Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
430 AM EDT Fri Oct 18 2019

Valid 12Z Fri Oct 18 2019 - 12Z Mon Oct 21 2019

...The West...

Days 1-3...
A pair of troughs push east across the Rockies today, bringing
moderate snow to higher elevations (above 4000ft for the northern
Rockies and 5000 to 7000ft for the central Rockies) through this
morning. Low amplitude ridging provides a short lull in snow
across the northwestern CONUS until a more potent trough digs
southeast from WA to CO late tonight through Sunday. Pacific
moisture with this next trough will allow a quick return of heavy
mountain snows to the Cascades and Rocky Mountains.

Ridging builds over the Pacific Northwest coast Saturday night
will direct further impulses into more interior locations such as
the northern Rockies where heavy higher elevation snow continues
into next week.

The surface low over the northern Plains strengthens Sunday night,
but the core does not look cold enough to produce much if any snow
over the Dakotas through Day 3.

The probability of significant icing is less than 10 percent Days
1-3.

Jackson