493
FXUS62 KCHS 050514
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
114 AM EDT Wed Jun 5 2024

.SYNOPSIS...
High pressure will extend across the area through Wednesday. A
cold front will approach from the northwest on Thursday, then
slowly move through on Friday. High pressure returns for the
weekend.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Early this morning: Radar imagery shows that convection just to
our west has continued to track eastward and is currently
impacting Jenkins, Screven, Candler counties and will at least
produce a few showers a bit further to the east for the next
couple of hours. IR satellite imagery shows that cloud tops have
been warming and this cluster of convection is definitely on a
diminishing trend. Otherwise, the rest of the overnight is
expected to be dry. There are no significant fog concerns and
lows still look to be on track for the upper 60s inland and low
70s along the coast. There could be a few of the typically
cooler spots that approach the mid 60s.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
Wednesday: A fairly active pattern will be in place as weak
mid-lvl ridging shifts further offshore and becomes replaced
with weak mid-lvl troughing across the Southeast United States.
A series of h5 shortwaves associated with the trough will
ripple across the area, the first of which occurs on Wednesday
and helps promote scattered to potentially numerous
showers/thunderstorms during peak heating hours. A seabreeze
circulation could provide an additional focus of activity and a
few stronger thunderstorms and/or isolated severe thunderstorm
can not be ruled out during peak heating hours, mainly inland.
Convection should then wane during evening hours. High temps
should range in the upper 80s to lower 90s away from the coast.
Overnight lows should range in the low-mid 70s away from the
immediate beaches.

Thursday: A southwest flow will help advect deep moisture to
the region (PWATs near 2.0 inches) ahead of a cold front
advancing toward the Southeast United States late day,
suggesting the most active weather day of the week. Numerous
showers and thunderstorms remain in the forecast during
afternoon hours when stronger h5 shortwave energy arrives and
the sfc front advances across the Midlands. Although wind fields
remain rather weak, moderate levels of instability could result
in a few pulse severe thunderstorms locally, especially if
thunderstorm boundary interactions occur with an inland moving
seabreeze across inland zones. Convection could persist into
evening hours as the front begins to shift across the local area
at night, posing a limited risk for a few stronger and/or
isolated severe thunderstorm closer to coastal areas before
midnight. However, the threat for stronger activity likely comes
to an end during the second half of the night as the front
begins to advance offshore. High temps for the day should range
in the lower 90s for most areas away from the beaches. Low temps
should dip into the upper 60s well inland to low-mid 70s closer
to the coast.

Friday: The cold front will likely reach the coast prior to
daybreak, with a deep westerly flow occurring across the region
in its wake during the day. There isn`t much in the way of cold
air advection post fropa to start off the weekend and with a
substantial downslope wind in place temps are likely to remain
warm, perhaps in the lower 90s. However, moisture will likely be
driven offshore with the front and subsidence associated with
the downslope flow suggests precip chances will remain fairly
limited to southern most areas, perhaps near the I-95 corridor
across southeast Georgia. Given the amount of heating, a few
thunderstorms can not be ruled out, but stronger/severe
convection is not expected.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Although temps will remain fairly warm this weekend, the
airmass will noticeably change due to substantially lower
dewpoints. This should also limit the potential for convection.
An increase in moisture early next week and some shortwave
energy will bring a return to scattered diurnal convection.

&&

.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions are expected to prevail at KCHS, KJZI, and KSAV
through 06z Thursday. The main forecast challenge will be
afternoon and evening shower and thunderstorm activity and if it
can impact any of the terminals. KSAV seems to be the primary
candidate and we have introduced VCTS in the 21-00z time period.
This activity could shift eastward into the vicinity of KCHS and
KJZI later in the evening, but confidence is too low to add
anything into the TAF`s at this time.

Extended Aviation Outlook: Brief flight restrictions are
possible with showers and thunderstorms Thursday with a passing
front. VFR conditions should then prevail Friday and persist
through Sunday.

&&

.MARINE...
Tonight: Under the control of high pressure that extends
directly across the area, southerly winds of 10 or 15 kt will
prevail. Seas will be just 2 or 3 feet. We could see isolated
late night showers/thunderstorms, especially beyond 20 nm
offshore.

Wednesday through Sunday: High pressure will remain over the
western Atlantic Wednesday, maintaining southerly flow around 15
kt or less into early Wednesday night. The pressure gradient
should then show signs of strengthening heading into Thursday as
a cold front approaches from the west Thursday night into early
Friday. Southwest winds gusting upwards to 15-20 kt are
possible ahead and immediately post fropa, before the pressure
gradient weakens and winds turn more offshore heading into the
weekend. Seas should also build up to 3-4 ft into Thursday
night, then subside to 2-3 ft during the weekend.

&&

.TIDES/COASTAL FLOODING...
Astronomical tides will continue to rise this week. Although
meteorological conditions are not very favorable for elevated
tides, we are expecting the threat for a positive tidal anomaly
of 0.5 to 0.7 ft. Therefore, the evening high tides Wednesday
and Thursday could reach at least 7.0 ft MLLW in Charleston,
necessitating Coastal Flood Advisories.

&&

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

&&

$$

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