North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

147
FXUS62 KCHS 251102
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
702 AM EDT Sun Oct 25 2026

.WHAT HAS CHANGED...
Aviation updated to represent the 12Z aviation forecast.

&&

.KEY MESSAGES...
- 1) A significant, multi-day coastal flooding event is
  expected this weekend through at least the middle of next
  week.

- 2) Strong northeast flow this weekend and into early next week
  will result in several hazards including gusty lake winds, rip
  currents, high surf, and beach erosion.

- 3) Dry conditions and below normal temperatures will continue
  through early next week before gradually warming up by the
  end of the week.

&&

.DISCUSSION...
KEY MESSAGE 1: A significant multi-day coastal flooding event is
expected this weekend through at least the middle of next week.

Astronomical tides will continue to rise through the remainder
of the weekend and into next week due to the upcoming full moon
(10/26) and the lunar perigee (10/28). Large tidal departures
are already ongoing, and with an extended period of strong
northeast flow this weekend and into next week, these departures
will increase in magnitude. The combination of the highest
astronomical tides of the year and persistent strong northeast
flow will result in a multi-day moderate to major coastal
flooding event for the entire southeast GA/SC coast.

Sunday Morning: Tide levels at the Charleston Harbor are
forecast to reach 7.9-8.1 ft MLLW, resulting in a Coastal Flood
Warning for Charleston and coastal Colleton. In addition, at
these tide levels, up to half a foot of saltwater inundation
will be possible for tidal Berkeley county, resulting in a
Coastal Flood Advisory. Lastly, a Coastal Flood Advisory has
been issued for Fort Pulaski as well, from Beaufort County in SC
to McIntosh County in GA, with forecast values of 10.0-10.2 ft
MLLW. Current departures are running a little behind forecast;
however, winds offshore are expected to increase throughout the
morning as we approach high tide and much like yesterday morning
we should see things quickly increase through the morning.

Sunday Evening: Tide levels at the Charleston Harbor are
forecast to reach 7.4-7.6 ft MLLW, whereas at Fort Pulaski the
tide is expected to reach 9.6-9.8 ft MLLW. Coastal flood
advisories will most likely be needed.

Next Week: The highest water levels are expected to occur with
the Monday, Tuesday, and Wednesday morning high tide cycles.
During these cycles, confidence is increasing that Charleston
will exceed major flood stage (8.0 ft MLLW) and Fort Pulaski
will exceed moderate flood stage (10.0 ft MLLW). There is even
concern that Fort Pulaski could reach or exceed its major flood
stage (10.5 ft MLLW), which has never happened in its history
(records begin in 1935) outside of a tropical system. The one
thing keeping us from considering major flooding at Fort Pulaski
outside of climatology is that the winds offshore should relax
some heading into early next week. While astronomical tides will
be running high, the relaxed wind field will likely not support
as high departures and without any other considerations for
increased departures such as rainfall, there is not enough
support for us to feel we can push past the climatological
normal. Nonetheless, Coastal flooding will likely occur with
both the morning and evening high cycles for several days,
though the evening tide will be the lower of the two. Coastal
Flood Advisories will definitely be needed, and Coastal Flood
Watches/Warnings are very likely for some or all of the coast
from Sunday through Wednesday.


KEY MESSAGE 2: Strong northeast flow will result in several hazards
including gusty lake winds, rip currents, high surf, and beach
erosion.

Rip Currents: Strong northeast winds, increasing long-period swell
and wave action will continue to support dangerous rip currents
along all SC/GA beaches. A High Risk for rip currents is in place
for all beaches Sunday and Monday. An enhanced risk of rip currents
will likely continue through the rest of the week.

High Surf/Beach Erosion: Breaking wave heights will peak this
evening between 4 and 6 ft along area beaches. A High Surf Advisory
remains in effect for the entire Southeast SC/GA coast into Monday,
when breakers should subside below 5 ft. Another round of high surf
conditions are possible mid-week as the pattern holds, although
appears to fall just short of criteria along the SC/GA coast at this
time. Additionally, the combination of elevated tides, increased
wave action, and persistent gusty northeast winds will likely
produce beach erosion, with the most significant erosion occurring
around the high tide cycles Sunday and Monday.

