Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
209 PM EDT Sun Oct 19 2025

Valid 00Z Mon Oct 20 2025 - 00Z Thu Oct 23 2025

...Pacific Northwest and Northern Rockies...
Day 1...

Radar and IR satellite composite are doing a great job with
identification of the progressive cold front migrating through the
interior Northwest CONUS with snow likely falling in-of the Lewis
and Bitterroot ranges this morning. Frontal progression will
continue to move swiftly to the southeast with frontal proxy
likely to encounter the Absaroka down through the Wind River Range
by later this afternoon and evening leading to crashing snow levels
and eventual snowfall. High snow levels will initially begin
>8000ft, falling to around 5000-6000ft in wake of the front cold
front. The quick movement of the system will limit duration of the
snow, but periods of moderate to heavy snow will still induce a
relatively solid accumulation before shutting off from northwest
to southeast overnight, clearing the area by late Monday morning.

WPC probabilities for >8" of snowfall are between 50-80% in the
Bitterroots and Lewis Range above 5000-6,000ft. Probabilities are
lower over western Wyoming -- generally <40% with the strongest
signals targeted >8000ft. Highest totals will be focused over the
Lewis Range where >12" hovers between 40-70% probability just south
of Glacier National to the east of Flathead National Forest.

The probability of significant freezing rain across CONUS is less
than 10 percent.

Kleebauer/Fracasso