Area Forecast Discussion
Issued by NWS Wilmington, NC-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS62 KILM 170559
Area Forecast Discussion
National Weather Service Wilmington NC
1259 AM EST Fri Feb 17 2017
High pressure will reach across the Carolinas as it moves by to
the south through early Saturday. A fair day Saturday may be
followed by a chance of rain Saturday night into early Sunday.
High pressure will build in Sunday afternoon through Tuesday. A
chance of rain will return to the area the middle of next week
as a storm system moves across the Southeast.
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
As of 930 PM Thursday...Surface high pressure centered along the
central Gulf Coast will move into southern Georgia by daybreak
Friday. Surface winds are already calm inland from the beaches,
and this would set the stage for excellent radiational cooling
if it weren`t for mid and upper level clouds advecting in from
the northwest. These clouds are rooted in a stream of moisture
up above 600 mb with the flow there sculpted by a pair of shortwaves
that will cross Virginia and northeastern North Carolina late
Models show the southern edge of the upper level moisture
getting down to around the NC/SC state line overnight. For this
reason I have tweaked sky cover up by 10-20 percent across
Southeastern North Carolina overnight with minor increases in
forecast temperatures as well. No changes are being made across
northeastern South Carolina where clearer skies and better
radiational cooling conditions should prevail.
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
As of 300 PM Thursday...Mid level trough exits to the east Fri,
replaced by building 5h ridge and increasing heights. Height
increase is accompanied by development of low level return flow
as surface high shifts off the east coast of FL. Both will work
to push temperatures Fri through Sat above climo with highs well
into the 60s on Fri and likely above 70 on Sat. Forecast
soundings show subsidence inversion in place Fri and Sat,
keeping the region dry and free of cloud cover into Sat
afternoon. Later Sat increasing upper level moisture ahead of
the next system will manifest as afternoon cirrus. Weak southern
stream shortwave moving east along the Gulf coast Sat will pass
just south of the area Sat night into Sun, spreading cloud
cover and some light precip over the area. As this feature is
not connected to the northern stream there will not be much, if
any cold air behind it. Cloud cover and south then west winds
Sat night will keep lows well above climo. Any rainfall Sat
night is likely to be light with limited qpf. Precipitable water
values remain under 1 inch for the event and the weak nature of
the system does not offer much in the way of dynamics. The
nocturnal timings also ensure available instability will be
.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 300 PM Thursday...Shortwave and associated sfc low will
be tracking over and off the coast through Sunday morning with
deeper NW flow developing as high pressure builds in from the NW
through the afternoon. There may be some lingering clouds early
morning but overall expect clearing skies and dry weather late
Sunday through Tuesday as high pressure builds over the
Carolinas. As for temps, recovery will be less than other days,
but it will start off milder due to increased cloud cover Sat
night and will rebound into the mid 60s most places. Also, the
ridge will build in quickly behind this shortwave trough with
increasing heights through Sun aftn. High pressure will build in
from the west late Sun into Mon as ridge builds up the
southeast coast in the mid to upper levels. This will produce
plenty of dry air and subsidence with warming temps reaching up
into the 70s on Monday with bright sunshine.
By late Mon into Tues high pressure pushes down from Canada
giving a shot of slightly cooler and drier air Mon night into
Tues. This high will extend in from the north as it shifts east
through Tues. Therefore winds will shift around from the N to
the E by late Tues. This will also produce a cooler on shore
flow. Overall expect a slightly cooler day in general on Tues
with temps in the mid to upper 60s most places. The high will
shift off the coast on Wed leaving a warmer and moister return
flow with temps reaching back into the 70s. Should see some
increasing clouds on Wed as low pressure system tracks along the
Gulf coast increasing pcp chances for Wed night into Thurs.
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --As of 06Z...VFR conditions thruout this 24 hr TAF cycle. Weak
vort aloft within NW flow aloft, will pass bye just north of the
terminals and off the NC Coast early this morning. SCT to BKN
thin to opaque cirrus will accompany it. Otherwise, skies mainly
Weak pressure pattern across the area this morning as weak
ridging extends from Florida. Looking at WNW to NW less than 5
kt becoming variable or even going calm for a few hrs early this
morning. Some slight tightening of the sfc pg as the sfc high
moves east and offshore from Florida. Winds will become SSW to
SW around 10 kt across all terminals by midday and continuing
thru the aftn, then dropping back to around 5 kt after sunset.
EXTENDED OUTLOOK...Primarily VFR. Possible
MVFR/IFR conditions in showers Sat night thru early Sun due to
the passage of a weak low pressure system.
-- End Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
As of 930 PM Thursday...High pressure centered over the central
Gulf Coast will move into southern Georgia by daybreak Friday.
Northwest winds will gradually die down overnight and turn more
northerly with time. Spectral wave plots show seas are an equal
mix of 9-second easterly swell and 4-second wind wave. Both wave
components should die away overnight with seas falling from the
currently 2-4 feet (highest near Cape Fear) to 1-2 feet late.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 300 PM Thursday...High pressure centered south of the are
Fri morning will shift east during the day with light northerly
winds backing to southwest in the afternoon. Gradient becomes a
little more defined as the high moves east and southwest flow
increases slightly. Diurnal increases in southwest flow later
Fri and again Sat are likely with winds peaking at a solid 15 kt
each afternoon. Shortwave passes to the south Sat night
increasing rain chances but lack of a well defined surface
feature minimizes any increase in winds with only a shift to a
more offshore direction late in the period following passage of
weak surface wave. Seas around 2 ft on Fri build to 2 to 3 ft
late in response to slight increase in speeds late in the
LONG TERM /SUNDAY THROUGH TUESDAY/...
As of 300 PM Thursday...Winds will shift to the NW through Sun
morning as as shortwave and associated surface low exit off to
the east. As high pressure builds in from the west the winds
will shift to a more northerly direction through late Sunday,
but will remain 10 kts or less. By Monday a stronger area of
high pressure will build down from Canada with a decent N-NE
surge through the day. May see winds off shore reach up to 15 kts.
The winds will also come around to a more NE to E direction by
late Tues into Wed as the high to the north moves off the coast.
Overall expect seas to be lowest Sun morning, less than 3 ft,
with an increase through Monday up to 4 ft or so in outer