North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

986
FXUS62 KCHS 291812
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
212 PM EDT Mon Jun 29 2026

.WHAT HAS CHANGED...
All sections updated.

&&

.KEY MESSAGES...
- 1) A Heat Advisory is in effect for coastal southern SC and
  counties roughly south of I-16 in southeast GA as hot and
  humid conditions dominate the forecast area again today.

- 2) High temperatures will be slightly above normal on Tuesday,
  then gradually rising through the holiday weekend. Heat
  Advisories could be needed during the holiday weekend across
  portions of our area.

&&

.DISCUSSION...
KEY MESSAGE 1: A Heat Advisory is in effect for coastal southern SC
and counties roughly south of I-16 in southeast GA as hot and humid
conditions dominate the forecast area again today.

Today the region will remain under the eastern periphery of mid-
level ridging centered over the Deep South. At the surface a weak
boundary will attempt to slide southward across the forecast area as
high pressure centered over New England nudges southward. While the
upper level pattern remains a very similar synoptic setup to
yesterday, the surface pattern is quite different. Whereas yesterday
the flow at the surface was westerly, yielding a pinned sea breeze,
today the flow will be much weaker and out of the NW. The sea breeze
is expected to begin its inland progression around 2 PM, a few hours
earlier than yesterday. With the surface setup today the region will
see less mixing out of dew points, allowing heat index values to
climb upwards of 108 degrees at several locations across the region.
A Heat Advisory is in effect from Beaufort County, SC southward to
counties roughly along and south of I-16 in southeastern GA through
6 PM this evening. Elsewhere conditions will still be hot and muggy,
but in the 100-105 degree heat index range (shy of Heat Advisory
criteria).

A fly in the ointment in regards to today`s forecast is the potential
for afternoon convection. The 12Z CAMs are in fairly decent
agreement on scattered to widespread coverage across southeastern
GA, generally where the Heat Advisory is in effect. The Heat
Advisory may be canceled early if the coverage of convection is
great enough to lower heat index values below criteria. While
widespread severe weather is not anticipated, forecast soundings
show DCAPE values upwards of 1200 J/kg. Therefore, a strong to
marginally severe storm is possible, especially where boundary
interactions occur.


KEY MESSAGE 2: High temperatures will be slightly above normal on
Tuesday, then gradually rising through the holiday weekend. Heat
Advisories could be needed during the holiday weekend across
portions of our area.

Ridging aloft will remain the dominant synoptic feature this week,
initially centered over the TN Valley on Tuesday. It will then shift
eastward towards the East Coast by the end of the week and remain in
place through the holiday weekend. The main forecast highlight will
continue to be the temperatures. Wednesday will feature highs
slightly above normal, with temperatures warming to above normal
into the holiday weekend. High temperatures could again reach into
the mid to upper 90s late week and into the holiday weekend, which
combined with dewpoint values in the 70s will likely yield heat
index values in the 100-110 range. Heat Advisories could be required
for portions of the forecast area at the end of the week and into
the holiday weekend. Generally a dry forecast has been maintained,
with PoPs trending upwards towards a more typical summertime
pattern in the later half of the holiday weekend.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Prevailing VFR through the 18Z TAF period at KCHS/KJZI/KSAV. Winds
at KCHS/KJZI initially out of the NW around 18Z will shift to the
S/SE as the afternoon sea breeze works its way inland over the next
hour or so. KSAV has the best chance of seeing afternoon
showers/thunderstorms today, with a TEMPO group in place from 18 to
21Z. Once convection wanes this evening conditions overnight should
remain precipitation free, with winds shifting back to the NE in the
early morning hours.

Extended Aviation Outlook: Brief flight restrictions are
possible with isolated showers and thunderstorms Tuesday afternoon.

&&

.MARINE...
Rest of This Afternoon and Tonight: SE winds this afternoon
gusting to around 10 to 15 knots will shift to the NE, remaining
elevated.

Extended Marine: The synoptic pattern will generally support
winds from the NE or E through Thursday. Then, they will clock
around to the SW by Friday morning. Friday into the holiday
weekend, winds will have a typical summertime pattern. This will
consist of some backing during the day, with the highest winds
along the land/sea interface with the formation of the sea
breeze. Gusts could approach 20 kt, especially in Charleston
Harbor as the sea breeze moves through. At night, expect winds
to veer and possibly ease a few kt. Seas should stay 5 ft or
less. No Small Craft Advisories are expected.

&&

.CLIMATE...
Record High Temperatures:

June 29:
KCHS: 99/1998
KSAV: 101/1959

July 4:
KCHS: 98/2023
KSAV: 99/1997

Record High Minimum Temperatures:

July 3:
KCHS: 78/2016

July 4:
KCHS: 79/2016
KSAV: 79/1931

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Heat Advisory until 6 PM EDT this evening for GAZ114-115-137-
     216>219-238>241.
SC...Heat Advisory until 6 PM EDT this evening for SCZ148-151.
MARINE...None.

&&

$$