675
FXUS62 KCHS 020837
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
437 AM EDT Tue Jul 2 2024

.SYNOPSIS...
A stalled front will linger near the area today before
dissipating offshore. A hot and humid air mass will build over
the region during the latter half of the week. A weak cold
front could approach the region by Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Today: Sfc analysis shows a stalled boundary/front currently draped
east to west across the local area, from the South Carolina coastal
waters through the Savannah, GA area and inland toward the
Glennville, GA area. The environment remains very moist along and
south of this feature (PWATS around 2+ inches), and continues to be
a focus for showers and thunderstorms redeveloping heading into
daybreak. Very little movement is expected of this feature this
morning, given a lack of large scale features to steer the front.
However, a slightly northward nudge is possible this morning before
h5 shortwave energy rounds the eastern periphery of a ridge
extending across the Deep South. Until this occurs, an onshore wind
will continue to drive deep moisture onshore, leading to additional
showers/thunderstorms during late morning into afternoon hours.
Given PWATs approaching 2.25 inches and slow storm motions, some
showers and thunderstorms could be heavy rainfall producers,
particularly where moisture convergence is enhanced along the coast
and the nearby front/boundary. WPC does currently have southern most
portions of the South Carolina coast and much of southeast Georgia
under a Marginal Risk for excessive rainfall, which falls in line
with latest guidance and current trends. A few Flood Advisories are
not out of the question given the setup. High temps today will be
cooler with clouds and precip across the area, generally ranging in
the mid-upper 80s, warmest across southeast Georgia.

Tonight: Latest guidance has trended a bit more toward holding onto
precip activity south of the front across southeast Georgia.
However, diurnal heat loss should result in most convection to wane
during evening hours. Additional showers and thunderstorms could
redevelop across coastal waters and make a run toward the coast
late. At this time, scattered showers and thunderstorms remain in
the forecast across coastal areas through much of the night to
account for this possibility. Low temps should range between the low-
mid 70s inland to upper 70s near the beaches.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
High pressure off the mid-Atlantic coast will extend across the area
on Wednesday, while a stalled front lingering nearby eventually
dissipates. Aloft, a mid level ridge will build over the Southeast.
Best potential for convection will be near the southern South
Carolina coast and across southeast Georgia where deepest moisture
resides. Further inland and to the north should not see as much
activity. Highs will be in the upper 80s to lower 90s. Lows
Wednesday night will range from around 70 inland to upper 70s at the
beaches.

Mid level ridge will dominate the pattern aloft Thursday and Friday.
The surface will feature high pressure offshore and a trough of low
pressure inland. Mainly just isolated to perhaps scattered diurnally-
driven showers and thunderstorms are expected each afternoon and
evening. Otherwise, temperatures and humidity will be on the rise.
Highs will be in the low to mid 90s on Thursday, with heat indices
topping out in the 100-105 range. Friday will be a bit hotter, and
heat indices could approach local Heat Advisory criteria of 108
degrees in spots. Lows will be in the 70s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
Guidance is in good agreement in the extended. Mid level ridge will
hold over Southeast coast into the weekend, before weakening. At the
surface, a trough of low pressure will persist inland with high
pressure offshore. It should get a bit more convectively active than
previous days with better instability and possibly weak upper
support. Current forecast highlights chance PoPs (generally 40-50%)
each day with coverage peaking in the afternoon and evening. We are
continuing to monitor the potential for excessive heat. Highs temps
mainly in the mid to perhaps upper 90s combined with elevated dew
points will make it feel even hotter. Heat indices are forecast to
approach or exceed 108 in many locations, with some potential to
even hit 113. Excessive heat headlines could eventually be needed.
Convection could disrupt temperature trends.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
KCHS/KJZI: TEMPO IFR cigs/vsbys are possible between 08-10Z this
morning as light showers impact the terminals, but should gradually
improve to MVFR around daybreak, then VFR by late morning.
Thereafter, VFR conditions are anticipated Tuesday afternoon and
should persist through 06Z.

KSAV: Light showers will continue to impact the terminal during the
next few hours. Regardless, TEMPO IFR cigs in place until 10Z this
morning and could need to be extended a few hours as showers and
thunderstorms drift back north near a front this morning. Otherwise,
MVFR cigs/vsbys should prevail into at least mid morning hours after
daybreak. Additional showers and thunderstorms remain possible at
the terminal Tuesday afternoon with a nearby front and ample
moisture in place. TEMPO flight restrictions will likely be needed
in future TAF issuances to account for activity directly impacting
the terminal. Outside of precip, MVFR cigs look to return by around
02Z Wednesday and could prevail through the night.

Extended Aviation Outlook: Brief flight restrictions are possible in
showers and thunderstorms, mainly in the afternoon and evenings
through the period.

&&

.MARINE...
Today and Tonight: A fairly enhanced pressure gradient remains
across local waters this morning, north of a stalled front/boundary
currently positioned across southern SC waters. Northeast winds
gusting up to 15-20 kt will be common through the morning north of
this feature, while to the south and somewhat lighter southerly wind
will prevail with gusts to around 15 kt. Seas could build upwards to
3-5 ft early today, highest across northern SC waters off the
Charleston County coast. Overnight, the front should begin to drift
south of local waters and/or dissipate, but showers and thunderstorms
will continue to pose localized higher wind gusts and reduced
vsbys at times until that occurs. Outside of this activity,
winds should gradually weaken (10-15 kt) and seas should subside
to 2-4 ft.

Wednesday through Sunday: Northeast/east winds initially will turn
southerly by late week. Marine conditions should stay solidly below
small craft advisory criteria with speeds 15 knots or less and seas
no higher than 4 feet.

&&

.TIDES/COASTAL FLOODING...
Favorable onshore winds and the approach of the new moon will lead
to elevated tides over the next few days along the Charleston and
Colleton county coasts. Tides levels could approach minor coastal
flooding criteria of 7 ft MLLW in the Charleston Harbor. Further
south, no tide issues are expected.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.

&&

$$

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