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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KCHS 100158
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
958 PM EDT Fri Jun 9 2023

.SYNOPSIS...
High pressure will build into the region tonight into Saturday.
A front will lift northward through our region on Sunday,
followed by a cold front advancing into the region Monday into
Tuesday. The front could linger across the region into the
middle of next week.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
-- Changed Discussion --
While does show a stray shower south of the Altamaha River and
east of the waters in the Gulf Stream, no rainfall is expected
through the night over the local counties. Winds have gone light
or calm in many places, setting the stage for a cool night for
June standards, down into the upper 50s and lower 60s inland,
with mid and upper 60s closer to the coast. A few places across
Berkeley, Dorchester and Colleton County could dip into the mid
50s. There is still not enough evidence for fog to be included
in the forecast. But we will continue to monitor.

Previous discussion...
Any isolated showers will end by sunset, and the night will be
controlled by high pressure near the spine of the Appalachians,
as the cold front is to the south of the region. Winds will
quickly decouple this evening, and under clear or mostly clear
skies and the dry air mass, we`re looking at an unusually cool
June night. We lowered most temps by about 1-2F degrees, and
might have to adjust further pending later trends. There remain
indications of some late night fog and also low stratus, and we
might need to consider adding it to the forecast at a later
time. The sky remains smoky/hazy from the Canadian wildfires,
and it`s interesting that the local air quality is now actually
worse than New York City according to the fire.airnow,gov
website. Any reduction in surface visibilities remains too low
to mention in the actual forecast.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
Pattern Synopsis/Forecast: W-E oriented stalled boundary stretches
through the Gulf Coast states/southern Georgia and into the Atlantic
with surface high pressure to our north. Boundary will remain more
or less stalled heading into the weekend before advancing back
northward through our area late in the weekend into early next week.

Meanwhile, larger scale ridging remains prominent across the western
CONUS with downstream troughing across the northeast and down
through the east coast. This pseudo blocking pattern will remain in
place through the weekend and into early next week while another
piece of strong short-wave energy dives out of Canada and carves out
a deep closed low across the Great Lakes and Ohio Valley. Deepening
upper level low will eventually help push a cold front into our area
early next week.

Details: Saturday still looks to be the quietest day of the
upcoming weekend with slightly drier air and surface high pressure
across the region, and the boundary still stalled south of our area.
Only caveat will be down across far SE Georgia where some showers
could again kick off in the vicinity of the boundary and aided by
the sea breeze. However, with the drier air, precip chances are too
low to add to the forecast at this juncture.

Sunday and Monday will turn a bit more active. Upper level flow
across the southeast CONUS will become a bit more cyclonically
amplified as aforementioned short-wave energy carves out a deep
closed low over the Great Lakes and Ohio Valley. Increasing
southwesterly flow will finally draw the stalled boundary northward
up through our region on Sunday with showers and some thunderstorms
expected to develop along the advancing boundary and impacting the
region. Surface cold front will follow heading into early next week,
pressing into the southeast region on Monday and potentially through
our area early Tuesday. This will bring another period of increased
rain chances on Monday...and potentially some stronger thunderstorms
as well. Will need to keep an eye on that as we go through the
weekend.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Larger scale troughiness will remain the dominant player through the
balance of week as the closed upper low pinwheels through the Great
Lakes region. Surface cold front from Monday could slow/stall along
or just off our coast and down through the Gulf Coast states and may
set the stage for additional rounds of showers and thunderstorms to
impact the region through the week. But, lots of differences among
the long term guidance regarding how that all unfolds. We have
periodic chances for showers/storms through the week, although
details in timing/placement will need adjusting as we go along.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
VFR is forecast at all sites through 00Z Sunday. However, there
is a risk for at least temporary flight restrictions in fog
and/or low stratus from about 08Z to 13Z, especially at KSAV.
Probabilities are not yet high enough to include with the latest
TAF set.

Extended Aviation Outlook: VFR conditions will prevail at the
CHS/JZI/SAV terminals during the period. However, brief flight
restrictions are possible due to afternoon showers and or
thunderstorms through Wednesday.

&&

.MARINE...
-- Changed Discussion --
Overnight: Continental high pressure will build into the area
as a stationary front drifts further south and away from the
forecast area. With the building high pressure winds that are 10
or 15 kt early on will diminish to 5 or 10 kt overnight. Seas
will be around 2 feet or less.

Extended Marine: High pressure will build across the local waters
this weekend leading to northeast winds around 10 kt and seas
between 1-2 ft on Saturday. A warm front will then advance northward
through the region on Sunday veering winds into the south and
eventually southwest on Monday. Winds on Monday will become a bit
gusty, with some gusts potentially touching Small Craft Advisory
criteria Monday afternoon and Monday night, particularly across the
Charleston nearshore waters and the Georgia outer waters. Seas are
looking to remain below 6 feet however. Winds and seas will back off
some for the balance of the day.
-- End Changed Discussion --

&&

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

&&

$$

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