596
FXUS62 KCHS 141642
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
Issued by National Weather Service Columbia SC
1242 PM EDT Wed May 14 2025

.SYNOPSIS...
Broad high pressure will remain across the area through early
next week, resulting in generally hot and dry conditions.

&&

.NEAR TERM /THROUGH TONIGHT/...
No major changes were needed for the noon update.

Shortwave energy, the remnants of the former upper low over the
Tennessee Valley, will exit the area later this afternoon as
heat and instability (highs mid-upper 80s, mid-upper 70s
beaches) build across the region. The greatest local mesoscale
and synoptic forcing looks to occur across the Charleston Tri-
County where some enhancements near the lake breeze near Lake
Moultrie and the afternoon resultant sea breeze is possible.
This will likely support the development of scattered
showers/tstms during the mid-late afternoon hours before waning
this evening. Farther to the south, weak subsidence in the wake
of the passing shortwave should limit convection somewhat,
although the latest RAP soundings do not show much in the way of
convective inhibition during peak heating. Net moisture is a
bit lower south of the Charleston Tri-County which this may be
enough to limit the overall risk for convection there until
possibly later this evening if convection over northern/central
Georgia and work in from the northwest. Pops 20-40% look on
track from Colleton County into the Charleston Tri- County
(highest north of I-26) with pops around 10% elsewhere. The need
for pops over Southeast Georgia into far southern South
Carolina will be reassessed later this afternoon pending
mesoscale and radar trends.

Modified soundings yield solid instability for mid-May with
SBCAPE >2000 J/kg. There is a fair amount of DCAPE based on RAP
soundings and with WBZ heights holding just over 10.0 kft, there
is a risk for damaging winds and marginally severe hail with any
tstms that develop this afternoon, especially north of the I-26
corridor where mesoscale boundary interactions are the most
likely. The latest SPC Day 1 WFO guidance highlighting a
marginal risk for this area look on track.

Tonight: Thunderstorms sourced from the NC mountains will track
to the SE. Based on the suspected storm motions, these storms
should remain just north of the CWA as they reach the Carolina
coast late tonight. H5 heights should continue to rise from the
west during the overnight hours, maintaining a dry and warm
conditions. Low temperatures are forecast to range from the mid
60s inland to around 70 along the coast.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
Thursday: A mid-level trough will shift off the Mid-Atlantic
coastline while ridging builds into the southeastern states from
the Gulf. At the surface high pressure will build into the
region from the south, while a weak trough persists across the
SC Midlands. Quiet weather is expected, with little to no rain
chances and plentiful sunshine. Temperatures are forecast to
reach into the upper 80s to around 90 across the region, several
degrees above normal. Overnight lows will similarly be above
normal, only dipping into the upper 60s to low 70s.

Friday: The flow aloft will shift to be more zonal, while high
pressure remains in control at the surface. A dry forecast has
been maintained, along with above normal temperatures. Friday is
forecast to be a few degrees above the temperatures seen on
Thursday, with low to mid 90s in the forecast. In addition to
the above normal temperatures, dew points are forecast to surge
into the upper 60s to even low 70s. The dew point values
combined with the above normal temperatures will yield heat
index values of 100-105F away from the beaches. While below Heat
Advisory criteria, this will likely be the region`s first real
shot of summer heat and humidity. Overnight lows will once again
be above normal, dipping into the upper 60s to low 70s.

Saturday: Zonal flow will prevail aloft while at the surface
high pressure holds strong to the south, with a trough inland
across the SC Midlands. Once again a dry forecast has been
maintained. Temperatures will remain in the low to mid 90s,
however with dew points forecast to be in the 60s heat index
values will likely remain below 100F.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
Zonal flow aloft will dominate the synoptic pattern through the
weekend, with weak ridging developing early next week. Models
are indicating a weak shortwave could ripple across the
southeastern states on Sunday. At the surface high pressure will
hold strong with the exception of a weak front that attempts to
push into the region on Sunday with the aforementioned
shortwave aloft. Generally quiet weather is expected, with the
only real chance of precipitation on Sunday in the form of
isolated showers associated with the weak front. The summer-like
feeling will continue through the period as temperatures remain
above normal and heat index values reach into the upper 90s
each afternoon.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
14/18z TAF Discussion:
KCHS/KJZI/KSAV: VFR through early Thursday afternoon. A few
tstms could pass north of KCHS and KJZI from mid-afternono
through early evening. Storms would get closest to KCHS. VCTS
will be highlighted 21-00z to account for this.

Extended Aviation Outlook: VFR.

&&

.MARINE...
Today and tonight: The pattern across the marine zones should
support SSW winds between 10 to 15 kts with periods of gusts
around 20 kts. Seas should generally range between 2-4 ft this
morning, subsiding to 2 to 3 ft by this afternoon.

Thursday through Monday: Generally quiet conditions are
forecast across the marine waters through the weekend and into
early next week as high pressure remains the dominant feature.
Expect southerly winds 15 knots or less and seas averaging 2 to
3 feet. A surge in gusts can be expected along the direct
coastline and the Charleston Harbor each afternoon associated
with the afternoon sea breeze.

&&

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

&&

$$