385
FXUS62 KCHS 082017
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
417 PM EDT Sat Jun 8 2024

.SYNOPSIS...
High pressure will prevail through the weekend, before a cold
front moves through the area on Monday. The pattern is expected
to turn more unsettled through mid to late next week.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Afternoon analysis reveals surface high pressure from the Ohio
Valley to the Gulf Coast, centered across the Gulf Coast region.
Wedge of drier air/PWAT values an inch or less continues to edge
through the southeast CONUS this afternoon and surface dewpoints
have dipped into the 50s for most areas away from the coast.
Thus, quiet weather is the rule with just a touch of Cu from
Savannah into Beaufort County along the marine boundary.

Tonight: Surface high pressure will weaken across the region
while we see a bit of a rebound in deep layer moisture/PWAT
values and surface dewpoints through the night. Nonetheless,
conditions will remain quiet although with some mid and high
cloud cover pressing into the region from the W/NW. Overnight/
early Sunday morning low temperatures should end up similar to
last night...upper 60s to around 70, warmer along the coast.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
Sunday: The mid-levels will initially consist of High pressure
in the northeast Gulf of Mexico and Low pressure north of the
Great Lakes region. The High will weaken as time progresses,
while the Low strengthens and forms a trough along the East
Coast. At the surface, weak High pressure will initially be over
the region in the morning. A cold front will approach from the
northwest overnight, possibly making it to our northernmost
counties by daybreak Monday. The High will bring our area mainly
dry conditions into the afternoon. The combination of low-level
thickness values, mostly sunny skies, and a sea breeze limited
mainly to the coast will support high temperatures just short of
record values. Highs should peak in the mid to upper 90s,
except cooler at the beaches. However, dew points will be in the
upper 50s to lower 60s away from the immediate coast, which
will equate to heat indices at or just short of 100 degrees
across our area. Moisture increases during the evening and
overnight ahead of the front. The models point towards isolated
convection, but disagree on the location. Therefore, we kept
slight chance POPs closest to the front. While, SPC did put the
northernmost portion of our area under a Marginal Risk for
severe storms late at night, we feel like this may be overdone
at this point. Low temperatures will remain mild, falling into
the low 70s far inland and the mid/upper 70s near the coast.

Monday: The mid-levels will consist of a positively tilted
trough amplifying over the East Coast. At the surface, a cold
front located over our northernmost counties at daybreak will
slowly shift southeast during the day, likely becoming located
offshore to our southeast by late at night. There will be a
plume of moisture ahead of the front, with PWATs peaking around
2". Temperatures will few cooler compared to Sunday, with highs
ranging from the upper 80s across our northernmost tier, to the
mid 90s near the Altamaha River. Lift from the front and the
sea breeze will combine with the moisture to generate afternoon
convection. It appears the highest instability is along our GA
coast, where MLCAPEs could reach 1,500 J/kg. Shear increases
there, with DCAPEs possibly exceeding 1,000 J/kg. So a few
marginally severe thunderstorms with damaging winds cannot be
ruled out. We`ll also need to monitor the front, sea breeze, and
boundary interactions as there is the concern backbuilding
storms could lead to locally heavy rainfall, mainly along our GA
coast. This will need to be refined with future updates. For
now, we have chance POPs in the afternoon and evening. But
models are showing hints that strong convection could persist
through the night, especially closer to our entire coast. Low
temperatures will range from the mid 60s far inland to the lower
70s near the coast.

Tuesday: The positively tilted trough prevails over the East
Coast. Meanwhile, a stationary front will meander just off our
coast. Additionally, High pressure will be centered to our
northwest. There is some uncertainty regarding whether moisture
associated with the front will combined with the afternoon sea
breeze to bring our area unsettled conditions, or if drier air
from the High will overspread enough of our area to limit
convection. We have chance POPs along the coast, especially our
GA coast. But the models hint at it being drier as opposed to
wetter. Highs will peak in the upper 80s to lower 90s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
The general pattern is for a large, unorganized area of Low
pressure to potentially develop somewhere in the Gulf of Mexico.
Most models indicate that at least some of the deep
layer/tropical moisture associated with this feature could
spread northeastward toward our region, especially mid to late
next week. We will continue to monitor the potential for
locally heavy rainfall, but it remains too early to determine
QPF/rainfall totals. Temperatures should be near to slightly
below normal.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
VFR conditions will prevail at KCHS, KJZI, and KSAV through 18Z
Sunday. Sea breeze will push across the terminals this
afternoon, turning winds into the southeast along with an uptick
in wind speeds. Winds go near calm tonight. Some mid and high
cloud cover will be advancing into the region from the west
through the course of the night and into Sunday.

Extended Aviation Outlook: VFR through Sunday night. The chance
for convection and periodic flight restrictions increases
Monday through Thursday.

&&

.MARINE...
Tonight: Northeast winds 10 to 15 knots will persist across the
coastal waters into the evening before veering around to the
south/southwest and diminishing to 10 knots or less tonight.
Seas 3 feet or less persist.

Extended Marine: A cold front will approach from the northwest
Sunday night, slowly moving through our waters on Monday, then
meandering to our southeast Monday night through the middle of
next week. Winds will initially surge Sunday night, but stay
below Small Craft Advisory criteria.

&&

.CLIMATE...
Record High Temperatures
June 9:
KCHS: 99/1986

&&

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

&&

$$