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133
FXUS62 KCHS 242247
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
647 PM EDT Mon Jun 24 2024

.SYNOPSIS...
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High pressure will remain over the western Atlantic while a
weak cold front approaches the area. This front will likely
linger near the area through mid-week.
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&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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Tonight: A notable differential heating boundary created by clouds
near the coast vs mostly sunny skies well inland late day has
recently become the focus of convection firing along/near a sfc
trough axis just upstream of the local area. This activity could
drift across inland zones during the next few hours as the trough
nudges toward the Southeast Coast through the night, with a low, but
non-zero risk for a stronger and/or perhaps severe thunderstorm
across far inland locations during the next few hours. By mid
evening, some guidance suggests the tail-end of convection moving
across the Tri-County area and interacting with a sea breeze,
sparking off addition showers and thunderstorms, a few of which
could be strong with gusty winds given DCAPE values in excess of
1000 J/kg, 0-3km lapse rates around 7.5 to 8 C/km and the position
of the trough axis nearby. However, instability will be on the
downward trend during this time frame, would should limit the
overall severe weather risk locally. Once convection moves offshore
and/or dissipates, a warm/humid night will remain in place with lows
ranging in the low-mid 70s well inland to lower 80s at the beaches
and Downtown Charleston.
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&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
Broad troughing will persist across the East Coast on Tuesday,
gradually shifting to zonal flow on Wednesday and a return to
broad troughing Thursday. At the surface a weak cold front will
likely linger in the vicinity of the forecast area through
midweek. 850 hPa temperature anomalies will remain rather warm
through the period, which combined with little mixing each day,
will yield hot and humid conditions. Heat index values are
forecast to reach 102-107F inland. A few spots may make a run at
108F along the coastal counties, however coverage of these
values is not enough to warrant Heat Advisories at this
juncture. Each afternoon isolated to scattered showers and
thunderstorms will be possible, as PWATs remain elevated with
the front in the vicinity. PWAT values are forecast to remain
near 1.6-1.8", which is slightly above normal for this time of
year. CAPE values are forecast to reach around 1500 J/kg, with
model soundings indicating >1000 J/kg of DCAPE. A strong to
marginally severe thunderstorm cannot be ruled out any
afternoon, with strong wind gusts as the main hazard.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
An anticyclone aloft will be positioned over the southern U.S.
and will slowly shift eastward over the southeastern states
through the weekend. At the surface high pressure will extend
into the forecast area from the east with the center of high
pressure centered over Bermuda. Hot and humid conditions will
likely persist into the weekend. Head index values are forecast
to reach from around 103- 105F inland with values approaching
108F along the coastline. Head Advisories may be required. A
summertime pattern is expected through the period, with the
highest precipitation chances in the afternoon hours.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
24/18z TAF Discussion:
KCHS/KJZI/KSAV: Best chances for tstm impacts this afternoon
will be at KSAV and possibly a far north as KJZI. VCTS will be
highlighted at both terminals from roughly 19-21z with a TEMPO
for MVFR conditions in TSRA at the same time at KSAV. Risk for
showers/tstms could increase at KCHS by mid-evening as some
interaction with an approaching surface trough and inland moving
sea breeze occurs. VCSH was highlighted 02-05z for now to
trend. Otherwise, VFR through the period.

Extended Aviation Outlook: Brief flight restrictions will be
possible at all terminals with afternoon showers and
thunderstorms.

&&

.MARINE...
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Tonight: The pressure gradient will remain enhanced this evening
between high pressure centered well offshore and a trough advancing
toward the coast. As a result, south to southwest winds between 15-
20 kt will be common across local waters, with even a few wind gusts
up to 25 kt at times, but the duration of stronger gusts should be
short-lived and not sufficient for a Small Craft Advisory. A few
stronger thunderstorms could impact coastal waters this evening,
primarily across South Carolina waters until the trough advances
offshore. Expect southwest winds to slightly weaken once fropa
occurs later tonight, with gusts upwards to around 15 kt across
nearshore waters and perhaps 20 kt across offshore Georgia waters.
Seas will average between 3-5 ft, largest beyond 10 nm from the
coastline.

Tuesday through Friday: Generally tranquil marine conditions
are expected through the period. Winds will gradually back each
day and veer overnight, strongest along the coastline as the
afternoon sea breeze/overnight land breeze develops. Seas should
average 2 to 3 ft.
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&&

.CLIMATE...
The low temperature at KCHS so far today is 80. If this holds,
this will break the previous record high minimum of 79 set back
2016.

&&

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

$$

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