Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
329 AM EST Fri Nov 15 2019

Valid 12Z Fri Nov 15 2019 - 12Z Mon Nov 18 2019


...Pacific Northwest...
Day 1...
A progressive trough crosses the Pacific Northwest today. The
combination of elevated moisture and upper level forcing as a jet
streak approaches from the northwest will promote heavy snow in
the preferred western slopes of the WA Cascades today and northern
Rockies of ID/MT tonight.

A deeper plume of Pacific moisture arrives into WA Saturday.
Elevated moisture from tropical sources in this plume will raise
snow levels over 10000ft and thus eliminate the heavy snow threat.

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

Jackson