Hilton Head Island, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

797
FXUS62 KCHS 252307
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
707 PM EDT Sat Jul 25 2026

.WHAT HAS CHANGED...
The aviation section was updated for the 26/00z TAFs. Key
Message 1 was updated to reflect near term trends.

&&

.KEY MESSAGES...
- 1) Locally heavy rainfall is possible through Sunday as a
  stalled front remains in the vicinity of the South Carolina
  Lowcountry.

- 2) Hot and humid conditions return to Southeast South Carolina
  and Southeast Georgia during the middle of next week.

&&

.DISCUSSION...
KEY MESSAGE 1: Locally heavy rainfall is possible through Sunday as
a stalled front remains in the vicinity of the South Carolina
Lowcountry.

Tonight: Earlier convection has dissipated, but regional radars
are already showing a secondary wave of showers/tstms developing
from the southern Midlands into central Georgia with the
approach of another mid-level shortwave. There remains plenty of
MLCAPE in the wake of earlier convection and should help sustain
this activity for a few more hours as it works east to the
coast.

Sunday: Given continued weak shortwaves aloft and the stalled
front remaining nearby, Sunday may start off with scattered
showers and isolated thunderstorms, especially across portions
of southeast South Carolina. By the late morning/early
afternoon, a surface high pressure moving in from the north
begins to shift the front to the south. As that occurs, some
models are developing a weak surface low along the front as it
shifts southwards, leading to the continuation of heavy rainfall
risks on Sunday. The 12Z HREF has a 70-90% chance for 1"/3hrs
over the Charleston tri-county area during the afternoon hours,
with a 30-50% chance for 3"/3 hrs, with probabilities decreasing
as the front/low moves to the south. In addition to the heavy
rainfall threat, steep low-level lapse rates with the high PWATs
may enhance downdraft strength, bringing a risk for strong
damaging wind gusts of 50 to 60 mph.

KEY MESSAGE 2: Hot and humid conditions return to Southeast
South Carolina and Southeast Georgia during the middle of next
week.

The mid-levels will consist of a very strong ridge over the Rockies
and Plains early to mid next week. Meanwhile, troughing will be
along the Eastern Seaboard. We`ll generally be on the eastern
periphery of the ridge, with NNW flow overhead. At the surface, weak
High pressure will prevail over or nearby early to mid next week.
Hot and humid conditions are expected to return during the middle of
next week. Tuesday and Wednesday look to be the hottest days of the
week, with highs in the mid to upper 90s, with some spots possibly
reaching the 100 degree mark across far inland GA. Even temperatures
at the coast will be in the 90s. Dewpoints are expected to be in the
low 70s far inland, but pool into the mid to upper 70s at the coast
with the afternoon sea breeze. This will equate to heat indices in
the 100-105 degree range inland, and the 108-112 degree range for
our coastal counties on Tuesday. Though, the range could increase to
110-115 degrees for our coastal counties on Wednesday. If this pans
out, at least our coastal counties would need heat headlines both
days. The wild card would be afternoon convection. Tuesday is
looking fairly dry. But Wednesday may have scattered convection,
which would quickly lower temperatures. It could also lead to strong
to marginally severe storms. But those details will get ironed out
in later forecasts. The heat and humidity is expected to drop to
near normal values on Thursday with the arrival of a front.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
26/00z TAF Discussion:
KCHS/KJZI/KSAV: Earlier convection has dissipated, but radar is
showing a secondary wave of showers/tstms starting to develop
from the southern Midlands into central Georgia. This activity
will continue to push east/southeast this evening, possibly
impacting all three terminals. Preliminarily, PROB30s were
introduced to account for this activity, but TEMPO groups may be
considered just before the final TAF package is released.
Conditions would be limited to MVFR for now. Quiet conditions
overnight. Risk for showers/tstms will once again maximize
during the afternoon hours Sunday. PROB30 was introduced 20-23z
at KCHS and KJZI given models are hinting at better coverage
across the South Carolina Lowcountry. No mention was included at
KSAV for now given confidence is a bit lower there.

Extended Aviation Outlook: Brief flight restrictions are possible
Wednesday and Thursday due to showers and thunderstorms.

&&

.MARINE...
Through Thursday: A stationary front nearby will continue
southwesterly winds today. Expect modest winds and seas Sunday
and Monday. Winds and seas will be much higher late Tuesday into
Wednesday, so Small Craft Advisories may be needed for most of
our waters.

&&

.CLIMATE...
Record High Temperatures:

July 28:
KCHS: 101/1949
KCXM: 100/1936
KSAV: 102/1949

July 29:
KCHS: 100/1993
KCXM: 99/1999
KSAV: 103/1993

Record High Minimum Temperatures:

July 25:
KCHS: 80/2011
KCXM: 82/2016
KSAV: 80/1893

July 29:
KCHS: 80/2016
KCXM: 85/1999
KSAV: 82/1878

&&

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

&&

$$