North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

558
FXUS62 KCHS 111819
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
219 PM EDT Tue Aug 11 2026

.WHAT HAS CHANGED...
All sections have been updated.

&&

.KEY MESSAGES...
- 1) Hot and humid conditions continue into the weekend. A Heat
  Advisory is in effect today and Wednesday afternoon along the
  coastal corridor. Additional Heat Advisories will likely be
  needed, though an Extreme Heat Watch/Warning will also be
  possible, especially toward the end of the week.

- 2) Scattered to numerous thunderstorms will develop across
  southeast Georgia and the lower South Carolina Lowcountry,
  especially near the coast. A few storms may produce damaging
  wind gusts and heavy downpours this afternoon and evening.
  Another round of strong to severe thunderstorms remain
  possible across portions of our area late Wednesday.

&&

.DISCUSSION...
KEY MESSAGE 1: Hot and humid conditions continue into the
weekend. A Heat Advisory is in effect today and Wednesday
afternoon along the coastal corridor. Additional Heat Advisories
will likely be needed, though an Extreme Heat Watch/Warning
will also be possible, especially toward the end of the week.

Today: Latest surface observations indicate widespread heat indices
of 105-110F with temperatures in the low to mid 90s and dew points
in the mid to upper 70s. A Heat Advisory remains in effect for the
coastal counties through 8 PM, but increasing coverage of showers
and thunderstorms this afternoon could shorten the duration that
heat indices stay at the 108 criteria, particularly along the
southeast Georgia coast.

Wednesday: Similar to today, will see highs rise into the mid 90s,
with dewpoints behind the sea breeze surging into the mid to upper
70s. This will yield heat index values up to 110 degrees east of I-
95. Thus, after collaboration with neighbors, have issued another
Heat Advisory which will be valid 11 AM to 8 PM. We encourage folks
to stay hydrated, take frequent breaks in the shade or AC, and check
on vulnerable populations like children and the elderly.

Thursday and Friday: Upper level ridging amplifies during the later
half of the week, which will result in the warmest temperatures of
this heat wave. Highs in the upper 90s will be common, with perhaps
a few locations briefly touching 100 degrees. These temperatures
combined with dewpoints in the 70s will yield heat index values
between 105-108 degrees west of I-95, with areas east soaring as
high as 115 degrees. While additional Heat Advisories remain likely,
can`t rule out needing an Extreme Heat Watch/Warning for some
locations.

This Weekend: Will see the aforementioned ridge shift a bit westward,
resulting in a slight downtick of temperatures, especially Sunday
with highs forecast in the low to mid 90s. Nonetheless, with
dewpoints remaining in the 70s, will unfortunately see oppressive
heat continue as heat index values reach upwards of 110 degrees
along the coastal corridor.

KEY MESSAGE 2: Scattered to numerous thunderstorms will develop
across southeast Georgia and the lower South Carolina Lowcountry,
especially near the coast. A few storms may produce damaging wind
gusts and heavy downpours this afternoon and evening. Another round
of strong to severe thunderstorms remain possible across portions
of our area late Wednesday.

Rest of today: Radar imagery early this afternoon showed increasing
coverage of showers and thunderstorms across the area. Focus for
highest convective coverage through the remainder of the afternoon
and early evening should be roughly Colleton county and south
through southeast Georgia. Per SPC Mesoanalysis, the environment is
characterized by 3000-3500 J/kg MLCAPE, steep low level lapse
rates, and DCAPE on the order of 800-1000 J/kg. A few storms
have the potential to become strong to severe, with damaging
wind gusts being the primary hazard. In addition, locally heavy
rainfall will be possible in any storm that develops. 12z HREF
highlights coastal areas roughly Colleton county south to the
Altamaha River as having the highest probabilities for 3-hr
rainfall totals of >1 inch and even >3 inches. Localized
flooding is possible. Convection should largely wane later this
evening with loss of heating.

Wednesday: Upper level ridging continues to push eastward
Wednesday, with the center becoming focused across the Gulf. As
a result, NW to SE heights may align over our area. Latest
guidance suggest that dry conditions should largely prevail
through the afternoon, with precipitation chances then
increasing through the evening and overnight period.
Nonetheless, model consensus on timing and location still remain
rather poor. While some CAMs support isolated storms mainly
across southeast GA, others show an MCS tracking from upstate
South Carolina into the Coastal Plains, suggesting that coverage
could become a bit more widespread/displaced across our area.
Given that there are a lot of factors in play that could cause
this forecast to bust, want to emphasize that the severe threat
will be highly conditional on how storms/boundaries evolve
upstream. In the event that storms DO become severe, expect
damaging gusts to be the primary hazard, along with brief heavy
downpours and lightning.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Prevailing VFR through 18z Wednesday. Radar early this afternoon
showed increasing coverage of showers and thunderstorms. There is
potential for gusty winds and brief reductions in ceilings and
visibilities within any storm that directly impacts the terminals,
with highest probabilities of occurrence at KSAV. Coverage will wane
overnight with loss of heating. Another round of showers and
thunderstorms will be possible Wednesday, particularly at KSAV,
however activity looks to occur beyond the valid TAF cycle.

Extended Aviation Outlook: Periodic flight restrictions may occur
with any shower and thunderstorm late Wednesday. Otherwise, expect
VFR conditions to prevail.

&&

.MARINE...
The pressure pattern will support south winds around 10-15 kts
today, shifting from the southwest tonight. Wave heights are
forecast to remain between 2 to 3 ft. Scattered to numerous
thunderstorms may push over the nearshore waters late this
afternoon and evening. A few of these storms may produce wind
gusts in excess of 34 kts, especially the nearshore GA and lower
SC waters.

Wednesday through Saturday: A weak coastal trough will set up across
the marine waters this week, persisting into the start of the
weekend. Small Craft Advisories are not expected at this time, as
southwesterly gusts remain around 15 to 20 kts, with seas between 2
to 3 ft.

Coastal Flooding: While elevated tidal cycles are expected this
week due to the upcoming perigee and new moon, the south-
southwesterly surface flow should keep tidal departures low,
limiting the overall coastal flood threat. For the evening high
tide tonight (occurring at 749 PM in the Charleston Harbor),
tide levels look to peak around 6.7-6.8 ft MLLW, with some
probabilistic guidance indicating only a 10% chance of reaching
6.9 ft MLLW.

&&

.CLIMATE...
Record High Temperatures:

August 11:
KCHS: 98/1968
KCXM: 97/1954

August 12:
KCHS: 98/1957
KCXM: 98/1998
KSAV: 100/1999

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

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

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

Record High Minimum Temperatures:

August 10:
KCHS: 80/2007
KSAV: 79/2024

August 11:
KCHS: 79/1983
KCXM: 82/2021
KSAV: 78/1878

August 12:
KCHS: 79/1999
KSAV: 80/1878

August 13:
KCHS: 81/2023
KCXM: 83/2023
KSAV: 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
KSAV: 78/2019

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Heat Advisory until 8 PM EDT this evening for GAZ217>219-
     239>241.
     Heat Advisory from 11 AM to 8 PM EDT Wednesday for GAZ217>219-
     239>241.
SC...Heat Advisory until 8 PM EDT this evening for SCZ148>152.
     Heat Advisory from 11 AM to 8 PM EDT Wednesday for SCZ148>152.
MARINE...None.

&&

$$

ETM/SST