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000
FXUS62 KCHS 220723
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
323 AM EDT Mon Apr 22 2024

.SYNOPSIS...
High pressure will extend across the region this week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Today: 1025 hPa high pressure centered over Arkansas this
morning will build slowly east today while extending east across
the Southeast States. A powerful upper trough will pivot over
the area this morning. There may be just enough moisture in the
600-700 hPa layer to support a few showers or sprinkles over
the Charleston Tri-County as trough pushes through. This
activity should not amount to much of anything and looks to be
mainly centered in the 6am-9am period. Dry weather will prevail
once the trough shifts offshore. Any lingering cloud cover this
morning will gradually diminish through day with sunny skies
prevailing by afternoon. The low/mid-level thermal advection
will be come fairly neutral by afternoon as heights begin to
rise in in the wake of the upper trough. Full insolation
1000-850 hPa thickness schemes support highs in the upper 60s to
near 70, warmest south of the I-16 corridor. Winds may become
at tad gusty this morning, but should ease off by early/mid-
afternoon.

Tonight: High pressure will settle over the area tonight as a
zonal flow dominates aloft. The boundary layer will likely
decouple fairly quickly after sunset with calm/light winds
prevailing for much of the night. Clear skies, low dewpoints and
calm/light winds will support strong radiational cooling away
from the coast. Lows tonight were trended to the colder side of
guidance with localized/mesoscale adjustments made to account
for the usual cold spots (i.e. Francis Marion National Forest).
Water temperatures near the beaches are running in the lower
70s, so large temperature gradients will be found near the
immediate coast and larger bodies of water such as harbors, the
Santee-Cooper lakes and wide rivers like the Broad River. Lows
will range from the upper 30s/lower 40s well inland to the mid-
upper 50s at the beaches.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
High pressure centered over the region Tuesday morning will slip
offshore through the day and into Wednesday. Aloft, ridging will
briefly pass through, before the next trough moves towards the East
coast. No weather concerns with little to no clouds and moderating
temperatures. Highs mainly in the low to mid 70s on Tuesday will
warm to around 80/low 80s for Wednesday. Lows Tuesday night range
from the upper 40s inland to upper 50s at the coast.

A cold front will sink into the region Wednesday night into
Thursday. There are some signals a few light showers could develop,
especially during the latter half of the day, but maintained a dry
forecast for now. Highs near normal in the upper 70s to lower
80s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
High pressure ridges south into the area Thursday night into Friday
and remains the primary feature through the weekend as the high
transitions offshore. Some models hint at a few showers developing
but probabilities are too low so a dry forecast was maintained
through the period. Temperatures will be within a few degrees of
normal.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
22/06Z TAF Discussion:
KCHS/KJZI/KSAV: A brief stint of IFR cigs could impact KCHS and
possibly KJZI through about 07-08z. Otherwise, MVFR cigs will
give to VFR conditions prior to daybreak. Gusty winds near 20 kt
will be possible late morning through mid-afternoon at all three
terminals.

Extended Aviation Outlook: Prevailing VFR.

&&

.MARINE...
Today: North winds 15-20 kt with gusts to 25 kt will be common
across the waters today as a brief surge of cold air advection
ensues in the wake of a powerful shortwave moving offshore.
Winds will run a tad lower in the Charleston Harbor with 15 kt
with gusts to 20 kt. Seas will peak 4-6 ft in the South Santee-
Edisto Beach nearshore leg, 3-5 ft from Edisto Beach south to
the Altamaha Sound out 20 NM and 5-7 ft for the Georgia offshore
waters from 20-60 NM offshore. Small Craft Advisories remain in
force for all legs with the exception of the Charleston Harbor
for today.

Tonight: Winds will veer to the northeast and diminish overnight
as high pressure moves into the Southeast States. Speeds will
diminish to 10-15 kt after midnight with seas subsiding to 3-4
ft within 20 NM and 4-6 ft over the Georgia offshore waters
20-60 NM offshore. Small Craft Advisories for all nearshore legs
will end early this evening, but will remain in force for the
Georgia offshore waters through the night for 6 ft seas.

Tuesday through Saturday: Northeasterly winds initially will
become southerly through mid week as high pressure shifts
offshore. A cold front drops into the region Wednesday night
into Thursday, with high pressure returning thereafter. The
ongoing Small Craft Advisory for the outer Georgia waters will
persist into early Tuesday afternoon for 6 ft seas, but
otherwise conditions are expected to remain below advisory
criteria through the period.

Rip Currents: The combination of 10-11 second swells around 2
ft, gusty conditions and lunar influences will support a
moderate risk for rip currents for all beaches today.

Rip Currents: Winds will have eased, but lingering 9 second
swell and proximity to the new moon will keep an elevated risk
of rip currents at the Georgia beaches. A Moderate Risk is
forecast there, with a low risk northward at the South Carolina
beaches.

&&

.EQUIPMENT...
The KCLX radar will undergo maintenance April 23-26th. Critical
electrical work is planned at the radar site which will require
the radar to be offline until the work is completed. Once the
radar is taken down, it will remain offline until all electrical
work is finalized. The radar is tentatively scheduled to return
to service by April 26.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for AMZ350.
     Small Craft Advisory until 4 PM EDT this afternoon for AMZ352-
     354.
     Small Craft Advisory until 2 PM EDT Tuesday for AMZ374.

&&

$$