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588
FXUS62 KILM 130344
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
1044 PM EST Sun Jan 12 2025

.SYNOPSIS...
A series of cold fronts Monday night and Tuesday night will maintain
dry weather and below normal temperatures for most of this week.
Low pressure developing to our west late in the week could bring
rain chances back to the Carolinas beginning late Friday night.

&&

.UPDATE...
-- Changed Discussion --
Forecast on track for clear and cold night. Had to adjust temps
down for more ideal radiational cooling conditions.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH MONDAY/...
Surface high pressure and upper ridging currently in place with very
dry air across the area. Mid to high clouds will begin to move in
from the southwest late tonight ahead of a system developing in the
northern Gulf. Timing of the clouds is almost near morning, meaning
plenty of time for radiational cooling especially for southeast NC.
Have leaned towards cooler guidance for tonight`s lows, with temps
in the low to mid 20s for SE NC (potential for upper teens in the
cold spots of northern Pender and Bladen) and near 27F for NE SC
(except along the coast). For Monday, bulk of the moisture will
remain far to our south, with a gradient of mostly cloudy skies for
southern areas and partly cloudy skies northern. Have only kept
minimal pops in far southern Williamsburg and Georgetown counties,
but with lingering subsidence and low level dry air it`ll be tough
for any rain to develop. High temps Monday near 50F.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
A slug of mid level Gulf moisture should slide off the Carolina
coast Monday evening. Any rain chances associated with this
moisture should already be off the SC coast by nightfall, and
dry weather is forecast for Monday night. A cold front filtering
in behind the disturbance should shift winds to the north
Monday night as low temperatures fall into the mid-upper 20s.

A shortwave moving across the Great Lakes Tuesday and off the
Northeast coast Tuesday night will push an arctic cold front
southward, likely moving off the Carolina coast Tuesday evening.
The GFS is much slower with its depiction of this front
arriving than most other models, and may be an outlier with its
late frontal timing. After a sunny day Tuesday with highs near
50, Tuesday night`s lows should dip into the mid 20s with 10 mph
north winds developing behind the front pushing wind chills
into the upper teens by daybreak. Portions of southeastern North
Carolina could approach the 15 degree wind chill threshold for
a Cold Weather Advisory.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Arctic high pressure across the Ohio Valley Wednesday should
weaken and shift south to the Gulf Coast Thursday. Dry offshore
winds and well below normal temperatures will continue here
across the Carolinas. Wednesday night appears to the coldest
night of the week as -4C to -6C 850 mb temps and weakening low
level winds should allow temps to fall into the lower 20s away
from the beaches. We`re not even halfway through climatological
winter yet and Wilmington has had 4 nights in the lower 20s (23
or colder) which is the most in a single winter season since
2017-2018.

Shortwave energy cutting off from the flow aloft off the
California coast Monday will spin for several days over the
Pacific, but should get picked up again by a new shortwave
digging south across the Rockies on Friday. Significant timing
differences exist among the 12z operational model runs with how
quickly the phased upper energy translates eastward, eventually
leading to synoptic low development and Gulf moisture advection
northward across the Southeast next weekend. The operational
ECMWF together with a significant number of other model ensemble
members show rain chances appearing as early as Friday night
across the eastern Carolinas, then peaking Saturday into Saturday
night. The GFS is at least 18 hours slower with its depiction of
this system and doesn`t show a peak in rain potential until
Saturday night to Sunday. Confidence is obviously quite low given
the timing differences observed in guidance. Assuming the 12z GFS
is an outlier, I`ve broadly followed NBM blends for PoPs and
temperatures late this weekend into the weekend.

&&

.AVIATION /04Z MONDAY THROUGH FRIDAY/...
VFR. Calm and clear skies tonight with very light SW to W winds
into Mon. Mainly mid level clouds spreading northward over the
area between 14 and 17z with moisture increasing through the
column from 6k to 18k ft with ceilings mainly 10 to 15k ft
with some lowering to 4 to 7 kft by 18z.

Extended Outlook...VFR.

&&

.MARINE...
Through Monday...Benign marine conditions through Monday with
northwest winds less than 10 kts tonight increasing slightly to 10
kt westerlies Monday afternoon (gusts to 15 kt). Seas in the 1-2 ft
range, primarily due to E swell with weak wind chop mixed in.

Monday night through Friday...Cold temperatures and offshore
winds will dominate the weather much of this week. A cold front
will move across the area Monday night, chasing a weak wave of
low pressure moving east off the Florida East Coast. This should
lead to a period of 10-15 knot N/NW winds through Tuesday. A
second cold front will move offshore Tuesday night. Arctic air
pouring offshore in its wake should produce winds near 20 knots
and wind chills in the 20s Tuesday night into Wednesday. Given
the wind trajectories behind both of these fronts, seas should
build to no greater than 3-4 feet within 20 miles of shore, but
with short, choppy wave periods.

Arctic high pressure will weaken as it moves toward the East
Coast Thursday into Friday with diminishing offshore winds
expected.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...None.
SC...None.
MARINE...None.

&&

$$

SYNOPSIS...TRA
UPDATE...RGZ
NEAR TERM...VAO
SHORT TERM...TRA
LONG TERM...TRA
AVIATION...RGZ
MARINE...TRA/VAO