Subj : HVYSNOW: Probabilistic Heavy Snow And Icing Discussion To : All From : Mike Powell Date : Mon Apr 27 2026 08:25:28 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 $$ --- MultiMail/DOS * Origin: Project Scorpio TEST (618:250/6) .