830
FXUS62 KCHS 291820
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
220 PM EDT Sun Jun 29 2025

.SYNOPSIS...
High pressure will extend across the region through early week.
A cold front will then approach the area around the middle of
the week, possibly stalling near the coast through late week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Latest SPC mesoanalysis indicated that most of the forecast area
feature SBCAPE around 2500 J/kg with little to no CIN.
Scattered showers and thunderstorms will likely develop as a
slow moving sea breeze pushes inland this afternoon and evening.
12Z observed sounding indicated the freezing level was slightly
over 15 kft. Some of the storms this PM may achieve echo tops
in excess of 40 kft. However, with DCAPE values between 600-800
J/kg, strong storms with gusty winds should remain very limited.
Given PW values as high as 1.9 inches, a few locations may see
very heavy downpours resulting in localized amounts between 2-3
inches. The greatest potential for heavy rainfall appears across
inland SE GA this afternoon into early this evening. Deep convection
across SE GA/SC should dissipate late this evening, some shower
activity may develop over portions of the Atlantic waters late
tonight. Low temperatures are forecast to range from near 70
inland to the mid to upper 70s along the coast.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
Monday and Tuesday: Weak, broad low pressure will be present over
the Southeast in the upper levels Monday and Tuesday. The area is
also positioned along the western periphery of ridging in the mid
levels, as well as surface high pressure fixed over the Atlantic,
otherwise no real defined synoptic features will be present. Models
show PWAT values approaching 2.0" each afternoon, which combined
with sufficient instability will be supportive of convection each
afternoon. Given the lack of large scale forcing thunderstorms will
likely focus along the afternoon sea breeze and boundary
interactions. The forecast features PoPs generally 40-60% each
afternoon; the greatest chances across southeastern GA where the
greatest moisture/instability is focused. Temperatures will be
consistent with highs both days in the upper 80s/lower 90s, and min
temps in the low to mid 70s.

Wednesday: Ensemble guidance is in fairly good agreement that an
upper level disturbance will cross New England with trailing
vorticity all the way towards FL. As this occurs, a cold front will
approach from the northwest Wednesday morning. Deep moisture noted
by a slight surge in PWAts to around 2.2", combined with sufficient
instability should support numerous to widespread showers and
thunderstorms. Seasonable temperatures are forecast with highs in
the upper 80s to low 90s.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
The aforementioned cold front shows signs of stalling over or near
the forecast area just before reaching the coast Thursday. Although
it appears the axis of deep moisture will nudge offshore Wednesday
night, enough moisture will remain to support scattered showers and
thunderstorms Thursday, especially with llvl convergence to focus
convection near the front. The upper level disturbance will then
eject off the Northeast coast Friday. As this occurs, a return to a
more climatological summer pattern is forecast with a chance of
showers and thunderstorms during the afternoons. However a lesser
confidence, but potential scenario, is that a weak surface low forms
along the remnants of the front near the end of the week, which
could keep elevated rain chances through next weekend. Temperatures
will remain in the low 90s through next weekend.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Prior to the 18Z TAFs, KCLX detected isolated showers near KCHS.
In addition, visible satellite indicated developing Cu near
KSAV. Both KCHS and KSAV TAFs will feature a mention of VCSH at
the start of the 18Z TAFs. Based on satellite trends and recent
runs of the CAMs, TEMPOs from 19-23Z will be added to KCHS and
KSAV for -TSRA with gusty winds and at least MVFR visibility.
Convection should slide inland of the terminals by 23z, the rest
of the TAF period should remain dry and VFR. South winds are
timed to strengthen between 5 to 10 kts by 15z Monday.

Extended Aviation Outlook: Brief flight restrictions are possible
Monday and Tuesday afternoon during convection. Wednesday and
Thursday, more widespread coverage of showers and thunderstorms are
forecast as a cold front approaches from the northwest. This could
provide more frequent periods of ceiling and visibility
restrictions.

&&

.MARINE...
Tonight, the marine zones will remain between high pressure centered
over the western Atlantic and broad trough across the middle
Carolinas and GA. This pattern should yield southerly winds
generally between 10-15 kts. Seas are forecast to range between
2 to 3 ft.

Monday through Friday: High pressure over the Atlantic will prevail
through the upcoming week, yielding south/southwest flow. Gusts
along the coast could reach 20 knots each afternoon in association
with the afternoon sea breeze. With the approach of a cold front mid
week, winds could surge across the local waters Tuesday evening.
Small Craft Advisories could be needed, especially across the
Charleston County nearshore waters. Seas will build to 2-4 ft by
Monday night and remain through the period.

&&

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

&&

$$

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