Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
320 AM EST Mon Nov 13 2023

Valid 12Z Mon Nov 13 2023 - 12Z Thu Nov 16 2023

...Northern Rockies...
A pair of shortwave troughs are forecast to sweep across the
northwestern U.S. this period.  Winter weather impacts associated
with the initial wave will be confined to the high elevations as
it moves across the region Monday and Tuesday.  Impacts with the
next system may be slightly more far-reaching as it dives
southeast across British Columbia and amplifies over the northern
Rockies late Wednesday into Thursday.  Guidance shows
precipitation filling in along the associated low-to-mid level
front, with snow levels at or below pass level across northern
Idaho and northwestern Montana.  This includes Marias Pass, where
WPC probabilities show a Moderate Risk (40 percent or greater) for
accumulations of 4 inches or more from Wednesday into early
Thursday.

Pereira