Advisory Archive

Strong winds will be the main weather event today. At 4 a.m. ridgetop winds were blowing 20-40 mph from the west in the Bridger Range and southwest elsewhere. Temperatures were in the upper teens except near West Yellowstone where they were in the upper single digits. Since yesterday morning a trace to 1 inch of snow accumulated near Bozeman, Big Sky and Cooke City, and these areas should get an additional 1-2 inches by tomorrow morning. 4-5 inches of snow accumulated near West Yellowstone and the southern Madison Range since yesterday. These areas should receive 3-4 inches by tomorrow morning. Temperatures at 9000ft will be in the low 20’s F and winds will blow 30-40 mph from the west-southwest with gusts in the 50’s.

Over the past 48 hours, 10 inches of snow has fallen in the mountains near West Yellowstone, and 7-8 inches has fallen elsewhere. This new snow combined with snow already on the ground provides more than enough for an avalanche, especially if strong winds have formed wind slabs. The new snow will be found on a variety of surfaces that can range from bare ground to weak faceted snow. Regardless of the underlying surface, avalanches are most common immediately after a storm.