Hilton Head Island, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

619
FXUS62 KCHS 250020
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
820 PM EDT Sun May 24 2026

.WHAT HAS CHANGED...
Aviation.

&&

.KEY MESSAGES...
- 1) Increased chances for showers and thunderstorms early this
  week.

&&

.DISCUSSION...
KEY MESSAGE 1: Increased chances for showers and thunderstorms
early this week.

Aloft, a similar setup remains across the region today along the
western periphery of an Atlantic ridge, with h5 shortwave energy
rippling across the Deep South and Southeast United States and
promoting shower and thunderstorm development across a moist (PWAT
1.8 to 2.0 inches) and warm environment this afternoon into early
evening. Convection today should occur in two waves. The first is
ongoing with numerous shower and thunderstorms developing near and
inland of a sea breeze circulation across Southeast South Carolina.
This convection is likely to remain sub-severe given an earlier
start today and a lack of stronger deep-layer shear, but still
capable of producing gusty winds up to 35-45 mph and heavy downpours
during early-mid afternoon hours with a focus of heaviest rainfall
across a stretch from Dorchester into Berkeley Counties going
forward. Hourly rainfall rates exceeding 2 inches per hour could
lead to minor flooding, especially in poorly drained areas.

The second wave of convection should arrive across Southeast Georgia
late afternoon, in a slightly more unstable environment marked by
MLCAPE around 2000-2500 J/kg, but still within weaker shear (0-6
Bulk Shear around 20 kt). Some hires guidance seems to be picking up
on this scenario, with convection spreading across Southeast Georgia
mid-late afternoon when sfc high temps have peaked in the upper 80s
and where mid 70 dewpts reside along/ahead of a sea breeze
circulation making way inland. Additionally, an outflow boundary has
developed from ongoing convection across Southeast South Carolina
and has entered Southeast Georgia early this afternoon, which could
provide another focus for convection to initiate and/or become
enhanced during peak heating hours across or just inland to the
local area. Similar to the previous day, the environment should
support numerous to widespread showers and thunderstorms spreading
into the area from the south/southwest by late afternoon hours, with
a few storms embedded in convective clusters capable of producing
damaging wind gusts given favorable low-lvl lapse rates (7 C/km) and
DCAPE (700-900 J/kg) during peak heating. Activity should wane by
mid evening hours as instability weakens due to the loss of daytime
heating. The Storm Prediction Center continues to highlight much of
Southeast Georgia in a Marginal Risk for severe weather along/west
the I-95 corridor in the Day 1 Convective Outlook.

Another concern with late day/early evening convection is localized
heavy rainfall, given corfidi vectors indicating slow storm motions
generally around 10 kt or less in a highly moist environment (PWATs
1.8-2.0 inches) and activity running parallel to the inland
approaching sea breeze. Similar to yesterday, WPC has highlighted
inland tier counties across Southeast Georgia and Southeast
South Carolina (west of I-95) in a Day 1 Excessive Rainfall Outlook.

Memorial Day: Conditions are not expected to change much from today,
with comparable temperatures and moisture content. The sea breeze
will again be the focus for the initial thunderstorm activity, then
coverage should expand across inland areas. Locally heavy rainfall
is possible generally along and west of I-95.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
There`s a low chance for very brief MVFR ceilings overnight
tonight due to substantial low-level moisture remaining after
the daytime convection. Another round of widespread convection
expected on Monday, with KCHS/KJZI/KSAV most likely to be
impacted early in the afternoon before the sea breeze pushes the
brunt of the activity farther inland.

Extended Aviation Outlook: TEMPO flight restrictions possible with
showers and thunderstorms at CHS/JZI/SAV terminals during the
afternoon hours through the week.

&&

.MARINE...
This Afternoon and Tonight: High pressure centered over the
western Atlantic will remain the dominant feature across local
waters, favoring south-southeasterly winds generally around
15 kt today (slightly higher along the land/sea interface), then
topping out in the 15-20 kt range overnight. Seas will range
between 3-5 ft, largest across outer waters overnight.

Monday through Friday: Conditions are forecast to remain below Small
Craft Advisory criteria through the week, with daily chances for
showers and thunderstorms. High pressure to the east will drive
onshore ESE flow each day, with wind speeds mostly topping out in
the 10-15 knot range. Each afternoon and evening there could be some
local enhancement along the land/sea interface with the diurnal sea
breeze. Seas will average 2-4 feet through the period.

Rip Currents: A modest easterly swell around 3-4 ft/8s and sea
breeze influences each afternoon will keep the rip current risk in
the moderate category at all area beaches through at least
Tuesday.

&&

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

&&

$$

BRS/DPB/JRL