079
FXUS62 KCHS 030719
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
319 AM EDT Sat Oct 3 2026

.WHAT HAS CHANGED...
All sections have been updated.

&&

.KEY MESSAGES...
- 1) Unsettled weather expected today through Monday.

- 2) Cooler temperatures along with breezy to windy conditions
  are expected next week.

- 3) Coastal flooding is likely next week.

&&

.DISCUSSION...
KEY MESSAGE 1: Unsettled weather expected today through Monday.

Today: Weak high pressure meandering across the western Atlantic
will gradually give way/drift east further offshore with the
approach of large-scale troughing across the Midwest to Northeast
regions. Deep moisture return (PWATs ~2.25 inches) occurring along
the western edge of the Atlantic high along with vort energy
traversing inland should favor greater rain/shower coverage,
initially starting out as light rain activity that drifts north
across Southeast Georgia into Southeast South Carolina late this
morning, then increasing in coverage heading into peak heating hours
this afternoon. Although instability is meager, deep moisture and
modest forcing could support moderate showers with a few rumbles of
thunder this afternoon into early evening, mainly in the form of
beneficial rains with a rather limited concern for minor flooding
across inland zones.

Sunday and Monday: Shower/thunderstorm coverage is likely to
increase as the digging mid-upper trough advances toward the Mid-
Atlantic and Northeast, eventually forcing a cold front toward the
local late weekend into early next week. This backdoor cold front
could stall near the area on Sunday while low pressure shifts across
the local area, then offshore. PWATs and forcing peak late Sunday,
especially during overnight hours with a fair amount of isentropic
lift in place, setting the stage for widespread rains with embedded
thunderstorms during much of the night and into early morning
Monday. Rainfall totals in the 1-3 inch range remain reasonable
across the area with locally higher amounts possible while the front
slowly shifts south and offshore as low pressure develops over the
western Atlantic and high pressure builds in from the north Monday
afternoon. There should be a decent gradient of precip Monday
afternoon, depending on the position of the sfc front, but a
decreasing trend from north to south is the anticipated outcome late
day and/or evening. Given deep moisture, ample forcing, and the
slower progression of the front, some spots have the potential for
seeing minor and/or perhaps flash flooding issues, especially if
activity trains over same areas than have seen rainfall during the
48 hour period. The latest WPC Excessive Rainfall Outlook includes
Southeast South Carolina and Southeast Georgia in a Slight Risk for
excessive rainfall on Sunday, and Marginal Risk for excessive
rainfall on Monday.

KEY MESSAGE 2: Cooler temperatures along with breezy to windy
conditions are expected next week.

Ahead of an approaching cold front, daily highs will remain in the
lower to mid 80s over the weekend. As a surface low pressure moves
off the northeast coast on Monday, the cold front will slide across
the area ushering in cooler temperatures with highs in the mid to
upper 70s. Surface high pressure moves in from the Great Lakes
region onto the northeast coast overnight into Tuesday starting a
cold air damming (CAD) event, sending additional cooler air down the
eastern seaboard. High temperatures will be limited to the lower to
mid 70s Tuesday and Wednesday, though isolated instances of highs in
the upper 60s can`t be ruled out for inland areas. Overnight lows in
the lower 50 to lower 60s are expected Wednesday through Friday
morning, coolest for inland areas.

The CAD event will also feature breezy/windy conditions as the
surface pressure gradient gets pinched, with northeast winds
developing Monday with gusts expected to remain below 20 mph. As the
strong surface high pressure moves to the east coast, the pressure
gradient is further increased, with additional increases from a
coastal surface low pressure that may develop along the cold front.
As a result, Tuesday will be breezy/windy with areas furthest away
from the coast potentially seeing wind gusts to 30 mph, while those
along the coast may see gusts to 40 mph. Wednesday will see winds a
touch lower as the surface high pressure begins to weaken, with
areas along the coast likely seeing gusts to 35 mph, while inland
areas will be closer to 20 mph. A Lake Wind Advisory for Lake
Moultrie may be warranted on Tuesday and again on Wednesday.

KEY MESSAGE 3: Coastal flooding is likely next week.

Breezy northeasterly winds associated with strong cold air damming
in combination with high astronomical tide levels will likely
support coastal flooding issues next week. The pattern suggests a
minor/moderate saltwater inundation setup mid week next week,
but even major coastal flooding cannot be ruled out during the
peak of the event given persistent/strong northeasterly winds
and building seas along the Southeast Coast. Coastal Flood
Watches/Warnings and/or Advisories could eventually be needed
along the Southeast SC/GA coasts.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
CHS/JZI: VFR conditions are likely to prevail through daybreak,
prior to light rain/showers drifting north and eventually impacting
the terminals late Saturday morning and afternoon. PROB30 groups
with MVFR conditions remain between 17-23Z Saturday at CHS and 17-
21Z at JZI. Guidance suggests a short break of precip activity prior
to MVFR conditions developing/spreading across the terminals
Saturday evening. PROB30 groups between 02Z-06Z Sunday have been
introduced at both terminals due to MVFR conditions associated with
light showers returning.

SAV: Pockets of light rain/showers will continue to drift north
across the area, causing little impact at the terminal overnight,
but cigs could begin to lower late night/around daybreak Saturday.
TEMPO MVFR conditions have been introduced between 10-14Z Saturday
based on latest trends. Additional rounds of showers could lead to
MVFR conditions Saturday afternoon into early evening, which remains
under a PROB30 group between 17-23Z. Conditions should then remain
VFR between 00Z-06Z Sunday.

Extended Aviation Outlook: Flight restrictions are possible with
increasing showers and thunderstorms on Sunday and into early next
week. Gusty winds are likely on Tuesday and Wednesday.

&&

.MARINE...
Today and Sunday: Wind/seas are expected to remain well below
Small Craft Advisory levels as high pressure lingers across the
western Atlantic this weekend. In general, onshore winds should
top out near 10-15 kt, with modest surging each afternoon along
the land/sea interface. Seas will generally range between 1-3
ft. However, increasing chances of showers/thunderstorms are
expected through this weekend, which could lead to gusty winds
and reduced vsbys at times, especially late Sunday.

Monday - Thursday: A cold front will be pushing through the region
Monday morning, pushing the heaviest rainfall south of the area by
the evening. Greater impacts are expected from the switch to
northerly winds that will be strengthening through the day as
surface high pressure moves in, causing marine conditions to worsen
quickly. Expect winds to increase Monday evening into overnight
Tuesday into the 25 to 34 knot gusts range, further strengthening
into Gales (35 to 45 knots) Tuesday morning through Wednesday. 6
foot waves are expected to quickly move in overnight into Tuesday
morning, pushing up along the coast by Tuesday afternoon as 10 to 11
ft waves build 20 to 60 nm offshore, with wave heights beginning to
very slowly subside on Wednesday. Conditions are expected to improve
on Thursday, though rough seas will likely persist into at least
Friday especially for the 20 to 60nm offshore zones. Small Craft
Advisories, Gale Watches, and Gale Warnings will likely be needed.
The hazardous marine conditions will likely result in hazardous
beach conditions, including dangerous rip currents, high surf, and
possibly beach erosion.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.

&&

$$