370
FXUS61 KLWX 200235
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
935 PM EST Thu Feb 19 2026

.WHAT HAS CHANGED...
18z deterministic and ensemble guidance continues to show a high
degree of spread between model solutions. Overall ensemble
snowfall probabilities have increased, but this is also being
guided by the more inflated GEFS forecast. Otherwise, tonight`s
forecast appears on track with low clouds, drizzle, and fog
appearing likely within the cold-air damming wedge.

&&

.KEY MESSAGES...
- 1) Low pressure tracking nearby brings a Slight winter storm
  threat to the forecast area this weekend, followed by colder
  than normal temperatures early next week.

- 2) Cloudy, rainy, and foggy conditions are expected through
  Friday morning as a stalled front meanders nearby.

- 3) A cold frontal passage may bring strong winds to the
  mountains Friday afternoon and evening.

&&

.DISCUSSION...
KEY MESSAGE 1...Low pressure tracking nearby brings a Slight
winter storm threat to the forecast area this weekend,
followed by colder than normal temperatures early next week.

A high energy but low predictability pattern looms for late this
weekend. The pattern is forecast to be very amplified but in flux as
a deep upper-level low digs out of the Gulf of Alaska inducing a
downstream ridge-building event over the western U.S. This pattern
amplification in the vicinity of western North America comes with
low predictability due to data sparse regions over the North
Pacific. Meanwhile, a pair of downstream upper lows interact/merge
over Maritime Canada, with inherent low predictability with two
cutoff lows interacting.

If the upstream ridge-building event takes place a bit further west
near 120 W longitude on Saturday, downstream trough amplification
would be favorable for phasing over the mid MS Valley into the OH/TN
Valleys Saturday night. A subsequent low track hugging the coast
would become more likely in this scenario, aided by downstream
blocking and a potential source of cold air given the upper lows
over Maritime Canada and surface high pressure attempting to ridge
into northern New England.

There is an appearance of an inverted trough signature in a subset
of model guidance over the last couple cycles, given interaction
between a more amplified northern stream wave and a bit more distant
offshore southern stream low. This could factor into precipitation
amounts and placement.

After reviewing the 18z model guidance suite, uncertainty
continues to plague the forecast. This is again largely due to a
number of complicating factors which were addressed in the above
paragraphs. The 18z GFS/GEFS solutions have come down a tad, but
still produce measurements on the order of feet versus inches.
Meanwhile, the 12z EPS ensembles came up some, but at much more
conservative levels. In the net, the 19z NBM did indicate a rise
in snowfall probabilities, especially along and east of I-95.
However, until the ensembles get into slightly better agreement,
the range of possibilities remain quite large for a system only
60 to 72 hours away.

As described above, there are a substantial number of very
complex variables at play here, and all of them have to come
together at just the right time in just the right place in order
for us to get snow, and especially significant snow. At
present, there are three scenarios at play here.

 1) The phase of all of these upper level features occurs too late,
    with low development offshore and too far southeast.

 2) Similar to scenario 1, but an inverted trough on the back side of
    the low brings snow to eastern portions of the region.

 3) Low develops closer to shore and strengthens along Delmarva
    Peninsula, resulting in the most snow for our areas.


Exactly how all this occurs will be the difference between a couple
of strung out waves passing through with little fanfare, a modestly
impactful period of snow showers, and a more significant wintry
precip event. We are firmly in the "wait and see" period with this
storm, so just take precautions now, should the worst case scenario
play out. Having a preparedness kit stocked up is never a bad idea.

Lastly, no matter what plays out further east, it seems much more
likely that the mountains will see another round of upslope snow.
The key here will be with how much we manage to get. That will
depend on the storm track as well, but it seems much more likely for
at least advisory level accumulations through the Sunday/Monday
period along/west of the Allegheny Front.

Of note, the higher sun angle later in the season becomes a factor
especially for lower elevations if precip occurs during the day.
Cold air will also be filtering into the region as the storm in
question approaches, rather than being locked-in beforehand,
which offers another layer of uncertainty in p-type.

Regardless of exactly how the details of the Sunday-Monday system
play out, another shot of below normal temperatures is favored for
early next week. Currently, high temperatures in the 40s (30s in the
mountains) with lows in the 20s (teens in the mountains) are
forecast through Tuesday night, with some midweek moderation
after.


KEY MESSAGE 2...Cloudy, rainy, and foggy conditions are expected
through Friday morning as a stalled front meanders nearby.

Per the 00Z surface analysis performed by the Weather Prediction
Center, the parent frontal zone generally arcs just south of the
Virginia-North Carolina border and back across the Ohio Valley.
Prevailing winds in the cool sector have generally ranged
between northerly and easterly which continues to bring in
cool/damp air into the area. In response to warm advection aided
lift, a fairly widespread area of light to moderate rain
continues to push eastward across the region. A relative dry
slot will move overhead later this evening into the early
overnight hours as the initial wave exits the area. Rain may
decrease in coverage and intensity, but some drizzle may persist
as overrunning continues. Remnant convection from today`s
severe weather threat in the Ohio Valley will reach the area
late tonight into Friday morning. Severe weather isn`t expected
locally, but a few thunderstorms could reach the Allegheny
Mountains before they outrun the elevated instability. However,
this activity could result in some briefly heavier rain rates.
Storm total rainfall amounts will be one half to one inch for
many areas, with the greatest potential for higher totals closer
to the Allegheny Mountains. WPC has a Marginal Excessive
Rainfall Outlook in this area. However, we have already seen
most of the snow pack melt in our area, and ice has been
breaking up on rivers. Thus, this amount of rainfall is
unlikely to cause too many issues. Most of the rain should push
out of the area by noon Friday.

