Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Little Yoho, Sunshine, West Side 93N.
Heavy snowfall has resulted in 15-75+ cm of new snow, with more in the northern areas (Bow Summit). The avalanche danger is expected to remain HIGH over the next few days.
Parks Canada will be conducting avalanche control on Mt Bosworth and Mt Stephen on Monday, March 10. No access to these zones on March 10.
Confidence
High
Avalanche Summary
An ongoing natural avalanche cycle up to size 3 is expected to continue. Stay out of all avalanche terrain.
Snowpack Summary
25 to 75+ cm of new snow since Saturday with strong to extreme SE-SW winds. This sits over previous surfaces, including sun crust on steep solar aspects and surface hoar in sheltered areas. The weak Jan drought facet layers are down 40-100 cm. In shallower eastern regions, the mid and lower snowpack is mostly facets and depth hoar, while deeper western regions are more consolidated with fewer facets. Treeline snowpack depths range from 90 cm in the east to 180+cm in the west.
Weather Summary
An atmospheric river will continue to bring heavy snowfall to the region Sunday night. This system has primarily affected the northern parts of the region. Snow amounts so far ranges from over 50 cm at Bow Summit to 10 cm in the Simpson area. An additional 20 to 30 cm of snow is possible Sunday night before conditions begin to clear. Winds will start to decrease Monday, and freezing levels will drop to valley bottoms.
Terrain and Travel Advice
- Avoid avalanche terrain during periods of heavy snowfall.
Avalanche Problems
Storm Slabs
20-80 cm HST since Saturday and strong southerly winds creating storm and wind slabs at all elevations. Greater amounts in the northern forecast area (Bow Summit).
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1.5 - 3
Persistent Slabs
Storm snow is forecast to overload the persistent layers in the midpack and basal layers.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 2 - 3
Loose Dry
Lots of snow available for transport and strong winds will create loose dry avalanches at treeline and above.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Very Likely
Expected Size: 1 - 2