Area Forecast Discussion
Issued by NWS Wilmington, NC-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS62 KILM 061458
Area Forecast Discussion
National Weather Service Wilmington NC
958 AM EST Tue Dec 6 2016
-- Changed Discussion --A storm system moving northeast over the Carolinas will bring
periods of rainfall today, cutting off this evening. 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
Sunday, and especially into Monday.
-- End Changed Discussion --
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --As of 958 AM Tuesday...No changes to categorical pop values and
temperatures trending into the 60s late morning into afternoon.
ENE winds to prevail 8-13 mph inland and 12-22 mph by the sea.
Sharp drying in the mid-levels by evening will curtail rainfall
nearly as sharply. The previous forecaster discussion follows.
Miller type B storm system to affect the area today. At the
sfc, currently a rather strong wedge has developed across the
Carolinas with the offshore frontal system now slowly backing to
the north. What once was a closed mid- level low over TX last
night, has opened up into a s/w mid- level trof now over LA and
MS early this morning. Modest Sfc low is basically underneath
this upper s/w trof. The dynamics aloft will track to the NE
today, staying west and north of the ILM CWA this morning and
afternoon. The sfc low underneath is progged to weaken and fill
in while off the southeast NC coast a new low will develop early
this afternoon on a frontal system that has been back and forth
across the coastal and adjacent offshore waters the past couple
days. Models bring this frontal system to the coast and just
like the previous scenario, the front may temporarily push just
inland from the coast by midday thru this afternoon. This will
play havoc with temperatures, with 40s and 50s west and north of
this front and 60s to around 70 south and east of the coastal
front. In addition, the frontal position will become the focus
of isolated thunderstorms due to enough instability either sfc
based or elevated for convection to key off of. West and north
of this front, expect overrunning ie. isentropic lift, light to
moderate rains with embedded heavier showers. The low will
slowly intensify as it moves northeast along the coastal front
this afternoon, reaching off the Outer Banks early this evening.
The pcpn will come to an end from southwest to northeast during
the mid to late afternoon hours. QPF from this storm system
will observe a nice uniform 1 to 1.5 inches of rainfall.
Tonight, will see a drying trend with residual low cloudiness
possible given various models rh time height displays. Lows will
drop back into the 40s. Northwest winds during this evening
with diminish enough for possible patchy fog.
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.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 400 AM Tuesday...Looking at benign weather Wednesday thru
Thursday afternoon as weak high pressure prevails with basically
the FA under a rather low amplitude longwave trof aloft that
affects much of the U.S. with Pacific origins. The trof aloft
amplifies-some during Thu into Fri enabling a piece of a 1050+
mb Arctic High to break and push toward the area late Thu
night. The cold or arctic front ahead of it is progged to push
across Thu afternoon and early evening. A thin band of moisture
along this front may be enough to squeeze out a few hundredths
of an inch of rain. With no tapping of any moisture, this front
may end up being a dry passage. The sfc pg tightens after its
passage Thu night and combined with excellent CAA as evidenced
with a nice packing of the various thickness fields dropping
across the FA, especially in the low levels when looking at the
1000-850mb thicknesses. Have basically stayed with a blend of
model guidance for max/min temps this period with temps running
at or slightly higher than the 30 year normals.
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 300 AM Tuesday...Very cold temperatures greet the extended
as an arctic front will be well offshore Friday morning. Highs
and lows Fri/Sat will be 10-15 degrees below climo, peaking in
the upper 40s both aftns, and dropping into the low 20s by
Saturday morning. This will be the coldest air since last
winter, and gusty winds Friday will create an even more
significant "bite" to the air despite full sunshine. The cold
Canadian high pressure responsible for this chill will push
offshore quickly by Sunday thanks to broad cyclonic flow aloft,
setting up a warming trend back to seasonable values Sunday and
into early next week. As this high moves offshore, return flow
develops, and a weak coastal trough may develop offshore,
advecting warm and moist air into the region for Monday ahead of
a rapidly approaching cold front for Monday night. This will
allow Monday to warm to above seasonable temps, but at the same
time rain chances will increase ahead of the front late on
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
As of 12Z...Expect MVFR/IFR through the valid TAF period as
unsettled weather continues.
Latest radar imagery depicts widespread showers moving across the
area this morning. Embedded heavy showers along with low cigs and
areas of fog will allow for MVFR/IFR to prevail throughout the day.
Isolated thunderstorms are possible today, but given low confidence
attm, have not introduced into going TAF. Rain will taper off by
this evening, and while latest guidance is in a bit of a
disagreement, expect low cigs and areas of fog to persist into
Wednesday morning. As a result, MVFR/IFR with the potential for
LIFR, is expected. Northeast winds today around 10 to 15 kts with
occasional higher gusts will back to the northwest this evening,
around 10 kts, becoming light overnight.
Extended Outlook...Fog possible Wednesday night. VFR conditions
expected to prevail late week through this weekend.
-- Changed Discussion --NEAR TERM /THROUGH TONIGHT/...
As of 958 AM Tuesday...Small Craft Advisory all waters, as NE
waves every 5-6 seconds interacts with building SSW waves every
7-8 seconds. Changeable wind direction over the waters can be
expected as a coastal low migrates NE over the waters. Frying
Pan reporting S winds now with 7 ft waves every 7 seconds. The
ocean will remain dangerous today and tonight before seas and
winds begin to ease into Wednesday.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 415 AM Tuesday...Leftover SCA or SCEC conditions possible
Wed morning. Overall, winds and seas will diminish and
subside respectively Wed thru Thu as weak high pressure
prevails. By late Wed afternoon thru early Thu, winds will
have become variable in direction at 10 kt or less. In lieu of
forecasting variable, will indicate a predominate direction.
A cold or arctic front is progged to push off the coast late Thu
afternoon and across the local waters and well offshore during
Thu evening. After the CFP, the sfc pg will tighten dramatically
and excellent CAA will prevail across the area waters Thu night.
Guidance indicates NW winds increasing to 15 to 25 kt with gusts
over 30 kt possible as the core of the cold air begins pushing
across the local waters during the pre-dawn Fri hours.
Significant seas having mellowed to around 2 ft early Thu, will
rapidly build Thu night. With a NW wind direction, an offshore
trajectory, will indicate a range of seas building. Could see 1
to 3 ft near shore and 3 to 6 ft across the outer waters from
10 to 20 nm out.
LONG TERM /FRIDAY THROUGH SATURDAY/...
As of 300 AM Tuesday...SCA conditions possible to greet Friday
morning as an arctic front will be positioned well offshore. In
the wake of this front early Friday, NW winds of 20-25 kts will
push seas up to 4-6 ft, and an SCA may be required. These winds
and elevated seas will fall through Friday however as high
pressure builds eastward. As this surface high moves eastward
and offshore the Mid-Atlantic region during the wknd, winds will
weaken to around 10 kts by late Saturday, with a slow veering
to the NW. Seas fall quickly late Friday and on Saturday as
well, from 3-5 ft Friday aftn to just 1-2 ft at the end of the
-- End Changed Discussion --
MARINE...Small Craft Advisory until noon EST Wednesday for AMZ250-252-