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fxus62 kchs 222132 
afdchs

Area forecast discussion
National Weather Service Charleston SC
532 PM EDT Thu Jun 22 2017

Synopsis...
Atlantic high pressure will give way to a cold front
which will move into the area Sunday. The front will slowly push
offshore as high pressure brings drier conditions for mid to late
week.

&&

Near term /until 6 am Friday morning/...
as of 320 pm: visible satellite indicated a sea breeze as
developed just inland of the southeast Georgia and extreme southern SC
coast. Cumulus across the rest of the SC coast appeared very
shallow. Latest Storm Prediction Center mesoscale analysis indicated normalized cape
between 0.10-0.15 M/s2. Deep convection should develop near the
sea breeze, then track north-northeast between 5-10 kts. Later this
afternoon and evening, storms should develop along the outflow
boundaries associated with the coastal thunderstorms. As this
process continues, coverage of convection may reach into the
likely range across inland SC/Georgia by early this evening. Shortly
after sunset, forecast soundings and convective allowing models
indicate that the environment should below less supportive for
showers and thunderstorms. After midnight, no mention of deep
convection will be included in the forecast. Late tonight,
stratus is forecast to develop over the marine zones and will
build east during the pre dawn hours. Given the thick low clouds
and steady light south winds I will not expect fog to form.
Using a blend of guidance, low temperatures are forecast to
range in the mid 70s.

&&

Short term /6 am Friday morning through Sunday/...
the area will remain on the western fringes of Atlantic high
pressure through Saturday before a cold front approaches Saturday
night and pushes into the local area Sunday. Expect low
shower/thunderstorm chances Friday, mainly during the afternoon as
the sea breeze pushes inland as highs get back closer to normal in
the lower 90s inland. High humidity will support heat indices
slightly over the century mark away from the coast.

Rain chances will go up Saturday, mainly for areas to the north and
west toward the Pee Dee/midlands, as deeper moisture returns ahead
of an approaching cold front. Deep layer shear will also be on the
increase and could support a few severe storms. Stronger southerly
winds will help boost temperatures a bit higher into the mid 90s
especially across southeast Georgia where the least cloud cover is
likely. Heat indices once again should peak in the lower 100s
inland. The front should near inland areas by Sunday morning keeping
elevated rain chances across the area Saturday night with lows
remaining quite mild in the mid to upper 70s, although could be a
bit lower depending on the amount of rainfall.

High chances of showers and thunderstorms will continue Sunday as
the front slowly moves through the area. The severe storm risk looks
low overall, mainly confined to southeast portions of the area into
Georgia where instability should be a bit greater. Highs should be held
down a bit in the upper 80s most locales except toward the Altamaha
river where lower 90s are expected.

&&

Long term /Sunday night through Thursday/...
Atlantic high pressure will extend over much of the southeast
this weekend before a cold front associated with the remnants of
Tropical Storm Cindy approaches the area early Sunday into
Monday. At this time, chances of showers and thunderstorms are
forecast over the entire area, but greater coverage of precip is
possible as pwats in excess of 2.0 inches occur during the
timing of fropa. Scattered showers and thunderstorms could
linger into early next week as the front slowly shifts offshore.
However, dry and slightly cooler conditions are anticipated
during the middle and later half of the week as high pressure
builds over the region. In general, high temps should peak in
the mid 80s under some clouds Monday and Tuesday, then warm a
degree or two Wednesday and Thursday under more sunshine.
Overnight lows will range in the low/mid 70s Sunday night, then
upper 60s/lower 70s through the middle of next week.

&&

Aviation /22z Thursday through Tuesday/...
radar and satellite trends indicate that tsras will develop over
or near ksav through 23z. Convection should have the greatest
chance of impacting ksav between 19z-21z, I will highlight with
a tempo. Deep convection appears to have a greater chance inland
from kchs, I will indicate a thunderstorms in the vicinity until 1z. Forecast soundings
and MOS time the development of MVFR ceilings to develop over
the terminals late tonight into early Friday morning. Mixing
following sunrise should bring a return to VFR conditions
between 14z-16z.

Extended aviation outlook: VFR conditions should then prevail Friday
and Saturday. Better chance of restrictions will come Saturday night
and persist through early next week as a cold front slowly moves
through.

&&

Marine...
tonight: south winds will continue between 10 to 15 kts tonight.
Wave heights are forecast to range from 2 to 4 feet through the
overnight hours, greatest across amz374. Convection is expected
to remain near the coast this afternoon, then spreading inland
through this evening.

Friday through tuesday: Atlantic high pressure will remain east of
the waters into the weekend before a cold front moves through Sunday
night into Monday. Winds will remain elevated into Sunday ahead of
the front, possibly reaching advisory levels mainly across the
Charleston County nearshore waters Friday night/Saturday. Seas will
build as well but should stay below advisory criteria of 6 feet.

Rip currents...increasing astronomical influences and onshore winds
will lead to an enhanced risk of rip currents across area beaches
through late week.

&&

Tides/coastal flooding...
tides will be running high given the increased astronomical
influences and onshore winds could help push levels high enough
to produce shallow coastal flooding around the times of the
evening high tide through the weekend, especially along the
South Carolina coast.

&&

Chs watches/warnings/advisories...
Georgia...none.
SC...coastal flood advisory until 10 PM EDT this evening for
scz048>050.
Marine...none.

&&

$$
Near term...Ned
short term...rjb

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