Hilton Head Island, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

063
FXUS62 KCHS 250120
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
920 PM EDT Fri Jul 24 2026

.WHAT HAS CHANGED...
Key Message 1 was updated to reflect a slight extension of the
Flood Watch.

&&

.KEY MESSAGES...
- 1) A Flood Watch is in effect for the Charleston Quad-County
  in the SC Lowcountry. Locally heavy rainfall will be possible
  today and again Saturday.

&&

.DISCUSSION...
KEY MESSAGE 1: A Flood Watch is in effect for the Charleston
Quad-County in the SC Lowcountry. Locally heavy rainfall will
be possible today and again Saturday.

Tonight: The Flood Watch was extended until 2 AM. Despite
earlier convection, there remains a healthy amount of MLCAPE out
there late this evening with values approaching 2000 J/kg.
Upstream convection moving across east-central Georgia is
showing signs of expanding/intensifying and is poised to impact
the Flood Watch area over the coming hours. Some areas have
already received as much as 4-5" so additional rainfall could
yield some hydrologic issues into the early morning hours
Saturday.

Saturday: A mid-level trough will be over most of the East Coast,
with it`s axis shifting eastward as time progresses. Additionally,
there will be several subtle shortwaves moving through the broader
flow. At the surface, the stationary front will be over the
Charleston Tri-County or just north of this area. There will be a
large area of very deep moisture across the Southeast U.S. PWATs
should peak in the 2.25-2.5" range across our area. This would be
near record values for CHS per SPC Sounding Climatology and 2-3
standard deviations according to NAEFS. The combination of lift from
the front along with the deep moisture will generate numerous to
widespread showers and thunderstorms across our area. They`ll likely
ongoing early in the morning, mainly north of I-26. But the coverage
and intensity will increase into the afternoon, especially along the
seabreeze. Though, both the deterministic models and the CAMs point
towards the higher QPF amounts being along the immediate coast.
Rainfall productions should be very efficient and weak steering
winds should cause storms to move very slowly and/or stay in place.
If heavy rainfall occurs over the Charleston and/or Savannah metro
areas, then flash flooding concerns would quickly escalate,
especially if there are saturated soils from Friday`s rainfall.
Therefore, WPC has most of our SC counties under a Slight Risk for
Excessive Rainfall. The rainfall should gradually decrease in both
intensity and coverage Saturday evening and overnight.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
25/00z Aviation Discussion:
KCHS/KJZI/KSAV: Risk for tstms is diminishing at all terminals.
Risk will increase again Saturday afternoon for all sites. Risk
highest roughly 20-00z, maybe a tad earlier at KCHS and KJZI.

Extended Aviation Outlook: A stationary front nearby will
continue to bring periods of flight restrictions through Sunday
due to showers and thunderstorms.

&&

.MARINE...
Tonight: Southerly wind regime will persist. Winds 15 kt or less
with seas 2-3 ft.

Saturday through Wednesday: A stationary front nearby will
bring southwesterly winds on Saturday. Winds will briefly veer
to the north and northeast on Sunday, then again Monday morning,
followed by a shift to the southeast Monday afternoon. Winds
will become elevated Tuesday night into Wednesday, so Small
Craft Advisories may be needed for portions of our waters.

&&

.CLIMATE...
Record High Minimum Temperatures:

July 24:
KCHS: 81/2024

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

July 29:
KCHS: 80/2016

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...Flood Watch until 2 AM EDT Saturday for SCZ043>045-149-150-152.
MARINE...None.

&&

$$