will steadily break down on Friday into
Saturday as the nor`easter moves closer to New England and
secondary high pressure builds in from the northwest. Friday
night looks noticeably cool with lows dropping into the 48-52
degree range inland to the mid 60s at the beaches. Temperatures
will gradually moderate through the period with average to
slightly above average temperature returning Monday into
Tuesday. Dry weather will prevail for much of the extended
period.


KEY MESSAGE 2: The coastal flood risk ramps up due to persistent
northeast winds and high astronomical tides.

A nor`easter located offshore of the Mid- Atlantic will lead to
the continuation of breezy northeasterly flow across the
region. The combination of these breezy winds with the upcoming
full moon (9/26) result an increase in minor to moderate coastal
flooding with each high tide cycle through the weekend (esp.
for the Charleston Harbor).

Coastal flooding concerns will continue tomorrow (9/26) with
the potential to reach moderate flood stage for Charleston and
Colleton County with the morning high tide (~7AM) and the
evening high tide (~8PM). Additionally, guidance indicates the
Saturday morning`s high tide could see minor coastal flooding.

Fort Pulaski: Tidal levels could reach 9.5 ft MLLW for this
evening`s high tide in Fort Pulaski (approx. at 718PM), thus
this will yield minor coastal flooding impacts across lower
South Carolina and southeast Georgia. This would prompt a
Coastal Flood Advisory for this evening`s high tide, however
confidence levels remain low as there remains some uncertainty
regarding if the tidal departures will reach 1.76 ft MLLW. Thus,
we will hold off on issuing a Coastal Flood Advisory for lower
South Carolina and southeast Georgia. Conditions will continue
to be monitored through the afternoon and will issue a Coastal
Flood Advisory if tidal departures start trending that way.
Additionally, guidance indicates tomorrow evening`s high tide
could also see minor coastal flooding.


KEY MESSAGE 3: A High Risk of rip currents continues through
this evening, followed by a Moderate Risk Friday. The rip
current risk could remain elevated through the weekend.

A strengthening area of low pressure offshore will continue to
drive strong gusty winds along the coast and the coastal waters
through tonight and into Friday. Also, this low will help to
push ~8 second swell along the coast which will increase to
longer period swell (10- 12 seconds) on Friday. This setup will
continue to support a High Risk of rip currents at all beaches
through this evening, followed by a Moderate Risk at all beaches
on Friday. An elevated risk could linger into Saturday thanks
to lingering swell. A lesser risk if expected Sunday as the low
moves away and its influence along the Southeast coast
dissipates.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
0Z TAFs: A band of showers and isolated thunderstorms passed
over KCHS and KJZI prior to the onset of the 0Z TAFs. The KCHS
and KJZI TAFs will initialize dry as convection slides offshore.
The rest of of this evening will feature MVFR ceilings and
gusty north winds. MOS and forecast soundings indicate that
llvl clouds may dissipate overnight, resulting in restrictive
ceilings to end late tonight. The rest of the TAF period should
remain VFR with north winds gusting to around 20 kts.

Extended Aviation Outlook: Gusty winds will persist into
Thursday, possibly Friday.

&&

.MARINE...
Through Tonight: Overall conditions are expected to peak across
the local waters this evening and into the early morning hours
as an offshore low strengthens and lifts northward. Across the
outer waters, gusts as high as 35-40 knots are likely and the
Gale Warning remains in effect through the overnight. For the
nearshore waters, gusts up to 30 knots will continue and a Small
Craft Advisory continues. For Charleston Harbor, gusts up to
around 25 knots continue to be the main concern through the late
evening which will then diminish into the low 20 knot range
through the overnight. The Small Craft Advisory continues there
through the late evening. Seas will continue to build through
the evening and are forecast to peak around 4-8 ft out to 20 nm
and 8-11 ft beyond.

Friday through Saturday: Marine conditions are expected to
gradually improve on Friday as the offshore low lift northward
closer to the New England coast and and the pressure gradient
starts to relax across the local waters. The Gale Warning for
the outer GA waters will need to be replaced with a Small Craft
Advisory, and the ongoing Small Craft Advisory for the
nearshore waters will continue through Friday evening/night. By
Saturday winds and seas will diminish further and the only
remaining headline will likely be the Small Craft Advisory for
the outer GA waters into Saturday night.

Sunday through Tuesday: Quiet conditions will return and winds
and seas will be well below Small Craft Advisory thresholds.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...High Risk for Rip Currents until 8 PM EDT this evening for GAZ217-
     219-239-241.
SC...High Risk for Rip Currents until 8 PM EDT this evening for
     SCZ148>151.
     Coastal Flood Advisory until 10 PM EDT this evening for SCZ149-
     150.
MARINE...Small Craft Advisory until 11 PM EDT this evening for AMZ340.
     Small Craft Advisory until 2 AM EDT Saturday for AMZ360-362.
     Small Craft Advisory until 8 AM EDT Saturday for AMZ364.
     Gale Warning until 6 AM EDT Friday for AMZ380-382-384.

&&

$$