106
FXUS62 KCHS 281743
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
143 PM EDT Sat Jun 28 2025

.SYNOPSIS...
High pressure will extend across the region through early next
week. A cold front will then approach the area around the
middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 140 PM, SPC mesoanalysis indicated that CAPE across the
region was between 1000-1500 J/kg. Satellite showed develop
cumulus across portions of inland GA/SC. KCLX detected the
initial showers near Awendaw, SC and west of Sylvania, GA.
Isolated to scattered showers and thunderstorms should continue
to develop through the rest of the afternoon as the sea breeze
drifts inland.

Today: An area of low pressure remains closed across the
southeastern United States as a mid-level ridge continues to anchor
near Bermuda. On Friday, the upper level axis had a northwest/
southeast orientation with a surface weakness near the Midlands of
SC. Today, the upper level low axis is forecast to be oriented
north/ south as another mid-level low retrogrades across the
Bahamas. Forecast soundings for today advertise a relatively
saturated layer from 800 to 600 mb with PWATs around 1.85". K
index values are also forecast to be in the 31 - 35 range. The
analysis above would support a return of convection along an
inland moving sea breeze, with convective initiation occurring
first in Charleston County (due to the curvature of the coast).
High temperatures will again be in the 90 to 95 degree F range
with heat index values topping out between 100 to 105 degrees F.

Tonight: Convection will slowly move inland and come to an end this
evening. Low temperatures will be in the lower 70s.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
Broad low pressure will be present in the mid-levels on Sunday,
slowly transitioning to broad troughing over the southeastern states
by Tuesday. At the surface a weak trough is forecast to develop
along the southeastern coastline on Sunday, lingering into Monday.
High pressure will briefly build into the region on Tuesday. Models
are showing PWAT values approaching 2.0" each afternoon, which
combined with 1500-1800 J/kg of CAPE will likely be supportive of
convection each afternoon. Given the lack of large scale forcing
thunderstorms will likely focus along the afternoon sea breeze and
other boundary interactions. The forecast features PoPs generally 40-
60% each afternoon, with the greatest chances across southeastern
GA. High temperatures will reach into the low to mid 90s, with heat
index values around 100-103F. Overnight lows will be in the 70s.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
On Wednesday a mid-level trough will be present across the eastern
CONUS, persisting through the end of the week before ejecting off
the New England coast on Saturday. At the surface a cold front will
approach the region on Wednesday, likely stalling in the vicinity
into Thursday. The greatest coverage of precipitation is expected
Wednesday and Thursday, owing to the front. The GFS shows PWAT
values pushing 2.3" on Wednesday afternoon. This deep moisture
combined with CAPE values across the region of 1000-1500 J/kg should
support numerous to widespread afternoon showers and thunderstorms.
Temperatures will be slightly cooler than the previous week, due to
the increased precipitation chances, with highs in the upper 80s to
low 90s.

&&

.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
18Z TAFs: Generally VFR conditions expected across the terminals
through the TAF period. Prior to the TAFs, cumulus clouds were
developing along a sea breeze, located between KCHS and KJZI.
Isolated to scattered showers and thunderstorms should develop
along and ahead of the sea breeze later this afternoon. Based on
satellite trends and recent runs of the CAMs, the KCHS and KSAV
TAFs will feature a mention of VCTS between 20Z to at least 0Z
Sunday. Winds should decrease to 5 kts or less by late this
evening, then increasing from the SW around 10 kts by late
Sunday morning.

Extended Aviation Forecast: VFR will generally prevail through the
period, however brief flight restrictions are possible during
afternoon and evening showers and thunderstorms through the weekend.
Increased coverage of precipitation could bring additional
restrictions into the middle of next week.

&&

.MARINE...
Today and Tonight: A typical summertime pattern will persist for the
marine zones as surface high pressure remains centered southwest of
Bermuda. Southwest winds in the morning will back to the south and
then southeast as the sea breeze begins to move inland. Expect wind
gusts generally 15 kts or less (slightly higher along the coast as
the sea breeze pushes inland) with seas 2 to 3 ft.

Sunday through Wednesday: High pressure will prevail across the
marine waters through the weekend and into early next week, yielding
generally southerly flow 10 to 15 knots. Gusts along the direct
coastline could reach 20 knots each afternoon in association with
the afternoon sea breeze. Seas should average 2 to 3 ft through the
period.

&&

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

&&

$$

NEAR TERM...NED
SHORT TERM...CPM
LONG TERM...CPM
AVIATION...NED
MARINE...CPM/Haines