North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

999
FXUS62 KCHS 231811
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
211 PM EDT Sun Aug 23 2026

.WHAT HAS CHANGED...
All sections updated.

&&

.KEY MESSAGES...
- 1) Strong to severe thunderstorms are possible this afternoon
  and again Monday afternoon.

- 2)Increasing rain chances mid to late week with the potential
  for locally heavy rainfall.

&&

.DISCUSSION...
KEY MESSAGE 1: Strong to severe thunderstorms are possible this
afternoon and again Monday afternoon.

The synoptic pattern aloft today and tomorrow will be similar,
featuring large scale troughing along the eastern CONUS. A weak
surface front will linger in the vicinity of the SC Midlands into
the middle of the week. Shortwave troughs are expected to ripple
across the southern periphery of the large scale troughing aloft
today and Monday. This synoptic set up will allow for strong to
severe thunderstorms to develop both this afternoon and again Monday
afternoon.

Today: Plentiful dry air aloft was observed with the 12Z KCHS RAOB
sounding, yielding a PWAT value of 1.47". PWATs this afternoon are
only forecast to increase slightly across the region, in the 1.5 to
1.6" range. This will limit the overall heavy rain threat today.
However, with the dry air aloft the 12Z sounding this morning also
observed a DCAPE value of 1100 J/kg. DCAPE values this afternoon are
forecast to increase upwards of 1500 J/kg. Damaging wind gusts will
be a threat with any storm that is able to form this afternoon.
Machine learning guidance for this afternoon depicts the main threat
area across the SC Lowcountry. Current GOES satellite imagery shows
a rather agitated cumulus field across the SC Lowcountry and the
KCLX radar has detected the first shower of this afternoon as of 2
PM in northern Charleston County. As the sea breeze progresses
further inland and additional outflow boundaries interact isolated
to scattered thunderstorms are forecast this afternoon. The entire
forecast area remains outlooked in a Marginal Risk (Level 1 of 5)
from the Storm Prediction Center. Thunderstorm activity will wane
with nightfall.

Monday: Forecast soundings paint a similar picture to Sunday on
Monday afternoon, however with PWATs increasing to around 1.7 to
1.8". Coverage of thunderstorms is forecast to be greater, with
scattered to numerous PoPs in the forecast. DCAPE values are still
forecast to be upwards of 1500 J/kg. Damaging wind gusts will again
be the main hazard. Machine learning guidance shows the main threat
area across SE Georgia, with slightly higher probabilities of
damaging wind gusts than portrayed on Sunday. The current outlook
from the Storm Prediction Center is another Marginal Risk (level 1
of 5).


KEY MESSAGE 2: Increasing rain chances mid to late week with the
potential for locally heavy rainfall.

Wednesday through Thursday, the region will remain between a Bermuda
high and low pressure over the Southern Plains. This pattern should
support steady southwest H85 winds across the Deep South and
Southeast U.S., aiding in rising PW values across the region. By
Thursday, GFS forecast soundings indicate PW values exceeding 1.9"
across SE GA and SC. As temperatures warm into the low to mid 90s, a
sea breeze should develop each afternoon, pushing inland through the
early evening hours. Instability could pool into moderate levels
given dewpoints in the upper 70s to near 80 degrees. The forecast
will indicate scattered to numerous PoPs for showers and
thunderstorms.

Friday into Saturday, GFS and ECMWF indicates that the weakness
between the western Atlantic and south Rockies ridges will deepen
across the region. A weak cold front could drape across the forecast
area during the late week. In addition, an afternoon and evening sea
breeze is expected to develop each day. Given warm and humid
conditions across the region, the cold front and sea breeze
boundaries should yield areas of numerous showers and thunderstorms.

This pattern may provide weak flow, resulting in storm motions
around 15 mph. In addition, multi-cell storms could develop along the
sea breeze and any outflow boundaries. Provided PW values near 2
inches, excessive rainfall could occur, especially over areas of
recent heavy rainfall.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
KCHS/KJZI: VFR to start the 18Z TAFs with VCTS beginning at 20/19Z.
A TEMPO group has been introduced at each terminal to highlight
flight restrictions from TSRA this afternoon. VFR will prevail
thereafter.

KSAV: Prevailing VFR through the 18Z TAF period. Confidence was not
high enough in impacts from TSRA to include mention in a TEMPO group
so have just included a few hours of VCTS this afternoon.

Extended Aviation Outlook: Prevailing VFR with scattered showers and
thunderstorms each afternoon potentially bringing temporary
restrictions.

&&

.MARINE...
Today through Friday: The pressure pattern should favor
southwest winds between 10 to 15 kts. As a result, seas will
likely remain between 2 to 3 ft. Any thunderstorms that move
over the waters have the potential to bring higher wind gusts
and frequent lightning, especially late Monday afternoon/evening
off the GA and lower SC coast.

&&

.CLIMATE...
Record High Minimum Temperatures:

August 24:
KCHS: 76/2010
KCXM: 80/1975

August 25:
KCHS: 77/1982

August 28:
KCHS: 77/2020

&&

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

&&

$$

CPM/NED