591
FXUS62 KCHS 090716
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
316 AM EDT Thu Oct 9 2025

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

&&

.NEAR TERM /THROUGH TONIGHT/...
Prior to daybreak: A cold front will continue to shift south across
the local area, entering Southeast South Carolina during the next
hour, then reaching Southeast Georgia prior to sunrise. Few to
scattered showers along with isolated thunderstorms are possible
with the front with a couple spots capable of receiving around 1/4
inch of rainfall. Once fropa occurs, a noticeable uptick in north-
northeasterly winds is expected, with wind gusts approaching the 15-
20 mph range. Further south, winds will remain lighter prior to
daybreak, before cold air advection occurs post fropa, but wind
gusts are expected across Southern Southeast South Carolina and
Southeast Georgia around or shortly after sunrise as well. Low temps
will range in the lower 60s inland to mid-upper 60s closer to the SC
coast and south across inland areas of Southeast Georgia.

Today: Aloft, weak mid-lvl ridging stretched across the northern
Gulf into parts of the Southeast will shift south of the local area
in response to a large-scale trough progressing east across the
Northeast/Mid-Alantic states, and a cut-off low attempting to
develop across the Southeast along its base this afternoon. At the
sfc, a cold front will quickly depart the local area south of the
Altamaha River early-mid morning, making way for strong and
noticeably cooler high pressure building across the local area from
the north throughout the day. Cold air advection occurring with this
airmass change is expected to result in rather breezy north-
northeasterly winds (20-25 mph) throughout the day with slightly
higher gusts occurring near the coast (25-30 mph). Despite early
fropa, few to scattered showers along with an isolated thunderstorm
remain possible across Southeast South Carolina and Southeast
Georgia due to mid-upper lvl low arriving, but precip trends should
become more focused across Southeast Georgia during the afternoon.
High temps will become noticeably cooler than the past several days,
topping out in the low-mid 70s locally while a north-northeasterly
wind persists throughout the period.

Tonight: Aloft, a mid-upper lvl low arrives from the west and slowly
meanders across the region overnight while a sfc wedge of high
pressure is draped across the Southeast, strongest just inland and
north of the local area. Guidance insists few to scattered showers
linger across Southeast Georgia and along the immediate South
Carolina coast, but precip is expected to be light, generally 0.1
inch or less overnight. Cold air advection will continue to spill
into the area through the night, likely maintaining northeasterly
winds gusting up to 15-20 mph across most areas, and a bit higher
gusts along the immediate beaches. Temps will be some 5-8 degrees
cooler than the previous night, with lows ranging in the mid-upper
50s inland to lower 60s near the coast and south of I-16 in
Southeast Georgia.

Lake Winds: Strong cold air advection in wake of a cold front and
associated with building high pressure across the region will lead
to gusty north-northeasterly winds around 25 kt across Lake Moultrie
today and tonight. A Lake Wind Advisory will remain in effect
throughout the day and night as a result.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
A complicated set up will ensue Friday and into the weekend. Aloft,
a mid level cyclone will dominate over the southeastern states. This
will help induce cyclogenesis at the surface off the southeast coast
this weekend. While low pressure rapidly develops off the coast, a
wedge of high pressure will build into the region from the north.
Between these two features the region will see a very pinched
pressure gradient. This will yield breezy conditions, especially
along the immediate coastline and on high bridges and overpasses
where gusts up to 30 to 35 mph will be possible. Rainfall will be
possible along the direct coastline, however amounts will be highly
dependent on the location of the low pressure. Most recent guidance
suggests the bulk of the precipitation will stay just offshore,
however any little change in the lows position could bring higher
rain chances along the coastline. The current forecast features
rainfall totals Friday around 0.5" to 1" along the coastline.
Temperatures on Friday will be below normal, only reaching into the
low 70s, with overnight lows in the upper 50s inland and 60s
elsewhere.

Saturday will feature the same set up as the low pressure at the
surface is slow to depart the region. Rain chances Saturday
afternoon will be lower (20-30% along the coastal counties) as the
low is expected to pull far enough away from the region. Breezy
conditions will remain, however temperatures will warm slightly to
the mid to upper 70s, warmest south of I-16 in GA.

By Sunday the surface low is forecast to progress northeastward to
the Mid-Atlantic states. High pressure will still dominate over the
region, however breezy conditions will begin to wane as the low
continues to progress further away from the region. A dry forecast
has been maintained, with temperatures warming into the upper 70s to
around 80 in SE GA.

Lake Winds: Winds on Lake Moultrie will remain elevated into the
weekend as a strong, pinched gradient dominates in response to
building high pressure across the region and cyclogenesis off the
coast. A Lake Advisory is in effect for Lake Moultrie through
Saturday afternoon for NE wind gusts 20 to 30 knots and waves 2 to 3
ft.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
The pattern aloft next week will feature building high pressure
centered over Texas building in from the west, while the mid-level
cyclone is positioned off the Mid-Atlantic coast. At the surface
high pressure will build into the region from the north. A dry
forecast has been maintained, with warming temperatures through the
period to mid-October normals.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
A cold front shifting across the local area could bring a few
showers along with TEMPO MVFR cigs to CHS/JZI terminals from 06-10Z
Thursday and 07-09Z Thursday at SAV. However, the main issue will be
breezy winds developing post fropa with north-northeasterly winds
gusting upwards to 18-23 kt and the potential for MVFR cigs at the
terminals. TEMPO MVFR cigs are possible at CHS/JZI terminals between
11-15Z Thursday as high pressure builds across the region. At SAV,
TEMPO MVFR vsbys are possible between 07-09Z Thursday due to
showers, followed by prevailing MVFR cigs as the front nears between
09-12Z Thursday, then followed by another TEMPO MVFR group between
12-16Z Thursday with lower cigs associated with high pressure
building across the area. Once breezy northeasterly winds develop
post fropa, they could very well continue throughout the day and
into the night.

