865
FXUS62 KCHS 292313
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
713 PM EDT Tue Sep 29 2026

.WHAT HAS CHANGED...
The Aviation section has been updated for the 00z TAF issuance.

&&

.KEY MESSAGES...
- 1) The coastal flood risk will linger through the end of this
  week.

- 2) Warm and dry conditions will extend through most of the
  week.

- 3) Unsettled weather will return late week into the weekend
  with fall-like conditions early next week.

&&

.DISCUSSION...
KEY MESSAGE 1: The coastal flood risk will linger through the
end of this week.

As the nor`easter travels further up the Eastern Seaboard,
coastal flooding will still pose a risk through the end of the
week (esp. for the Charleston Harbor). It`s possible that the
lingering conditions could be from the build up of tidal waters
across the inland waterways and/or the movement of the gulf
stream has slowed.

Charleston Harbor: Tidal levels could reach 7.3 ft MLLW in the
Charleston Harbor for tomorrow morning`s high tide (~11AM).
Therefore, a Coastal Flood Advisory will likely be issued for
tomorrow morning`s high tide for Charleston and Colleton
Counties. Saltwater inundation will be possible 2 to 3 hours
before and after high tide, and will likely result in some roads
becoming impassable.

Thereafter, minor coastal flooding conditions could continue
through the end of the week for the Charleston Harbor.

Fort Pulaski: Tidal levels could reach 9.2 ft MLLW for tomorrow
morning`s high tide in Fort Pulaski (~11AM), thus this will not
warrant a Coastal Flood Advisory for lower South Carolina and
southeast Georgia.

KEY MESSAGE 2: Warm and dry conditions will extend through most
of the week.

Ridging aloft will build into the southeastern states through
the week, yielding a rain-free pattern through Thursday. High
temperatures will climb into the mid to upper 80s daily, roughly
5 degrees above normal for late Sept/early Oct, with parts of
Southeast Georgia reaching the lower 90s. Lows will gradually
warm each night, hovering in the mid to upper 60s inland and low
to mid 70s near the beaches.

KEY MESSAGE 3: Unsettled weather will return late week into the
weekend with fall-like conditions early next week.

Net moisture levels will begin to steadily increase Friday and
persist into the weekend as a modest return flow sets up along
the backside of subtropical high pressure centered well
offshore. A cold front will approach Saturday then cross the
area Sunday before settling over Florida Monday into Tuesday as
high pressure wedges south across the Carolinas and Georgia.
PWATs are forecast to surge as high as 2.25-2.50" ahead of the
front which will run ~2 standard deviations above climatology
for early October. Weak forcing aloft is noted in model cross-
sections owing to subtle DCVA ahead of a weak, mostly sheared
southern stream shortwave. So, Despite the presence of a high
net moisture values, there is much uncertainty with regards to
how much rainfall and resulting QPF will occur given this weak
forcing pattern. This is reflected in the latest guidance
showing a fairly large interquartile range (IQR) in the various
QPF forecasts across the entire set of GFS and ECMWF ensemble
members. Pops for the Saturday into Monday time periods were
limited to the likely range for now given this uncertainty.
Another strong cold air damming (CAD) event is expected to setup
for early next week with a return to cooler, fall-like
conditions becoming increasingly likely along with breezy to
windy conditions possible, especially at the coast.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions are expected to prevail at KCHS, KJZI, and KSAV
through 00z Thursday. The only real forecast issue is the
potential for some shallow ground fog around sunrise, as well as
the low end potential for low stratus to try and spread in from
the west. For now we have kept the forecast VFR. KSAV likely has
the best chance of seeing sub-VFR conditions, but current
thinking is that the more notable fog and stratus concerns will
remain inland.

Extended Aviation Outlook: There will be an elevated risk for
sub-VFR conditions in showers and thunderstorms over the
weekend.

&&

.MARINE...
Through Tonight: Quiet marine conditions will prevail across
the local waters with easterly winds 10 kt or less and seas less
than 2 ft.

Wednesday through Friday: An east to southeast flow will
prevail across the coastal waters through Friday as high
pressure is forecast to remain to the east, well offshore. Local
sea breeze enhancements look likely each afternoon near the
land/sea interface and Charleston Harbor, but no meaningful
impacts are expected. Wind speeds will generally remain 10 kt or
less (except 10-15 kt within the sea breeze circulation each
afternoon) with seas 3 ft or less.

Rip Currents: A Moderate Risk of rip currents is in place for
all southeast South Carolina and southeast Georgia beaches
Wednesday due to 13 second swell moving in.

&&

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

&&

$$