Avalanche Forecast

Tuesday night: Snow and flurries, 10-15 cm accumulating overnight. Alpine temperature -5 C, southwest wind, 40-55 km/hr.

Wednesday: Cloudy with scattered flurries, trace to 10 cm accumulation. Alpine temperature -6 C, west wind 10-30 km/hr.

Thursday: Cloudy and flurries, 5-10 cm. Alpine temperature -10 C, southwest wind 15-30 km/hr.

Friday: Snow, 10-20 cm. Alpine temperature -6 C, southwest wind 25-35 km/hr.

A natural avalanche cycle was observed in Glacier National Park on Tuesday. Numerous size 2 storm slab avalanches were observed on all aspects at 2200 m and above. Additionally, 2 size 3 storm slab avalanches were observed on a north aspect at 2165 m and a northwest aspect at 2400 m.

Explosives also triggered a size 3 storm slab avalanche on a north aspect at 2200 m along the Trans-Canada Highway corridor.

Near Revelstoke, storm slab avalanches to size 2 were reacting easily to explosives, many occurring on north and northeast aspects from 1800-2300 m.

Snowfall deposited upwards of 30-40 cm of snow by the end of Tuesday. Westerly winds have begun to redistribute new snow into lee features and cross-loaded terrain.

The new snow has fallen on a faceted upper snowpack and previously wind-affected surfaces. Below the 15-35 cm layer of old, wind-affected snow, a layer of surface hoar (feathery crystals) may be found in sheltered areas around treeline and below. In these areas old, stubborn wind slabs may still be reactive where they overly the weak surface hoar on a crust.

Snow depths range from 60-150 around treeline elevations. A variety of crusts from late October are buried deeper in the snowpack.