315
FXUS62 KCHS 290555
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
155 AM EDT Fri Aug 29 2025

.SYNOPSIS...
High pressure will extend across the area as a stationary front
lingers well to the south and offshore into the middle of next
week. A cold front is then anticipated to arrive late next
week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Early this morning, GOES water vapor product shows a band of
vorticity tracking across GA. Regional radar indicates several
patches of weak returns across the region, with light rainfall or
sprinkles detected by a few weather stations. This activity should
push over the Atlantic and south of the region by daybreak.

The band of channelized vorticity is forecast to reach the FL/GA
line by early this afternoon. Near term guidance indicates that
slightly drier conditions will build south across the forecast area
this afternoon. Forecast soundings indicates that mixing to deepen
between 5.5-6.5 kft during the heat of the afternoon. As a result,
dewpoints should lower to the low to mid 60s across the forecast
area. Given high temperatures in the mid the upper 80s, CAPE values
should be limited to 500 J/kg or less. Coverage of showers and
thunderstorms should remain limited the SE GA.

Deep moisture will gradually increase from the southwest through
tonight, PW values rising between 1.5 to 1.8 inches by daybreak
Saturday. A H5 shortwave is timed to lift across SE GA/SC during the
late night hours. This feature should support the development of
showers and thunderstorms. NAM12 indicates that a in-situ wedge
could develop within the area of rainfall late tonight. If this
occurs, the coverage and intensity of showers may increase across
the forecast area. Low temperatures are forecast to range from the
upper 60s inland to the low 70s along the coast.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
Aloft, mid-lvl shortwave energy will ripple across the Southeast
United States along the southern base of a large trough centered
across the Northeast this weekend. At the sfc, a nearly stationary
front will remain south of the local area as mid-lvl troughing
continues, but mid-upper lvl divergence along/near this feature
could help spawn low pressure over Florida, which then tracks east-
northeast to the nearby Atlantic. Although quite a bit of
uncertainty remains in the eventual development and path of low
pressure, a bulk of guidance indicates ample moisture and mid-upper
lvl support for scattered to numerous showers/thunderstorms locally,
with the greatest precip coverage likely to occur along and south of
I-16 across Southeast Georgia and nearby coastal waters given sfc
high pressure spilling into the area from the north. WPC does
indicate a Marginal Risk for excessive rainfall across this noted
area on Saturday and for much of the area on Sunday, which seems
reasonable given the large amount of rains seen across the area
during the past week.

Heading into Monday, a mid-lvl low attempts to become cutoff across
the Mid-Atlantic states, positioning more subtle waves of h5 vort
energy across the Southeast. The setup will tend to favor additional
shower and/or thunderstorm activity across the local area, although
PWATs are noticeably less than previous days, suggesting precip
coverage and intensity to be more isolated/scattered with a lessor
chance of flooding concerns.

Temperatures will remain below normal this weekend into early next
week as east-northeast/northeast winds occur with high pressure
nudging in from the north. In general, afternoon highs will be
cooler on Saturday (upper 70s to lower 80s) when a northeasterly sfc
wind and potential for precip coverage is greater. Sunday and Monday
should see high temperatures in the low-mid 80s. Overnight lows will
generally range in the mid-upper 60s inland to lower 70s near the
coast.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
A mid-lvl low prevails across the Mid-Atlantic states early week,
setting up a period of continued h5 shortwave energy rippling across
the Southeast United States. Latest guidance suggests a secondary
surge of energy within the trough, helping form sfc low pressure
across of just south of local area, highly dependent on how strong
high pressure attempts to wedge across the Carolinas from the north.
The setup should trend to higher afternoon shower/thunderstorm
coverage each day (isolated to scattered), as deeper moisture and
isentropic ascent become more favorably placed across Southeast
Georgia and Southeast South Carolina heading into the middle of next
week. Afternoon showers/thunderstorms continue heading into the
second half of the week ahead of a cold front approaching from the
west/northwest late week.

Temperatures are expected to remain below normal through at least
midweek, generally ranging in the low-mid 80s, but will show signs
of warming into the mid-upper 80s depending on the strength/erosion
of high pressure and precip coverage well ahead of the front late
week. Overnight lows should gradually trend warmer mid to late next
week, generally ranging in the mid-upper 60s inland to low-mid 70s
near the coast.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
06Z TAFs: VFR. A mid-level vort max will track across SE GA
early this morning. A patch of light rain to sprinkles should
develop ahead of the disturbance, KSAV TAF will indicate light
rain from 8-11Z. The rest of the TAF period will feature light
winds with rounds of clouds.

Extended Aviation Forecast: VFR conditions should generally prevail
at CHS/JZI/SAV terminals through early next week, although brief
periods of flight restrictions are possible each afternoon due to
showers and thunderstorms impacting the area. Greatest chances for
flight restrictions appear to be on Saturday, especially at SAV as
low pressure attempts to pass nearby. Additional chances for
afternoon flight restrictions are possible heading into the middle
of next week as showers and/or thunderstorms develop with broad low
pressure nearby.

&&

.MARINE...
Today and Tonight: Winds should generally favor a east-southeast
direction through the period. Wind speeds are forecast to range
around 10 kts. Seas should range between 2 to 3 ft.

Saturday through Wednesday: A weak area of low pressure will attempt
to develop/track across Florida to the nearby Atlantic this weekend
while sfc high pressure holds across the Carolinas into Central
Georgia. Although conditions remain below Small Craft Advisory
levels through a bulk of the weekend, the pressure gradient shows
signs of strengthening Sunday afternoon/night, supporting
northeasterly winds gusting up to 20-25 kt and seas building to 4-6
ft. A Small Craft Advisory should eventually be needed across a
portion of local waters Sunday night into at least Monday, although
the potential for gusts near 25 kt and seas in the 3-5 ft range
could persist through Wednesday depending on the overall strength of
high pressure inland.

&&

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

&&

$$

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