625
FXUS62 KCHS 171128
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
728 AM EDT Tue Jun 17 2025

.SYNOPSIS...
Atlantic high pressure will continue to build across the
Southeast through the week. A cold front could approach the
region late week, though most indications are for the front to
stall to our northwest.

&&

.NEAR TERM /THROUGH TONIGHT/...
The center of a 593 DM ridge will remain off the GA coast through
this afternoon. At the sfc, the forecast area will remain between a
high centered over the western Atlantic and a developing lee trough.
This pattern will support southwest flow today, shifting from south
with a sea breeze late this afternoon. Given strong insolation, late
sea breeze, and very mild llvl thicknesses, high temperatures are
forecast to range in the low to mid 90s. Heat index values may peak
between 100-105 degrees for most areas this afternoon, especially
across the coastal counties. Isolated to scattered showers and
thunderstorms may provide some relief from the heat this afternoon.
High resolution guidance indicates that the greatest coverage is
expected across SE GA along the sea breeze.

Tonight, any convection that develops this afternoon should
dissipate by mid-evening. The rest of the night is forecast to
remain dry and mild. Low temperatures should range from near 80
along the coast to the mid 70s inland.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
Upper level ridging with a surface high pressure over the Atlantic
continues through Wednesday. As low-mid level moisture continues to
flow up along the coast from the southwest, 1-2 kJ/kg of CAPE if the
weak cap can be broken will allow for scattered showers and
thunderstorms on Wednesday. High resolution models would suggest
coverage to be far and few between, so have kept pops limited to 20
percent, with best chances during the afternoon hours as a sea-
breeze is expected to push ashore. Throughout the day on Thursday, a
mid-level shortwave begins to flatten the ridge allowing for
additional moisture to be advected in from the west, which looks to
allow for increased coverage in showers and thunderstorms with pops
in the 30-40 percent range. While 1-2 kJ/kg of CAPE remains
possible, the lack of mid-level flow and thus low shear values leads
to low chances for severe weather. Overnight and continuing into
Friday, the weak trough axis moves across the area with ridging
building in from the west. A cold front is expected to move down out
ahead of a building surface high pressure, though most guidance
continues to show the front stalls off to our northwest. The front
will act to focus additional chances for showers and thunderstorms
throughout the day, with pops currently in the 30-50% range. High
temperatures look to remain fairly consistent in the lower to mid
90s, with heat indices in the upper 90s to lower/mid 100s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
The aforementioned front washes out throughout the weekend, with
upper level ridging building in from the west and a surface high
pressure remaining over the Atlantic. Temperatures remain largely in
the lower to mid 90s with heat indices topping out 100-105F. Diurnal
showers and thunderstorms continue throughout the weekend and
into the beginning of next week.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
12Z TAFs: VFR conditions with southwest winds through the TAF
period. Winds could become gusty during the afternoon hours,
especially at KJZI. It is possible that isolated showers or
thunderstorms may develop along the sea breeze near KSAV late
this afternoon, coverage too limited to highlight in the TAF at
this time.

Extended Aviation Forecast: Brief flight restrictions are possible
in showers and thunderstorms each day, mainly in the afternoon.

&&

.MARINE...
Today and tonight, the forecast area will remain between a high
centered over the western Atlantic and a developing lee trough. This
pattern should support SSW winds between 10-15 kts with gusts to 20
kts through the near term period. Seas are forecast to range from 3
to 4 ft.

Wednesday through Sunday: A broad, south-southwesterly wind regime
can be expected with winds generally averaging 15 kt or less, except
a bit higher along the land/sea interface and Charleston Harbor each
afternoon with the sea breeze which could exceed 20 knots through
Thursday. Seas will remain 4 ft or less through the period.

&&

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

&&

$$

NEAR TERM...NED
SHORT TERM...APT
LONG TERM...APT
AVIATION...APT/NED
MARINE...APT/NED