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

Valid 12Z Sat Apr 02 2022 - 12Z Tue Apr 05 2022

...Eastern Great Lakes and Northeast...
Day 2...

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 in the Catskills and
portions of the Green Mountains. WPC probabilities for more than 4
inches are low.

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

Area of low pressure will skirt through the region this morning
with a burst of snow before zipping eastward. Brief surge in
precipitable water along with a focused area of frontogenesis with
sufficient lift into the DGZ will squeeze out a couple inches or
so more of snow after 12Z this morning along the WI/IL border with
another inch or two across northern Lower Michigan. Next system
(currently moving through the Pacific Northwest) will quickly move
into the High Plains overnight and into the Upper Midwest/Corn
Belt Sunday into Sunday night. An inch of two of snow is possible
with this system, focused over northern WI into Lower Michigan.
Three day totals may exceed 4 inches there.

...Northwest...
Days 2-3...

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. Lesser amounts are expected into Oregon Day 2
where snow levels will be higher. By the end of Day 3, 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...
Day 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.


Fracasso/Pereira