612
FXUS62 KCHS 060804
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
404 AM EDT Mon May 6 2024

.SYNOPSIS...
Atlantic high pressure will remain across the Southeast U.S.
through mid week. A cold front will move through the region
late week bringing cooler conditions heading into the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
A shortwave ridge will remain across the forecast area this morning.
The ridge should ripple over the western Atlantic this afternoon as
a broad trough approaches from the west. At the sfc, the pattern
will feature high pressure from the western Atlantic to the northern
Gulf of Mexico and a warm front across the Ohio River Valley. This
pattern should yield south-southwest winds across the forecast area
today. As temperatures peak in the upper 80s across SE GA and mid
80s across the SC Lowcountry in the mid afternoon, a weak sea breeze
should develop. High resolution guidance indicates that the sea
breeze will push slowly inland late this afternoon, then becoming
nearly stationary 20-30 miles from the coast. Forecast soundings
along and west of the sea breeze indicate that CAPE favor values
around 1500 J/kg with DCAPE between 500-1000 J/kg. Shear values may
increase with the arrival of the mid-level trough this afternoon, 0-
6 km shear between 25-30 kts. Scattered to numerous showers and
thunderstorms are forecast to develop by late this afternoon,
especially across inland portion of the SC Lowcountry. Given the
forecast environment, it is possible that one or two strong to
severe thunderstorms may develop late this afternoon, gusty winds
the primary hazard. In addition, slow storm motions and PW values
around 1.7 inches may yield some inland locations receiving
localized heavy rainfall.

Tonight: Coverage of showers and thunderstorms will gradually
decrease through the evening hours. However, isolated showers may
linger in spots into the late night hours. Low temperatures are
forecast to range between 65-70 degrees.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
Mid-level ridging will briefly set up over the region Tuesday into
Wednesday before becoming quasi-zonal Wednesday into Thursday. The
Southeast U.S. will still be positioned on the western grip of
Atlantic high pressure as a series of surface lows pass across the
northern CONUS. Lingering moisture from a recent passing shortwave
could result in the initiation of a stray isolated shower or
thunderstorm along the sea breeze Tuesday. The forecast currently
features POPs ranging 10-20% considering most locations will likely
stay dry. Conditions will remain dry through Thursday morning with a
mix of clouds and sun. The main focus during the short-term forecast
period is on temperatures, with a couple of unseasonably hot days
ahead. High temps will reach the upper 80s/low 90s Tuesday, rising
to the low 90s both Wednesday and Thursday, with some locations
reaching the mid 90s. Locations along the beach however will be
cooler, topping out in the mid 80s. Record setting high temperatures
are possible both days (see Climate section below). Dew points in
the upper 60s will keep heat indices from reaching the 100 degree
mark. Overnight, both Tuesday and Wednesday will be mild with min
temps in the upper 60s/low 70s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A cold front will push across the area Friday bringing the next
chance for showers and thunderstorms. Guidance has trended the
timing of the front slightly quicker, and now shows the potential
for convection to spread in as early as Thursday evening and then
potentially another round Friday afternoon. In the wake of the
front, high pressure will build bringing dry conditions and cooler
temperatures through the weekend.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
VFR conditions are expected at CHS/JZI/SAV terminals through
this morning. This afternoon, a mid-level disturbance is
expected to arrive front the west. At the sfc, a sea breeze
should develop early this afternoon, possibly drifting just a
county or two inland before becoming nearly stationary. High
resolution guidance indicates that thunderstorms will develop
near KCHS, beginning at 19z. Convection may spread near the KSAV
terminal by 23Z. The KCHS and KSAV will highlight the period of
greatest thunderstorm potential with TEMPOs.

Extended Aviation Outlook: Outside of a possible stray shower
Tuesday, VFR conditions are expected through the week.

&&

.MARINE...
At the sfc, the pattern will feature high pressure from the western
Atlantic to the northern Gulf of Mexico and a warm front across the
Ohio River Valley. This pattern should yield south-southwest winds
across the marine zones. Speeds are forecast to favor values between
10-15 kts today and tonight. Seas should range between 2-3 ft
through the near term period. Beyond 50 nm, seas may build to 4 ft
late tonight across the outer GA waters.

Tuesday through Saturday: Atlantic high pressure will maintain
relatively benign conditions over the local marine waters.
Southeasterly winds in the morning will back slightly during the
afternoon and evening hours each day as the sea breeze develops.
Winds will average 10-15 kt with seas 2-4 ft. Winds will increase
Thursday into Friday as a cold front approaches. Small Craft
Advisory conditions are possible as gusts approach 25 kt, but look
marginal at this juncture. By Saturday, winds will shift out of the
north around 10 kt with seas dropping to 3 ft or less.

&&

.TIDES/COASTAL FLOODING...
The upcoming New Moon (May 8) and recent Perigee (May 5) will lead
to high astronomical tides over the next few days. Minor coastal
flooding is possible along Charleston and coastal Colleton Counties,
including Downtown Charleston, during the evening high tides through
Thursday.

&&

.CLIMATE...
May 8:
KCHS: 93/1986

May 9:
KCHS: 95/1963
KSAV: 95/1962

&&

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

&&

$$

NEAR TERM...NED
SHORT TERM...Adam/BRM
LONG TERM...BRM
AVIATION...BRM/NED
MARINE...BRM/NED