Area Forecast Discussion
Issued by NWS Charleston, SC

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FXUS62 KCHS 282008
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
408 PM EDT THU JUL 28 2016

.SYNOPSIS...
Atlantic high pressure along with an inland trough will prevail into
early next week. High pressure will then migrate offshore which
could allow a cold front to approach from the north by the middle
part of next week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A strong mid-level subtropical high just off the coast and
extensive deep layered ridging will prevail. No precipitation is
forecasted. Expect warm, humid conditions with mostly clear skies.
Lows will be in the mid to upper 70s inland to the lower 80s at
the beaches.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
The pattern will feature a large mid/upper lvl ridge of high
pressure over the southeastern United States while a broad trough of
low pressure persists over the Midwest and Northeast. At the sfc,
the area will remain situated between the western edge of Atlantic
high pressure and the eastern edge of a low pressure trough extended
over the Midlands. The pattern will result in mainly dry conditions
on Friday when the mid/upper lvl ridge is strongest, but should
favor increasing chances of showers and thunderstorms as the ridge
becomes more elongated across the region with weak h5 shortwave
activity passing just to our north on Saturday. By Sunday, a more
direct onshore wind component combined with a gradual eastward shift
of the inland sfc trough could support even higher chances of
showers and/or thunderstorms, particularly within the Tri-County
area where an inland moving seabreeze interacts with the sfc trough
during peak heating. At this time, the threat of strong or severe
thunderstorms remains low given a lack of shear, but an isolated
occurrence cannot be ruled out, especially on Sunday.

Temps will remain above normal through the period given a west-
southwest flow aloft. However, showers and thunderstorms could limit
overall high temps a few degrees on Saturday and Sunday. In general,
highs will range in the mid to upper 90s each day outside convective
activity. These temps in combination with dewpt temps in the upper
60s to lower 70s will likely produce heat index values between 105-
109 each afternoon, but some mixing out of low-lvl moisture should
result in conditions remaining just below Heat Advisory levels.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The upper level ridge will gradually slide off the coast early next
week as the base of a broad upper level trough dips closer to our
area, resulting in a more unsettled period. At the surface: Atlantic
high pressure slides further out to sea, allowing troughing that has
been confined well inland over the past week to gradually spread
toward the coast. A weak cold front may approach, and possibly fully
cross, the area Tuesday, providing at least a temporary break from
the above normal temps for the middle portion of next week.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
VFR through 18Z Friday.

Extended Aviation Outlook: Brief flight restrictions are possible
with afternoon showers/thunderstorms Saturday into early next week.
Otherwise, VFR conditions are expected at both CHS and SAV terminals.

&&

.MARINE...
The low level jet should be slightly stronger tonight than
previous nights. Expect SW winds 15-20 kt. A few gusts up to 25 kt
are possible. Seas will average 2-3 ft. The areas with the
strongest winds, which will generally be beyond 15 nm for AMZ350
and for all of AMZ374, could have seas building to 4 ft.

Friday through Tuesday: Atlantic high pressure will dominate the
waters this weekend into early next week while a sfc trough prevails
inland. The pattern will favor a southerly wind between 10-15 kt
over most waters, but occasional surges around 20 kt could occur
along the coast each afternoon with a sea breeze circulation and at
night due to nocturnal jetting. Seas will range between 2-4 ft.

&&

.CLIMATE...
Record high minimums for 28 July possible:
KCHS: 80 set in 2014...
KCXM: 83 set in 1999...

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...CEB
AVIATION...
MARINE...
CLIMATE...


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