801
FXUS62 KCHS 051927
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
327 PM EDT Sun May 5 2024

.SYNOPSIS...
Atlantic high pressure will remain across the Southeast U.S.
through much of next week. A cold front will move through the
region late week bringing cooler conditions heading into next
weekend.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Today: The sea breeze has continued to slowly push inland this
afternoon with showers and thunderstorms forming along the inland
moving boundary. MLCAPE values have risen to around 1000 J/kg so far
this afternoon and will likely increase to around 1500 J/kg by peak
heating. Showers and thunderstorms will persist along the boundary
and slowly propagate inland while advecting slowly towards the
northeast. Expect coverage to be higher across the Charleston Tri-
County thanks to weak upper level support in the form of a mid-level
wave (as seen on water vapor this morning and afternoon). High
temperatures will mostly be in the mid 80s across the region today.

Tonight: Showers and thunderstorms from this afternoon/ early
evening will quickly come to an end overnight as daytime heating is
lost and the weak mid-level wave exits the region to the east.
Expect low temperatures mostly in the mid 60s inland and near 70
degrees along the coast.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
Larger scale ridging will be in place through the early part of the
week with surface high pressure off the coast stretching across the
Bermuda region. That said, convectively induced short-wave trough
(originating with convection moving through the lower/middle
Mississippi River Valley today) will advance through the Carolinas
and mid Atlantic region Monday afternoon into Monday night.
Temperatures warming into the 80s away from the coast and dewpoints
in the lower to middle 60s will yield a decent amount of instability
with MLCAPE values running 1000-1500 J/Kg Monday afternoon and
minimal convective inhibition. Modest forcing with the wave in
tandem with the inland pressing sea breeze should kick off scattered
to numerous showers and thunderstorms across the forecast area while
additional showers and storms develop through central Georgia into
the Midlands and potentially press into the region later in the day.
We will be maintaining 60 to 70 pops across inland areas Monday
afternoon with convection slowly diminishing Monday night...but
higher (categorical) pops may eventually be needed as convective
evolution becomes more clear in the near term. Severe weather threat
looks low overall although relatively slower moving storms and
healthy PWAT values could present a heavy rain threat.

Short-wave trough moves off the Atlantic coast Monday night followed
by low amplitude ridging building through the southeast CONUS for
Tuesday and Wednesday. Quieter conditions anticipated, although some
spottier shower/thunderstorms are possible across the Carolinas to
the mid Atlantic Tuesday and again Wednesday, although it`s tough to
pin down pops/timing at this juncture. We have maintained some lower
end precip chances across southeast South Carolina on Tuesday
followed by dry weather on Wednesday as mid level warming/capping
takes shape.

Otherwise, temperatures will continue to warm through midweek as
upper level ridging builds through the region and convective
coverage dwindles with highs in the middle to upper 80s Monday to
the lower 90s by Wednesday. Heat index values remain well below any
heat related headline criteria, but daytime high temperatures will
be pushing record high readings by Wednesday.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Unseasonably warm temperatures carry into Thursday with highs in the
lower and potentially middle 90s. Again, heat index values will
remain below headline criteria. But record high temperatures are a
good possibility again Thursday.

Otherwise, low amplitude upper level ridging will hold through the
beginning of the long term period before stronger short-wave energy
dives out of the Midwest and down through the mid Atlantic/southeast
CONUS late in the week into early part of the weekend. Associated
surface cold front will swing down into the region...slated to move
through the forecast area on Friday. This will be our next decent
chance for showers and thunderstorms...possibly as early as Thursday
afternoon from anything that gets going upstream, although the
higher precip chances come Friday with the boundary moving through.
Quieter and cooler (70s to 80s) weather settles in for next weekend
with possibly some showers lingering across the southern part of the
forecast area Saturday in the vicinity of the boundary.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
KJZI: An afternoon sea breeze has already moved inland, or past
Charleston Executive and therefore VFR conditions are forecast
this afternoon. Showers and thunderstorms that do form this
afternoon, will likely be along the sea breeze or inland of the
terminal. Expect south/ southeast winds to persist this
afternoon and be gusty at times. Overnight, VFR conditions are
forecast. There is a slight chance of some patchy fog, but
overall conditions don`t look to conducive. The crossover
temperature at KJZI is 68 degrees, with low temperatures not
forecast to get below that. Monday, a leftover MCV will approach
the terminals from the west. Current TAFs aren`t advertising any
mention of thunder, but this will likely need to be added in
future TAF issuances.

KCHS/ KSAV: The sea breeze has currently just passed KSAV and is
very close to KCHS. Convection has developed along the boundary
and is forecast to continue through the afternoon hours. Both of
these terminals are carrying a tempo for thunder this afternoon
until the sea breeze moves far enough inland to bring an end to
convection. Overnight, VFR conditions are forecast. There is a
slight chance of some patchy fog, but overall conditions don`t
look to conducive. The crossover temperature at KCHS/ KSAV is
66 degrees, with low temperatures not forecast to get below
that. Monday, a leftover MCV will approach the terminals from
the west. Current TAFs aren`t advertising any mention of
thunder, but this will likely need to be added in future TAF
issuances.

Extended Aviation Outlook: Overall conditions will remain VFR
through the week although brief flight restrictions are possible at
the terminals Monday and to a lesser extent Tuesday.

&&

.MARINE...
High pressure will remain off the coast of New England through
tonight, allowing south/ southeast winds across all waters around 10
to 15 kts. A slight uptick in the winds is forecast this afternoon
in the Charleston Harbor and Savannah Entrance as the sea breeze
circulation strengthens, but this will be transient. Wave
heights 2 to 3 ft are forecast today and tonight.

Monday through Friday: Atlantic high pressure will maintain
relatively benign conditions over the local marine waters.
Southeasterly winds in the morning will back slightly during the
afternoon and evening hours each day as the sea breeze develops.
Winds will average 10-15 kt with seas 2-4 ft. Winds will increase
toward the end of the week as a cold front approaches. Small Craft
Advisory conditions are possible as gusts approach 25 kt, but look
marginal at this juncture.

&&

.CLIMATE...
May 8:
KCHS: 93/1986

May 9:
KCHS: 95/1963
KSAV: 95/1962

&&

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

&&

$$

NEAR TERM...Haines
SHORT TERM...Adam
LONG TERM...Adam
AVIATION...Adam/Haines
MARINE...Adam/Haines