Area Forecast Discussion
Issued by NWS Wilmington, NC-- Remove Highlighting --
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FXUS62 KILM 180532
Area Forecast Discussion
National Weather Service Wilmington NC
1232 AM EST Sat Feb 18 2017
-- Changed Discussion --High pressure to our south will move offshore overnight and
Saturday. An upper level disturbance may bring some light
showers Saturday night. Warmer temperatures during the weekend
should last through next week. Dry weather most of next week may
turn wetter late in the week.
-- End Changed Discussion --
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
As of 930 PM Friday...Surface high pressure centered over the
northern Bahamas will move eastward out toward 70 degrees W
by daybreak Saturday. Upper level low pressure over southeastern
Oklahoma will move eastward into the Ozarks by morning. High-
level moisture increasing out ahead of this system has already
spread a few thin cirrus into the central and eastern Carolinas,
and this trend should accelerate around daybreak Saturday as
deeper moisture down to 500 mb arrives.
None of this should have much impact on radiational cooling or
our low temperatures tonight. Boundary layer winds are light
away from the beaches and winds have even decoupled in a couple
of spots like Lumberton and Whiteville. Most locations should
see temperatures reach the lower to middle 40s late tonight.
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
As of 240 PM Friday...An area of low pressure, surface and aloft,
will be positioned across the Ark-La-Tex at the start of the period
with a shortwave ridge traversing the Carolinas. The southern stream
system to our W will move toward the NE as the ridge lifts out Sat,
but in a weakening state. We will see clouds increase ahead of this
feature. A short-lived, but deepening and strengthening SW flow will
struggle to transport moisture northward. However, by later Sat
afternoon and Sat night, the depth of moisture does adequately
increase and can`t rule out isolated showers, but rainfall amounts
will be on the order of only a few hundreths where rain does fall.
The upper trough and weak surface reflection will move off the coast
Sunday morning, ending the risk for any light precipitation,
shifting light SW winds to NW and bringing a clearing trend. Weak
high pressure will follow on Sun.
Highs will be in the lower 70s both days, except along the immediate
coast where mid and upper 60s will be most common. There could be
some mid 70s across the extreme southern portions of the Forecast
Area away from the cooling influences of the Ocean. Lows will be in
the upper 40s to lower 50s Sat night and perhaps a degree or two
lower Sun night.
.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 240 PM Friday...A closed mid level cyclone will move slowly
across the southern tier of the U.S. basically through most of
the extended period. There are indications this system will move
a bit to the north and maybe just off the North Carolina coast
by next Friday in a much weakened state. At the surface high
pressure will be in place centered over the northeast for most
of the period. Normally this is cool scenario for the area but
with ridging aloft extending to the southeast not necessarily so
this time around. Highs will be mostly in the 70s and overnight
lows in the upper 40s to lower 50s. We continue to advertise
low chance pops late in the period as the mid level system
spawns a coastal trough which may lead to some unsettled
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --As of 06Z...VFR expected through the forecast period. Light
southwest flow overnight with possible ground fog around sunrise.
Southwest flow will increase through the day on Saturday. A weak and
diffuse upper low will approach the region by Saturday evening, with
some isolated/scattered convection possible.
EXTENDED OUTLOOK...Possible MVFR/IFR conditions in isolated
showers Sat night thru early Sun due to the passage of a weak low
pressure system and cold front. VFR Mon and Tue. Chance of showers
-- End Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
As of 930 PM Friday...High pressure over the northern Bahamas is
moving eastward and out to sea. A modest pressure gradient
exists on the north and west side of this high, sufficient to
maintain 10-15 knot winds overnight. Windier conditions earlier
today have continued in a stripe out toward the Frying Pan
Shoals buoy this evening, and this added wind energy has worked
up the sea state considerably more than earlier models
indicated. Seas at both the Frying Pan Shoals buoy and at the
Harbor buoy south of Southport are 4 feet at last check. Winds
are probably not high enough to sustain seas this large for much
longer, but a large area of 3 foot seas can be expected in the
5-20 mile offshore winds overnight.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 240 PM Friday...SW winds will continue on Sat and Sat eve
ahead of a weakening southern stream system. Then in the wake of
this system, the wind direction will shift to the NW overnight Sat
with NW winds persisting during Sun before veering to N Sun night as
weak high pressure moves further E. Strongest winds this period will
be up to 10 to 15 kt. Seas will be up to 2 to 3 ft tonight,
otherwise 2 ft or less.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
As of 240 PM Friday...Expect mostly northeast winds through the
period as high pressure, anchored well off to the northeast is
the main driver of the winds. Speeds will be very modest
hovering around ten knots or so. By Wednesday the system becomes
very diffuse and winds gain a southeast component mainly driven
by the sea breeze. Significant seas will be 2-4 feet early
dropping to 1-3 feet as time progresses.