371
FXUS62 KCHS 170001
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
801 PM EDT Mon Sep 16 2024

.SYNOPSIS...
Low pressure will shift inland across the Carolinas and weaken
tonight into mid week. High pressure should develop inland late
week into the weekend.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Tonight: Low pressure centered north of the local area will move
slowly northwest and inland across the Carolinas, gaining latitude
and shifting further away from the region overnight. South of this
feature, sfc winds should gradually back to the north-northwest this
evening, then west-northwest by midnight, slowly diminishing as the
low tracks further away from the region. A few light showers could
drift into northwest locations of Berkeley County this evening,
before drier air (depicted on latest water vapor imagery) overtakes
lingering low-lvl moisture. Expect dry conditions to prevail across
all areas by midnight. Latest vis sat imagery continues to indicate
broken to overcast low clouds locally early this evening, but
expect some of these clouds to erode with drier air shifting into
the area through the night. Given breaks in clouds and sfc winds
weakening overnight, temps should dip into the mid 60s inland to
upper 60s near the coast. Some lower 60 temps are not out of the
question across Southeast Georgia well inland should clouds
erode more quickly overnight.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
The remnant low of PTC8 should be somewhere over the Carolinas at
the start of the period. The surface low will continue to weaken
with time. An associated trough axis/weak boundary should transition
back towards the coast and possibly offshore on Thursday. Tuesday
should actually be rain-free over the local area, then isolated to
perhaps scattered showers will return for Wednesday and Thursday
with deeper moisture and upper trough moving back overhead. High
temperatures a touch below normal on Tuesday will warm to the mid to
even upper 80s for mid week. Lows will range from the upper 60s
inland to low/mid 70s at the immediate coast.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Mid level trough axis initially stretched down the east coast should
push a bit east over the weekend as a ridge centered over southern
Texas nudges into the region. Still some spread between models
during the latter half of the weekend with regards to if a mid level
low forms off the coast and how far offshore that would be. At the
surface, high pressure is expected to build south into the Carolinas
and Georgia. This pattern generally favors lower rain chances, so
PoPs are no higher than 20% and only located closer to the coast.
Temperatures will lean on the cooler side of normal through the
period.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
MVFR cigs will prevail at CHS/JZI through about 06Z Tuesday, before
trending to VFR by around 08Z Tuesday as drier air filters into the
local area. VFR conditions will then prevail at both terminals
through 00Z Wednesday. At SAV, tempo MVFR cigs have been introduced
through 02Z Tuesday, before VFR conditions prevail for much of the
night. Expect VFR conditions to then persist through 00Z Wednesday.

Extended Aviation Outlook: Low chance for brief flight restrictions
in showers and thunderstorms Wednesday and Thursday.

&&

.MARINE...
Tonight: Conditions will gradually improve as low pressure centered
north of the area moves slowly northwest and further away from the
region overnight. Small Craft Advisories will remain in effect
across local waters outside the CHS Harbor this evening, but trends
suggest northwest/west winds and seas to drop below advisory
criteria across nearshore waters south of Edisto, SC during the next
few hours, then potentially across Charleston County waters around
midnight. 6 ft seas will likely linger across offshore Georgia
waters through the night, so a Small Craft Advisory is expected to
continue into Tuesday.

Tuesday through Saturday: Fairly benign marine conditions are
expected through at least Friday with wind speeds generally less
than 15 knots. Seas will subside on Tuesday, settling in 2-4 foot
range thereafter. High pressure should build south into the
Carolinas and Georgia late week into the weekend. Winds will turn
out of the northeast and could see some increase in speeds with the
pressure gradient tightening.

Rip Currents: Lingering swell of around 3 ft every 10 seconds and
astronomical influences from the full moon and perigee will maintain
a High Risk of rip currents for all beaches through Tuesday. It
is worth noting that local calculations for Georgia beaches were
borderline moderate-high but opted to maintain the High for now.

&&

.TIDES/COASTAL FLOODING...
This Evening: Latest departures are near 0.6 ft at the Charleston
tide gauge. With these departures expected to hold during the
next hour, minor coastal flooding is occurring. A Coastal Flood
Advisory remains in effect for Charleston and Coastal Colleton
Counties until 9 PM.

Tides are expected to remain below Coastal Flood Advisory Levels
for the remainder of our coastline from Beaufort County, SC
southward to McIntosh County, GA.

As we continue into mid to late week, the risk for at least
minor flooding will continue for Charleston and Coastal Colleton
Counties due to high astronomical tides with the full moon on
September 17th.

Beaufort County, SC, south to McIntosh County, GA: Waters levels
could be close to minor flood levels later this week as onshore
winds return.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...High Risk for Rip Currents through Tuesday evening for GAZ117-119-
     139-141.
SC...High Risk for Rip Currents through Tuesday evening for SCZ048>051.
     Coastal Flood Advisory until 9 PM EDT this evening for SCZ049-
     050.
MARINE...Small Craft Advisory until midnight EDT tonight for AMZ350-352-
     354.
     Small Craft Advisory until 1 PM EDT Tuesday for AMZ374.

&&

$$

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