023
FXUS62 KCHS 071132
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
732 AM EDT Tue Oct 7 2025

.SYNOPSIS...
High pressure will persist into Wednesday. A cold front will
drop south through the area Wednesday night into Thursday with
inland high pressure prevailing into early next week. Low
pressure could develop off the Southeast U.S. coast this
weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Today: Aloft, mid-upper lvl ridging will become stretched
across the Mid-Altlantic and Southeast United States, while at
the sfc a weak, but persistent coastal trough begins to shift
onshore along the southern periphery of high pressure extending
across the Mid- Atlantic States and the interior Carolinas. Much
like the previous morning, coastal showers will be driven
onshore within a easterly wind, producing light to moderate
rains across the South Carolina and Georgia coastal corridor
into late morning before activity becomes more focused across
Southeast Georgia and shifts inland as the coastal trough
presses westward and weakens/dissipates across land early
afternoon. Showers could produce a brief downpour capable of
around 1/2 to 3/4 inch rainfall accumulation, but these
instances are likely to be quite sparsely located along coastal
Georgia and inland along the Savannah River area. A large
portion of the afternoon will see partly cloudy to mostly sunny
conditions as convection weakens or departs inland as well as
light northeasterly winds veering more easterly in wake of the
trough, with wind speeds topping out in the 10-15 mph during
peak diurnal heating hours. The pattern/trends favor high temps
in the low-mid 80s away from the beaches.

Tonight: The mid-upper lvl ridge will persist across the Southeast
while weak sfc high pressure gradually spreads into the local area
from the western Atlantic. Dry conditions are expected under mostly
clear skies for much of the night, and with the coastal trough no
longer offshore, shower activity is not anticipated late. Winds
should decouple shortly afternoon sunset, becoming light/variable
for much of the night. There are some signals for fog late night
with favorable condensation pressure deficits in place and lingering
low-lvl moisture, particularly for locations that experienced a
shower during the day. Patchy fog has been introduced across
Southeast South Carolina and Southeast Georgia away from the coast
within a few hours of daybreak late. Overnight lows should dip a
degree or two cooler than the previous night, generally ranging in
the mid 60s inland to upper 60s/lower 70s near the coast.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
Wednesday: A potent shortwave trough will pass to the north of the
region, along the southern periphery of larger scale troughing aloft
over New England. A cold front will approach the region from the
west, associated with the passing shortwave aloft. Decent moisture
ahead of the front combined with the forcing aloft will yield
showers and maybe a thunderstorm in the afternoon through the
evening hours. Temperatures will reach into the mid to upper 80s
across the region, dropping into the 60s overnight.

Thursday and Friday: After FROPA at the surface Thursday, high
pressure will build into the region, centered over New England.
Aloft the region will remain along the southern periphery of large
scale troughing over the eastern CONUS. Due to the building high
pressure at the surface, temperatures will only reach into the low
70s across SE SC and mid 70s in SE GA on Thursday and Friday.
Additionally, low temperatures will drop into the mid 50s inland and
low 60s along the coastline. A mostly dry forecast has been
maintained, however a slight chance of showers is possible along the
coastline Friday afternoon. Gusty NE winds will be present across
the region as the high pressure builds in, especially along the
beaches.

Lake Winds: Winds on Lake Moultrie will become elevated early
Thursday morning and into the weekend as a strong, pinched gradient
develops in response to building high pressure across the region.
Winds could approach Lake Wind Advisory level criteria (sustained 20
kt or frequent gusts to 25 kt) during this time and a Lake Wind
Advisory may be required.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
Generally the weekend and into early next week will be dominated by
high pressure at the surface. A low pressure system could develop
off the SE coastline this weekend, however the strength and track of
that system is still unknown. A dry forecast has been maintained,
with dry high pressure holding strong. Gusty NE winds will begin to
diminish through the weekend across the region as the center of high
pressure over New England weakens. Temperatures through the period
will slowly warm, although highs will remaining a couple of degrees
below normal.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
Light to moderate showers will continue to shift onshore early
morning, likely impacting CHS/JZI during the next few hours and more
briefly at SAV. TEMPO IFR conditions remain in place at CHS between
12-14Z this morning, and TEMPO MVFR at JZI/SAV terminals between 12-
14Z this morning. Shower coverage could linger a few more hours into
late morning/early afternoon, but confidence is too low to include
in the 12Z Tuesday TAF issuance. VFR conditions are then expected to
prevail as CHS/JZI/SAV for a bulk of the afternoon through 06Z
Wednesday. However, latest guidance suggests the potential for fog
to develop locally late tonight. Prevailing MVFR conditions
have been included at all terminals to indicate timing of when
vsbys are likely to decline, generally between 09Z-12Z Wednesday.

