Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
436 AM EDT Sun Apr 27 2025

Valid 12Z Sun Apr 27 2025 - 12Z Wed Apr 30 2025


...Great Basin and Northern Rockies...
Days 1-2...

Upper low over central NV will slowly track to northern UT through
today where it will stall and fill through tonight. Mountain snow
continues over the higher NV ranges with snow levels of
6000-7000ft. The Ruby Mtns stand out in NV for impacts with Day 1
snow probs for >8" 50-90%.

A reinforcing trough ejects over the northern High Plains tonight
into Monday which allows a slowly pivoting swath of moderate to
locally heavy precip this afternoon through Monday morning from
central ID through southern MT. Snow levels in this swath start
high, above 8000ft through this evening, but decrease overnight to
5000 to 6000ft over the northern Absarokas. The resulting
positively-tilted trough axis shifts south Monday bringing some
moderate snow to terrain in WY. Day 1.5 snow probs for >8" are
70-90% in the Red Lodge area of the northern Absarokas in southern
MT (where storm totals over 2ft are locally likely) and 50-80% in
the Madison/Gallatin ranges, Absarokas east of Yellowstone, and the
Bighorns.


The probability of at least 0.10" of freezing rain across CONUS is
less than 10%.



Jackson