601
FXUS62 KCHS 052040
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
440 PM EDT Wed Jun 5 2024

.SYNOPSIS...
High pressure will extend across the area through tonight. A
cold front will approach from the northwest on Thursday, then
slowly move through on Friday. High pressure returns for the
weekend, then another cold front will move through Monday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Late Afternoon and Tonight: Aloft, the axis of a ridge will remain
placed offshore while h5 shortwave energy nudges across the local
area. Hi-res models continue to indicate showers and thunderstorms
developing locally along the western periphery of sfc high pressure,
gradually tracking east-northeast toward the I-95 corridor where
SBCAPE around 2500-3000 J/kg, low-lvl lapse rates near 8-8.5 C/km
and DCAPE upwards to 600-800 J/kg resides. Bulk shear remains weak,
but instability suggests a few thunderstorms could become strong or
perhaps marginally severe during the next few hours with damaging
wind gusts being the primary concern. Outflow from this activity
combined with a late day seabreeze circulation could drive some
convection further east-northeast into southeast South Carolina
early evening, but the general consensus is that activity will
weaken/wane within a hour of sunset. By nightfall, activity will
continue a downward trend in coverage and the overall concern for
severe weather will become quite limited due to diurnal heat loss
and a lack of shear. The focus of shower/thunderstorm activity
should then shift offshore by midnight as the bulk of h5 shortwave
energy crosses over the western Atlantic. Low temps will remain
fairly mild within a light southerly flow. In general, lows should
range in the upper 60s/around 70 well inland to mid-upper 70s near
the coast.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
Thursday: A shortwave trough is poised to ripple through the
southeastern states in the afternoon to evening hours. At the
surface a cold front will be positioned well to the west of the
forecast area. Ahead of the cold front moisture will pool into the
region, with PWATs increasing to around 1.6 inches. A combination of
the increased moisture and forcing from the shortwave and the
approaching cold front should result in decent shower and
thunderstorm coverage in the afternoon. PoPs are generally in the 40-
50% range across the region, decreasing from west to east in the
overnight hours. High temperatures are forecast to reach into the
low to mid 90s, with overnight lows in the low to mid 70s.

Friday and Saturday: Broad troughing will prevail aloft on Friday
and Saturday, while at the surface a cold front slowly pushes
through by Friday night. High pressure will begin building in at the
surface on Saturday. Not much in the way of precipitation is
expected with the cold front, however it will likely bring a
decrease in dew points. A slight chance of showers and thunderstorms
is possible on Friday afternoon, mainly along the coastal counties
associated with the passing cold front`s interactions with the local
sea breeze. PWATs Saturday are forecast to drop below 1 inch on,
with a dry forecast maintained. Temperatures each day are expected
to reach into the low 90s, with overnight lows in the mid to upper
60s, with around 70 at the beaches.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A return to a typical summertime pattern of afternoon showers and
thunderstorms should return late in the weekend and into early next
week. A cold front is expected to approach the forecast area early
next week, with PWATs increasing to around 1.5 inches by mid week.
Isolated to scattered showers and thunderstorms are possible each
afternoon through mid week due to the increased moisture and
interactions with the local sea breeze. Temperatures are expected to
be right around normal to slightly above normal.

&&

.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
VFR conditions are expected to prevail at CHS/JZI/SAV terminals
through 18Z Thursday. However, afternoon/evening showers and
thunderstorms are expected to develop across the area and could
impact any terminal. The SAV terminal will have the greatest
chance of experiencing a shower/thunderstorm this afternoon into
early evening. For now, VCSH and TEMPO IFR conditions associated
with TSRA remains in the TAF for SAV until 21Z, then VCTS with
TEMPO MVFR conditions and gusty winds up to 25 kt remains in the
TAF for SAV between 22-24Z. Further adjustments will likely be
needed based on trends, and conditions could be lowered to IFR
should a thunderstorm directly impact the SAV terminal during
the evening as well. Thunderstorm activity could shift east-
northeast into the vicinity of CHS and JZI later in the evening,
but confidence remains too low to include in the latest TAF
issuance at this time.

Extended Aviation Outlook: Brief flight restrictions will be
possible Thursday afternoon with showers and thunderstorms.
Otherwise, prevailing VFR.

&&

.MARINE...
Late Afternoon and Tonight: Southerly flow will prevail across
the local waters through the period with speeds mostly in the
10-15 kt range, but the pressure gradient should become slightly
stronger with modest nocturnal surging overnight, suggesting
the potential for winds to gust between 15-20 kt at times. Seas
are expected to average between 2-3 feet.

Thursday through Sunday: SW winds on Thursday afternoon will shift
to the NW by Friday afternoon as a cold front slowly pushes through
the region. SW winds will resume by Sunday afternoon. Wind speeds on
Thursday will be slightly elevated, with 15 to 20 knots across the
marine zones. Thereafter, speeds should remain around 10 knots. Seas
are expected to average 2 to 3 ft through the period.

&&

.TIDES/COASTAL FLOODING...
Astronomical tides will remain elevated today and again on
Thursday. Although the wind direction along the coast isn`t
ideal for driving large positive tidal departures, conditions
should still be sufficient to produce departures in the 0.4 to
0.6 ft. Therefore, the upcoming evening high tide and again
Thursday evening could peak right around 7.0 ft MLLW in Charleston.
Coastal Flood Advisories could be needed for Charleston and
coastal Colleton counties.

&&

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

&&

$$

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