583
FXUS61 KLWX 140900
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
400 AM EST Wed Jan 14 2026
.WHAT HAS CHANGED...
The previously issued Winter Weather Advisory has been expanded
into western Garrett County. A Cold Weather Advisory has been
issued for western Grant and western Pendleton Counties. A Small
Craft Advisory has been issued for all waters tonight through
the day Thursday. A Gale Watch has been issued for all waters
for Thursday night.
&&
.KEY MESSAGES...
- 1) Light rain at lower elevations and accumulating snow in the
Alleghenies is expected tonight.
- 2) Cold and windy conditions are expected on Thursday behind a
strong cold front.
- 3) A low pressure system may bring snow to the Allegheny Mountains
Friday through Saturday night.
- 4) The weather will turn colder Sunday into early next week with
weak weather disturbances possible.
&&
.DISCUSSION...
KEY MESSAGE 1...Light rain at lower elevations and accumulating
snow in the Alleghenies is expected tonight.
Water vapor imagery shows a vigorous shortwave digging southward
across the Upper Midwest this morning, as a much broader
longwave trough starts to take shape across the eastern half of
the CONUS.
At the moment, low pressure is tracking well to our
north across Quebec, with southerly flow in place ahead of the
approaching trough. Southerly flow and high cloud cover has kept
temperatures mild overnight, with temperatures currently in the
40s. Southerly flow will continue through much of the day
today, allowing temperatures to climb well into the 50s for most
(upper 30s/40s mountains) beneath cloudy skies.
As we continue through the day, the aforementioned trough will
continue to dig across the eastern half of the CONUS, with the
trough axis progressing eastward across the Ohio Valley. As this
occurs, low pressure will form at the surface just ahead of an
approaching closed mid-level low and track northeastward toward
New England tonight. With such a track, most of the stratiform
precipitation shield will remain displaced off to our north
during the daylight hours today. However, some rain may develop
this afternoon in the vicinity of Martinsburg/Hagerstown within
the equatorward entrance region of a jet streak to our north.
Rain will also move into the Alleghenies and begin to mix with
snow during the mid to late afternoon hours. However, surface
temperatures will likely remain above freezing during the
daylight hours, meaning that little to no accumulation is
expected.
Later this evening, stronger large scale ascent ahead of the
approaching trough will overspread the area while the system`s
cold front simultaneously moves through from west to east. As
this occurs, a few hour long period of light precipitation is
expected across the majority of the forecast area. This
precipitation will fall largely in the form of rain to the east
of the mountains, but could end as a brief period of mixed rain
and snow or very wet snow. Most locations will have no
accumulation to the east of the Alleghenies, although
relatively higher elevations such as the Catoctins, Blue Ridge,
and Parr`s Ridge could pick up a quick coating.
In the Alleghenies, upslope enhancement as winds turn
northwesterly behind the front will allow for an uptick in
precipitation rates this evening as temperatures crash and the
snow starts to stick. A Winter Weather Advisory is in effect for
western Pendleton, western Grant, and western Garrett Counties,
where 2 to 4 inches of snow is expected through tomorrow morning
(with most of it falling the first half of tonight).
As temperatures rapidly drop behind the front, a flash freeze
appears possible in the Alleghenies. There may also be some
refreeze of residual moisture to the east of the mountains as
well late tonight as temperatures drop back below freezing.
Overnight lows are forecast to be in the 20s for most, with
teens and upper single digits in the mountains.
KEY MESSAGE 2...Cold and windy conditions are expected on
Thursday behind a strong cold front.
Very cold and windy conditions are expected through the day
Thursday in the wake of tonight`s cold frontal passage.
Conditions will dry out for most, but a few snow showers will
linger on and off through the day in the Alleghenies. Any
additional snow accumulations there will be light (generally
less than an inch). 850 hPa temperatures will crash to around
-15 C, which will yield daytime high temperatures around or
below freezing. Northwesterly winds gusting to around 25-35 mph
will make it feel even colder, with wind chills tomorrow only
in the teens for most (below zero in the mountains). Cold
Weather Advisories have been issued for western Pendleton and
western Grant Counties late tonight through tomorrow night,
where wind chills are forecast to be in the double digits below
zero.
KEY MESSAGE 3...A low pressure system may bring snow to the
Allegheny Mountains Friday through Saturday night.
One, possibly two low pressure centers will meander through the
Great Lakes Friday into Saturday as a series of shortwave troughs
result in amplifying long wave troughing into the eastern US. There
may be some light snow showers along the Allegheny Mountains on
Friday, but the higher chances will arrive Friday night through
Saturday night as the main trough approaches. Temperatures may
attempt to rise above freezing Saturday in some of the valleys
before the cold front pushes through, but profiles will be cold
enough for all snow for most locations along and west of the
Allegheny Front. Accumulations resulting in travel disruptions are
possible. To the east of the Alleghenies, there are mixed signals
whether any precipitation falls, but it will be related to the
push of warm advection Saturday morning and/or the cold frontal
passage Saturday afternoon/evening. Some snow or a mix could
occur depending on the timing of any precipitation, but at the
moment, impacts appear limited at the lower elevations. For
temperatures, Saturday is expected to be the warmest day of the
weekend before the cold front pushes through.
KEY MESSAGE 4...The weather will turn colder Sunday through the
first half of next week with several weather disturbances likely.
Below to well below normal temperatures are the highest confidence
part of the medium range forecast. Relentless waves will reinforce
Arctic air over the Mid-Atlantic early next week, with the coldest
conditions most likely Monday night through Tuesday night. When
combined with a blustery west/northwest wind, apparent temperatures
could drop into the single digits to near zero east of the Blue
Ridge and Catoctin Mountains, with single digits below zero possible
along and west of the Blue Ridge and Catoctin Mountains, and 10 to
20 degrees below zero over the Allegheny and Potomac Highlands. Cold
Weather headlines may be necessary, especially early Tuesday morning.
