Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
342 AM EST Sun Jan 19 2020

Valid 12Z Sun Jan 19 2020 - 12Z Wed Jan 22 2020


Day 1...

...Great Lakes/Northeast...
A secondary low developing along the southeastern coast of New
England is expected to deepen as it moves though the Gulf of Maine
Sunday, bringing a period of moderate to locally heavy snow to
eastern Maine before it moves into the Canadian Maritimes during
the afternoon.  Ongoing lake effect snows will continue through
Sunday morning, with westerly winds supporting locally heavy
amounts east of Lake Erie into western New York and northwestern
Pennsylvania.  By late Sunday, veering winds will reorient snows
south of the eastern Great Lakes before diminishing Monday morning
as high pressure extends across the region.

Days 2-3...

...Western U.S....
An upper low and associated frontal system are expected to move
into the Pacific Northwest, bringing widespread precipitation back
into the region on Tuesday.  As it moves across the region, this
system is expected to bring heavy mountain snows to portions of
the Olympics, Cascades and northern Sierra.

For Days 1-3, the probability of significant icing (0.25 inch or
greater) is less than 10 percent.

Pereira