313
FXUS62 KILM 220903
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
403 AM EST Wed Jan 22 2025

.SYNOPSIS...
Snow and sleet will linger along the coast through daybreak with
cloudy skies gradually clearing around midday. Temperatures well
below normal the next several day with wind chill values near
10 degrees tonight. Clouds return on Thursday with some light
rain or freezing rain possible in the morning along the
immediate coast of southeast North Carolina. Temperatures near
normal return next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Arctic high pressure building in from the west with very dense
cold air in place and weak low pressure off to the east led the
way to a decent snow event across the area overnight. Enough of
warm nose along the coast has kept sleet in the mix for much of
the overnight hours, cutting into the amounts. The max snowfall
was across inland Horry county and Columbus county with 5 to 6
inch amounts. The rest of the snow amounts were mainly in the 1
to 4 inch range.

The snow will taper off from W-SW to E-NE over the next few hours as
system moves off to the east. Once the shortwave shifts east later
this morning, skies will clear out for the aftn. Arctic air mass
will remain in place with temps struggling to get to freezing. The
combination of snow on the ground and better radiational cooling
tonight will lead to extremely cold overnight lows tonight mostly
between 10 and 15 degrees. With near calm winds, the wind chill
values will be the same as the low temps for the most part. But,
either way, the temps should reach criteria for a Cold Weather
Advisory once again which will most likely be issued when the
current one expires by late morning.

Hazardous travel and frigid temperatures will be the primary concern
through tonight as temps limited to below freezing through much of
the day will prevent much in the way of melting. Whatever melting
that does occur will quickly refreeze around sunset prolonging
hazardous driving conditions.


&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Broad 5h trough remains over the eastern CONUS Thu into Fri with the
trough axis west of the area. Surface high wedging down the coast
Thu morning gradually retreats during the day, allowing for some
very weak warm advection as the winds become west-northwest. Weak
low develops along a coastal trough well offshore. The location of
the trough/low combo continues to be nudged a bit farther offshore,
which has big implications as far as ice is concerned. The eastward
shift lessens the potential for freezing rain/ice Thu morning. Some
of the forecast soundings continue to show a profile that would
support freezing rain/drizzle for the immediate coast through 15Z,
but there are a lot of solutions that keep the region dry Thu. The
abundance of low level dry air looms large with respect to getting
light rain or drizzle to the surface, especially with how weak the
forcing is. Highs Thu will remain confined to the upper 30s with
lows in the low to mid 20s.

High pressure builds in from the west Fri with the mid-level trough
axis moving closer to the area then crossing the area late Fri
night. The 5h trough drags a dry cold front across the area; the
cold advection behind the front is rather weak. Cloud cover and
northerly winds on Fri will keep highs well below normal with most
areas in the lower 40s. Some boundary layer mixing behind the front
Fri night, but clear skies and fairly light winds will allow for
some radiational cooling. Lows well below climo continue with upper
teens to lower 20s for most areas.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Flat mid-level flow over the weekend becomes weakly amplified
Mon/Tue in response to a southern stream cutoff over the 4 Corners.
Surface high moves overhead Sat, leading to one last day with
temperatures well below climo.Lows Sat night still end up well below
climo with excellent radiational cooling conditions in place. The
high shifts offshore late Sat night into Sun and warming begins Sun.
Temperatures approach climo on Sun then stay at or just above climo
through Tue. Rain chances return Mon and possibly Tue as deeper
moisture moves over the Southeast and a weak front settles into the
region. Weakly divergent flow aloft Mon as the weak boundary sags
south. No cold air or forcing with the front, allowing it to linger
in the region through Tue. Weak convergence along the boundary may
promote scattered showers Mon and possibly Tue (if the front hasn`t
slipped south of the area), but not expected a lot of coverage or
much total rainfall at this point given the weak nature of the
surface features. Expect several weak waves moving east along the
boundary that could aid shower development, but trying to time these
on days 6/7 is all but impossible.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
VFR/MVFR conditions will continue in snow, with brief IFR
possible until conditions improve between 09-12z from west to
east across the area terminals. Some mixing with snow pellets
and sleet will likely occur along the immediate coast, but the
dominant p-type will remain snow. Dry air builds across the
region tomorrow morning with VFR returning with SKC 16z-18z.

Extended Outlook...Another system could cause flight restrictions
on Thursday into Friday.

&&

.MARINE...
Through Tonight...
Tightened gradient flow between low pressure offshore and
Arctic high pressure building in from the west will maintain
stiff northerly flow over the waters through today. In addition
to winds, seas will be in the 4 to 6 ft range. A Small Craft
Advisory will remain in effect until 6pm before winds and seas
diminish into tonight. Snow, sleet, and rain farther offshore
will also add to navigation difficulties.

Thursday through Sunday...
High pressure to the west keeps northwest flow in place through
Sat before winds become light and variable Sat night and Sun as
the high moves overhead and then offshore. A weak, dry cold
front will move across the waters Fri night into Sat, but lack
of strong cold advection or a tightening gradient will keep
winds under 15 kt. Seas 2-4 ft the first half of Thu will drop
down to 2-3 ft later Thu and remains 3 ft or less through
Sunday. Seas will be a mix of a north to northeast wind wave and
an easterly swell.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Winter Storm Warning until 8 AM EST this morning for NCZ087-
     096-099-105>110.
     Cold Weather Advisory until 11 AM EST this morning for NCZ087-
     096-099-105>110.
SC...Winter Storm Warning until 8 AM EST this morning for SCZ017-
     023-024-032-033-039-054>056-058-059.
     Cold Weather Advisory until 11 AM EST this morning for SCZ017-
     023-024-032-033-039-054>056-058-059.
MARINE...Small Craft Advisory until 6 PM EST this evening for AMZ250-
     252-254-256.

&&

$$

SYNOPSIS...ILM
NEAR TERM...RGZ
SHORT TERM...III
LONG TERM...III
AVIATION...RGZ
MARINE...III/RGZ