Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
338 AM EST Wed Feb 18 2026

Valid 12Z Wed Feb 18 2026 - 12Z Sat Feb 21 2026


...Pacific & Interior Northwest...
Days 1-2...

The longwave trough that has led to multiple days worth of
accumulating snowfall looks to continue through at least Thursday
morning before a upper level ridge pattern builds in late in the
day Thursday and persist through Friday. Snow levels along I-5 will
creep as far down as 500ft this morning and again on Thursday
morning, but moderate-to-locally heavy snow will reside in the
>2,000ft elevations of the OR Cascades and above 3,000ft in the WA
Cascades. Farther east, the Blue Mountains on east into the
Bitterroots and Sawtooths will be heavy snow above 3,000ft (Blues &
Bitterroots) and above 4,000ft (Sawtooth). The heaviest snowfall
will unfold in the Absaroka, Tetons, Wind River, and Bear River
Ranges where they not only have the higher elevations, but also
reside where the riches 700-300mb moisture source will be and
beneath the diffluent left-exit region of a 250-500mb layer jet
streak. WPC probabilities moderate-to-high chances (40-70%) for
snowfall >12" in the peaks of these mountains ranges, as well as
the peaks of the OR Cascades. In the Willamette Valley, most
snowfall totals are likely to be less than 1", although some areas
close to Eugene, OR could eclipse 1". Expect hazardous travel
conditions in the passes of the Northern Rockies and OR Cascades
through Thursday morning.

...California...
Days 1-2...

...Heavy, disruptive snowfall for the California ranges to persist
through Thursday...

California remains ideally placed ahead of 500mb disturbances
rotating around the western flank of a large longwave trough
anchored over the western U.S.. Snow levels in northern CA are as
low as 1,000ft, down to 2,500 ft in the Sierra Nevada, and
4,000-5,000 ft in the Transverse Ranges this morning. After a day
generally upslope-driven snowfall on Wednesday, by Thursday, a
phasing of shortwaves diving southeast from the Pacific NW coast
will produce heavier snowfall totals throughout the CA mountain
ranges. Similar to the Northwest, upper ridging will provide a
break in the heavy snowfall threat beginning late Thursday and
continuing into Friday.

Additional snowfall of 1-2 feet are likely for the northern Sierra
Nevada above 3,000ft, while in the southern Sierra, elevations
above 4,000 can expect several more feet in the highest elevations.
The WSSI continues to indicate widespread Major impacts are likely
for just about all of the Sierra NEvada above 4,000ft Sierra
Nevada through Thursday. This includes not only Donner Pass, but in
the Shasta/Siskiyou where Moderate to locally Major Impacts are
possible along I-5 mountain passes. In Southern California,
additional snowfall accumulations over a foot are forecast above
6,000ft in the Transverse Ranges with localized amounts exceeding 2
feet possible in the peaks of the San Gabriel and San Bernadino
Mountains through Thursday.


...Intermountain West/Southwest to the Rockies...
Days 1-3...

Pacific moisture spilling over the Cascades and Sierra-Nevada will
provide a much-needed boost to the Intermountain and Rocky Mountain snowpack.
Following a warm start, snow levels will drop into the valleys as
the leading shortwave moves inland on Wednesday. A brief lull is
expected on Thursday, except for Nevada and the Four Corners
region, where the next shortwave will bring the threat for heavy
mountain snow into Friday. Probabilities for storm total amounts
over a foot exceed 70 percent for several areas including the high
elevations of the Nevada mountains, the southern Utah mountains,
the northern Arizona plateaus to the central Mogollon Rim, and much
of the central Rockies - particularly the northern Utah and
western Colorado ranges.


...Northern Plains & Upper Great Lakes...
Days 1-2...

The winter storm is ongoing this morning with heavy snow blanketing
much of northern ND, northern MN, and into the northern tier of
MI's Upper Peninsula. Heavy snow will continue to the north of the
500mb low as it tracks across southern MN and into northwest WI,
placing the MN Arrowhead perfectly placed beneath not just the
strongest upper-level divergence, but easterly flow off Lake
Superior is upsloping into the Arrowhead. Snowfall rates of 1-2"/hr
will be common this morning and through midday but rates should
gradually weaken this afternoon and tonight. The closed low will
meander over the western MI U.P. through Thursday morning, keeping
periods of light-to-moderate snow in the forecast over northern MN
through Thursday morning. Snowfall totals of 1-2 feet are expected
in the MN Arrowhead with localized amounts surpassing 30" possible
by the time this storm concludes.