Extended Aviation Outlook: Gusty N to NE winds will impact
KCHS/KJZI/KSAV Thursday and Friday, possibly lingering into the
weekend as high pressure builds over the region.

&&

.MARINE...
Today and Tonight: Easterly winds in the 10-15 kt range will
prevail across all waters late morning through the evening while
weak coastal troughing shifts onshore during the day. During
the night, the pressure gradient is anticipated to weaken as
high pressure settles across local waters, indicating winds to
improve even more so after midnight. The main issue will
continue to be seas with a Small Craft Advisory starting out
across nearshore Georgia waters, but coming to an end at 10 AM.
Further offshore, 5-7 ft seas across outer Georgia waters will
support a Small Craft Advisory for the day and night.

Wednesday through Sunday: High pressure well offshore will dominate
on Wednesday, yielding NE winds generally 10 to 15 knots and seas
averaging 3 to 4 ft. A cold front will sweep through the region
Wednesday night into Thursday, bringing deteriorating marine
conditions. NE winds will increase to 20 to 25 knots on Thursday,
with gusts to around 30 knots. Seas will also increase Thursday to 5
to 7 ft. The marine zones will become pinched through the weekend
between high pressure inland and a developing low pressure system
off the SE coast. This will yield persistent NE winds around 25
knots with gusts as high as 35 knots. Gale Watches and Warnings may
be required later this week for all waters outside of the Charleston
Harbor. Within the Charleston Harbor winds are forecast to be
slightly lower, however still within Small Craft Advisory criteria.
These conditions will continue through Saturday, diminishing
slightly on Sunday.

Rip Currents: The risk for rip currents will be highest along
the Georgia beaches today while a moderate risk occurs along
South Carolina beaches. A blend of the latest rip current MOS
with local rip current calculations support a moderate risk of
rip currents at all area beaches on Wednesday. An enhanced risk
of rip currents will persist into the weekend due to building
surf and increasing winds associated with the building high
pressure.

High Surf: The risk for high surf will increase Thursday night into
the start of the weekend as wave heights increase across the local
waters. A High Surf Advisory may be required for some area
beaches

&&

.TIDES/COASTAL FLOODING...
Latest tide observations and guidance support moderate coastal
flooding for Charleston and Coastal Colleton Counties and minor
coastal flooding from Beaufort, SC and south across Southeast
Georgia coastal communities during the morning high tide cycle. A
Coastal Flood Advisory is effect from 6 AM to 10 AM this morning.
High tide today is at 8:23 AM at Charleston Harbor, SC and 8:33 AM
at Fort Pulaski, GA. Additional coastal flooding is possible with
the evening high tide cycle and could necessitate another Coastal
Flood Advisory for Charleston and Coastal Colleton Counties.

Astronomical tides will continue to increase this week due to the
full moon today (Oct 7) and perigee (Oct 8). Additionally, tidal
departure values will begin to increase again late week and into the
weekend due to strong NE winds. As a result, the threat for minor to
moderate coastal flooding continues through mid-week. Late week the
threat for major coastal flooding arrives for the late morning high
tides.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Coastal Flood Advisory until 10 AM EDT this morning for GAZ117-
     119-139-141.
     High Risk for Rip Currents through this evening for GAZ117-119-139-
     141.
SC...Coastal Flood Advisory until 10 AM EDT this morning for
     SCZ048>051.
MARINE...Small Craft Advisory until 10 AM EDT this morning for AMZ354.
     Small Craft Advisory until 6 AM EDT Wednesday for AMZ374.

&&

$$

NEAR TERM...DPB
SHORT TERM...CPM
LONG TERM...CPM
AVIATION...CPM/DPB
MARINE...CPM/DPB