800
FXUS62 KCHS 172354
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
754 PM EDT Wed Jul 17 2024

.SYNOPSIS...
High pressure will persist offshore, while a weak trough
resides inland. A cold front will approach the region late week
and likely stall nearby, before High pressure returns next
week.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Latest SPC mesoanalysis indicated a large pocket of instability
across the SC Lowcountry. Isolated to scattered showers and
thunderstorms should continue to develop across the region well
into this evening. In addition, remnant stratiform rain across
SE GA should continue for a couple hours, then dissipating later
this evening. The forecast update will feature areas of rain-
cooled air across SE GA and portions of the SC Lowcountry. In
addition, adjustments were made to the hourly sky cover and
PoPs.

Lows tonight will range from the lower-mid 70s across the
interior to around 80 at the beaches and Downtown Charleston.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
The mid-levels will consist of broad troughing prevailing over the
eastern half of the U.S. Thursday and Friday. High pressure begins
to build into the region from the east on Saturday. At the surface,
High pressure will persist offshore, while a weak trough resides
inland on Thursday. A cold front will approach the region Friday,
likely stalling nearby into the weekend. Though, it appears to be
closest to our region on Friday. There will be deep moisture across
the region, with PWATs over 2". High temperatures are expected to be
in the lower to middle 90s each day across most of our area, except
cooler at the beaches. This heat and moisture will combine to
generate plenty of instability, causing scattered to numerous
convection each afternoon and evening. Though, the most coverage and
intensity appears to be on Friday. Given the time of year, a strong
to marginally severe thunderstorm is certainly possible each day,
with the main concern being damaging winds. Locally heavy rainfall
is also possible in areas where there is storm training. Though,
steering flow may help move the storms along each day. As for heat
indices, they are expected to approach 105-108 degrees along the
coast each day. But the duration and coverage may not be enough to
warrant Heat Advisories, especially considering afternoon convection
will cool temperatures down. Overnight lows will remain in the
70s.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A summertime pattern will persist with High pressure in the western
Atlantic and troughing along or near the Southeast U.S.
This synoptic flow will keep abundant moisture across the region.
With highs in the 90s, instability will generate afternoon
convection, trending lower during the overnight hours.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
Prior to the 0Z TAFs, KCLX detected an area of stratiform rain
across KSAV, remnant of earlier thunderstorms. This area of rain
should dissipate by 2Z. Based on radar trends, showers may pass
near KCHS and KJZI late this evening. Otherwise, terminals
should remain VFR with steady light SW winds. A cold front will
approach from the west Thursday afternoon. Southwest winds at
KCHS and KJZI are forecast to strengthen, with gusts near 20kts
during the afternoon hours.

Extended Aviation Outlook: Convection could produce brief flight
restrictions, especially each afternoon/evening.

&&

.MARINE...
Tonight: Pressure gradient will remain a bit tight across the
coastal waters through much of tonight, supporting 15 to 20 knot
sustained winds. Gusts to around 25 knots will continue over
the South Santee-Savannah River nearshore legs through much of
tonight (where Small Craft Advisories are in effect), and in
Charleston Harbor until early this evening. Seas will build 3-5
ft.

Extended Marine: High pressure will persist near Bermuda, while a
weak trough is inland Thursday. A cold front will approach the
region Friday, stalling nearby through the weekend. There should be
a surge of winds Thursday afternoon. It`ll be borderline whether
Small Craft Advisories will be needed, mainly for the Charleston
waters. Otherwise, expect mainly southerly winds 10-15 kts, stronger
along the land/sea interface with the formation of the afternoon sea
breeze. Some nocturnal jetting is also possible. Seas should average
2-4 ft.

Rip Currents: Thursday: The combination of a 2 ft swell every 8-9
seconds and gusty onshore winds will support a Moderate Risk for rip
currents at all of our beaches.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until midnight EDT tonight for AMZ330.
     Small Craft Advisory until 6 AM EDT Thursday for AMZ350-352.

&&

$$

NEAR TERM...NED
SHORT TERM...
LONG TERM...
AVIATION...NED
MARINE...