877
FXUS62 KCHS 171713
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
113 PM EDT Mon Jun 17 2024

.SYNOPSIS...
A stationary front will dissipate across the area today, as
high pressure builds from the northeast. High pressure will
then continue to ridge in from offshore mid to late week.

&&

.NEAR TERM /THROUGH TONIGHT/...
This Afternoon: Aloft, a large ridge will remain centered across the
Southeast and Mid-Atlantic states, favoring large scale subsidence
across the local area. At the sfc, high pressure centered across the
western Atlantic off the Mid-Atlantic and Northeast Coast will
extend south across the local area, providing an onshore flow
throughout the day. Despite the onshore flow, dry air depicted on
water vapor imagery favors rain-free conditions across most coastal
areas and for much of southeast South Carolina. However, inland
locations across southeast Georgia could experience a few showers
this afternoon where adequate moisture and SBCAPE between 1500-2000
J/kg resides. Subsidence aloft will limit the strength of convection
across the noted area, but a few showers (or perhaps a thunderstorm)
could produce gusty winds given strong low-lvl lapse rates around 8
C/km and DCAPE around 1200 J/kg. 1000-850mb thicknesses along with
ample sunshine favor high temps in the upper 80s closer to the coast
to lower 90s inland.

Tonight: There is very little change in the pattern, both surface
and aloft, with deep high pressure firmly in control. With the dew
points generally down in the 60s, winds slackening off through
the night, and no worse than mostly clear or partly cloudy skies,
minimum temperatures look to drop to 65-70F well inland, lower
and middle 70s closer to the Atlantic.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
High pressure both aloft and at the surface will be centered over
New England, extending into the local forecast area from the NE on
Tuesday. This pattern will persist into Wednesday, when the centers
of high pressure begin to shift eastward, taking up residence closer
to Bermuda. Subsidence aloft will begin to break down as the high
pressure moves further offshore. A weak coastal trough is expected
to form along the southern periphery of the ridging aloft, leading
to isolated to scattered showers and thunderstorms Tuesday and
Wednesday afternoons. Precipitation will likely be confined to the
coastal zones of extreme southern SE SC and SE GA. Precipitation
chances will gradually increase through the week, as well as an
increase in areal coverage, as persistent onshore flow brings an
influx of moisture into the region. Temperatures are expected to be
around normal, to maybe even slightly below normal. The forecast
features highs in the upper 80s to low 90s and overnight lows in the
upper 60s to low 70s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
Subsidence will continue to diminish aloft with the retreating high
pressure at the surface and aloft. The forecast will trend back
towards a more typical summertime pattern, with isolated to
scattered showers and thunderstorms in the afternoon hours. Moisture
is forecast to begin streaming into the region late week as a
possible low pressure lingers off the east coast of Florida. This
additional moisture will help to enhance afternoon showers and
thunderstorms, especially across southeast GA later in the week.
Temperatures are expected to remain near normal.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
KCHS/KJZI/KSAV: Strong subsidence and considerably dry air between
about 10K and 40K feet will result in little or no convection at any
of the sites through 12Z Tuesday. Thus, prevailing VFR conditions
are expected at all terminals. However, a brief period of MVFR
ceilings is possible at the SAV terminal early afternoon due to
the onshore flow. Gusty easterly winds will peak around 15-20 kt
for all terminals this afternoon, before dropping off with sunset.

Extended Aviation Outlook: Prevailing VFR. Brief flight restrictions
are possible in afternoon showers/thunderstorms Tuesday and
Wednesday, especially at KSAV. Chances of flight restrictions
increase at CHS/JZI/SAV terminals later in the week with showers and
thunderstorms moving onshore.

&&

.MARINE...
This Afternoon and Tonight: High pressure will remain the dominant
weather feature, extending across the region from the north and
enhancing the pressure gradient across local waters. The gradient
along with an afternoon seabreeze circulation and nocturnal low-lvl
jetting will favor easterly winds between 15-20 kt this afternoon,
then around 10-15 kt with gusts to around 20 kt at times overnight.
Seas will also slowly build during the period due to a prolonged
onshore fetch. In general, seas should build to 3-4 ft across
nearshore waters and 4-5 ft across offshore Georgia waters, largest
overnight.

Tuesday through Friday: Generally, high pressure will prevail over
the local waters through the period. With high pressure extending
into the region from the northeast and a developing low pressure off
the east coast of FL the pressure gradient is expected to pinch
Tuesday into late week. This pinched gradient will likely result in
E winds 15 to 20 knots with gusts to 25 knots and seas building to
as high as 5 to 6 ft across the nearshore waters and 8 to 9  ft
across the 20-60 nm offshore GA waters. Small Craft Advisories will
likely be needed for most, if not all, marine waters beginning as
early as Tuesday night for the 20-60 nm offshore GA waters.

Rip Currents: A continued onshore wind that averages around 15
mph, plus a small swell will produce a Moderate Risk of rip
currents at the area beaches today.

A Moderate Risk for rip currents will remain in place through
Tuesday with increasing swells. At least a Moderate Risk for
rip currents will likely continue for all beaches through the
middle of the week as swell energy continues to increase ahead
of a low pressure approaching the Southeast United States late
week.

&&

.EQUIPMENT...
Our office phones are down, with the telephone company working
on correcting the problem.

&&

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

&&

$$

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