Area Forecast Discussion
Issued by NWS Charleston, SC
FXUS62 KCHS 281942
Area Forecast Discussion
National Weather Service Charleston SC
342 PM EDT Fri Oct 28 2016
High pressure will prevail through the weekend. A backdoor cold front
will move through the Carolinas on Monday, followed by high pressure
into the middle of the upcoming week.
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
This Evening and Tonight: High pressure will build from the north
behind a low pressure system shifting over the Western Atlantic. As
a result, expect dry conditions through the overnight period. Winds
will likely go calm over a majority of the area as the atmosphere
decouples early under clear skies. There is some concern for fog in
spots away from the coast late tonight given favorable radiational
cooling under clear skies, fair crossover temps and fog fsi values
near 15-25. Have therefore added some patchy fog to the forecast
late tonight, mainly for locations south of I-16 in Southeast
Georgia. Overnight lows will range in the mid/upper 50s inland to
lower 60s along the immediate coast.
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
Saturday through Monday: No change to the going forecast which
continues to feature tranquil, dry weather. Broad upper ridging will
briefly build in on Saturday, before shifting offshore on Sunday
ahead of a low amplitude trough. The trough will cross Sunday night,
followed by a much more prominent ridge building in on Monday.
Surface high pressure across the region will gradually diminish
through Sunday. A dry back backdoor cold front is then progged to
drop southward through the area on Monday. Deep dry air will
prevail, resulting in mostly clear skies through the period. High
temperatures will be in the low 80s on Saturday, and will then top
out in the low to mid 80s on Sunday and Monday. Overnight lows will
be mild, ranging from the mid 50s well inland to around 60 along the
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Strong, deep layer ridging settles overhead once again for the
middle of next week, keeping a rain-free forecast in place for all
land areas. Surface high pressure over eastern Canada slides south
and elongates meridonally over the southern Mid-Atlantic and North
Carolina through the day Tuesday. Anomalously strong subsidence will
keep temps well above normal through the middle of the week, though
high pressure centered just north of the area will prompt light
onshore flow that should moderate temps to below record levels. Weak
ridging offshore could prompt a few showers over the waters,
especially at night middle-to-late week, but not currently expecting
anything to reach the beaches.
Next significant pattern change may come late next week as upper
level troughing digs across the eastern United States.
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
VFR conditions are expected at both CHS and SAV terminals through
09Z/29. The potential for fog could increase late tonight as clear
skies and calm winds prevail. However, confidence remains too low
to include in the latest 18Z TAF issuance. VFR conditions will
then prevail by 14Z/29 at both CHS and SAV terminals.
Extended Aviation Outlook: VFR conditions expected to prevail
through this weekend with low probabilities for late night or early
morning restrictions in patchy fog, especially Monday night/Tuesday
This Evening and Tonight: Weak high pressure this evening will be
reinforced by stronger high pressure building from the north
tonight. However, conditions are expected to remain well below Small
Craft Advisory levels over all waters. In general, northeast winds
could reach 10-15 kt at times, highest in offshore Georgia waters.
Otherwise, most waters will see wind speeds up to 5-10 kt. Seas will
range between 2-3 ft in nearshore waters and 3-5 ft in offshore
Saturday through Wednesday: High pressure will remain in control
across the local waters through Sunday, ahead of a southward moving
cold front expected to cross on Monday. Behind the front, high
pressure will return through the middle of the week. Winds will
remain less than the 10-15 knot range through Monday, with a modest
increase possible by Tuesday. During this time, winds could increase
into the 15-20 knot range mainly beyond 20 nm. Seas could be as high
as 5 ft for the outer waters and 2-4 ft for the nearshore waters
through mid week.