893
FXUS61 KLWX 302356
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
656 PM EST Tue Dec 30 2025

.SYNOPSIS...
An upper-level disturbance will pass through late tonight into
Wednesday morning before another upper-level disturbance and its
reinforcing cold front move through late Wednesday night into
Thursday morning. High pressure will briefly return for Friday
before low pressure passes nearby or to our south Saturday. High
pressure will return for Sunday.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
An area of stratocumulus remains evident along and west of the
Appalachians, spilling over into north-central MD and the
eastern WV panhandle as of early this evening. Some flurries
continue along the ridges of western MD and eastern WV mainly
along and west of the Allegheny Front.

Winds will continue to gradually subside tonight as the
gradient continues to weaken along with the loss of diurnal
mixing. An upper-level disturbance in the northern stream will
move into the area late tonight. This system will lack a
substantial moisture source, but most guidance shows upward
motion in the mid-levels that is aligned with saturation and the
DGZ. This will obviously fight low-level dry air, but flurries
and perhaps even a period of light snow cannot be ruled out. As
of now, it appears that the best chance will be near/west of the
Allegheny Front. Those areas could actually pick up a couple of
inches overnight into early Wednesday morning. Across our
eastern areas (northeast Maryland and perhaps down through the
Baltimore and DC metro areas into southern Maryland), have
increased POPS a good bit today given a lot of agreement between
hi-res guidance and even the Euro this afternoon that there is
at least a 20-30% chance of a light coating of snow. If
accumulating snow does occur, even light amounts would have an
impact due to the very cold conditions and this would impact the
Wednesday morning commute. A Special Weather Statement was
issued for this threat, highlighting the potential impacts on
the morning commute.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
The upper-level disturbance will depart Wednesday morning and
any flurries or light snow should dissipate by mid-morning,
except for along/west of the Allegheny Front where some snow
showers may linger. Do think there will be a lull out there
prior to the bigger system arriving in the afternoon.

Dry and chilly conditions are expected for most areas later
Wednesday morning into Wednesday evening behind the departing
upper-level disturbance.

Another upper-level disturbance in the northern stream along
with a reinforcing cold front will pass through the area late
Wednesday night into Thursday morning. This system will be a
bit stronger, despite limited moisture east of the mountains.
Another period of light snow or flurries is possible, and again
with cold conditions any light accumulation may be impactful.
However, for locations along and west of the Allegheny Front,
an upslope component to the low-level wind will bring heavy
accumulating snowfall. A Winter Storm Warning is now in effect
for areas west of the Allegheny Front, with western Highland and
extreme western Allegany Counties both in Winter Weather
Advisories. The combination of the upslope flow, strong mid-
level forcing and saturation within the DGZ along with
instability and high SLRs suggest that significant accumulation
is possible (around 6" along and west of the Allegheny Front).
Strong winds gusting to around 40 to 50 mph will also create
poor visibility at times, with near-blizzard conditions
possible. Of particular concern is the timing, with the onset of
the worst conditions likely occurring right around, or just
before, midnight on New Year`s Eve/New Year`s Day. When all is
said and done, areas in the warnings could see anywhere from 6
to 9 inches, with the areas in advisories between 2 and 4
inches.

High pressure will build overhead behind this system later
Thursday through Thursday night, bringing more dry and cold
conditions. Gusty northwest winds Thursday into Thursday evening
will make it feel blustery as well.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Surface high pressure builds overhead beginning Friday and
persists through the weekend. Overall, dry conditions are
expected each day with high temperatures in the 30s to mid 40s.
Overnight lows drop into the teens to 20s each night. A cold
front stalled will yield increased clouds Friday and Saturday
with otherwise seasonable and dry conditions for the weekend.

Come Monday, a low pressure system tracking east from the Great
Lakes towards New England will push the associated warm front
through the area. A slight chance of precipitation is expected,
mainly in the northern portions of the forecast area. Precipitation
in the morning may be a rain/snow mix as temperatures rise above
freezing before transitioning to all rain in the afternoon.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions will continue through tonight. Gusty northwest
winds will continue gradually diminishing. A period of light
snow or flurries cannot be ruled out late tonight into Thursday
morning (around 8Z through 13Z). This is most likely at DCA,
BWI, and MTN. MVFR is possible in some light snow during this
time. Any accumulation will be light, but with it being cold it
would only take light accumulations for impact.

VFR conditions are expected for the rest of Wednesday through
Wednesday evening. Another upper-level disturbance may bring a
period of light snow or flurries late Wednesday night into
Thursday morning. MVFR/IFR vsbys are possible during this time
and any light accumulation may have impact due to the cold
conditions.

VFR conditions are expected as surface high pressure builds over the
region Thursday through Saturday. West winds on Friday shift to
northwest on Saturday, gusting around 10 knots each afternoon.
Light and variable winds are expected overnight.

&&

.MARINE...
Winds will continue to gradually diminish over the waters
tonight, but an SCA is in effect for all of the waters this
evening and for the Chesapeake Bay/lower tidal Potomac River
overnight.

An SCA is in effect for the waters Wednesday ahead of an
approaching cold front, and SCAs will likely be needed
Wednesday night as well. The cold front will pass through late
Wednesday night into Thursday, and more gusty northwest winds
are expected behind the cold front. An SCA will likely be needed
for the waters with gusts around 30 knots possible. A brief
period of gales can`t be ruled out right with frontal passage
early Thursday.

High pressure will build overhead later Thursday through
Saturday. West winds on Friday shift to northwest on Saturday,
with winds expected to stay below Small Craft Advisory criteria
each day.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Winter Weather Advisory from 4 PM Wednesday to 10 AM EST
     Thursday for MDZ501.
     Winter Storm Warning from 4 PM Wednesday to 10 AM EST Thursday
     for MDZ509-510.
VA...Winter Weather Advisory from 4 PM Wednesday to 10 AM EST
     Thursday for VAZ503.
WV...Winter Storm Warning from 4 PM Wednesday to 10 AM EST Thursday
     for WVZ501-503-505.
MARINE...Small Craft Advisory until 6 PM EST Wednesday for ANZ530>534-
     537>543.
     Small Craft Advisory until 9 PM EST this evening for ANZ535-
     536.
     Small Craft Advisory from 10 AM to 6 PM EST Wednesday for
     ANZ535-536.

&&

$$

SYNOPSIS...BJL/DHOF
NEAR TERM...DHOF/CJL
SHORT TERM...BJL/DHOF/CJL
LONG TERM...AVS
AVIATION...BJL/AVS/DHOF/CJL
MARINE...BJL/AVS/DHOF/CJL

NWS LWX Office Area Forecast Discussion