642
FXUS62 KCHS 061120
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
720 AM EDT Mon Apr 6 2026

.WHAT HAS CHANGED...
A short duration Small Craft Advisory is now in effect for the
Charleston Harbor through 10 AM as well as a Lake Wind Advisory
for Lake Moultrie. The Aviation Section has been updated for
the 12z TAFs.


&&

.KEY MESSAGES...
- 1) High pressure will build into the SC Lowcountry and SE GA
  from the north today and remain through mid-week. This set-up
  will yield dry and cooler conditions, along with an elevated
  fire risk.

&&

.DISCUSSION...
KEY MESSAGE 1: High pressure will build into the SC Lowcountry and
SE GA from the north today and remain through mid-week. This set-
up will yield dry and cooler conditions, along with an elevated
fire risk.

A wedge of high pressure will set up along the eastern side of the
Appalachian Mountains today, resulting in a cold air damming (CAD)
regime across the local area. Cooler temperatures are expected
today, with highs only reaching into the upper 60s to around 70.
With the building high pressure, wind gusts out of the northeast
will be around 20 mph through most of the day, diminishing in the
evening. Strong mixing will occur due to the gusty NE winds,
allowing dew points to drop into the mid 30s far inland. These
values will yield RH values 25-30% across areas west of I-95.

A brief respite from building high pressure will occur Monday night,
with another CAD regime setting up Tuesday into Wednesday. This high
pressure is forecast to be stronger than the initial high pressure
on Monday. Northeast gusts Tuesday and Wednesday afternoons are
forecast to reach 20-25 mph on Tuesday, with gusts to 30 mph
possible on Wednesday. RH values are forecast to be 25-30% west of I-
95. These conditions are hazardous for fire weather and a Fire
Danger Statement or even a Fire Weather Watch/Red Flag Warning may
be required for portions of the forecast area both Tuesday and
Wednesday.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
Prevailing VFR through the 12Z TAF period at KCHS/KJZI/KSAV.
Gusty northeasterly winds will develop around sunrise, gusting
to around 20-25 knots at all terminals. Gusts will diminish
around sunset.

Extended Aviation Outlook: VFR, with breezy NE winds Wednesday and
Thursday.

&&

.MARINE...
Today: A surge in winds is expected to develop into the morning
hours as a surface high pressure dives down towards the Gulf Coast,
creating sustained winds in the 20-25 knot range out of the
northeast with gusts to 30 knots. Waves will rise to the 3-4 ft
range along the coast to 7+ ft in the offshore Georgia waters, with
winds briefly subsiding this evening.

Tuesday through Friday: As a stronger surface high pressure moves
across the Great Lakes region Tuesday, the surface pressure gradient
again tightens leading to sustained winds in the 20-25 knot range
with gusts to 30 into the morning hours on Tuesday. A high pressure
wedge sets up along the northeast coast on Wednesday, and will lead
to an increasingly pinched gradient where A Gale Watch has been
issued for all waters off the coast, and a Small Craft Advisory
issued for the Charleston Harbor. Wave heights on Wednesday just
offshore look to be in the 7 to 8 ft range, possibly exceeding 15
feet in the offshore Georgia zone 60nm off the coast. Gale
conditions subside overnight into Thursday, though breezy NE winds
continue into Friday before decreasing below Small Craft Criteria
threshold with unsettled seas lingering into early Saturday.

Rip Currents: Increase NE winds and building swells will result in a
moderate risk for rip currents along all areas beaches today and
Tuesday. The rip current risk will remain elevated for the rest of
the upcoming week.

High Surf: High surf and beach erosion could impact the beaches
Wednesday through Friday as seas build 8+ feet over the coastal
waters. High Surf Advisories may be needed.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...Lake Wind Advisory until 10 AM EDT this morning for SCZ045.
MARINE...Small Craft Advisory until 10 AM EDT this morning for AMZ330.
     Small Craft Advisory until 2 AM EDT Wednesday for AMZ350-352.
     Gale Watch from late Tuesday night through late Wednesday
     night for AMZ350-352-354-374.
     Small Craft Advisory until 2 AM EDT Wednesday for AMZ354-374.

&&

$$

APT/CPM