North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

709
FXUS62 KCHS 042249
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
649 PM EDT Fri Sep 4 2026

.WHAT HAS CHANGED...
All sections have been updated. KEY MESSAGE 3 has been added
for coastal flooding potential next week.

&&

.KEY MESSAGES...
- 1) Hot and humid conditions expected this weekend.

- 2) Unsettled weather will continue through Labor Day weekend,
  with increasing chances of rain each day. Increased risk for
  flooding Sunday.

- 3) Coastal flooding potential increases behind a cold front
  early next week.

&&

.DISCUSSION...
KEY MESSAGE 1: Hot and humid conditions expected into the upcoming
weekend.

Aloft, a ridge of high pressure will extend from the Central United
States to the Southeast United States this weekend, although could
slightly break down across the local area as a broad trough develops
across the Northeast and Mid-Atlantic regions. Even though the setup
suggests conditions less favorable for hot conditions this weekend,
a strong day of sfc heating and a compressional heating component
along/ahead of an approaching cold front should still support
hottest conditions Saturday afternoon, when temperatures push into
the upper 80s/lower 90s near the beaches to mid 90s inland. Sfc
dewpts will likely mix out into the low-mid 70s inland, but should
still pool into the upper 70s/near 80 across portions of the coastal
corridor along/behind a sea breeze circulation. This will push heat
index values into the 108-110 range, especially across the lower
South Carolina coast. Given the placement of high pressure and
downward trend in precip chances during peak heating hours, a Heat
Advisory has been issued from Berkeley and Charleston County north
to Effingham/Chatham GA Counties south from 11 AM to 8 PM Saturday.
Further south and well inland, conditions appear more marginal with
heat index values in the 102-107 range, short of Heat Advisory
criteria. However, conditions will need to be monitored for possible
inclusion of remaining areas into the advisory should temperatures
or dewpts trend warmer/higher than currently anticipated. There is
also some risk (although quite low) of isolated convection during
peak heating hours Saturday afternoon, which could provide some
relief from the heat. A backdoor cold front and numerous/widespread
convective coverage will likely keep conditions below Heat Advisory
thresholds Sunday.

KEY MESSAGE 2...Unsettled weather will continue through Labor
Day weekend, with increasing chances of rain each day. Increased
risk for flooding Sunday.

Saturday into Saturday night: A rather unsettled pattern will begin
to setup on Saturday as our upper ridge begins to breakdown and a
large upper low will dig into the northeast. This will begin to push
a "cold" front into the area by late Saturday night into Sunday. For
Saturday, conditions should remain rather dry throughout the day on
Saturday as the ridge still has some hold on the area; however, as
we head into the late afternoon and evening we should begin to see
some isolated to scattered showers and storms start to develop with
the influences of the upper trough and increasing moisture build
into the area. Rain chances look to increase in to the overnight
hours on Saturday as the slow moving front pushes down from North
Carolina. A cluster of thunderstorms will likely move towards the
Tri-county area. These storms could be strong to severe with a few
instances of damaging winds. However, by the time they likely reach
the area we will be approaching midnight and instability should be
limited which would limit any severe potential.

Sunday: The front will enter our area sometime Sunday morning and
widespread showers and thunderstorms will likely develop along and
around the front. PWATS are expected to climb above 2 inches along
and ahead of the slowly advancing boundary and given deep layer wind
profiles parallel to the boundary and slow storm motions could
result in storms lingering and building along the front. Couple this
with likely heavy rain rates of 1 to 3 inches per hour and some
concern for locally heavy rainfall will be possible. The question is
how fast does the front progress and is there potential for storms
outflow to help modify and push the front further south with time.
The faster the front the less concern for heavy rainfall; however,
if the front slows or stalls then some locations closer to the coast
could easily start to see the rain totals pile up and localized
flash flooding could be possible. Rainfall totals of 1 to 3 inches
look to be possible Sunday afternoon; however, there is a avenue
where localized rainfall totals might push 3 to 5 inches in the
heaviest bullseyes. This certainly raises some concerns across the
Charleston Metro on Sunday afternoon for some flooding potential
lining up with the peak high tide approaching 7 feet MLLW (more on
this later in the discussion). On-top of the heavy rainfall risk, a
few storms could get strong to severe given rather strong
instability approaching 2000-2500 J/kg with deep moist profiles
capable of wet microbursts if storms can cluster up enough. While
this scenario really does not scream severe; there`s enough of a
potential to worth a mention and a gee whiz strong to severe storm.
Storms should slowly progress southward through the evening and
weaken during the overnight hours as instability weakens.

