568
FXUS62 KCHS 171133
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
733 AM 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/...
The day begins with some patchy dense fog near and west of
US-301, which will dissipate by 9 am. Otherwise, various layers
of clouds, generally scattered to broken will exist, leading to
partly to mostly sunny skies. Temperatures will warm into the
80s all locations before 10 am. It`s possible that the
fog/stratus far inland could leave behind a differential heating
boundary, which might be a boundary for something to potential
form on this afternoon. Still think there is too much
subsidence, so we maintained no mention of showers or t-storms
in the forecast.

Today: Strong ridging aloft covers much of the eastern states,
including the immediate area. Meanwhile at the surface, a
stationary front will dissipate, as an elongated region of high
pressure off New England extends overhead. The large scale
subsidence, poor thermodynamics, and plenty of dry air between
about 700 mb and 300 mb will likely prevent any convection from
developing. However, it`s rare to not have any activity this
time of year, so we carry a "silent" 10% POPs well inland this
afternoon, just in case something is able to form along the
inland penetrating sea breeze.

Water vapor satellite imagery shows that dry air circulating in
from the north and east around the anticyclone aloft, and this
will allow for dew points to dip into the 60s for most
communities. That along with modest easterly winds off the
Atlantic will actually make it feel somewhat bearable, even
though max temperatures still reach the upper 80s and lower 90s
away from the ocean.

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 /12Z MONDAY THROUGH FRIDAY/...
KCHS/KJZI/KSAV: Strong subsidence and considerable dry air
between about 10K and 40K feet will result in little or no
convection at any of the sites through 12Z Tuesday. Thus we are
showing VFR conditions, with maybe a brief period of MVFR
ceilings at any of the airports this morning due to the onshore
flow. Gusty E 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...
Today and tonight: The main feature will be an expansive area
of a strong 1027-1029 millibar high pressure system centered
off New England that covers the local waters. There`s a decent
gradient in place, and that along with sea breeze influences
during the afternoon and evening, and nocturnal low level
jetting, E winds will be up near 15 kt and gusty through the
period. Seas will work their way up to 3 or 4 feet within 20 nm
due to the favorable onshore fetch, while 4 to 5 feet will be
reached on the Georgia waters 20-60 nm out.

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...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...