Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
359 AM EDT Sun Sep 30 2018

Valid 12Z Sun Sep 30 2018 - 12Z Wed Oct 03 2018


Days 1-3...

...Northern Rockies and High Plains...
Mixed precipitation, resulting in some light snow accumulations is
expected to continue this morning across portions Montana,
northern Wyoming and western North Dakota.  Warming conditions
after 12z should limit the potential for any widespread
significant amounts on Sunday.  Any significant snowfall threat is
forecast to remain north of the Canadian border on Monday into
early Tuesday.  However, heavy snows may extend south along the
Canadian Rockies into northwest Montana as a well-defined
shortwave trough digs southwest across western Canada into the
northwestern U.S. Tuesday night into Wednesday morning.  WPC Day 3
probabilities (ending 12 UTC Wed) indicate a Slight Risk for
accumulations of a foot or more in the higher elevations of the
northern sections of Glacier National Park.

The probability of significant icing is less than 10 percent.

Pereira