513
FXUS62 KCHS 011554
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1154 AM EDT Mon Jul 1 2024

.SYNOPSIS...
A cold front will impact the area today into Tuesday before
dissipating offshore. High pressure will return for the latter
half of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
This Afternoon: Late morning MSAS analysis showed broad
convergence slowly increasing ahead the southward moving cold
front. Still expect clusters of showers/tstms to develop along
the coast over the next few hours. The cold front is moving a
bit slower than expected, but a broad area of strong moisture
convergence is still progged to develop over the middle South
Carolin coast through the afternoon as mixed-layered builds,
which should help to enhance convection and rainfall rates even
further. Some slight adjustments to pops were made to lower then
slightly across the interior, but 90-100% pops were maintained
in the coastal corridor. PWATs nearing 2.50" coupled with MLCAPE
in excess of 1500 J/kg will support intense rainfall rates,
possibly reaching as high as 3 in/hr at times. A Flood Watch
continues for all areas except Tattnall County to Allendale
County. QPF progs for the 01/12z HREF are down about 10% across
the 1", 2" and 3" thresholds, but are still quite elevated
considering the time of year.

Tonight: By mid evening, convection will trend weaker and wane
overnight, although some showers and thunderstorms could persist
across far southern areas should the front stall and/or linger
nearby prior to daybreak. A northeast wind post fropa and previous
shower/thunderstorm activity will lead to noticeably cooler low
temps. In general, lows will range in the upper 60s/lower 70s well
inland to mid-upper 70s near the beaches.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
A stalled front will linger just off the coast and to the south near
the Altamaha on Tuesday. The front is expected to become more
diffuse through the day on Wednesday. Aloft, a mid level ridge
centered over the Gulf coast states will expand over the local area
with time as troughing offshore shifts further away. Scattered to
numerous showers and thunderstorms will be possible each day, with
highest coverage over southeast Georgia where deeper moisture of
PWats >2 inches is expected to still reside. Locally heavy rainfall
is possible. Areas further inland and to the north should not see as
much activity. There will be notable relief from the heat,
especially on Tuesday when highs only peak in the mid 80s. Lows both
nights will mainly be in the low to mid 70s.

Atlantic high pressure will prevail on Thursday, while a trough of
low pressure develops inland. Upper ridge settling overhead will
help limit convection with just isolated to scattered showers and
thunderstorms possible with the sea breeze. Temperatures will rise
back up to the low to mid 90s, but heat indices should remain in
check below headline criteria (peaking 100-105F).

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
Strong upper level ridge initially overhead will transition offshore
through the weekend. The surface will feature troughing inland and
high pressure offshore. Main concern this period will be the heat.
The pattern will favor increasing temperatures and humidity. Some
interior locations could even see max temperatures hit triple
digits. Excessive heat headlines are certainly possible. Otherwise,
isolated to scattered diurnally-driven showers and thunderstorms are
expected.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
01/18 TAF Discussion:
KCHS/KJZI/KSAV: Showers/tstms are expected to expand in area
through the afternoon/evening as a cold front approaches.
Prevailing tstms will be highlighted from 20-23z at KCHS and
KJZI with TEMPO conditions as low as IFR at KCHS and LIFR at
KJZI. For KSAV, impacts may be a bit later, closer to 23-02z.
Amendments will be needed as convective trends become clearer.
The front should move south of KCHS/KJZI by 00z and KSAV by 05z
with VFR cigs filling in behind it. These will linger through
the night.

Extended Aviation Outlook: Flight restrictions in low clouds could
linger into Tuesday. Otherwise, brief flight restrictions are
possible in showers and thunderstorms, mainly in the afternoon and
evenings through the period.

&&

.MARINE...
Today and Tonight: A cold front will shift south across the
area this afternoon, turning south/southwest winds to east-
northeast in its wake by tonight. Widespread showers and
thunderstorms could also reduce vsbys across local waters to 1
NM of less at times and produce gusty winds, some of which could
necessitate Special Marine Warnings. There will be a bit of a
post-frontal surge tonight with speeds increasing to 15-20 kt
over the South Santee to Edisto Beach nearshore leg and 10-15 kt
elsewhere. Seas should also build upwards to 3-5 ft tonight
(highest across Charleston County waters late).

Tuesday through Saturday: Gusty northeast winds are expected on
Tuesday in between high pressure inland and a stalled front
offshore, especially across the Charleston county waters. Conditions
look to hold below small craft advisory criteria. Gradient weakens
for mid to late week with winds 15 knots or less and seas averaging
2-3 ft.

&&

.CLIMATE...
Daily Rainfall Records for July 1:
KCHS: 2.66 set in 1948
KCXM: 1.64 set in 1966
KSAV: 2.76 set in 1871

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Flood Watch until 9 PM EDT this evening for GAZ101-116>119-
     137>141.
SC...Flood Watch until 9 PM EDT this evening for SCZ042>045-047>052.
MARINE...None.

&&

$$