547
FXUS62 KCHS 171750
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
150 PM EDT Fri Oct 17 2025

.SYNOPSIS...
High pressure will remain across the region through Saturday. A
cold front will move through Sunday night, followed by high
pressure early next week. Another cold front will then arrive
during the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Ridging in the mid and upper levels will prevail through the
remainder of today and through tonight, with upper air analyses
showing the center of the ridge extending northward through the
Great Lakes. High pressure at 850 hPa and at the surface will be
anchored over the Mid-Atlantic through the remainder of today,
shifting slightly eastward overnight. Quiet conditions will
prevail through the remainder of this afternoon and tonight.
Temperatures this afternoon will peak in the low to mid 70s,
with some spots along the Altamaha River possibly touching 80.
Some high clouds are forecast to move in overnight, which will
limit the radiational cooling potential. Overnight lows are
forecast to dip into the 50s.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
Aloft, a large ridge will extend across the Southeast United States
this weekend, in advance of a high amplitude trough advancing east
across the Central United States and to the Midwest/Great Lakes
region. This will help maintain dry and sunny conditions on Saturday
with high temps peaking in the lower 80s well inland to mid-upper
70s closer to the coast. Despite another night of clear skies, a
light southerly wind should pick up late, suggesting lows to only
dip into the mid-upper 50s inland to low-mid 60s near the coast
Saturday night.

On Sunday, the mid-upper lvl trough will help force a sfc cold front
across the local area during afternoon and evening hours, resulting
in few to scattered showers as a breezy southerly flow advects a
swath of moisture (PWATS near 1.50 to 1.75 inches) across the local
area during peak heating hours. Instability remains rather meager
near/during fropa and the front looks rather progressive, suggesting
rainfall accumulations to remain quite limited locally. However, a
few thunderstorms remain possible across nearby waters once the
front shifts offshore (higher instability area). High temps should
peak in the upper 70s to lower 80s. Overnight lows will become
noticeably cooler post fropa, generally dipping into the upper
40s/lower 50s inland to upper 50s near the coast.

Dry and cooler high pressure will prevail across the Southeast on
Monday, becoming centered directly across the local area while a
cold front continues to shift further away from the region over the
Atlantic. Despite sunny conditions, weak cold air advection
associated with a northerly wind should limit afternoon highs to the
low-mid 70s (warmest across Southeast Georgia).

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
A strong radiational cooling setup occurs Monday night with weak
high pressure supporting a light/calm wind during the bulk of the
night. Lows should dip into the mid-upper 40s inland to mid-upper
50s closer to the coast. By Tuesday, a southwest flow in advance of
dry cold front will help push afternoon highs into the upper
70s/lower 80s, before fropa occurs late day while a strong mid-upper
trough advances from the Great Lakes region to the Northeast. This
will once again favor below normal highs Wednesday and Thursday,
with peak temps anticipated in the low 70s across Southeast South
Carolina and mid 70s across Southeast Georgia each afternoon.
Overnight lows should also dip into the mid 40s away from the
coastal corridor Wednesday night, before temps recover a bit heading
into the second half of the week as high pressure prevails under a
zonal flow aloft.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
12Z TAFs: VFR.

Extended Aviation Outlook: VFR conditions are expected at
CHS/JZI/SAV terminals through Tuesday. However, gusty southerly
winds (15-20 kt) are possible at all terminals Sunday in advance
of a cold front.

&&

.MARINE...
Rest of Today and Tonight: High pressure centered over the Mid-
Atlantic states will prevail through the period, with ENE winds
generally around 10 knots. Seas are forecast to average 3 to 4
ft in the nearshore waters and 5 to 6 ft in the 20 to 60 nm
offshore GA waters, where a Small Craft Advisory remains in
effect until tonight.

Saturday through Wednesday: High pressure will dominate the pattern
this weekend, keeping wind/sea conditions well below Small Craft
Advisory levels across local waters for Saturday. On Sunday, the
pressure gradient will begin to tighten in advance of a cold front,
followed by cold air advection occurring with building high pressure
in its wake, favoring gusty southwesterly winds Sunday night turning
more northerly by daybreak Monday. Wind gusts could approach the 20-
25 kt while seas build upwards to 4-6 ft (largest across outer
Georgia waters and beyond 15 nm from the Charleston County Coast).
Low-end Small Craft Advisories could eventually be needed Sunday
night. High pressure will then prevail across the region later
Monday into Tuesday, supporting wind/sea conditions that remain
below Small Craft Advisory levels. A dry cold front is anticipated
to shift across the local area Tuesday night, but the pressure
gradient and cold air advection appear less supportive for Small
Craft Advisory conditions with gusts primarily in the 15-20 kt range
and seas between 2-4 ft. High pressure will then prevail across the
region Wednesday leading to quieter marine conditions.

Rip Currents: There is a Moderate Risk of rip currents for our
Georgia beaches into this evening. Another period of enhanced rip
currents is possible for all beaches Sunday due to increasing swell
and gusty onshore flow ahead of an approaching cold front.

&&

.TIDES/COASTAL FLOODING...
There is a threat for minor coastal flooding with the early evening
high tide cycle along the Charleston and Colleton county coasts. The
current forecast keeps tide levels on the lower end of minor
flooding thresholds, but the latest departures suggest tides could
fall just short of 7.0 ft MLLW. Conditions will continue to be
monitored for the need of a possible Coastal Flood Advisory. The
risk should be lower as we head into the weekend as high pressure
shifts overhead and eventually offshore, and the wind direction
becomes less favorable.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until 9 PM EDT this evening for AMZ374.

&&

$$

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