671
FXUS62 KMHX 191442
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
942 AM EST Sun Jan 19 2025

.SYNOPSIS...
Developing low pressure will move northeast across NC this
afternoon and drag a cold a cold front across the area this
evening. High pressure then builds in on Monday. By mid- week,
another area of low pressure is forecast to pass well offshore
of the Southeast U.S. coastline and is expected to bring wintry
precip concerns, anomalously cool temps, and strengthening
winds.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 0930 Sunday...Only minor adjustments to cool hrly Ts (and
all the subsequent grids) through the morning hours. Temps are
still expected to rise into the upper 50s and maybe the low
60s, but with the warm front still S of most of mainland ENC and
clouds and rain lingering, have lowered heating expectations for
the next few hours.

Previous disco...Rain is developing across southeast NC early
this morning as expected as developing low pressure approaches
the area. The rain will increase in coverage for the remainder
of the morning and move through the entire region this morning
and afternoon as the low passes to our west. In addition
widespread fog, locally dense with visibilities down to 1/4 of a
mile, continues. The fog and associated low cloudiness is
expected to persist across the area well into the afternoon
though visibilities are forecast to improve as the rain moves
through. The rain should end across most of the area by late
afternoon except for extreme northern locations where it could
linger into early evening.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
As of 315 AM Sunday...The cold front will sweep across the area
this evening. A narrow line of showers could form along the
front as it crosses but most of the models indicate a mostly dry
passage. Drier and much colder air will move into the area in
the NW flow behind the front. Winds will increase and skies will
clear overnight as cold advection occurs causing temps to
plummet into the 20s inland

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
As of 350 AM Sunday...

KEY MESSAGES:

 - Notable arctic airmass to invade ENC this week

 - Confidence in wintry weather is moderate-to-high for next
   week

Monday - Wednesday: In the wake of today`s cold front, an
arctic airmass will ooze south and east out of Canada and
blanket much of the U.S. east of the Rockies for several days.
Meanwhile, an upper level shortwave will dive southeast along
the Rockies on Monday, then translate east across the Gulf Coast
States Tuesday or Wednesday. Medium range guidance are in solid
agreement with the wave as it dives through the Rockies. We may
be seeing the start of more robust model consensus as it
approaches the eastern CONUS, although two scenarios remain:

SCENARIO #1 - The upper wave remains positively-tilted, and
progressive, as it traverses the Southeast U.S. This scenario
favors a weaker, faster, and more suppressed, low track from the
Gulf of Mexico east into the SW Atlantic. This scenario
supports the potential for a glancing swath of light,
accumulating snow, across parts of ENC, with the greatest risk
along the coast, and a decreasing chance further inland. In an
extreme case, the low may end up being too far suppressed to the
south and ENC would remain cold and dry with little winter
precip. After looking less likely yesterday, this morning`s 00z
guidance has snapped back rather strongly towards this scenario
and our official forecast leans in that direction.

SCENARIO #2 - The upper wave slows down as it emerges out of the
Southern Rockies, and takes on a negative tilt before translating
across the Southeast U.S. This scenario favors a deeper surface low
over the Gulf, with a subsequent track closer to the Gulf and
Southeast U.S. coastline. For ENC, this would be the more impactful
scenario, as it would potentially open the door for a period of
moderate to heavy wintry precip. If a deeper low tracks too
close to the coast, however, that could introduce more warmer
air and less wintry weather, especially along the water.
Deterministic guidance has largely backed off of this idea,
although there are some ensemble members of the Canadian and
Euro that still suggest this scenario.

In addition to potential snowfall, strong northerly winds are
forecast to develop as the pressure gradient north of the parent
low quickly tightens, and some ensemble members suggest gusts in
excess of 35 mph are plausible. If this does occur along with
any amount of snow, blizzard conditions may develop with the
highest risk along the Outer Banks. At this point the
probability of this is low (less than 20%).

The shortwave driving this whole system is forecast to push
across the Pacific Northwest later today, and ideally with
better in-situ sampling guidance will continue to converge
towards a high-confidence solution over the next few runs. Until
then, large run-to-run changes remain possible as clearly
exhibited over the past 24 hours. Our message remains the same:
there is moderate-to-high confidence in a winter weather event
on Tuesday and Wednesday, but its intensity remains uncertain
and the range of potential snowfall amounts remains large.
Please continue to stay tuned as the forecast is fine-tuned over
the next few days.

