Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
319 AM EST Thu Feb 12 2026

Valid 12Z Thu Feb 12 2026 - 12Z Sun Feb 15 2026


...Central & Southern Rockies...
Days 1-2...

A broad upper-level trough west of Baja California is funneling
anomalous moisture into the Four Corners region today with modest
500-700mb Q-vector convergence over the central Rockies. The lack
of a continental polar (cP) airmass is keeping periods of snow
confined to elevations above 8,000ft in the Wasatch and CO Rockie
today and into Thursday night. A brief lull in the snowfall occurs
Thursday night, but heavier snowfall returns to the Central and
Southern Rockies on Friday as the aforementioned upper trough
moves east towards AZ. 700-500mb height falls, 500mb PVA, and PWs
above the 90th climatological percentile will support mountain
snow as far south as the Gila Mountains to as far east as the
Sangre De Cristo range. Similar to Thursday's snowfall, the lack of
a reasonably cold airmass will keep snow levels above 7,000ft,
with the heavier snowfall totals residing above 8,000ft. The
increased upper-level synoptic-scale forcing will improve snowfall
rates in the higher terrain compared to Thursday. 48-hour WPC
probabilities show low-to-moderate chances (40-60%) for snowfall
totals >4" in the Wasatch, the AZ Gila Mountains, and the CO/NM
Rockies, with the higher confidence in snowfall >4" being above
9,000ft. In the peaks of the CO Rockies and Gila Mountains, there
are some low chance probabilities (<30%) for snowfall totals >8"
through Saturday morning.

...Northern New York...
Days 2-3...

A progressive 500mb vorticity max over Ontario Friday afternoon
will provide sufficient upper-level ascent atop a low-level warm
front driven by a narrow sliver of 850mb WAA. Guidance is coming
into better agreement on a period of moderate snow, potentially
falling heavily at times, along the shores of Lake Ontario on east
into the Tug Hill and Adirondacks Friday night. Mean flow out of
the NW with residual 700-300mb moisture will support lingering
periods of snow into the Tug Hill and Adirondacks into Saturday
morning before tapering off by Saturday afternoon. Most snowfall is
likely to range between a coating-3" for much of northern New
York, although the Tug Hill and Adirondacks do show low chances
(<20%) for localized amounts >4" through Saturday morning.

...Washington Cascades & Northern Rockies...
Days 2-3...

An upper-level trough in the Gulf of Alaska will dive south just
off the coast of British Columbia and direct a plume of rich
Pacific moisture at the Pacific Northwest Friday afternoon and
through Saturday morning. A passing cold front and height falls in
advance of the encroaching upper trough will cause snow levels to
drop as low as 2,000ft in the Olympics and Cascades. Elevations in
the WA Cascades above 4,000ft sport the better chances for snowfall
amounts surpassing 6", while most elevations below 3,000ft range
between a coating-3". WPC probabilities for at least 4 inches of
snow for Stevens and Snoqualmie passes are between 30-50%. The
plume of Pacific moisture spills eastward into the Northern Rockies
with the Bitterroots, Sawtooth, and Lewis Ranges most likely to
receive measurable snowfall starting Friday evening and continuing
throughout the day Saturday. Similar to the Cascades, most snowfall
totals will be minor (coating-3"), although some localized totals
>6" in the peaks of the Bitterroots and Lewis Range are possible.


The probability of significant icing across the CONUS is less than
10 percent.


Mullinax