Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
226 PM EDT Wed Oct 23 2024

Valid 00Z Thu Oct 24 2024 - 00Z Sun Oct 27 2024

...Northern Rockies...
Day 1...

Fast moving compact shortwave will race from OR to WY while
weakening through Thursday. Modest PVA and accompanying height
falls will combine with upper diffluence to provide ascent into the
region, combining with a modest surge in downstream 700-500mb RH
to spread precipitation across the area. The forcing is generally
transient, and moisture erodes quickly by Thursday evening, but
modest upslope flow behind the trough should enhance ascent
sufficiently to produce moderate snow accumulations above snow
levels falling to 6000-7000 ft. WPC probabilities are highest in
the vicinity of Yellowstone NP but remain modest at 20-40% for 4+
inches in the highest terrain.

The probability of significant ice across the CONUS is less than
10 percent.

Weiss