685
FXUS62 KILM 191508
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
1008 AM EST Sun Jan 19 2025

.SYNOPSIS...
Low pressure will bring milder temperatures and some rain back
to the area today. An arctic cold front will sweep through
tonight bringing some dangerously cold conditions that will
become entrenched across Southeast NC and Northeast SC for much
of the upcoming week. In addition, there is an increasing
likelihood for wintry precipitation to occur late Tue into
early Wed and possibly again toward the end of the work-week.

&&

.UPDATE...
No major changes coming down the track at the 10 AM EST
forecast update.

&&

.NEAR TERM /THROUGH TONIGHT/...
One final day of above normal
temperatures before the big chill comes. Another wave of pcp
came overnight as low pressure tracks up from Georgia into the
Carolinas early this morning. Some heavier showers were aided by
shortwave energy aloft but this will be tracking off the east
through this morning as sfc low heads northeast putting an end
to the pcp across the area by early aftn. Gusty westerly winds
will increase on the back end of the departing low, beginning
the advection of dry and cold air into the Carolinas with clouds
starting to break up.

The deepening and broad mid to upper trough will push a cold
front through tonight with continued strong cold and dry
advection. Temps reaching up into the 60s today will begin to
plummet in stiff W-NW winds through this evening. Dewpoint temps
up in the 50s will be down in the teens by morning. Temps will
drop a good 30 degrees reaching down or just below freezing for
lows by early Mon morning. Factoring in the NW winds, it will
feel like the lower 20s early Mon morning.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Expansive and amplified longwave upper trof to dominate this
period, keeping a direct line of Arctic air pumping across the
area from Canada. Mon night could see apparent temps (wind
chills) reach Cold Weather Advisory thresholds of 15 degrees F
or less. For Tue, sfc baroclinic zone will lie just offshore
from the SE States Coast. A southern stream mid-level s/w trof
will dive out of the Rockies and pick up Gulf moisture and a
developing low pressure system by early Tue. The sfc system will
push off the FL east Coast during Tue evening, hooking up with
the existing baroclinic zone. Although the s/w trof aloft
remains pos tilt, the entire pcpn shield off the SE Coast does
retrograde to the coast and onshore with overrunning dynamics
playing a key role. Look for wintry pcpn to break out across the
FA at the coast initially Tue aftn and further inland by
evening. The pcpn activity will peak its intensity Tue evening
thru the pre-dawn Wed hrs as the sfc low tracks NE, remaining
well offshore as it moves by the FA. With winds staying more
northerly in direction at the sfc, do not expect the "mild" air
from off the Atlantic to play with pcpn type, even along the
immediate coast. This could very well end up as a majority snow
event. The amount of workable PWs will be key to how much snow
is able accumulate given ground temp and conditions already
favorable for snow to stick and not immediately melt. This may
result in hier snow ratios, ie. greater than the 7:1 ratio
normally exhibited this far south. Northerly winds to become
quite active especially at the coast and over the adjacent
waters as the sfc pg tightens considerably. Wind chills will
again reach 15 or less Tue night into daylight Wed, likely
prompting a CWA in addition to a possible WSW for portions of
the FA given possible snow amounts exceeding 2 inches. Mon, Tue
and Wed highs will struggle into the 30s, possibly having a
difficult time reaching above 32 degrees Wed. Various models
continue to exhibit non-conformist characteristics. Making it
more difficult for a common scenario to be applied to this
winter storm event. Thus, its prudent to remain vigilant to this
winter storm and especially the bitterly cold conditions
expected thruout the upcoming workweek which the models do agree
on.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Main concern this period will be the continued bitterly cold
temperatures. Wed night, in the wake of the winter pcpn event,
will have a snow cover (depth still needing to be ironed out).
This will combine with the Arctic air across the region,
providing possibly the coldest night of this week. Widespread
teens with wind chills at or below 10 degrees which would
require a CWA. FYI, Extreme Cold Warning are when Apparent
temps, wind chills, reach 0 degrees or lower. At this point,
we are safe from that occurrence. Inverted sfc trof just off
the Carolina Coasts and offshore will result in possible
overrunning pcpn on the west side of the trof. Once again,
wintry pcpn remains possible given this trof not expected to
move onshore with accompanying mild temps. Instead these milder
temps will occur aloft and with temps at or below freezing,
could see a round or 2 of freezing pcpn Thu before temps climb
above 32 at the coast. Another re-enforcing shot of cold/Arctic
air to occur Fri into Sat as the longwave upper trof persists.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
Sub-VFR conditions will continue for vsbys and low ceilings
through the morning hours. Rain will also affect the terminals
or be in the vicinity as low pressure moves NE through the
eastern Carolinas. Expect some spots down into LIFR and VLIFR
through the morning hours in fog and low ceilings. Coverage in
rain gradually decreases from W-SW to E-NE after 15z as winds
veer and increase out of the west, becoming gusty and stronger
as cold front crosses the Carolinas later today. Transition back
to VFR by 18-20z with clearing but continued gusty with W to NW
winds as front moves through. NW winds near 10 kts will continue
overnight.

Extended Outlook...Next chance for flight restrictions comes
late Tuesday into Wednesday, where a Gulf low likely brings
wintry precipitation to the area. Back to VFR Wednesday
afternoon. Another system could cause flight restrictions on
Thursday.

&&

.MARINE...
Through Tonight...A Small Craft Advisory will be in effect
today through late tonight as winds increase out of the SW
through today with tightening gradient ahead of a cold front.
Initially low pressure will move up through the Carolinas moving
off to the north this afternoon. Winds on the back end of the
low will veer to the west and become gusty into this afternoon.
As the front moves through the coastal waters tonight, winds
will veer further, to the NW and remain around 20 kts with gusts
up to 30 kts. Seas increasing this morning up to 3 to 5 ft will
increase further up to 5 to 7 ft through this afternoon. Winds
and seas will diminish into Mon with SCA ending before daybreak.

Monday through Thursday night...SCA conditions to end early Mon
as NW-N winds diminish just below thresholds. Pieces of the once
1050+ mb Arctic high will split off (bubble highs) and track
from the central U.S., NE-ward to off the Mid-Atlantic and
Northeast states during this period. This will help reinforce
the Arctic air across the area with winds remaining active
thruout this period. Sfc low pressure, although weak/modest in
strength will move along the sfc baroclinic zone Tue thru Wed,
exiting NE of the area by late Wed. The pressure differences
between the the strong High, 1030 ish and 1040ish bubble highs,
and substandard lows, 1010ish, will result in a well tightened
gradient across the adjacent coastal and offshore waters. SCA
thresholds from winds and increased seas should eclipse SCA
thresholds Tue thru Wed, with Gale conditions possible Tue
night. In addition, will see reduced vsby from wintry pcpn,
especially nearshore, within 10 nm of the coast. For Thu thru
Thu night, the waters will see an inverted sfc trof develop just
offshore. Flow aloft is not conducive for it to be pulled
onshore, therefore winds will remain Northerly. Seas will be at
their minimum for the week during Mon, and definitely elevated
for the remainder of the work-week. Could observe double digit
seas just beyond our 20 nm coastal waters with active Northerly
winds, especially Tue night thru Wed night.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...None.
SC...None.
MARINE...Small Craft Advisory until 6 AM EST Monday for AMZ250-252-254-
     256.

&&

$$

SYNOPSIS...ILM
UPDATE...IGB
NEAR TERM...RGZ
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...RGZ
MARINE...DCH/RGZ