617
FXUS62 KCHS 230019
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
819 PM EDT Wed May 22 2024

.SYNOPSIS...
High pressure will persist into late week. Diurnal convection
and hot temperatures expected during the holiday weekend. A cold
front might bring impacts to our area on Tuesday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Tonight: Conditions will remain quite similar to the previous night
with sfc high pressure persisting across the local area under a
ridge axis aloft. The first half of the night will experience
favorable radiational cooling conditions with winds decoupling
and becoming light/calm under clear skies. However, some cirrus
should shift across the region overnight, limiting cooling
potential a few degrees late. Patchy fog becomes a possibility a
few hours prior to daybreak, mainly across inland areas of
southeast South Carolina where sfc temps dip into the lower 60s.
However, high clouds and drier grounds should limit greater fog
coverage late. Elsewhere, lows in the mid 60s are anticipated
across southeast Georgia while temps remain in the upper 60s/lower
70s closer to the beaches.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
Thursday: The day will begin with the H5 ridge along the coast,
shifting east through the afternoon. A shallow H5 trough will slide
over the southern Appalachians during the afternoon. At the sfc, a
wavy front should remain across the Ohio River Valley, with moisture
pooling to the east. Short term guidance indicates that a weak sea
breeze may develop Thursday afternoon. However, with poor lapse
rates lingering llvl CIN should keep the forecast area dry. High
temperatures are forecast to range around 90 degrees.

Friday, the H5 heights will remain generally zonal with a weak
trough across the Coastal Plain in the afternoon. Isolated to
scattered showers and thunderstorms are forecast to develop along a
sea breeze Friday afternoon. Given sfc conditions in the low 90s and
dewpoints in the upper 60s to low 70s, a wide field of instability
should develop during the heat of the afternoon.

Saturday, models indicate that broad H5 trough will develop across
the Southeast U.S. At the sfc, a weak trough is expected to form
along the coast, reinforced with an afternoon sea breeze. High
temperatures will once again favor values in the low 90s. However,
dewpoints should increase, generally ranging in the upper 60s to
around 70. Deep moisture convergence and instability along and west
of the sea breeze should support isolated to scattered thunderstorms.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Mid-level ridging should build across the region on Sunday. The
forecast area will remain between deep low pressure over the Ohio
River Valley and high pressure over the eastern Gulf of Mexico. This
pattern should provide the region with deep south winds. Given the
ridge overhead, showers and thunderstorms should hold off until the
afternoon and evening, forming along the sea breeze. Sunday is
expected to be the hottest day, with mid 90s possible across the
forecast area.

The H5 ridge will remain across the forecast area on Monday. Sfc
high pressure over FL is expected to ridge northward across the CWA.
The forecast will continue to feature isolated to scattered showers
and thunderstorms with highs in the low 90s.

A cold front is forecast to impact the region on Tuesday. At this
time, the forecast will feature PoPs in the high chance range. With
the late arrival of the front and convection, temperatures may reach
the low 90s.

Wednesday, temperatures may range a bit cooler, with values in the
upper 80s. Slight dryer conditions should result in lesser coverage
of afternoon and evening showers and thunderstorms.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
VFR conditions are expected at CHS/JZI/SAV terminals through 00Z
Friday. However, patchy fog could briefly produce MVFR vsbys between
the 09-13Z Thursday time frame. At this time, JZI includes TEMPO
MVFR vsbys during this time while CHS/SAV remain VFR.

Extended Aviation Outlook: Mainly VFR through Thursday night. Brief
flight restrictions are possible due to showers/thunderstorms each
afternoon/evening beginning on Friday.

&&

.MARINE...
Tonight: High pressure will persist across local waters, leading to
a fairly relaxed pressure gradient. Winds should remain around 10 kt
or less, slowly veering from southeast to south/southwest overnight.
Seas will be no higher than 1-3 ft, slowly subsiding through the
night as well.

Extended Marine: High pressure should yield typical summer-time
weather across the forecast area. In fact, a sea breeze is expected
to develop each afternoon through the holiday weekend. A cold front
may arrive on Tuesday, bringing an increase in thunderstorm
activity. Otherwise, conditions should remain below Small Craft
Advisory conditions.

Rip Currents: On Thursday, the combination of astronomical
influences from the Full Moon and a small swell will lead to an
enhanced risk of rip currents at all of our beaches. The in-house
Rip Current Calculator continues to indicate a Moderate Risk, while
the Rip Current MOS points to a Low Risk. For consistency, we
maintained the Moderate Risk. Rip currents are most likely at Tybee
Island.

&&

.TIDES/COASTAL FLOODING...
Minor flooding is briefly possible with the evening high tide
Thursday along coastal Charleston and coastal Colleton Counties.
There are no concerns along the remainder of our coast.

&&

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

&&

$$

NEAR TERM...DPB
SHORT TERM...
LONG TERM...
AVIATION...DPB
MARINE...DPB