Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
331 PM EDT Sat Oct 01 2022

Valid 00Z Sun Oct 02 2022 - 00Z Wed Oct 05 2022

...Northern and Central Rockies...

Day 1...

Upper-level low lingering above eastern ID/southwestern MT this
evening will begin to lift into the northern Plains on Monday.
Paired downstream divergence with upper level diffluence will
continue to combine with moist 700mb upslope flow to drive deep
layer ascent into the terrain of WY and southern MT tonight
supporting periods of moderate to heavy snow above 9000ft.
Specifically, an additional 4-8" are possible through early Sunday
over the highest portions of the northern Absarokas and Bighorns.
Farther south into the highest terrain of Colorado, as the
upper-level low slides northeastward, a sharpening trough over the
Great Basin will support a strengthening jet streak over Wyoming.
The San Juan Mountains are to be situated near the right entrance
region of said jet streak, which is likely to aid in blossoming
precipitation on Sunday. However, snow levels are forecast to
remain above 11000 ft, limiting chances for 4"+ amounts to the
tallest mountains/ranges.

For days 1-3, no icing is forecast.

Snell