Area Forecast Discussion
Issued by NWS Wilmington, NC-- Remove Highlighting --
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FXUS62 KILM 020524
Area Forecast Discussion
National Weather Service Wilmington NC
1224 AM EST Fri Dec 2 2016
High pressure will build in from the west and northwest over
the next several days, bringing dry weather and gradually
cooling temperatures. Low pressure developing to our south will
bring increasing rain chances by Sunday night and continuing
into Tuesday. A cold front is expected to move through the area
during the midweek period.
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
As of 945 PM Thursday...The 2ndry sfc cold front /trof dropping
south across the FA is taking it`s time and as a result have
tweaked temps/dewpts/winds for the remainder of this evening and
overnight. The forecast lows from earlier remain ok. Skies to
remain clear via latest satellite trends across and upstream
from the ILM CWA.
As of 300 PM Thursday...Although the main cold front moved
through the area this morning, there is a secondary surface
boundary still lingering across interior North Carolina that has
yet to come through. Light winds south of this boundary should
allow very good radiational cooling to develop this evening, and
by 10 PM temperatures should be pretty deep into the 40s. Once
the boundary slides through from the north overnight (I`m
estimating 10PM- Midnight for SE North Carolina, Midnight-4AM
for NE South Carolina) low-level lapse rates will steepen and
boundary layer winds will increase due to intensifying cold
advection, likely pushing surface temperatures back up by
Skies should remain clear tonight with perhaps a few
stratocumulus clouds at the base of the subsidence inversion
aloft. Lows within a couple degrees of 40 for most areas.
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
As of 300 PM Thursday...Surface high pressure centered over the
Dakotas Friday will move to Iowa on Saturday, then across the
central Appalachians Saturday night. This should keep a dry
and seasonably chilly northerly breeze in place both days.
Although dry weather is forecast, moisture will significantly
increase in the upper levels Saturday and Saturday night as the
subtropical jet is energized by a large cutoff low over the Baja
Peninsula. 200 mb wind speeds of 110-130 knots are indicated on
the GFS Saturday night.
Highs around 60 on Friday should cool to 55-60 on Saturday
due to increasingly opaque cirrus cloud cover. Lows 35-40 both
.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 300 PM Thursday...Mid and high-level moisture will be on
the increase Sunday well ahead of the northern Mexico closed
low. At the surface, high pressure over the Mid-Atlantic will
keep the low-levels dry as northeasterly winds are likely to
persist into the overnight hours. Think the overall chance for
precipitation on Sunday will be low, and would be light if it
occurs. Near saturation below 850 mb is expected by Monday, and
the 12Z GFS continues with the idea of a coastal trough and
damming setup Monday into early Monday evening. Although the
onset of precip is likely to temporarily reinforce the surface
wedge, the parent high is not forecast to be in an ideal
location for a prolonged wedge event. However the forecast
Monday-Tuesday is a little lower confidence than usual.
There is agreement in the models that drying above 850 mb
should begin by Tuesday afternoon with POPs trending down.
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --As of 06Z...High confidence for VFR through the valid TAF period.
Light winds tonight will become northerly Friday morning, increasing
to 8 to 10 kts in the afternoon hours. A shift to the west will
occur in the late afternoon/evening hours, with winds becoming light
and variable Friday night.
Extended outlook...Clouds and precipitation expected to return at
the end of the period with the potential for MVFR/IFR conditions
late Sunday through Tuesday. Otherwise expect VFR.
-- End Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
As of 930 PM Thursday...The 2ndry cold front/trof will continue
to make southward progress across the area waters...resulting in
winds veering to a WNW to NW direction after its passage. Wind
speeds will increase by atleast 5 kt after its passage.
Significant seas will continue their subsiding trend, even
more-so when wind directions take on a true offshore trajectory.
A 2 to 4 foot significant seas range will be forecast...lowest
near shore and hiest at 20 nm out. Some 5 footers possible off
Cape Fear where wind-sea interaction a bit more volatile given
SSTS likely in the 70s whereby CAA at the ocean sfc is a bit
more pronounced. This shown with JMPN7 winds currently 10 kt or
less with SSTs mid 60s, and 41013 at 10 to 20+ kt with SSTs in
the mid 70s.
As of 300 PM Thursday...The actual cold front moved off the coast
this morning, however there is a secondary boundary still hanging
back across central North Carolina that should sweep offshore
overnight. Westerly winds this afternoon of 15-20 kt should
diminish to 10-15 kt late this evening, then should turn
northerly after midnight with a short-lived increase in wind
speed. Seas still as high as 4-5 feet at the nearshore buoys
will only gradually diminish overnight.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 300 PM Thursday...High pressure over the Plains states on
Friday will build south and eastward into the central
Appalachians by late Saturday. This should provide steady
offshore winds with wind speeds peaking early Saturday morning
at 15-20 knots.
LONG TERM /SUNDAY THROUGH TUESDAY/...
As of 300 PM Thursday...High pressure centered north of the
waters Sunday will result in northeast flow Sunday into Sunday
night. A coastal trough will be located just south of the
waters, and will eventually lift north as a warm front,
although there is uncertainty in the exact timing of its
progression. The onset of precipitation is expected by Sunday
night, and this could delay the front from lifting north until
later Monday, and of course the wind direction forecast will be
entirely dependent on the location of this boundary. Once it
does lift north of the waters, which should occur by Tuesday,
southwest flow is expected to increase and there is potential
for small craft advisory thresholds being met Tuesday and