Area Forecast Discussion
Issued by NWS Wilmington, NC
FXUS62 KILM 090226
Area Forecast Discussion
National Weather Service Wilmington NC
926 PM EST Thu Dec 8 2016
Cold high pressure will build across the area tonight through the
weekend, ushering in the coldest temperatures of the season. A
warming trend will follow early next week ahead of the next
front. Expect seasonable and dry weather Tuesday as high pressure
builds in behind the next cold front. Another system will affect
the area during the middle of next week.
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 930 PM Thursday...Mid and high clouds associated with the
jet max over the Carolinas should diminish after midnight. Very
few changes are needed to temperatures and dewpoints as the
arctic air continues to push into the region. The big blue zero
line at 850 mb should be off the coast in the next hour. Discussion
from 630 PM follows...
Dewpoints are falling into the 20s and 30s across the area as a
cold front is now slipping off the coast. Fairly dense mid
clouds may persist for the evening hours but should clear out to
the east after midnight as the strongest jet winds at 500 mb
pass to our south and east. High pressure centered over the
Plains states will build eastward with steady cold advection
continuing through the night.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
As of 230 PM Thursday...Arctic high pressure will build into
the Eastern United States settling across the Mid-Atlantic and
Carolinas during Saturday bringing much colder, below normal
temperatures to the area. In fact, during late Friday night into
early Saturday morning lows are expected to range from the
lower 20s inland to the mid 20s at the coast. These min
temperatures are several categories below normal (37 at ILM/CRE,
36 at FLO, and 33 at LBT). Otherwise, zonal flow aloft each day
will help to maintain a dry column. Blend of MAV/MET number
appears reasonable. A little better radiational cooling appears
likely late Saturday night and have undercut guidance at that
time as a result.
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 400 PM Thursday...Cold dense air in place on Sunday will
be overrun with WAA in strong southerly winds just above the
surface. This should produce increasing clouds on Sunday and the
enhanced coastal troughing should keep the shallow cool dense
air in place much of the day. Once the coastal trough/warm front
blows inland, warm and moist air will make its way through the
forecast area producing increasing temps and dewpoints through
late Sunday and into Monday as gradient tightens ahead of cold
front. Expect chc of pcp possible associated with coastal trough
on Sunday and again as front moves through on Monday. Overall
plenty of clouds and increasing chc of pcp Sunday night and
Monday. WAA ahead of front will push temps up possible around 70
by Mon aftn.
High pressure will build in behind cold front with drier and
more seasonable air mass making its way south by Tues, but The
cold front may stall before making its way too far south. GFS
gives a slightly greater push to front but ECMWF keeps more
clouds and potential for pcp over area on Tues. The very broad
trough in the mid to upper levels will not give much of push
south and its tough to say just how far south it will make it.
Low pressure develops along lingering front through mid week and
may see a prolonged period of clouds and pcp. Both models show
next shortwave pushing strong cold front through as low moves
off to the NE scouring out all clouds and pcp on Thurs. Very dry
and cold air will make its way south into the Carolinas
as high pressure builds in behind cold front on Thurs.
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
As of 00Z...High pressure is building in with cold air advection
ongoing. Some mid and high clouds from the jet stream will linger.
Look for dewpoints to drop into the 20s overnight. Winds will not be
too gusty, but will stay above 7 kts. Winds will become gusty a
couple of hours after sunrise on Friday with nearly clear skies.
NEAR TERM /THROUGH TONIGHT/...
As of 930 PM EST Thursday...The front is now well offshore and
cold air is surging in on north-northwesterly winds. At 9 PM
observations included wind gusts as high as 16 knots at
Wrightsville Beach, 24 knots at the buoy off Wrightsville
Beach, and 27 knots offshore at the Frying Pan Shoals buoy.
Winds may increase another 1-2 knots but are pretty close to
the worst of this event. Look for wind speeds to begin to
diminish after sunrise Saturday morning.
The small craft advisory will remain in effect, although it`s
a marginal event as sustained wind speeds will have trouble
reaching 25 knots and the bulk of the 6+ foot seas should
remain outside of 20 nautical miles from shore given the short
effective fetch lengths on an offshore wind.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 230 PM Thursday...Gusty winds will persist into Friday
morning, then as the ridge builds farther east conditions will
gradually improve Friday night, and especially during Saturday. A
weak coastal trough may develop late in the period with northeast
winds returning again on the landward side of the boundary. Seas
will be highest Friday morning, especially away from the coast
then average less than 3 ft by Saturday and Saturday night.
LONG TERM /SUNDAY THROUGH TUESDAY/...
As OF 400 PM Thursday...Winds initially out of the SE on Sunday
with a weak coastal trough in place. Late in the day into
Sunday night this feature washes out and a SSW flow gets
established and strengthens some. Initially seas will be highest
off shore in stronger southerly flow, but as coastal trough
and southerly flow pushes inland Sun night into Monday, the seas
will ramp up and should reach 3 to 5 ft. Possible SCA
thresholds will be reached in outer waters, especially on Monday
as gradient tightens ahead of cold front. Winds will veer around
to the north by Tues down to 10 to 15 mph with seas diminishing
down to 2 to 4 ft.
MARINE...Small Craft Advisory until 6 PM EST Friday for AMZ250-252-254-