393
FXUS62 KCHS 252313
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
713 PM EDT Fri Sep 25 2026

.WHAT HAS CHANGED...
Aviation and tide sections were updated.

&&

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

- 2) The coastal flood risk will persist into early next week.

&&

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

GOES-E visible imagery and 25/17z surface analysis showed the
deepening Nor`easter well to the northeast of Cape Hatteras with
1026 hPa high pressure centered over Lake Superior extending
into the Southeast U.S. and Deep South. Direct influences from
the departing Nor`easter will gradually wane this afternoon with
gusty north/northwest winds quickly diminishing as sunset
approaches. Tonight looks to favor a solid radiational night.
The boundary layer should decouple fairly quickly this evening
and with fairly low dewpoints in place, temperatures should
steadily fall under clear skies. Typical for radiational nights,
the 25/13z NBM looks to exhibit a warm bias through daybreak
Sunday which is best highlighted by the large interquartile
range (as much as 4-7 degrees) at various observation sites
across the Lowcountry and Southeast Georgia. The coldest of the
guidance was favored for lows tonight as a result, ranging from
the upper 40s/lower 50s inland to the lower 60s at the beaches,
with further local adjustments made to account for typical and
well know mesoscale influences (i.e. Charleston Harbor, Broad
River, Santee-Cooper lakes, Francis Marion National Forest,
etc).

Temperatures will begin to moderate Saturday as ridging builds
aloft and surface high pressure maintains its influence on the
region. Highs look to warm into the upper 70s/lower 80s and are
fairly consistent with full-sun 850-1000 hPa thickness schemes.
Saturday night into Sunday morning will likely be another cool
night with strong radiational cooling likely coming into play
again within a decoupled boundary layer. The lower side of the
guidance envelop was favored with lows ranging from the lower
50s well inland to the lower-mid 60s at the beaches.

Dry conditions look to persist into much of next week with
broad high pressure prevailing. Temperatures will continue to
moderate with near to slightly above average conditions
expected. The next chances for rainfall should hold off until
Thursday into Friday of next week as net moisture values begin
to build back into the area along the backside of subtropical
high pressure centered well offshore over the Atlantic.


KEY MESSAGE 2: The coastal flood risk will linger into early
next week.

As a nor`easter churns offshore of the Mid-Atlantic coastline,
breezy north-northeasterly flow will continue across the region.
The combination of breezy winds with the full moon today will
result in minor (possibly moderate) coastal flooding with each
high tide cycle through the weekend (esp. for the Charleston
Harbor).

Charleston Harbor: With the ongoing environmental conditions,
tidal levels could reach 7.5 ft MLLW in the Charleston Harbor
for this evening`s high tide, peaking a bit after 8 PM.
Therefore, Coastal Flood Advisory has been issued from 6 PM to
10 PM this evening 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.

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 (~8AM). Thereafter,
it`s likely to see minor coastal flooding conditions through
early next week for the Charleston Harbor.

Fort Pulaski: Tidal levels could reach 9.4 ft MLLW for this
evening`s high tide in Fort Pulaski (approx. at 801PM), thus
this will be close to yielding minor coastal flooding impacts
across lower South Carolina and southeast Georgia. However, as
it remains borderline, we will continue to monitor conditions
through the next several hours and will issue a Coastal Flood
Advisory if it seems warranted. Additionally, guidance indicates
tomorrow morning`s and Sunday morning`s high tide could also
see minor coastal flooding.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
0Z TAFs: VFR with light NNW winds through the TAF period.

Extended Aviation Outlook: There are no concerns.

&&

.MARINE...
Through Tonight: Winds and seas are steadily diminishing across
the local marine area this afternoon a strong Nor`easter remains
centered well to the northeast of Cape Hatteras. North winds
will settle into the 10-15 kt with gusts to 20 kt range
overnight with seas subsiding into the 2-4 ft range across the
nearshore waters and 4-6 ft over the offshore waters, highest in
the Georgia offshore leg. Small Craft Advisories are poised to
end by 8 PM over the nearshore waters, but will linger through
the night across the Georgia offshore leg due to 6 ft seas.

Saturday through Wednesday: Seas 4-6 ft will linger over the
Georgia offshore leg through early Saturday evening and a Small
Craft Advisory remains in effect there. Otherwise, fairly quiet
marine conditions will dominate the coastal waters through the
middle of next week. Some localized sea breeze enhancements
should return across Charleston Harbor and the land/sea
interface by Tuesday, but wind speeds look to remain fairly
tame.

Rip Currents: A moderate risk for rip currents continues for
all beaches through this evening. A lingering 10-12s backswell
directed towards the Georgia and Florida coasts will support a
moderate rip current risk from Tybee Island south to Sapelo
Island both Saturday and Sunday. A low risk is anticipated for
the lower South Carolina beaches both days.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...Coastal Flood Advisory until 10 PM EDT this evening for SCZ149-
     150.
MARINE...Small Craft Advisory until 8 PM EDT Saturday for AMZ384.

&&

$$