077
FXUS62 KCHS 191945
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
345 PM EDT Wed Mar 19 2025

.SYNOPSIS...
Quiet conditions are expected tonight as high pressure remains
overhead. Otherwise, look for a weak cold front to push
eastward across the region Thursday, causing showers and breezy
winds to return to the forecast. High pressure then returns
heading into the weekend.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
A low pressure system is forecast to track across the Mid-West/Great
Lakes region tonight. The associated cold front will sweep east,
reaching the Southern Appalachians during the pre-dawn hours
Thursday morning. Return flow ahead of the cold front should support
steady southwest winds between 5 to 10 mph through tonight. High and
mid-level clouds should increase from the west, especially during
the late night hours. Low temperatures across the forecast area are
forecast to range between 50 to 55 degrees.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
Thursday: A mid-level trough will swing through the southeastern
states, while at the surface a weak cold front will push through the
region. Rain chances will begin across far western zones in the
morning, pushing eastward into the early afternoon. Showers are
forecast to push offshore by late afternoon. Forecast soundings
indicate little to no instability, therefore a thunder-free forecast
has been maintained. PWAT values are forecast to remain below 1.5",
yielding storm total QPF values generally between 0.1 and 0.2
inches. Some spots could see up to a quarter of an inch. After the
cold front pushes through winds will shift to the NW and become
breezy, with gusts over Lake Moultrie forecast around 25 mph. A Lake
Wind Advisory has been issued for the lake from 6 PM Thursday
through 8 AM Friday. High temperatures on Thursday will be
challenging, as they are heavily dependent on the timing of the
front. The current forecast features upper 60s to around 70 across
far western zones (where rainfall will occur first) to mid 70s along
the coastal counties (where locations have a chance to warm prior to
the arrival of rainfall). Post FROPA temperatures will plummet
overnight into the mid 30s far inland, with low to mid 40s along the
coastal counties. With breezy conditions overnight, wind chills
Friday morning are forecast to be in the low to mid 30s.

Friday and Saturday: Surface high pressure will build into the
region from the west, while zonal flow develops aloft. Quiet
conditions will prevail, with plentiful sunshine. CAA in the wake of
the departing cold front will keep Friday slightly cooler, with
highs in the mid to upper 60s. As high pressure continues to build
overhead, highs on Saturday will reach into the mid 70s.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Quiet conditions will prevail through Sunday as surface high
pressure remains overhead. The next chance for rainfall will be
Monday as broad troughing develops over the eastern CONUS and a
surface cold front pushes through the region. Dry conditions will
return Tuesday morning as high pressure returns. Temperatures will
be around normal through the period, with highs generally in the low
to mid 70s and overnight lows in the 40s.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
18Z TAFs: VFR conditions with steady SW winds expected through
tonight. A cold front will approach from the west Thursday
morning. As the front nears, SW winds should strengthen to 10-15
kts and gusts between 20-25 kts. A pre-frontal band of showers
is timed to reach KSAV between 15-18Z, highlighted with a TEMPO.
It is possible that the leading edge of the showers will near
KCHS/KJZI before 18Z Thursday. TAFs will feature a mention of
VCSH at KCHS and KJZI starting at 16Z.

Extended Aviation Outlook: Brief flight restrictions are possible on
Thursday as a weak cold front pushes through the region. Otherwise,
prevailing VFR through the weekend.

&&

.MARINE...
Tonight, the marine zones are forecast to remain between high
pressure over the western Atlantic and a cold front approaching from
the west. South-southwest winds are forecast to gradually strengthen
through tonight, ranging between 15 to 20 kts by late tonight. Seas
should build to 3 to 5 ft by late tonight.

Thursday through Sunday: A cold front will push through the region
on Thursday, bringing a surge in winds and seas to all marine
waters. Small Craft Advisories will be in effect for all marine
zones, including the Charleston Harbor through Friday morning for a
combination of winds and seas. NW wind gusts 25 to 30 knots are
expected over most of the nearshore waters, with some gusts in the
low 30s possible over the 20 to 60 nm offshore GA waters and the
Charleston County nearshore waters. Conditions appear borderline for
Gale Force gusts, therefore a Gale Watch was not issued at this
juncture. However, conditions will need to be monitored closely and
a Gale Watch/Warning cannot be ruled out. Seas over the nearshore
waters will build to 4 to 6 ft, with 6 to 8 ft possible over the 20
to 60 nm offshore GA waters. By Friday afternoon conditions will
improve over the waters, with SW winds generally around 10 knots and
seas decreasing to 2 to 4 ft. High pressure will build into the
region through the weekend, with quiet marine conditions
expected.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...Lake Wind Advisory from 6 PM Thursday to 8 AM EDT Friday for
     SCZ045.
MARINE...Small Craft Advisory from 11 AM Thursday to 2 PM EDT Friday
     for AMZ330-350.
     Small Craft Advisory from 2 PM Thursday to 2 PM EDT Friday for
     AMZ352.
     Small Craft Advisory from 5 PM Thursday to 2 PM EDT Friday for
     AMZ354.
     Small Craft Advisory from 8 AM Thursday to 2 PM EDT Friday for
     AMZ374.

&&

$$

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