Rantowels, South Carolina Weather Forecast Discussion

964
FXUS62 KCHS 241757
AFDCHS
Area Forecast Discussion
National Weather Service Charleston SC
157 PM EDT Wed Sep 24 2025
.SYNOPSIS...
A weak front will approach the region late this week, likely
stalling just offshore through the weekend and into early next
week.
&&
.NEAR TERM /THROUGH TONIGHT/...
This Afternoon: Aloft, the local area will remain situated along the
southeast periphery of a broad trough centered across the Great
Lakes region while ridging attempts to nudge into the area from the
south. At the sfc, high pressure centered across the western
Atlantic will favor a southerly flow across Southeast South Carolina
and Southeast Georgia under mostly sunny skies. Model consensus
indicates dry/warm conditions across all areas with little or non-
existent instability during peak heating. Forcing will also remain
weak, suggesting the bulk of the area to remain dry. However, much
like the previous couple days, a few showers can not be ruled out
across the Tri-County Area while a sea breeze makes way inland.
Activity is likely to be short-lived and light if able to develop
this afternoon.
West-southwest flow above southerly sfc winds will result in
afternoon highs 1-2 degrees warmer than the previous day. In
general, high temps will range in the upper 80s to lower-middle 90s
well inland, but should remain in the mid 80s near the beaches.
These temperatures in combination with dewpts in the low-mid 70
should yield heat index values around 100 degrees in some areas,
mainly along the I-95 corridor east of substantial low-lvl mixing
out of dewpts well inland.
Tonight: High pressure will remain the dominant weather feature
locally while a large-scale trough advances eastward across the
central/lower Mississippi Valley. Dry conditions and clear/mostly
clear skies are expected through the night, but a light southerly
wind will help to keep temps mild, with lows ranging around 70 well
inland to mid-upper 70s near the coast. There are less signals for
fog (or low stratus) development late tonight with some tendency of
favorable condensation pressure deficits, but questions in moisture
late. Coverage looks to be patchy at best and more likely confined
to the Tri-County Area within a few hours of daybreak, but currently
no fog is mentioned in the forecast.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
Thursday: An elongated trough will be present over the eastern
CONUS, while at the surface high pressure dominates over the local
forecast area. A very summer-like day is in store for the region,
with high temperatures topping out in the low to mid 90s away from
the coastline along with dew points in the upper 60s to low 70s.
This will yield apparent temperatures in the upper 90s to around 100
across the region. Even with some forcing aloft from the trough
aloft, precipitation chances are minimal. The forecast features PoPs
~15% far inland in the afternoon. The 13Z NBM has PoPs in the
evening hours around 20-30% across the forecast area, however the
12Z HRRR and HREF all show a generally dry forecast.
Friday and Saturday: The elongated trough will remain positioned
over the eastern CONUS into the weekend, with a cut-off low
developing in the mid levels over the southeastern states. At the
surface a weak front will approach the forecast area on Friday,
pushing through the region Friday night into Saturday. It is worth
noting that guidance came in slightly slower than previous forecast
runs, so there is still low confidence on the timing of the FROPA.
Once the front pushes through the region it is forecast to stall
just offshore of the southeastern coast. Precipitation chances
increase for both Friday and Saturday, given the approaching weak
front. Additionally, the summer-like airmass will remain in place on
Friday, with highs once again reaching to around 90 away from the
coastline. Saturday will see a slight decrease in temperatures given
the approaching front and increased cloud cover from
showers/tstorms, with highs in the low to mid 80s.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
The forecast becomes exponentially uncertain late this weekend and
into early next week as a complicated set up begins to take shape
over the southeastern states and adjacent western Atlantic waters.
The National Hurricane Center continues to monitor invests 93L and
94L in the western Atlantic for potential tropical development over
the next 7 days. It remains to be seen what develops from 93L and
94L and their potential impacts to the southeastern coast. The
stalled front off the southeast coast adds an additional
complicating factor. Currently models are struggling to agree, both
with each other and within each model from cycle to cycle. Cluster
analysis from the Weather Prediction Center shows the GEFS as the
outlier amongst the CMCE/GEFS/ECMWF. The extended forecast will
remain closely monitored over the next several days.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR conditions are expected at CHS/JZI/SAV terminals through 18Z
Thursday. However, TEMPO flight restrictions can not be ruled out
due to low clouds and/or patchy fog attempting to develop between
08Z-13Z Thursday. Confidence remains too low to introduce TEMPO
groups in the latest TAF issuance, but could eventually be needed,
mainly at CHS/JZI terminals.
Extended Aviation Outlook: Brief flight restrictions are possible
Friday and Saturday afternoons with showers/tstorms. Otherwise,
prevailing VFR.
&&
.MARINE...
This Afternoon and Tonight: A weak pressure gradient will prevail
across local waters between high pressure offshore and a trough
approaching the region from the west. The pattern supports southeast
winds no higher than 10-15 kt for the rest of the day, highest along
the land/sea interface. Overnight, winds should tip more south while
remaining between 10-15 kt across most waters. Seas will average 2-4
ft this afternoon, but are expected to slowly subside to 2-3 ft
tonight.
Thursday through Sunday: Marine conditions into the weekend will
remain rather tranquil as high pressure dominates over the marine
waters. A weak front will push into the marine waters Saturday and
linger in the vicinity through the weekend and into early next week.
Through Sunday conditions are expected to remain below Small Craft
Advisory criteria, with winds generally 10 to 15 knots and seas 2 to
3 ft. The forecast becomes significantly more uncertain late this
weekend and into early next week due to potential impacts from
either of the invest areas that the National Hurricane Center is
monitoring (93L and 94L).
Rip Currents: Elevated swell energy of 2-3 feet every 10-11 seconds
will be sufficient to produce a Moderate Risk of rip currents at all
beaches into this evening.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...DPB
SHORT TERM...CPM
LONG TERM...CPM
AVIATION...CPM/DPB
MARINE...BSH/CPM/DPB

NWS CHS Office Area Forecast Discussion