The most confident aspect of the forecast is the anomalously
cold airmass. A stretch of unusually cold temperatures still
appears likely, with record or near-record temperatures very
much on the table. If it verifies, it will be one of the
coldest stretches for our region since the January 2018 cold air
outbreak. If we get any accumulating snow, forecast low
temperatures could easily be 3-5 degrees lower than currently
advertised. This prolonged stretch of cold has the potential to
take its toll on pipes and other infrastructure not accustomed
to this magnitude of cold. Precautions are strongly recommended
in preparation of this stretch of cold weather.

Thursday through Saturday: Guidance is in loose agreement that
yet another strong shortwave will dive out of the Rockies at the
end of the week with the potential for yet another another
coastal low to develop off the coast. As mentioned yesterday,
confidence in any specific winter hazards with this system is
very low given the likely compounding errors from the Tues/Wed
system. Still, there is loose consensus on a thermal environment
that could favor some freezing rain especially across the
coastal plain, and added this to the forecast this AM. Dry
weather looks to make a return for the weekend.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /through Tonight/...
As of 315 AM Sunday...Widespread LIFR/IFR conditions are
occurring early this morning across eastern NC in dense fog, low
stratus, and rain. The LIFR to IFR conditions are expected to
persist well into the afternoon, with sub VFR conditions
continuing into early evening until the cold front passes. The
front will be followed by drier and sharply cold weather
conditions overnight with prevailing VFR conditions expected by
midnight. SW winds will initially increase and become gusty this
afternoon as developing low pressure passes by to the west.
Then winds will shift to NW and continue gusty this evening
behind a cold front.


LONG TERM /Monday through Thursday/...
As of 355 AM Sunday...A drier airmass moves in on Monday with
VFR conditions and lighter winds expected. Looking ahead, there
is a moderate to high chance of wintry weather Tuesday into
Wednesday, along with the potential for IFR, or lower,
conditions. The main precip mode is expected to be SN, although
there is a modest risk of -ZR along the immediate coast. Details
remain murky, so stay tuned as we continue to evaluate this
potential impact to aviation.

&&

.MARINE...
SHORT TERM /through Tonight/...
As of 315 AM Sunday...Hazardous marine conditions with winds to
gale force and seas to 10 ft will develop this evening and
continue tonight as developing low pressure passes west of the
waters today, then swings a strong cold front through the area
this evening. Gale Warnings are in effect for the central and
southern waters, with SCA`s in effect for the northern waters,
sounds and inland rivers. SW winds will increase to 20-35 kt
this afternoon into early this evening then shift to the NW
behind the front this evening and overnight. The winds are
expected to diminish to 15-20 kt late tonight as high pressure
begins to build in. Seas will build to 7-10 ft this afternoon
and evening then begin to subside to 4-7 ft early Mon as the
flow becomes offshore and decreases.

LONG TERM /Monday through Thursday/...
As of 355 AM Sunday...A pair of low pressure systems will move
northeast through the ENC waters, leading to an increased risk
of showers, elevated winds, and elevated seas. The highest risk
of SCA and/or gale- force winds will extend into Monday as the
deepest of the two lows moves through. High pressure eventually
builds in later Monday into Monday night with some improvement
to boaters for a brief time, before a second low passes well to
our south and east introducing a second, more widespread Gale
across area waters. This latter low may also produce snowfall
over the region, reducing visibilities to only a couple of
miles or less especially when combined with stronger winds.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory from 4 PM this afternoon to 4 AM EST
     Monday for AMZ131-136-137-230-231.
     Small Craft Advisory until 7 AM EST Monday for AMZ135.
     Small Craft Advisory from 2 PM this afternoon to 4 PM EST
     Monday for AMZ150.
     Gale Warning until 4 AM EST Monday for AMZ152-154-156-158.

&&

$$

SYNOPSIS...MHX
NEAR TERM...JME/CEB
SHORT TERM...JME
LONG TERM...TL/MS
AVIATION...JME/MS
MARINE...JME/MS