Hilton Head Island, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

828
FXUS62 KCHS 050634
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
234 AM EDT Sun Jul 5 2026

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

&&

.KEY MESSAGES...
- 1) Dangerous heat across portions of southeast Georgia and the
  South Carolina Lowcountry this afternoon. A few strong to
  severe thunderstorms are possible near the sea breeze this
  afternoon into early this evening.

- 2) Hot and humid conditions will persist through much of the
  week.

- 3) Typical summertime convection returns this week.

&&

.DISCUSSION...
KEY MESSAGE 1: Dangerous heat across portions of southeast Georgia
and the South Carolina Lowcountry this afternoon. A few strong to
severe thunderstorms are possible near the sea breeze this afternoon
into early this evening.

Sunday: The forecast area will remain between a mid-level trough
over the Mississippi River Valley and a 592 DM ridge centered over
the Bahamas. At the sfc, a broad trough will remain across the
middle Carolinas through this afternoon. Given strong insolation and
very warm llvl thicknesses, temperatures are forecast to exceed 90
by late this morning, then peaking in the mid to upper 90s.
Recent runs of the HRRR, indicates that a sea breeze will
develop during the mid-day, then pushing inland through this
afternoon. Sfc dewpoints in the wake of the sea breeze should
increase into the mid to upper 70s. There appears to be a couple
of hours heat index values around 108 across the coastal
counties of SC/GA. Highlighted with a Heat Advisory from 11 AM
until 7 PM.

Hot and humid conditions will likely result in SBCAPE values to
increase between 2000-3000 J/kg, potentially up to 3500 J/kg across
portions of the SC Lowcountry. In addition, DCAPE values may pool in
excess of 1000 J/kg across portions of the CWA this afternoon. High
resolution guidance indicate that thunderstorms may develop along
and near the sea breeze this afternoon. Coverage of thunderstorms
may remain the greatest across the SC Lowcountry, primarily from
Colleton County north to the Santee River. Moderate instability and
weak shear may support some strong to severe pulse-type
thunderstorms this afternoon and evening, with localized wind gusts.
It is possible that the strongest updrafts will require a Severe
Thunderstorm Warning or two. HREF indicates that PW values will
increase to around 2 inches east of the H5 trough. The deep moisture
and slow storm motions could result in some storms near the sea
breeze to produces pockets of 2-3 inch rainfall. The thunderstorms
should bring some relief from the heat late this afternoon.

KEY MESSAGE 2: Hot and humid conditions will persist through much of
the week.

Temperatures will remain above normal this week, with highs
generally peaking in the mid to even upper 90s in spots. Combined
with elevated humidity, it will feel even hotter. Heat indices over
100F are expected each afternoon, with areas closer to the coast
generally in the 105-110F range. Additional Heat Advisories will be
possible, especially in the first part of the week. It`s worth
noting that with showers and thunderstorms back in the forecast, any
convection that develops would limit the duration where heat indices
reach the 108+ criteria. Regardless, this extended stretch of hot
and humid conditions will bring a risk of heat-related impacts,
especially to those more vulnerable to heat or those without
adequate cooling/hydration.

KEY MESSAGE 3: Typical summertime convection returns this week.

A more typical summertime convective pattern is expected this week,
with daily shower and thunderstorm chances. Coverage will be highest
in the afternoon and early evenings, before dwindling after sunset
with loss of insolation. Environment favors mainly pulse-type
convection, however isolated strong to severe storms are possible
with damaging wind gusts as the primary hazard. This jives with some
of the AI/MLP guidance as well. Locally heavy rainfall is possible
in any storms with PWats near or over 2", but flooding risk looks
low especially given the hot and dry conditions of late.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
6Z TAFs: VFR conditions with light winds this afternoon. A sea
breeze is timed to push across KJZI by 16Z and KCHS and KSAV by 17Z,
resulting in south winds around 10 kts. Scattered to numerous
thunderstorms are forecast to develop near the sea breeze between 18-
22Z, highlighted with TEMPOs at each terminal. Convection should
decrease this evening.

Extended Aviation Outlook: Brief flight restrictions are possible in
afternoon showers/thunderstorms this week.

&&

.MARINE...
Today through tonight: The pressure pattern should support south
winds between 10 to 15 kts, with occasional gusts to 20 kts. Wave
heights are forecast to favor 3 ft today, increasing to 3-4 ft.

Monday through Friday: A fairly typical summertime pattern on
tap for this week. Southwest winds in the morning will back more
to the south for the afternoon and evenings. Speeds are
forecast to stay below Small Craft Advisory criteria through the
period, however gusts in the low 20 kt range are possible,
especially in the afternoon and evenings. Seas will average 2-4
feet.

&&

.CLIMATE...
Record High Temperatures:

July 5:
KSAV: 100/1902

July 7:
KCHS: 99/1954

July 10:
KCHS: 100/1986
KCXM: 99/1986


Record High Minimum Temperatures:

July 5:
KCHS: 78/2017
KCXM: 82/2016
KSAV: 78/2016

July 6:
KCHS: 79/1990
KCXM: 82/2024
KSAV: 78/2024

July 7:
KCHS: 80/2017
KCXM: 82/2022
KSAV: 80/1883

July 8:
KCXM: 83/2016
KSAV: 80/1990

July 9:
KCHS: 80/1998
KSAV: 80/1883

July 10:
KCHS: 81/1986
KCXM: 82/1986

July 11:
KCHS: 80/2016
KCXM: 82/2016

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Heat Advisory from 11 AM this morning to 7 PM EDT this evening
     for GAZ217>219-239>241.
SC...Heat Advisory from 11 AM this morning to 7 PM EDT this evening
     for SCZ045-148>152.
MARINE...None.

&&

$$

NED