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

Valid 00Z Tue Apr 29 2025 - 00Z Fri May 02 2025


...Northern & Central Rockies...
Days 2-3...

After light-to-moderate snow quickly ends across WY by the start
of day 1 following the departure of a postively-tilted trough
sliding eastward into the Upper Midwest, a separate upper shortwave
and associated cold front is forecast to swing over the northern
Rockies on Wednesday. This will lead to an area of broken
precipitation with an upslope emphasis on the highest peaks and
northward facing slopes as the system slides south into the CO
Rockies on Thursday. Snow levels will fall below 8,000ft in western
MT and northwest WY shortly behind the cold front and as low as
6,000ft. However, these relatively lower snow levels also coincide
with a drier column and only lighter precipitation. For the
central Rockies, snow levels are expected to remain around
8,000-9,000ft through the end of day 3. WPC probabilities for at
least 6 inches of snow during the days 2-3 time frame are moderate
(40-70%) across the high elevations of southwest MT, WY, and CO.
This primarily includes the Absarokas, Bighorns, Wind River Range,
and Medicine Bow Mts above 9,000-10,000ft.


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


Snell