Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
339 PM EDT Sat Apr 02 2022

Valid 00Z Sun Apr 03 2022 - 00Z Wed Apr 06 2022

...Eastern Great Lakes and Northeast...
Day 1...

Amplified shortwave will move through the region late tonight
through Sunday in tandem with an area of low pressure along the
NY/PA border. Snow in the morning will change to a rain/snow mix
over many areas during the afternoon, with generally light
amounts.  Some higher totals near 4 inches are possible, but will
likely be mostly confined to the higher elevations of the
Catskills.

...Corn Belt/Upper Midwest/Great Lakes...
Days 1-3...

A shortwave currently moving through the the northern Rockies will
quickly move into the High Plains overnight and into the Upper
Midwest/Corn Belt Sunday into Sunday night. An inch or two of snow
is possible over portions of western to central North Dakota, into
northeastern South Dakota on Sunday, before shifting farther east
into Wisconsin and Lower Michigan Sunday night into Monday.

...Northwest to the northern Rockies...
Days 1-3...

By Sunday night, a strong/extended jet (160 kts) across most of
the Pacific will aim into the Northwest coast with a significant
moisture flux reaching into western Washington/Oregon.
West-southwest flow will capitalize on upslope into the Olympics
and Washington Cascades where widespread accumulations of a foot
or more are likely and multiple feet are possible across the
higher peaks.  Significant accumulations are possible at some
passes as well. Along the Oregon Cascades, lesser amounts are
expected into early Monday where snow levels will be higher.  By
early Tuesday, snow levels will drop to around 2000ft across WA as
the precipitation only starts to wind down. Accumulations over the
Oregon Cascades will increase markedly on Monday. Also on Day 3,
as the trough or closed low and jet move east of the Divide, snow
will spread across Idaho/western Montana and into Wyoming with
several inches likely above 6000ft, but snow levels will lower
quickly Tuesday morning to most valley floor locations.


...Colorado/New Mexico Rockies...
Days 1-2...

Weak upper trough and surface cold front will lead to an increase
in snow over higher elevations of Colorado on Sunday, aided by
upslope flow as a small area of high pressure sinks southeastward
over the Plains. At least a few inches of snow can be expected
across the higher elevations of the central Colorado and far
northern New Mexico ranges.


For Days 1-3, the probability of significant icing of at least
0.25" is less than 10 percent.


Pereira/Fracasso