901
FXUS61 KLWX 280035
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
735 PM EST Sat Dec 27 2025

.SYNOPSIS...
High pressure will remain to the north through Sunday morning
before a strong frontal system moves through late Sunday into
Monday. A clipper-type system follows in the wake while
tracking through the area by mid-week. High pressure returns to
the area by later in the week.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
With surface high pressure centered over southern Quebec and a
wavy frontal zone arcing along the North Carolina-Virginia
border, prevailing winds have largely been out of the north to
northeast. The parent frontal zone is expected to drop further
south in time while the Canadian high dips down into New
England. The influence of this anticyclone will help decrease
winds into the evening and night. Expect clouds to expand
overnight with the approach of the next frontal system. Forecast
lows will fall into the mid/upper 20s, with some low/mid 30s
across the central Shenandoah Valley back into the Potomac
Highlands. East-facing slopes could see some drizzle later
tonight, and where temps fall below freezing (eastern WV and
western MD and perhaps the Blue Ridge) there could be some
patchy freezing drizzle.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
By Sunday morning, the warm frontal zone attached to the next
system will be located over eastern Kentucky down across the
Appalachians into the southeastern U.S. As the next trough
approaches from the west, expect this warm front to lift
poleward in time. However, its northward progression will at
times be stunted by the residual high pressure across the New
England coast. The current forecast package favors the mildest
temperatures across the Allegheny Front into the adjacent
mountain valleys. Highs are likely to push into the 50s to near
60 degrees as the warm front moves through late in the day.
Elsewhere, while southerly warm advection is noted in the model
guidance, the strength of this low-level flow might not be
strong enough to lift the boundary across the entire area.
Locations along/north of I-66/U.S. 50 may not escape the 40s
again.

In terms of the precipitation forecast, the model guidance has
trended lighter and less widespread relative to earlier runs.
Any warm advection showers would be confined to near I-70 and
back along the Alleghenies. Sunday night will start off quite
mild with midnight temperatures in the low/mid 50s across
western Maryland down into portions of the Allegheny Front.
Mountain wind fields will pick in strength overnight as a 50-55
knot southwesterly low-level jet passes overhead. Increasing
wind fields combined with extensive cloud cover should maintain
mild temperatures which will actually rise through the night.

The strong cold front is set to reach the Allegheny Front just
before daybreak on Monday. Some of the high-resolution model
suite indicates a narrow band of gusty rain showers may
accompany this frontal passage early Monday. As this cold front
races eastward, precipitation chances drop off as a downsloping
westerly wind dries out the downstream air mass. A blustery cold
advection wind takes over for the rest of Monday with
temperatures falling throughout the day. Thus, high temperatures
on Monday will likely occur earlier in the morning and not
follow the typical diurnal curve.

An anomalous tropospheric wind field accompanies the passage of
this trough with 250-mb winds on Monday rising to near 150
knots. At most critical pressure levels, wind anomalies are on
the order to 2 to 2.5 standardized deviations above average.
All of this adds up to a windy day on Monday with westerly gusts
up to 40 to 50 mph, locally up to 55 to 65 mph across much of
the Allegheny Front. Given high probabilities of 58 mph and
above gusts in the ECWMF ensembles, opted to expand High Wind
Watches across the Alleghenies. This is in effect from Monday
morning through Tuesday afternoon. The strong nature of these
mountain winds could blow down trees and power lines which may
lead to widespread power outages. Elsewhere, advisory-caliber
winds could impact those along/north of I-66.

The other aspect of this post-frontal air mass will be the cold
temperatures and upslope snow showers along/west of the
Allegheny Front. Some of the showers could spill over to the
east given high Froude numbers averaging between 3 and 6.
Conditions will be cold and blustery into Monday night with
widespread low temperatures in the 20s, with upper single digits
to teens in the mountains. For the latter, wind chill
temperatures on Monday night likely fall into the -10 to 0F
range which will be hazardous to those outdoors without proper
attire. Periods of snow showers continue through the night which
may lead to an inch or two of accumulations.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Strong winds will likely continue throughout the region on Tuesday
due to strong cold air advection behind a frontal passage. GFS and
Euro ensembles along the with the National Blend of Models are
showing solid wind advisory level winds for a good portion of the
region along with good probabilities for high wind warning level
winds along the Allegheny Front. High Wind Watches have been
issued for areas along the Allegheny Front on Tuesday to
highlight the elevated threat for damaging wind gusts.

