Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
433 AM EDT Mon Apr 28 2025

Valid 12Z Mon Apr 28 2025 - 12Z Thu May 01 2025


...North-Central Rockies...
Day 1...

Positively-tilted trough axis from the western Dakotas to Nevada
will sag south today as a leading shortwave tracks to the Upper
Midwest while a filling low drifts south over Utah. The surface low
associated with the leading wave is over SD with comma head/cold
conveyor belt flow resulting in a swath of moderate to locally
heavy precip across southern/eastern MT. Snowfall rates above the
6500ft snow levels in southern MT around 7000ft will rapidly rise
through this morning, particularly in the Red Lodge portion of the
northern Absarokas where rates will soon exceed 2"/hr per the 00Z
HREF. This precip swath will shift south over WY today where snow
levels will also be around 7000ft and rates in the higher terrain
will generally be 1-2"/hr. Day 1 snow probs for >8" additional
snow after 12Z are 40-70% in the Absarokas and 60-90% in the
Bighorns.


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


Jackson