Additionally, with the pronounced WAA rotating around the surface
low, an area of freezing rain is also expected, especially from
just south of Duluth, MN eastward across northern WI and into
northern MI where the warm nose will be most prevalent while
surface temps remain sub-freezing. This sets the stage for a
freezing rain/icing event that could last over 24 hours in parts
of northern WI and northern MI. WPC probabilities are moderate-to-
high (50-80%) for at least 1/10 inch of ice, with locally more
than a quarter inch possible, most likely across the tip of
Michigan's Mitten, mainly areas east of Grand Traverse Bay.


...Northeast...
Days 1-3...

A strong surface low moving slowly across the Dakotas/Minnesota
today will remain entrenched within an elongated mid-level trough
extending into the Mid-Atlantic states. Vorticity lobes downstream
of this wave will spread northeast from the Mid-Atlantic states
into the Northeast, before getting sheared to the east as mid-level
flow becomes strongly confluent south of the secondary shortwave
energy crossing Maine and Nova Scotia. The resultant mid- level PVA
and divergence will overlap with a narrow ribbon of impressive
low-level WAA to produce a stripe of moderate-to- locally heavy
precipitation from Upstate NY through southern/central New England.

Periods of snow will unfold from the eastern shores of Lake Ontario
going east across the Tug Hill, southern tier of the Adirondacks,
and as far east as the Green and Berkshires. Snowfall totals are
most likely to range between a coating to 3", although some
localized totals topping 4" are possible in parts of the
Adirondacks and Berkshires. While the atmosphere is likely to
remain below freezing in these areas, a narrow warm- nose aloft
from I-90 in western NY on east through the Catskills, Poconos, and
even portions of southern New England are likely to see freezing
rain. The section of western NY located along and north of I90,
including the Rochester area, are most concerning when it comes to
travel impacts. WPC probabilities show high chances (>70%) for ice
accumulations over one-tenth of an inch there and low-to- moderate
chances (20-50%) for totals over one- quarter inch. This area does
show the potential for Moderate Impacts (hazardous driving
conditions, closures possible) today. Farther east, most ice
amounts are likely to come in under a tenth of an inch from the
Finger Lakes on east through southern NY (not NYC proper), the
Poconos, and southern New England, but localized Minor Impacts are
denoted on the WSSI today.

Following a brief break in the action Thursday, a storm system
strengthening in the Midwest will direct a plume of 850-300mb
moisture towards the Northeast amidst increasing WAA Thursday
night. To the north, high pressure over southeast Canada is
building in with a weak CAD signature forming over the region. This
sets the stage for yet more ice from northern into the heart of
the Northeast. The Poconos, Catskills, southern Adirondacks, and
Berkshires have moderate chances (40-70%) for ice accumulations
over one-tenth of an inch, while many areas from the Lehigh Valley
on north and east into southern New England. The higher elevations
of the Poconos and Catskills could see localized ice accumulations
approach one-quarter inch. In the northern Appalachians, the
atmosphere will remain cold enough to support periods of snow that
look to fall heavily at times Friday and into Friday evening. WPC
probabilities show moderate-to- high chances (50-70%) for snowfall
totals >4" in the northern Adirondacks, Green, and White mountains
with low chances (10-40%) for localized amounts surpassing 8".


...Central Plains...
Days 1-2...

Tonight, a potent shortwave trough ejecting out of the Central
Rockies will take on a negative tilt as it heads into the Central
Plains. To the north of the 500mb vort max, strong 700mb Q-vector
confluence will focus a narrow area of strong vertical velocities,
coinciding with a pronounced TROWAL forming over the Black Hills on
east into the Sand Hills of NE early Thursday morning. Most
guidance agrees the impressive synoptic-scale support aloft (left-
exit region of a 250mb jet streak over head) and strong SErly 850mb
WAA will support heavy snowfall rates, and confidence is
increasing in the Black Hills and the Sand Hills being the hardest
hit. Latest WPC probabilities show moderate chances (40-60%) for
>6" of snow in the Black Hills and Sand Hills on east along the
NE/SD border and into southeast SD. It is worth noting there are
low-to-moderate chance probabilities (20-50%) for >8" of snowfall
in these areas as well. Given the strong dynamics and banding
potential, localized totals surpassing 10" cannot be ruled out.
Note that there does remain some uncertainty on the exact placement
of the heavy snow banding, but guidance is in fairly good
agreement a band of snow generating warning-level snowfall has
moderate chances (40-60%) over western NE. Residents in the
Central Plains should monitor the forecast from their local WFO
closely in the coming days. Minor snowfall accumulating of 1-4" are
possible as far west as east-central WY with some potential for
4-6" worth of snow in eastern NE to the north of the Omaha area.


Mullinax/Kleebauer/Pereira