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

&&

.MARINE...
Today and Tonight: A cold front is expected to shift across local
waters early morning with high pressure building in its wake. Strong
cold air advection associated with the airmass change and a tight
pressure gradient developing across the area will lead to
deteriorating marine conditions this morning through the afternoon
as northeast winds surge and seas build post fropa. Small Craft
Advisories are in effect early this morning across South Carolina
waters with winds expected to increase quickly with fropa, followed
by Georgia coastal waters at 8 AM. Gale Warnings remain unchanged,
beginning across all local waters (outside the Charleston Harbor)
early afternoon, then persisting through the night. Northeasterly
winds gusting up to 35-40 kt along with seas building up to 6-10 ft
across nearshore and 9-11 ft across outer Georgia waters are
possible by this evening and are likely to occur during the overnight.

Friday through Tuesday: A significant marine event will be ongoing
to start Friday, lasting into the weekend. Low pressure developing
off the southeast coast, combined with high pressure building over
land zones, will yield a pinched pressure gradient. This will result
in NE winds 20 to 30 knots with gusts up to 40 knots Friday into
Saturday night. A Gale Warning is in effect for all marine zones
outside of the Charleston Harbor through Saturday night. A Small
Craft Advisory is in effect for the Charleston Harbor for wind gusts
up to 30 knots through Saturday night. In addition to the gusty
winds, seas are forecast to increase into the weekend, peaking
Friday night into Saturday with 7 to 9 ft in the nearshore waters
and 10 to 11 ft in the 20 to 60 nm offshore GA waters. As the low
pressure offshore progresses to the NE towards the Mid-Atlantic
coastline Sunday into Monday conditions across the marine zones will
begin to improve. However, Small Craft Advisory conditions will
likely linger as building high pressure keeps wind gusts around 25
knots.

Rip Currents: Strong northeast winds and building seas will lead to
an enhanced risk of rip currents late week into the weekend. A High
Risk of rip currents is forecast at all area beaches for both today
and Friday, with the threat persisting into at least Saturday as a
coastal low develops offshore.

High Surf: Large breaking waves of 5+ feet are expected at all area
beaches beginning this afternoon and continuing into Saturday as
strong high pressure builds inland and low pressure develops
offshore. A High Surf Advisory is in effect for the entire
coastline.

&&

.TIDES/COASTAL FLOODING...
Strong NE winds resulting from building high pressure inland and
developing low pressure offshore will allow tidal departures to
increase through the next several high tide cycles. Astronomical
tide values are already elevated owing to the recent full moon and
perigee, which combined with increasing departures will result in
coastal flooding with each high tide cycle into the weekend. While
confidence is high in coastal flooding occurring, the position of
the developing low pressure will highly influence the tidal
departure.

Charleston Harbor Tide Gage: The late morning high tide cycles today
through Saturday have the potential to hit major coastal flooding
(>8 ft MLLW). A Coastal Flood Warning is in effect for Charleston
and Coastal Colleton Counties through Friday afternoon. A Coastal
Flood Advisory is in effect for Tidal Berkeley County through
Friday afternoon.

Fort Pulaski Tide Gage: The late morning high tide cycles through
Saturday have the potential to reach moderate coastal flooding (10
to 10.5 ft MLLW). A Coastal Flood Advisory is in effect from
Beaufort County, SC southward to McIntosh County, GA from 8 AM this
morning until noon today.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Coastal Flood Advisory from 8 AM this morning to noon EDT
     today for GAZ117-119-139-141.
     High Risk for Rip Currents from 8 AM EDT this morning through this
     evening for GAZ117-119-139-141.
     High Surf Advisory from 2 PM this afternoon to 8 AM EDT Sunday
     for GAZ117-119-139-141.
SC...Coastal Flood Advisory from 8 AM this morning to noon EDT
     today for SCZ048-051.
     High Risk for Rip Currents from 8 AM EDT this morning through this
     evening for SCZ048>051.
     High Surf Advisory from 2 PM this afternoon to 8 AM EDT Sunday
     for SCZ048>051.
     Lake Wind Advisory until 2 PM EDT Saturday for SCZ045.
     Coastal Flood Warning from 8 AM this morning to 3 PM EDT
     Friday for SCZ049-050.
     Coastal Flood Advisory from 8 AM this morning to 3 PM EDT
     Friday for SCZ052.
MARINE...Small Craft Advisory until 6 AM EDT Sunday for AMZ330.
     Small Craft Advisory until 2 PM EDT this afternoon for AMZ350.
     Gale Warning from 2 PM this afternoon to 11 PM EDT Saturday
     for AMZ350-352.
     Small Craft Advisory until 2 PM EDT this afternoon for AMZ352.
     Small Craft Advisory from 8 AM this morning to 2 PM EDT this
     afternoon for AMZ354-374.
     Gale Warning from 2 PM this afternoon to 8 PM EDT Saturday for
     AMZ354.
     Gale Warning from 2 PM this afternoon to 2 AM EDT Sunday for
     AMZ374.

&&

$$

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