College Park, South Carolina Weather Forecast Discussion

192
FXUS62 KCHS 121915
AFDCHS
Area Forecast Discussion
National Weather Service Charleston SC
315 PM EDT Fri Sep 12 2025
.SYNOPSIS...
A surface high pressure will remain across the region and allow
quiet and dry conditions to continue over the weekend.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
The sfc pattern will continue to feature ridging high pressure
centered over the western Carolinas with broad low pressure over the
Gulf Stream. This pattern should support steady northeast winds
across the forecast area tonight, periods of gusty winds possibly
across the beaches. This evening, fair weather cumulus clouds should
dissipate, with little to no cloud cover expected through the rest
of the night across SE GA/SC. Low temperatures are forecast to range
from the low 60s inland to the upper 60s along the coast.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
Saturday: An elongated mid-lvl trough will extend across the eastern
seaboard in the morning and then close off by the evening as strong
upper-lvl ridging across the central CONUS shifts eastward. This
pattern will enhance shower and thunderstorm development across the
local waters and PoPs to be almost zero over land. At the surface,
high pressure will continue to situate itself nearby as a stalled
cold front located well offshore filters in lower dewpoints in the
50s across the region. Stuck between this upper-lvl ridge and mid-
lvl trough, the surface pressure gradient will tighten up across the
region and cause for breezy northeastly winds to persist throughout
the day. Temperatures will be around normal for this time of year as
highs reach into the low to mid 80s, with overnight lows in the
upper 50s to low 60s inland and mid 60s along the coastline.
Sunday: As this closed off low separates from the upstream shortwave
trough that exits off the New England coastline, it will shift
offshore of the Carolinas and stall offshore through the rest of the
day. Sandwiched between this low offshore and the upper-lvl ridging
located over the Appalachians, surface pressure gradient will
continue to strengthen across the region and cause for breezy
northeasterly winds to persist. Temperatures will be similar to
Saturday`s weather as highs are forecast to reach into the low to
mid 80s again with dewpoints in the mid 50s.
Monday: Surface high pressure wedges itself on the lee side of the
Appalachians MTNS, as the pressure gradient finally begins to
relax. This aforementioned area of low pressure out over the
waters will likely retrograde and cause the stalled front to
undergo frontolysis. This process will likely cause humidity
levels to rise back up again across coastal SC/GA. At the
surface, northeasterly winds will slightly decrease as the
pressure gradient gradually loosens up. Also, there is slight
uptick in PoPs (mainly along the South Carolina coastline) as
moisture returns to the region.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
An amplified mid-level ridge located over the Great Lakes region will
remain in place and possible set up a blocking pattern through mid-
week. Thus, low chance PoPs are forecast through the mid-week as
this pattern holds. Closer to the end of the week, the pattern will
shift and humidity levels will slowly rise back up as dewpoints
reach into the upper 60s to low 70s. Along with the dewpoints,
temperatures gradually warm up into the upper 80s to low 90s.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
18Z TAFs: Expecting VFR conditions across the terminals through
the period. Northeast winds will remain gusty through the rest
of this afternoon. Winds should settle to around 10 kts across
the terminals this evening and remain into Saturday morning.
Gusty northeast winds should redevelop by mid-morning Saturday.
Extended Aviation Forecast: Mostly VFR through the week. Expect some
brief periods of restricted ceilings due to late night/early morning
stratus.
&&
.MARINE...
Tonight: The pressure gradient between an inland sfc ridge and a
trough over the Gulf Stream will support gusty NE winds across the
Atlantic waters tonight. By late tonight, all waters outside the CHS
Harbor should develop NE winds between 15-20 kts with gusts around
25 kts. In addition, seas should build through the night, reaching 5
to 7 ft late. At least isolated showers may pass over the Marine
zones tonight. The Charleston Harbor should remain with northeast
winds between 10 to 15 kts with gusts around 20 kts tonight.
Saturday through Wednesday: Breezy onshore northeastly winds will
persist through the local waters through the weekend as the surface
pressure gradient tightens and a broad area of low pressure tries to
form along a stalled front. Expect wind speeds of 20 to 25 kts with
gusts up to 30 kts as this pattern holds strong over the Atlantic
through the weekend. Seas will range from 5 to 7 ft through the
weekend as well. Heading into the work week, northeast winds will
gradually decrease as the pressure gradient loosens up and surface
low shifts farther away from the region. There is still some
uncertainty on timing the surface low chooses to move away, and this
will dictate when the northeast winds finally begin to back down.
Small Craft Advisories have been issued for all marine zones and
expected to expire Monday morning for increased winds and seas.
Rip Currents: The combination of persistent northeast winds,
astronomical factors, and elevated swell will yield a Moderate Risk
of rip currents at all beaches for the rest of the afternoon. The
risk for rip currents will remain Moderate for South Carolina
beaches on Saturday. However, a High Risk of rip currents is
forecast for Georgia beaches on Saturday.
&&
.TIDES/COASTAL FLOODING...
Total water levels will remain elevated from large tidal
departures due to a pinched pressure gradient with elevated
northeast winds. The potential for coastal flooding will
continue though through the weekend (especially at Charleston).
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...High Risk for Rip Currents from Saturday morning through Saturday
     evening for GAZ117-119-139-141.
SC...None.
MARINE...Small Craft Advisory until 6 AM EDT Monday for AMZ350.
     Small Craft Advisory from 8 PM this evening to 6 AM EDT Monday
     for AMZ352.
     Small Craft Advisory from 4 AM Saturday to 6 AM EDT Monday for
     AMZ354.
     Small Craft Advisory until noon EDT Monday for AMZ374.
&&
$$
NEAR TERM...NED
SHORT TERM...Dennis
LONG TERM...Dennis
AVIATION...Dennis/NED
MARINE...Dennis/NED

NWS CHS Office Area Forecast Discussion