FOUS11 KWBC 270720
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
320 AM EDT Mon Apr 27 2026

Valid 12Z Mon Apr 27 2026 - 12Z Thu Apr 30 2026

...Great Basin, Central/Southern Rockies, & Northern Plains... Days 1-2...

Two shortwave troughs; one heading for the Great Basin and another
over the Northern Rockies, are responsible for the periods of snow
enveloping the higher terrain of the Intermountain West today and
into early Tuesday. The heaviest snowfall (rates between 1-1.5hr
possible) are most likely to unfold along the higher terrain of
the Wasatch, Uinta, and Absaroka through tonight. Snow levels will
generally hover around 7,000ft in UT/NV, around 6,000ft in the
Northern Rockies, and t/above 8,000ft in the CO/WY Rockies. As the
500mb trough over the Great Basin reaches the Central Rockies
Monday night, enhanced vertical ascent aloft will work in tandem
with a surface high building in from the north to foster upslope-
enhanced snowfall over Laramie Range in WY on south into the Park
and Front Ranges of CO. Only light snow will linger over the remote
reaches of the Central and Northern Rockies on Tuesday as the
shortwave troughs exit to the north and east.

WPC probabilities show high chances (>70%) for additional snowfall
totals >4" in the Uinta, Absaroka of southern MT, the CO
Park/Front Ranges, and WY Laramie Range. Snowfall is welcomed
throughout these mountain ranges given the Rockies anywhere from
class 2 (severe) to class 4 (exceptional) drought condition.

The probability for significant icing over one-tenth of an inch is
less than 10 percent.

Mullinax
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