693
FXUS62 KCHS 051956
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
356 PM EDT Thu Jun 5 2025

.SYNOPSIS...
Weak low pressure will move north of the area through tonight.
A stationary front will pass to the north this weekend. Next
week the local area will remain between Atlantic high pressure
and a surface trough inland.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Late Afternoon/Early Evening: Sfc low pressure will gradually
meander north of the local area, becoming a bit more defined late
afternoon over northeast South Carolina into North Carolina while an
associated h5 shortwave aloft eventually ejects offshore to the
northeast. The atmosphere across Southeast South Carolina and
Southeast will remain warm, moist and unstable with conditions
continuing to favor development of showers and/or thunderstorms, the
bulk of which may organize along and east of I-95 where lingering
sfc troughing and a sea breeze interact. Latest hires guidance
suggests an additional few hour period of numerous showers and
thunderstorms within a moderately unstable (SBCAPE 2000-2500 J/kg)
but weakly sheared atmosphere (0-6 Bulk Shear less than 20 kt) with
poor mid-lvl lapse rates and limited DCAPE also in place, indicating
activity likely struggling to become more organized and/or severe.
However, a few stronger thunderstorms can not be ruled out with
gusty winds and brief heavy downpours being the primary concern.
High temps have likely peaked for the day, generally in the mid 80s
for locations outside of precip, and upper 70s/lower 80s at the
beaches.

Overnight: Rain chances will gradually end by around midnight as the
sfc trough shifts offshore. Skies will begin to clear early to mid
evening, but latest guidance does indicate stratus returning across
the area during the second half of the night. At this time, 1000 mb
geostrophic flow in the 10-15 kt range should limit stratus build-
down and the potential for areas to widespread fog. However, given
ample moisture and recent rains, along with somewhat favorable
condensation pressure deficits and lighter sfc winds late, patchy
fog could eventually need to be introduced to the forecast in later
updates. Lows will generally remain mild, especially if clouds
become more widespread later tonight. In general, lows should range
in the upper 60s to lower 70s inland to mid 70s at the beaches.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
As the aforementioned low officially moves offshore and well away
from the region on Friday morning, a weak cold front could
potentially pass through the region in the early morning hours of
Friday. Zonal flow should take control through the weekend as weak
longwave troughing forms over the Eastern CONUS by late Saturday.
Moisture looks to stick around with PWAT values ~1.50-1.75 inches. A
typical sometime pattern will take over on Friday through the
weekend with the seabreeze pushing inland each afternoon, sparking
up showers and thunderstorms in the wake of it. There are some hints
that instability could be more than the previous days due the decent
amount of diurnal heating and moisture in place. Looking at the
severe potential for Saturday ... SPC has placed the region under a
Slight Risk (except for the immediate coastline). A large MCS in the
Midwest will move eastward towards the region and try to make its
way down on Saturday. If this system holds together, there is
potential for scattered damaging wind swaths to occur on Saturday
afternoon through the evening. However, confidence remains extremely
low with this as it`s very possible this MCS will fall apart before
even reaching the region. Recent guidance indicates that shear will
be able to gradually increase through the weekend into Sunday, this
may cause for another severe threat on Sunday as well. Temperatures
for Friday and Sunday will reach into the upper 80s/low 90s and mid
90s on Saturday, with temperatures cooler at the beaches. Lows will
continue to be mild over the weekend with temperatures overnight
only dipping into the low to mid 70s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The long-wave troughing pattern should persist and become more
amplified along the Eastern CONUS through Tuesday. Some sort of
stationary front could possible pass to the north of the region
over the weekend as a cold front extending from a upper-lvl
trough situated over Eastern Canada begins to approach the area
early next week. This will continue this typical diurnal
summertime pattern of scattered showers and thunderstorms in the
afternoon as the seabreeze pushes inland. Expect temperatures
to be a few degrees above-normal through this period.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
KCHS/KJZI: Scattered to numerous showers/thunderstorms are possible
mid-late afternoon and into early evening, producing TEMPO flight
restrictions at both terminals at times. Have included TEMPO MVFR
conditions and gusts for thunderstorms between 18-21Z, followed by
VCTS until 01Z early this evening. A period of VFR conditions are
then expected this evening before MVFR and possibly lower cigs
return at the terminals and persist between 06Z-14Z Friday, then
improve back to VFR once again late Friday morning and prevail into
early Friday afternoon.

KSAV: Clusters of showers and/or thunderstorms will continue to
develop near or just south of the terminal, producing tempo MVFR
conditions at times mid-late afternoon into early evening hours.
Have included TEMPO MVFR conditions and gusts up to 20 kt for
thunderstorms between 18Z-22Z, followed by VCTS through 01Z early
this evening. A period of VFR conditions are then expected this
evening before MVFR and possibly lower cigs return and persist
between 08Z-14Z Friday, then improve back to VFR once again late
Friday morning and prevail into early Friday afternoon.

Extended Aviation Outlook: This typical summertime convection
pattern will bring periodic flight restrictions through Monday.

&&

.MARINE...
This Afternoon/Early Evening: Southerly winds upwards to 15-20 kt
will slowly veer to the southwest early tonight as low pressure
meanders north of the region. Seas will generally range between
2-4 ft. Scattered to numerous showers and thunderstorms will
also shift across coastal waters, a few of which could be strong
with gusts around 35 kt. An isolated waterspout can not be
ruled out across Georgia waters as well, particularly across
outer Georgia waters. Marine Weather Statements and/or Special
Marine Warnings could be needed at times prior to sunset.

Overnight: The bulk of convection will shift east of local
waters shortly after midnight, with southwest winds generally
between 10-15 kt continuing to turn more directly offshore late
night (become west). A subtle tightening of the pressure
gradient also suggests some areas gusting to 20 kt further
offshore, mainly across outer Georgia waters. Seas will
generally range between 2-4 ft.

Friday through Monday: With the coastal low slowly drifting further
and further away, a stationary front should pass to the north of the
region this weekend. Expect west south-westerly winds at 10 to 15 kt
to period. It could become a bit gusty on Saturday and Sunday
afternoon with gusts up to 20 to 22 kt possible with the sea breeze
pushing inland (gusts will be strongest across the Charleston
Harbor). South-easterly swell continues to mix into the Atlantic
waters and cause for some decent waves to take shape on Friday,
before tapering off on the weekend. Seas should range from 2 to 4 ft
for the rest of the period.

Rip Currents:
This Afternoon into Evening: Conditions remain supportive of rip
currents along Southeast South Carolina and Southeast Georgia
beaches late afternoon with a few rip currents already have been
reported by lifeguards along South Carolina beaches earlier
today. A Moderate Rip Current Risk will be maintained for all
beaches.

With the coastal low drifting further away and south- easterly
swell beginning to taper off some, a Low Risk of Rip Currents is
expected on Friday (tomorrow) and Saturday.

&&

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

&&

$$

NEAR TERM...DPB
SHORT TERM...Dennis
LONG TERM...Dennis
AVIATION...Dennis/DPB
MARINE...Dennis/DPB