Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
431 AM EDT Sun Oct 20 2019

Valid 12Z Sun Oct 20 2019 - 12Z Wed Oct 23 2019

...Pacific Northwest to the Northern High Plains...
A closed mid-level low will shift east from Wyoming today and
reach Lake Superior Monday night. Gusty winds and higher elevation
heavy snows are expected from eastern Wyoming to the Black Hills
today as the surface low deepens and a well defined comma head
develops. Probabilities for over eight inches are high in these
areas. As the low moves east across the northern Plains, warm air
will support mostly to all rain across the remainder of the
northern Plains and upper Midwest though wrap around bands may be
intense enough for localized snow, particularly at night through
Monday night.

While mid level energy embedded within northwest flow will
continue to support periods of organized precipitation across the
Pacific Northwest into the Rockies, snow levels will remain high,
hampering the threat for widespread heavy snow accumulations
Monday and Tuesday. A cold air intrusion from Canada along with an
Alberta Clipper will bring some snow chances to the high plains
Tuesday night.

The probability of significant icing is less than 10 percent.

Jackson