Area Forecast Discussion
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FXUS62 KCHS 302255
Area Forecast Discussion
National Weather Service Charleston SC
655 PM EDT THU JUN 30 2016
A stationary front will linger inland through tonight. Atlantic
high pressure will remain east of the area as a weak trough of low
pressure sits inland through this weekend. By early next week, a
nearly stationary front north of the area is expected to align
from west to east, while Atlantic high pressure prevails along the
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Convection will gradually end this evening. One last cluster of
strong tstms will impact interior Southeast South Carolina over
the next 1-2 hours. Isolated severe tstm is still possible, but
main focus remains locally heavy rainfall. Adjusted pops per going
radar trends. Some redevelopment to showers/tstms is possible
over the coastal waters later tonight, some of which may brush the
lower South Carolina coast. Adjusted pops slightly to reflect
this. Overnight pops will range from 20% inland to 40% along the
lower South Carolina coast.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
A pretty typical summer/early July weather pattern will be in
place through this weekend. The area will remain near the base of
a broad upper level trough and a deep layer ridge over the
Atlantic. The latest models are indicating lower mean RH levels
for Friday and even Saturday, which should translate to lower
afternoon convective coverage. Have nudged pops back a tad for
Friday and Saturday afternoons, but still around 40% given some
weak upper troughing just north of the area. Convection will be
mainly focused by the seabreeze. High temperatures range from the
mid 80s at the coast to the lower 90s inland for Friday and a
degree or so warmer Saturday. Lows in the lower 70s.
By Sunday, deep layer moisture starts to increase but upper heights
also rise as the Atlantic ridge builds slowly in from the southeast.
Thus, expect afternoon convective coverage to still be pretty
typical for this time of year, with pops around 40%, especially just
away from the coast. Highs will be hotter in the lower to mid 90s
with heat indices of 102 to 106 degrees likely.
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The overall thinking for the long term remains the same though the
most recent models runs have trended a bit further south with the
nearly stationary front situated to the north. The large subtropical
ridge still looks to build in from the east early in the week, with
a shortwave progressing into the Appalachians within the zonal flow
to the north. Ultimately, how far south this trough can penetrate
into the ridge will determine how active the pattern is for Tuesday
into Wednesday. The thinking is still that the ridge will remain
strong enough to keep the period relatively dry and hot. In fact,
chances look good for seeing upper 90s by mid week.
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR. Tstms could get close enough to KCHS 00-01z, but think any
impacts will remain to the north. Mid-level clouds will linger
through the night. Tstms are possible again Friday afternoon. Too
far to include a mention attm given uncertainties in
timing/coverage this far out.
Extended Aviation Outlook: Brief periods of flight
restrictions possible with mainly afternoon thunderstorms.
Otherwise, VFR will prevail.
Tonight: A light gradient across the waters will maintain south
to southwest winds generally under 15 kt. Seas will average 2 to 3
ft through daybreak Friday.
Friday through Monday: Atlantic high pressure will prevail across
the local waters through at least Monday with no highlights
expected. This will result in generally south-southwest flow of 15
knots of less and seas 3 to 4 feet or less. Could see the typical
nocturnal surge with winds reaching 15-20 knots in the late
night/early morning each day, and then again an increase close to
the coast during the afternoon due to the seabreeze.
By Tuesday, another upper trough may work toward the area from the
west-northwest, resulting in lowering surface pressures over the
southeast U.S.. This will increase the pressure gradient across the
waters, with southwest winds of 15-20 knots possible and seas 3 to 5
The upcoming Perigee occurs early Friday and the New Moon occurs
Independence Day. This scenario will support elevated tides, with
shallow coastal flooding possible late this week into early next