Monday into Monday night: By early Monday morning the front will
have pushed through most of the area and the best moisture will
likely be limited to parts of southeastern GA maybe just along the
boarder of GA/SC. Once again scattered to numerous showers and
storms should develop along the boundary and push south with time.
PWATS will still be in the 2 inch range south of the front and some
localized chances for heavy rainfall will still exist across Georgia
including the Savannah metro on Monday afternoon. However, coverage
may be a little less than Saturday leading to a slightly lower risk.
Drier conditions should improve by Tuesday as the front fully clears
the area and dry northwesterly flow begins to build over the
area.

KEY MESSAGE 3: Coastal flooding potential increases behind a cold
front early next week.

Elevated high tides return Sunday afternoon during the lunar Perigee
(09/06), and linger throughout the week until after the new moon
(09/11). With astronomical high tides ranging from 6.30-6.55 ft MLLW
in the Charleston Harbor throughout the week, tidal departures of
0.45-0.70 ft would result in minor coastal flooding. A high pressure
wedge could also set up along he East Coast next week, favoring
larger tidal departures and coastal flooding, especially along the
Charleston and Colleton County coasts. Latest trends suggest minor
coastal flooding could start as early as the Sunday afternoon high
tide, but even more likely with the Monday afternoon/evening high
tide cycle with departures up to 1 ft.

For the rest of the coast from Beaufort County, SC, south to
McIntosh County, GA, tidal departures would need to be larger to
reach minor coastal flooding issues, which appears unlikely at this
time. However, should the gradient pinch a bit more than expected
with the inland high pressure wedge, then the risk for coastal
flooding could increase.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
0Z TAFs: Recent KCLX images indicated that the sea breeze has
pushed well inland of the terminals this evening. The rest of
the night should feature dry conditions with light southwest
winds. On Saturday, the day should begin with west-southwest
winds between 5 to 10 kts. The sea breeze is timed to push
across KJZI by 17Z and KCHS and KSAV by 19Z, followed by a south
wind. Recent runs of the HRRR and HREF indicates that terminals
will likely remain dry through the TAF period.

Extended Aviation Outlook: Chances for flight restrictions with
showers/thunderstorms increase at all terminals Saturday night into
Sunday as a cold front passes through the region. Periodic flight
restrictions are possible through early next week with scattered to
numerous showers/thunderstorms and a wedge of high pressure building
north and inland. Breezy conditions could also develop at all
terminals as a wedge attempts to take shape inland.

&&

.MARINE...
Today and Tonight: High pressure will remain the dominant weather
feature across local waters while h5 vort energy continues to shift
onshore, favoring marine conditions that remain well below Small
Craft Advisory levels through the night. In general, southerly winds
will gust up to 15-20 kt, strongest along coastal areas this
afternoon, then turn more southwest-west overnight tonight. Seas
will range between 2-3 ft.

Saturday through Wednesday: The main concern centers on a
likely tightening of the pressure gradient associated with wedge
of high pressure that will develop Sunday night into Monday in
the wake of backdoor cold front. Expect northeast winds as high
as 20-25 kt to occur, especially across the South Carolina
coastal waters and 15-20 kt with gusts to 25 kt across the
Georgia waters as well as the Charleston Harbor. Seas could
reach as high as 3-5 ft, but could end up as high as 6 ft at
times, especially across the South Santee- Edisto Beach
nearshore and offshore legs. A Small Craft Advisory could be
needed for some waters for Monday into Monday night, possibly
extending into Tuesday.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Heat Advisory from 11 AM to 8 PM EDT Saturday for GAZ101-218-
     219.
SC...Heat Advisory from 11 AM to 8 PM EDT Saturday for SCZ042>045-
     147>152.
MARINE...None.

&&

$$

Black/DPB/NED