Area Forecast Discussion
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FXUS62 KILM 070528
Area Forecast Discussion
National Weather Service Wilmington NC
1220 AM EST Wed Dec 7 2016
Weak high pressure will build in behind exiting storm system
through tonight. Dry and seasonable weather can be expected
Wednesday and Thursday ahead of another cold front. Bone
chilling cold air associated with an Arctic High, will bring
sub-freezing temperatures deep in the 20s Saturday morning. A
warming trend however will get underway early next week.
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
As of 10 PM Tuesday...Precip is long gone as much dryer air
filters in behind a departing frontal system. Still looking at
lows in the mid 40s by daybreak. Previous discussion follows:
7 micron water vapor band reveals dramatic mid-level drying
occurring into the eastern Carolinas with rain now essentially
curtailed and sea-bound. Scouring entirely the resident cloud
cover remains a separate dynamic requiring into Wednesday to see
fruition. Partial clearing however can likely be inferred
through the visible band from WSW to ENE into the evening. The
muddiness, peeks of stars, and non-agressive winds could prompt
a pocket or bank of mist and fog to form overnight. Minimums
will bottom out at sunrise, 41-49, coolest over the far SE NC
interior and mildest along the Georgetown county coast.
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
As of 312 PM Tuesday...Primary headliners this period is a debut
of sunshine Wednesday as weak high pressure moves in, and the
onset of an Arctic air intrusion late Thursday. Isolated showers
Thursday may preceded the cold but QPF expectations are nil to
few hundredths. Coldest portion of this time period daybreak
Friday 30-35. The mildest part of this period where readings
will reach 60-65, both WED/THU aftn. Expect breezy conditions
late Thursday as cold air races in.
.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 330 PM Tuesday...The Carolinas will be experiencing bone
chilling temperatures and the coldest temps since last winter as
a deep N-NW flow carries arctic air into the region behind
exiting cold front. CAA will continue through Fri with GFS
showing 850 temps bottoming out around -6c through Fri night.
Any clouds on Fri will clear out with temps reaching just over
40 for a max temp. Gusty NW winds will make it feel even colder.
The dewpoint temps will be down in the teens most places early
Saturday but temps should hold in the 20s most places for a low
in continued CAA in lighter NW winds overnight Fri.
Temps will remain well below normal through much of the weekend,
even with plenty of sunshine, as the high pressure moves east
settling nearly overhead Sat night before exiting off the Mid
Atlantic coast on Sunday. Overall expect the air mass to modify
slowly with temps reaching back up toward normal by Sun and
returning above normal Mon as winds shift around to the SE and
eventually southerly. Increasing southerly return flow will
develop ahead of next cold front on Monday bringing warmer and
moister air into the area. Max temps should be back well into
the 60s on Mon. This next front should move through by Mon
night with increasing clouds and chc of pcp through Monday ahead
of the front. Expect drier and cooler high pressure behind
exiting cold front on Tues. Temps a good 10 to 15 degrees below
normal over the weekend will swing back up to 5 to 10 degrees
above normal on Monday.
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
As of 06Z...Guidance has backed off considerably on showing lowered
flight categories overnight due to visibility. Since the wind will
remain elevated enough for weak mixing this seems plausible. There
is little to rout out this low level moisture in the form of IFR
ceilings however. This will have to wait until deeper mixing ensues
after sunup. VFR from thereafter.
Extended Outlook...Fog possible Wednesday night. VFR conditions
expected to prevail late week through this weekend.
NEAR TERM /THROUGH TONIGHT/...
As of 10 PM Tuesday...Have dropped the SCA for AMZ256 in favor
of Exercise Caution headlines for the remainder of the
overnight hours. Otherwise all continues as before. Latest obs
show westerly winds of 15 to 20 kts with 4 to 7 ft seas.
Previous discussion follows:
Treacherous marine conditions prevail at this time through
early Wednesday. Frying Pan 7 feet at 6 seconds, very steep,
gusting to 26 knots/30 mph. Closer to shore 5-6 foot pitching
waves. Small Craft Advisory flags to remain flapping through the
overnight period. Stiff west winds tonight will turn NW, and
both directions may impose 25-30 KT gusts. Offshore navigation
tonight is discouraged. The ICW can expect gusty crosswinds. Low
tide early this evening and again right around sunrise on
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 311 PM Tuesday...Main headliner this period is a brief
window of manageable marine conditions on Wednesday with lower
sea heights and less wind trending. Even much of Thursday offers
opportunity but by mid to late afternoon, the leading edge of
an Arctic High will crank up NW-N winds in a hurry and by
Thursday night the ocean will become perilous again. Expect
deteriorating marine conditions late Thursday afternoon and
Advisory conditions all of Thursday night.
LONG TERM /FRIDAY THROUGH SUNDAY/...
As of 330 PM Tuesday...Expect gusty NW winds up to 30 kts in
strong caa behind arctic front Fri morning. The strong off shore
flow will keep highest seas off shore up to 6 to 7 ft early
Fri. Overall expect SCA conditions through most of Friday as
winds and seas diminish through Friday as high pressure builds
eastward. The winds and seas may spike up again as the cold air
rushes over the relatively warmer air overnight Fri, but overall
expect winds will diminish as they veer around through the
weekend become northerly Fri night into Sat and NE to E by
Sunday as high pressure moves further east. Seas will diminish
as well through the weekend as the high pressure shifts closer
overhead Sat night and then off the Mid Atlantic coast on
Sunday. Seas 3-5 ft by Friday aftn will be down less than 2 ft
by Sun morning by twill begin a rising trend late Sun as winds
become more on shore.
MARINE...Small Craft Advisory until noon EST Wednesday for AMZ250-252-