Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
333 AM EDT Mon Oct 14 2019

Valid 12Z Mon Oct 14 2019 - 12Z Thu Oct 17 2019

Days 1-3...

...Pacific Northwest...
At atmospheric river is directed into the Pac NW Tuesday night.
The tropically sourced moisture will start relatively warm and
have a rather high snow level, above 8000ft limiting heavy snow to
the higher Cascade peaks on Day 3/Wed. With the approach of the
upper trough, temperatures aloft start to fall, in turn allowing
snow elevations to decline. The best chance of significant snow
accumulation is at the higher elevations of the WA Cascades due to
longer duration of snow.

The probability of significant icing is less than 10 percent Days
1-3.
The probability of heavy snow is less than 10 percent Days 1-2.

Petersen