The other issue is fog. The 00Z IAD sounding indicated a
saturated column through at least the mid-levels of the
troposphere. While earlier fog has since lifted to being a low
hanging stratus deck, expect drizzle and fog to again prevail
tonight. While cloud bases have risen a tad, some of these lower
clouds continue to intercept area mountain ridges which is
resulting locally lower visibilities. Fog could become dense in
the dry slot tonight, but otherwise, elevation based issues
will continue. Some fog could form near the colder bay waters
again as well. Visibilities will improve from west to east on
Friday.

Even after the rain clears out, a cold air damming wedge may
persist over portions of the area until the cold front shifts
the wind to the west later in the afternoon and evening. Thus
low clouds may take some time to clear out, especially northeast
of the Potomac River. This will make the difference between
highs in the 40s versus 60s.


KEY MESSAGE 3...A cold frontal passage may bring strong winds to
the mountains Friday afternoon and evening.

Low pressure moving through the Great Lakes will send a cold
front toward the area Friday afternoon. Wind fields have been
trending stronger with the frontal passage, especially along the
Allegheny Mountains. Gusts could reach 40-50 mph on the ridges
Friday afternoon into Friday night, which could cause some
isolated/minor damage. There`s also a signal in some guidance
that these strong winds could downslope into the lee (US 220
corridor) during the evening hours. Further east, more stable
low level conditions are expected, so winds will remain
relatively tame besides on the higher ridges.

Lighter winds are expected Saturday as the front pushes south of
the area and stalls. Cold advection will be gradual, and above
normal temperatures are expected areawide under partly to mostly
sunny skies. The area which likely stays the coolest is
northeastern Maryland where a warm frontal passage may occur
much later in the day.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Despite some improvements at times, flight conditions will
remain IFR or LIFR straight through Friday morning due to low
ceilings. Occasional rain can be expected throughout the evening
hours, then there may be a bit of a dry slot for part of
tonight. Drizzle could still occur at times, and it`s possible
fog could also worsen. Remnant convection from the Ohio Valley
will move through late tonight into Friday morning. While it`s
unlikely any thunderstorms reach the TAF sites, there could be
some briefly heavier rain rates. The rain will exit by midday
Friday. However, low ceilings may persist into the afternoon,
especially for the metro terminals, as the warm front may still
not lift north. Overall winds will remain northeast to southeast
at 10 kt or less. If the warm front lifts north, winds will
shift to southerly before the cold front reaches the area during
the late afternoon or evening. West winds will follow this
front. Winds will also increase aloft with the frontal passage,
so have introduced low-level shear groups at the KIAD, KDCA, and
KBWI on Friday evening.

VFR conditions with light west winds can be expected Saturday.

Sub-VFR conditions appear likely on Sunday, regardless of the exact
storm track that takes place with the area of low pressure sliding
by to our south. The big question will be "how much snow?". It is
still too early to tell if we get any snow, and how much, but the
most likely time period for snow would start late Sunday evening and
into Sunday night. At this point though, there is still a good
chance for an all rain event as well, especially if the system
develops too far offshore. In that scenario, we may not even see
severe restrictions. With the level of uncertainty, this storm could
cause restrictions through Monday as well, but right now would favor
clearing by the afternoon.

&&

.MARINE...
The main concern through Friday morning will be fog. While
marine visibilities have generally improved this afternoon and
early evening, this should be a short-lived phenomenon.
Probabilities are pretty high tonight that visibility will drop
back below 1 NM. Another round of moderate rain will move
through late tonight into Friday morning. Should see improving
conditions by afternoon. Otherwise northeast to easterly winds
can be expected through tonight. Gusts may approach advisory
criteria this evening, but appears to be marginal/brief. The
warm front could shift winds back to the south Friday afternoon
before a cold front brings another shift to the west during the
evening. While a brief period of near-SCA winds is possible
Friday night, this is likely to be sporadic enough to not
warrant a Small Craft Advisory. Lighter west winds are forecast
Saturday.

A potentially strong low pressure system will slide by to our south
Sunday into Monday. There is a lot of uncertainty at this time, but
should this system track closer to our region and strengthen early
enough, some significant marine winds are possible. SCAs appear
likely at this time, but couldn`t completely rule out Gales in that
period too. However, that will largely be driven by the
track/strength of the low, which it is just too early to tell at
this time.

&&

.TIDES/COASTAL FLOODING...
Sensitive locations are likely to reach Action Stage during
high tide through Friday night before tides decrease a bit
through Saturday night behind a cold front. Greatest chance of
reaching minor flood stage will occur at Annapolis Friday
evening. Tides are uncertain with potential coastal storm Sunday
into Monday given divergent model solutions on the
track/strength. While some tidal flooding can`t be ruled out, a
more probable outcome is that strong north winds could result
in crashing tide levels.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$

DISCUSSION...ADS/BRO/CJL
AVIATION...ADS/BRO/CJL
MARINE...ADS/BRO/CJL

NWS LWX Office Area Forecast Discussion