Otherwise, deep troughing will remain entrenched over eastern NOAM
through the middle of next week. A stout shortwave/upper-level low
will glide into the Midwest down the east side of strong ridging
anchored along the West Coast on Saturday. A lead shortwave and
accompanying surface cold front look to cross the Mid-Atlantic
during the first half of the weekend. Upslope northwest flow into
the Appalachians may result in accumulating snow along and west of
the Allegheny Front. Farther to the east, forcing becomes somewhat
nebulous, though there may be enough moisture and ascent for a few
rain/snow showers. A lack of blocking downstream (evidenced by zonal
flow from New England through the Canadian Maritimes) likely allows
this lead wave to scoot offshore without much additional fanfare by
Saturday night.
Heading into Sunday, a trailing wave moves overhead. This may result
in additional mountain snow showers, and perhaps a snow shower or
two to the east as a reinforcing front drags across. Again, the lack
of downstream blocking won`t allow this piece to "phase" much with
the lead/Saturday wave (or another wave on its heels).
A third wave Sunday night into Monday attempts to dive a bit farther
to the south over the Ohio River Valley, with the potential for
cyclogenesis off the North Carolina coast. However, the continued
progressive flow probably means that the bulk of this wave`s energy
will consolidate well offshore. If some weak/transient blocking
downstream can take hold, and if the ridge out west maintains its
strength a bit longer, the trajectory of this wave around the base
of the longwave trough could bring that low pressure area a bit
closer to the coast. But the timing and amplitude would have to be
just right for that to happen. This continues to be a low
probability scenario, as evidenced by modest NBM probs (15-25%) for
>1" of snow over the Alleghenies and east of the Blue Ridge for the
24-hour period ending 12Z/7AM EST Monday.
Ensemble height plots show evidence of a 50-50 low developing at 500
hPa heading into the middle of next week, with centers anchored over
Hudson Bay and northeastern Newfoundland. This seems to be a bit far
to the north initially when compared to climatology for "big" snows
down into our area, but whatever precipitation falls out of waves
heading through the area will almost certainly be in the form of
snow given the continued below normal temperatures (which is extra
noteworthy given mid/late January is typically the coldest part of
the year). It is worth pointing out that long range ensembles are in
decent agreement on a -AO/-NAO pattern taking hold starting during
the middle of next week, so although the coldest temperatures may
relax briefly, the nearby reservoir of Arctic air may remain for the
foreseeable future.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions are expected at the terminals through the day
today. Rain appears likely at times at MRB through the day, with
the other terminals likely staying dry. Winds today will be out
of the south-southwest today. MVFR ceilings and rain appear
likely at all terminals for a few hours this evening. Snow may
briefly mix in with the rain before precipitation ends, but no
accumulation is expected. A strong cold front will move through
overnight, causing winds to shift to out of the northwest. Gusts
of 20-30 knots appear likely late tonight. VFR conditions and
continued west to northwest winds (gusting 20-25 knots) are
expected on Thursday. The winds may uptick slightly Thursday
night, with gusts to around 35 knots possible at times. VFR
conditions continue through Friday, with winds shifting to out
of the south and gusting to around 20 knots.
VFR conditions should largely prevail through Sunday. However, there
are low probs (15-25%) of some rain or snow showers Saturday as a
cold front moves through, and again Sunday (10-20%) as another wave
scoots by. S to SW winds could gust to 20 kt Saturday, then W winds
could gust to around 20 kt on Sunday.
&&
.MARINE...
SCA-level gusts continue across middle portions of the Bay early
this morning, but winds are gradually on the decrease. Sub-SCA
level south to southwesterly winds are expected over all waters
by mid-morning. Winds will remain sub-SCA level in nature until
a strong cold front moves over the waters later tonight. Winds
will abruptly shift to the northwest and pick up out of the
northwest. Most gusts are expected to be around 30 kt, but a few
gusts could briefly reach low-end Gale levels for a brief time
tonight immediately behind the front. SCAs have been issued for
tonight through the day tomorrow. An SMW or short-fused Gale may
need to be considered if winds trend stronger. Winds will
decrease in magnitude slightly during the day Thursday, but
still remain solidly at SCA level out of the west-northwest.
Another surge of wind is expected Thursday night within westerly
flow. At the moment it looks like either low-end Gale gusts or
very high end SCA gusts with that surge. A Gale Watch has been
issued for the Thursday night period.
Winds will decrease and shift to out of the south on Friday.
Gusts may potentially reach low-end SCA levels Friday afternoon
into Friday night.
SCAs are possible in southerly flow through Saturday. A cold front
will move through late Saturday, and additional advisories may be
needed in westerly flow through Sunday.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 7 AM EST this morning for MDZ008.
Small Craft Advisory from 10 PM this evening to 6 PM EST
Thursday for MDZ008.
Gale Watch from Thursday evening through late Thursday night
for MDZ008.
VA...None.
WV...Winter Weather Advisory from 7 PM this evening to 10 AM EST
Thursday for WVZ501-505.
MARINE...Small Craft Advisory until 7 AM EST this morning for
ANZ530>533-536-539>542.
Small Craft Advisory from 10 PM this evening to 6 PM EST
Thursday for ANZ530>543.
Gale Watch from Thursday evening through late Thursday night
for ANZ530>543.
Small Craft Advisory until 10 AM EST this morning for ANZ534-
537-543.
&&
$$
DISCUSSION...ADS/DHOF/KJP
AVIATION...DHOF/KJP
MARINE...DHOF/KJP
NWS LWX Office Area Forecast Discussion