Lake Winds: Gusty winds up to 25 kt early this morning across Lake
Moultrie will decrease quickly through late morning as the boundary
layer decouples over the relatively cool lake waters. After sunset
Sunday, winds will briefly ramp up once again as cold air advects
over the warmer lake waters, triggering strong vertical mixing and
tapping into 40 kt gusts aloft. An additional Lake Wind Advisory
could be needed, mainly between the hours of 8 PM Sunday and 4 AM
Monday when gusts 25-30 kt would be possible. Furthermore, the
combination of steady northeast winds and 2-3 ft waves could yield
minor lakeshore erosion along the southwest side of the lake along
with some overwash. This includes areas from roughly Pinopolis to
Blacks Camp near Cross.


KEY MESSAGE 3: Dry conditions and below normal temperatures
will continue through early next week before gradually warming
up by the end of the week.

A rather persistent synoptic pattern is expected through the
next week, with upper level ridging over the northern Gulf Coast
and an upper trough lingering around the Bahamas. At the
surface, high pressure centered over New England will dominate through
mid-week allowing for a wedge to remain in place across the
Carolinas. Temperatures through the remainder of the weekend
and into early next week should remain below normal with the
cooler air trapped within the wedge. The wedge of high pressure
will weaken slightly mid-week, with temperatures returning to
near normal by the end of the week as a result. The forecast
remains rain-free through the week.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
Northeasterly winds will slowly increase after sunrise. Areas
well away from the coast are expected to see gusts of 20-25
knots, while those along the coast will be closer to 30 knots.

Extended Aviation Outlook: Breezy north-northeast winds are expected
at KCHS/KJZI/KSAV daily through the week. There are no other high
confidence concerns.

&&

.MARINE...
Sunday through Monday: High pressure will continue to strengthen
across the Mid-Atlantic while low pressure organizes near the
Bahamas Sunday. This setup favors a sharp pinched pressure gradient
across the local marine area. Gale Warnings remain in effect for all
waters outside of the Charleston Harbor. Gale-force gusts will
persist across both nearshore and offshore legs into Monday,
lingering longest over the Georgia outer waters (20-60 nm). The
Charleston Harbor will see northeast gusts of 25 to 30 kt and waves
of 2 to 3 ft through Sunday night, and a Small Craft Advisory
remains in effect there.

Tuesday through Friday: Winds and seas will begin a slight downward
trend Monday night into Tuesday. However, a prevailing tight
gradient between inland high pressure and an offshore low will
maintain elevated winds and seas through the period. There is a
slight surge Wednesday evening when brief gales return to the
Georgia waters from 0-60 nm. However, at a minimum, Small Craft
Advisory level winds and elevated seas are expected to continue
across the coastal waters, outside of the Charleston Harbor, through
the rest of the week.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...High Risk for Rip Currents through this evening for GAZ217-219-239-
     241.
     High Surf Advisory until 5 PM EDT Monday for GAZ217-219-239-
     241.
     Coastal Flood Advisory until 10 AM EDT this morning for GAZ217-
     219-239-241.
SC...High Risk for Rip Currents through this evening for SCZ148>151.
     High Surf Advisory until 5 PM EDT Monday for SCZ148>151.
     Coastal Flood Advisory until 10 AM EDT this morning for SCZ148-
     151-152.
     Lake Wind Advisory until 11 AM EDT this morning for SCZ045.
     Coastal Flood Warning until 11 AM EDT this morning for SCZ149-
     150.
MARINE...Small Craft Advisory until 5 AM EDT Monday for AMZ340.
     Gale Warning until 5 AM EDT Monday for AMZ360-362-364.
     Gale Warning until 2 PM EDT Monday for AMZ380-382.
     Gale Warning until 2 AM EDT Tuesday for AMZ384.

&&

$$

Black/BRS