North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

393
FXUS62 KCHS 131143
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
743 AM EDT Thu Aug 13 2026

.WHAT HAS CHANGED...
The Aviation Section has been updated for the 12Z TAF issuance.

&&

.KEY MESSAGES...
- 1) Extreme/Excessive heat will remain a concern into early
  next week.

- 2) There is a risk of strong thunderstorms today.

&&

.DISCUSSION...
KEY MESSAGE 1: Extreme/Excessive heat will remain a concern into
early next week.

Today into Next Week: A large-scale ridge across much of the South
Central United States will expand eastward today through late week,
becoming centered across the Deep South and Southeast United States
and favoring a warm west/northwesterly aloft. Ample sunshine will
promote strong sfc heating during the next couple days, with 1000-
850 mb thickness levels supportive of afternoon highs in the mid-
upper 90s, with some locations touching 100 degrees away from the
coast through much of the weekend. In addition to hot temperatures,
conditions will be quite humid with sfc dewpts in the mid-upper 70s
each day. Although some mixing out of sfc dewpts is anticipated
inland with the downslope wind setup locally, a sea breeze will
eventually shift higher moisture content onshore each day for at
least a few hours. This will likely result in the higher
heat/moisture combination along coastal zones (along/east of I-95)
for the next couple days, with heat index values up to the 110-115
range this afternoon and again Friday afternoon. Further inland,
heat index values should top out in the 105-110 degree range. Given
the setup and expected heat index values, an Extreme Heat Warning
remains in effect for coastal counties from 11 AM to 8 PM today
while remaining areas are included in a Heat Advisory for the same
time period. The slightly more favorable position of the synoptic
ridge supports slightly higher heat index values along the coastal
corridor Friday. Therefore, an Extreme Heat Watch has been issued
for all Southeast SC/GA coastal zones from 11 AM to 8 PM Friday
afternoon. Another Heat Advisory could be needed for inland areas on
Friday as well.

Hot/humid conditions likely remain across the Southeast United
States late weekend into early next week with the large-scale ridge
centered over or nearby, although a front could lead to greater
shower/thunderstorm coverage that limits maximum heat conditions.
Additional heat headlines could be needed through early next
week.

KEY MESSAGE 2: There is a risk of strong thunderstorms today.

Strong ridging aloft will persist over the southeastern states today
while a shortwave ripples across the northern periphery of the
ridge. CAMs have struggled the last few days to get a handle on
convection given the northwesterly flow at the surface, but the
shortwave could be enough forcing to trigger thunderstorms across
the SC Midlands. The latest runs of the HRRR and the 00Z HREF depict
some convection firing in the later afternoon hours and tracking
into the SC Lowcountry and Southeastern GA into the evening.
Additionally, isolated convection is possible with the afternoon sea
breeze. Unlike on Wednesday, the sea breeze shouldn`t be pinned at
the coast and looks to be progressive this afternoon. The forecast
features slight chance thunderstorms this afternoon. Any storms that
are able to form or track into the forecast area have the chance to
become strong. The environment this afternoon is forecast to have
DCAPE values upwards of 1000 J/kg. The main threat this afternoon
would be damaging wind gusts with any of the stronger thunderstorms.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
VFR conditions are expected to prevail at CHS/JZI/SAV terminals
through 12Z Friday. However, there is a low risk for an
isolated shower and/or thunderstorm to impact the terminals this
afternoon, perhaps near a mid-late afternoon sea breeze. Confidence
remains too low to include mention of showers/thunderstorms and
associated MVFR conditions with the 12Z TAF issuance.

Extended Aviation Outlook: Prevailing VFR.

&&

.MARINE...
Today and Tonight: Conditions are expected to remain fairly quiet
across local waters between the western periphery of an Atlantic
high and weak troughing inland. Light westerly winds will turn
southerly this afternoon, topping out near 10-15 kt along the coast
where a sea breeze develops, then shifts inland mid-late day. There
could be some modest nocturnal surging during evening hours with
gusts up to 15-20 kt prior to midnight. Seas will be no larger than
2-3 ft.

Friday through Monday: Conditions are expected to remain below Small
Craft Advisory criteria into the weekend and early next week. A weak
coastal trough will persist across the marine waters this weekend
and into the start of next week. This set up will keep conditions
across the marine waters breezy with southwesterly winds gusting
around 15 knots with occasional gusts to 20. 2 to 3 ft seas are
expected across the marine zones this week.

Coastal Flooding: Tide levels could remain elevated due to the
recent perigee and new moon during the evening high tide cycle,
although a south-southwesterly wind should keep tidal departures
less favorable for a coastal flood threat. Should onshore winds
linger longer than anticipated, minor coastal flooding (~7.0 ft
MLLW) could become an issue in the Charleston Harbor during the
high tide this evening, which occurs ~9:30 PM.

&&

.CLIMATE...
Record High Temperatures:

August 13:
KCHS: 100/1995
KCXM: 98/1913
KSAV: 98/2010

August 14:
KCHS: 102/1995
KSAV: 102/1925

August 15:
KCHS: 96/2023
KCXM: 99/1918
KSAV: 100/1918

August 17:
KCHS: 102/1954
KSAV: 102/1954

August 18:
KCXM: 97/1995
KSAV: 100/1995

Record High Minimum Temperatures:

August 13:
KCHS: 81/2023

August 14:
KCHS: 80/2023
KCXM: 83/2023
KSAV: 80/2023

August 15:
KCHS: 78/1995
KCXM: 83/2021
KSAV: 80/1995

August 16:
KCHS: 78/2019
KCXM: 83/2016
KSAV: 78/2019

August 17:
KCHS: 80/2017
KCXM: 83/2017
KSAV: 78/2017

August 18:
KCHS: 80/2017
KCXM: 82/2017
KSAV: 78/2010

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Heat Advisory from 11 AM this morning to 8 PM EDT this evening
     for GAZ087-088-099>101-114-115-137-216-238.
     Extreme Heat Warning from 11 AM this morning to 8 PM EDT this
     evening for GAZ217>219-239>241.
     Extreme Heat Watch from Friday morning through Friday evening
     for GAZ217>219-239>241.
SC...Heat Advisory from 11 AM this morning to 8 PM EDT this evening
     for SCZ040-042>045-147.
     Extreme Heat Warning from 11 AM this morning to 8 PM EDT this
     evening for SCZ148>152.
     Extreme Heat Watch from Friday morning through Friday evening
     for SCZ148>152.
MARINE...None.

&&

$$