Estill, South Carolina Weather Forecast Discussion

883
FXUS62 KCHS 052140
AFDCHS
Area Forecast Discussion
National Weather Service Charleston SC
540 PM EDT Fri Sep 5 2025
.SYNOPSIS...
High pressure will extend across the area through Saturday. A
cold front will move through from the northwest late Sunday,
then stall offshore through the middle of next week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Satellite imagery shows the cumulus field gradually developing
as we warm into the upper 80s and low 90s. Hi-res model
solutions continue to suggest that isolated convection could
occur across our far inland tier late this afternoon and early
this evening. Even if this were to occur it should be weak and
short-lived. Overnight, the forecast area will remain within a
weakly forced area situated between a weak surface wave offshore
and a cold front entering the OH and TN valley areas. The only
real forecast issue overnight is the potential for some fog.
Low-level moisture has been gradually building for the last few
days and with mostly clear skies and calm winds conditions could
become supportive for the development of a bit of fog. So far
no model guidance suggests anything too widespread or
significant visibility reductions, but at least some shallow
ground fog will be possible late tonight. Lows are forecast to
be a bit warmer, with mostly upper 60s away from the coast and
low 70s along the coast.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
Saturday: A cold front will approach the forecast area from the
west through the day. Given the front remaining west of the
area through the daylight hours, high temperatures are forecast
to range in the low to mid 90s across SE GA/SC. Forecast
soundings indicates that a strong inversion centered at H7 will
remain across the CWA, capping the environment. The forecast
will feature dry weather. It is interesting to note on the
visible satellite a thick plume of wildfire smoke along and west
of the southern Appalachians, just west of the cold front as of
Friday afternoon. HRRR Smoke guidance indicates that the plume
may shift east following the front on Saturday, however, higher
concentrations of the smoke should remain north and west of the
forecast area on Saturday.
Sunday: Short term guidance indicates that the cold front will
push south and east across the forecast area during the daylight
hours. Potentially, the front could push across the region
during the morning. However, the NAM and ECMWF indicates that
the cold front may not arrive until the afternoon, possibly
interacting with a sea breeze. Models indicate that a least weak
instability will develop across the region, given afternoon
temperatures in upper 80s to low 90s. PoPs will peak during the
afternoon with values between 30-40 percent for showers and
thunderstorms.
Monday: The forecast area will remain under a sfc ridge,
centered over the western Carolinas, as the cold front remain
just offshore. Dry and stable air should gradually build across
the inland areas through the day. However, lingering moisture
and instability may remain over the coastal areas, supporting at
least a SCHC of convection. High temperatures should range in
the 80s, limited by gusty northeast winds and persistent cloud
cover.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
The sfc pattern across the forecast area should feature a wedge
of high pressure inland with broad low pressure over the
nearshore waters. Confidence in the day to day weather is low.
The ECMWF shows a rather dry pattern, dominated by stable high
pressure. However, the GFS is much more unsettled, showing a
coastal low or trough shifting inland during the early to middle
of next week. The forecast will indicate SCHC to CHC PoPs each
day, favoring the coast. Temperatures should peak each afternoon
in the 80s, remaining slightly below normal.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
06/00Z Aviation Discussion:
KCHS/KJZI: VFR for much of the period. A little bit of shallow
ground fog could develop just before sunrise, but no meaningful
impacts are expected.
KSAV: VFR for much of the period. Similar to the Charleston
terminals, some shallow ground could develop prior to daybreak.
There is a bit more of a signal for some more meaningful
reductions in vsbys with some data supporting a brief period of
vsbys as low as just below the alternate minimum threshold.
With model condensation pressure deficits progged to remain
quite high, this fog could remain very shallow, but although could
be locally thick at it meanders around the airfield. A TEMPO
group for MVFR vsbys 10-13z was maintained to address this.
Extended Aviation Forecast: There is a low chance for some
morning fog and stratus Sunday morning, mostly inland. The next
chance of showers and thunderstorms will be Sunday afternoon,
perhaps persisting into Monday and Tuesday afternoons. Ceiling
restrictions are possible Sunday night and Monday, as a front
sags into the area.
&&
.MARINE...
Through Tonight: Very quiet conditions will continue. Wind
speeds will drop off to be 5 knots or less late tonight with
seas averaging around 2 feet.
Saturday and Saturday Night: The marine zones will remain east
of a front approaching from the west. Conditions across the
coastal waters will remain from the ESE between 5 to 10 kt. Seas
will remain between 2 to 3 ft.
Sunday through Tuesday: A cold front will approach from the
northwest on Sunday, then move across the waters by Sunday
night. Northeast winds will strengthen early Monday, persisting
into late Tuesday. Small Craft Advisories will be needed for all
of our ocean waters during this time period for winds and seas,
and perhaps for the Charleston Harbor due to winds. Conditions
should improve on Wednesday, with winds and seas trending lower.
&&
.TIDES/COASTAL FLOODING...
Astronomical tide levels will continue to increase through the
weekend, getting as high as 6.4 ft MLLW by the Sunday evening
high tide cycle within the Charleston Harbor. However, winds
will not be particularly favorable for large tidal departures
during this time period but observed peak tides could still top
out around 7 ft MLLW at Charleston each evening through Sunday.
Astronomical tide levels will remain high through the middle of
next week, given a full moon (9/7) and lunar perigee (9/10). A
notable surge of northeast flow along the coast is expected to
produce increased tidal departures through at least the middle
of next week which will result in an increasing probability of
minor to moderate coastal flooding along portions of the SC
coast. Minor coastal flooding is possible along the lower SC and
GA coast beginning Monday evening.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$

NWS CHS Office Area Forecast Discussion