Cold air advection and the post-frontal pressure surge will
slowly weaken on Wednesday leading to a drop off in stronger
wind gusts. Upper-level troughing is forecast to build over the
region Wednesday and remain over the northeast U.S. through
early Friday. A shortwave passing through the upper-level flow,
Wed into Thurs, along with a strong west to northwesterly flow,
may combine and lead to an increased threat for upslope snow
showers along the Allegheny front. Model soundings in the
mountains are showing saturation through the DGZ along with well
below freezing temperatures which suggests high snow ratios
will be possible. Winter Weather Advisories may be needed for
areas along and west of the Alleghenies late Wednesday through
Thursday. Some snow showers could spill east of the mountains
depending on the strength of the low-level winds.

Ensembles and deterministic models are indicating the troughy
pattern will start to break down toward the end of next week
with upper-level ridging starting to build over the region
early next weekend.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
A residual CAD wedge persists over the area which has maintained a
deck of low stratus which continue to impact all terminals. Ceilings
have largely been right along the boundary of VFR/MVFR as broken
decks range from 2,500 to 3,500 feet. These ceilings likely persist
much of the night. Otherwise, northerly winds turn light tonight.

On Sunday, increasing low-level clouds will continue to bring
some MVFR ceilings to the area. However, like today, these
clouds could again be right on the fence between VFR and MVFR.
Any shower chances are largely relegated to KMRB and KMTN, and
even then chances are somewhat low. Southerly winds are expected
through Sunday ahead of a powerful cold front set to move
through early Monday. LLWS is likely beneath a strong LLJ Sun
night. A vigorous westerly wind field overspreads the entire
region on Monday with gusts up to 30 to 40 knots, perhaps up to
45 knots at the more northern terminals. Winds remain blustery
into the night as well.

Strong west to northwesterly winds are likely on Tuesday, but skies
should remain mostly clear with VFR conditions. Clouds are
likely to return for all terminals Wednesday through early Friday
morning leading to the potential for flight restrictions.

&&

.MARINE...
With high pressure to the north across southern Quebec and a
wavy frontal zone near the Virginia-North Carolina border, a
prevailing northerly wind is evident across the waters. Winds
have dropped off and will remain that way through much of
Sunday.

The influence of a strong cold front will aid in strengthening
southerlies by Sunday evening into the night. Small Craft
Advisories are likely needed during this uptick. The mentioned
cold front crosses the waters on Monday morning which shifts
winds over to southwest to westerly. Gusts on Monday morning
likely push into the 25 to 30 knot range before rising further
by the afternoon/evening. Gale conditions are looking
increasingly likely Monday. Gale Watches will likely be needed
soon for this upcoming wind event.

Gale force winds are likely on Tuesday and may even linger into
Wednesday morning. Additional Small Craft Advisories may be
needed through Wednesday.

&&

.TIDES/COASTAL FLOODING...
Tide levels will briefly dip in northerly winds through tonight,
then will rebound in southerly flow Sunday into early Monday.
Annapolis may near minor flood threshold.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...High Wind Watch from Monday morning through Tuesday afternoon
     for MDZ501-502-509-510.
VA...High Wind Watch from Monday morning through Tuesday afternoon
     for VAZ503-504.
WV...High Wind Watch from Monday morning through Tuesday afternoon
     for WVZ501>506.
MARINE...None.

&&

$$

SYNOPSIS...BRO/DHOF
NEAR TERM...BRO/DHOF
SHORT TERM...BRO/DHOF
LONG TERM...JMG
AVIATION...BRO/DHOF/JMG
MARINE...BRO/DHOF/JMG
TIDES/COASTAL FLOODING...LWX

NWS LWX Office Area Forecast Discussion