North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

321
FXUS62 KCHS 281121
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
721 AM EDT Thu May 28 2026

.WHAT HAS CHANGED...
Aviation section has been updated.

&&

.KEY MESSAGES...
- 1) Hot and humid conditions with periods of showers and
  thunderstorms across SE GA/SC through Thursday. Locally heavy
  downpours are possible.

- 2) An unsettled wet pattern is expected to develop Friday
  into the weekend, increasing the potential for heavy rainfall
  and localized flooding.

&&

.DISCUSSION...
KEY MESSAGE 1: Hot and humid conditions with periods of showers and
thunderstorms across SE GA/SC through Thursday. Locally heavy
downpours are possible.

The warm and moist airmass we`ve been experiencing the past couple
days will continue to impact the area, though a pattern shift is on
the way as a cold front begins to slide down towards the region
throughout the day. After overnight lows in the lower to mid 70s,
expect partly to mostly cloudy skies throughout the morning hours as
temperatures climb, with scattered showers also starting to form as
the cap erodes and convective temperatures are met.

Severe weather potential looks to remain limited given the weak
shear aloft, but deep convection amidst the moist environment with
PWATs remaining near 2 inches brings the risk of locally heavy
rainfall. HREF probabilities indicate a 50 to 70% chance for >=1" of
rainfall in 3 hours this afternoon, highest across southeast Georgia
and tapering off into southeast South Carolina, with a 30% chance
for >=3" of rainfall in 3 hours for portions of southeast Georgia.
With westerly surface flow strengthening throughout the day, the
expected sea-breeze looks to be pinned a closer to the coast today,
which is where the heaviest rainfall is expected to focus. Flood
Advisories or even a Flash Flood Warning could be needed where
heavier storms form.

Similar to Wednesday, today is expected to be another warm and humid
day as temperature climb into the upper 80s to lower 90s. Areas
along the coast will see dewpoint temperatures remaining in the mid
70s, which is expected to produce heat indices just above 100
degrees for a few hours.

This evening and overnight, the weak cold front begins to meander
into the region, which will continue rainfall chances into the
overnight hours given the provided lift. The cooler air doesn`t
filter in behind the front just yet, so expect overnight lows to
remain in the upper 60s to mid 70s across the region.

KEY MESSAGE 2: An unsettled wet pattern is expected to develop
Friday into the weekend, increasing the potential for heavy
rainfall and localized flooding.

On Friday, a cold front is forecast to slow as it pushes over the
Savannah River, expected to become stationary over SE GA Friday
afternoon. At H5, a broad weaknesses will develop over the Southeast
U.S. as the region remains longwave progresses across New England
and a 590 dm ridge is centered over Cuba. Using a blend of MOS, high
temperatures are forecast to range in the mid 80s, with dewpoints
around 70 degrees. The warm and moist conditions under the broad mid-
level weakness will produce a large field of SBCAPE between 1000-
1500 J/kg. In addition, guidance indicates that PW values along and
south of stationary front should range around 2" with values between
1.7" to 1.9" across the SC Lowcountry.

NAM12 indicates that high pressure may surge SW as the ridge becomes
blocked by the Southern Appalachians Friday afternoon. Deep moisture
convergence will likely develop along the NW to SE oriented front
across SE GA. High resolution guidance indicates that showers and
thunderstorms will rapidly develop across SE GA from late morning
through the afternoon hours. The convection will develop within an
area of tropical PW with RH between 850-300 mb near 90%, likely
producing periods of torrential downpours. The 0Z HREF highlights SE
GA with a 90% of 1"/3hr and a large area of 50% for 3"/hr for Friday
afternoon. Given the recent wet weather, these rainfall rates could
become excessive, producing localized pockets of flooding or flash
flooding.

Friday night, H5 heights across the forecast will become zonal, with
a shortwave rippling across the CWA overnight. Guidance, including
GFS and ECMWF based AI models, indicate a deepening sfc trough or
wave along the stationary front. Convection coverage should
concentrate within the trough or wave over the SC Lowcountry on
Saturday, then tracking offshore Saturday night. On Sunday, the
center of a sfc high is forecast to become centered off the coast of
the mid-Atlantic states. The sfc ridge should increase across the
CWA on Sunday, resulting in widespread isentropic lift through the
day.

The wet pattern is expected to persist through at least early next
week. Temperatures should cool through this weekend, with highs in
the upper 70s to around 80 for Sunday and Monday. Lows in the 60s on
Sunday and Monday.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
12Z TAFs - As expected, very scattered ground fog is observed across
portions of the area, with some near MVFR cigs occuring as well. As
the morning progresses, expect the fog to dissipate and ceilings to
rise. By late morning/early afternoon, a round of scattered showers
and thunderstorms is expected to get started. Latest trends continue
to favor southeast Georgia for seeing rainfall first, but have kept
PROB30s going at all terminals with SAV seeing their start at 20Z
and CHS/JZI shortly after. A cold front begins to meander into the
region this evening and overnight, which may again bring a round of
showers and thunderstorms along with it. Patchy fog may form
overnight for areas that see heavy rainfall today.

Extended Aviation Outlook: More periodic flight restrictions are
possible Friday into the weekend as the potential for widespread
showers/thunderstorms increases. In addition, patchy overnight fog
and/or stratus cannot be ruled out after recent rains.

&&

.MARINE...
Today and Tonight: As a surface high pressure remains off to our
east throughout the day, winds will remain out of the southeast at
10-15 knots with a few gusts to 20 knots possible. In addition,
scattered shower and thunderstorms are expected to develop later
this morning with chances continuing into the evening and overnight
hours as a weak cold front begins to slide into the region.

Friday through Monday: On Friday, ENE winds may surge as the cold
front pushes across the SC waters, with gusts approaching 25 kts. It
is expected that gusts will remain just below Small Craft Advisory
criteria on Friday. However, wave heights should build through the
day, reaching 3-5 ft by Friday afternoon. The pressure gradient may
lessen on Friday night into Saturday as a frontal wave develops over
the marine zones. However, as the wave slides east on Sunday, high
pressure will surge south across the coastal waters, pinching the
pressure gradient. As a result, ENE winds will strengthen on Sunday,
with gusts approaching gales during the daylight hours. Wave heights
are forecast to build over 6 ft on Sunday, the receding below 6 ft
Sunday night. A weaker pressure gradient should develop on Monday,
yielding improving wind and sea conditions.

Rip Currents: An elevated rip current risk will remain through the
week with a modest easterly swell around 3 to 4 feet every 8 seconds
and sea breeze influences. A moderate risk of rip currents is in
place for all area beaches through Friday.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.

&&

$$

APT/DPB