Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N.
An Arctic air mass has moved into the forecast region, bringing temperatures as low as -25°C. When recreating in the backcountry, be prepared for these cold temperatures, as even a minor setback could have serious consequences.
Confidence
High
Avalanche Summary
Minimal natural avalanche activity was observed during a flight across the forecast region on Friday. Avalanche control triggered very few slab avalanches today, with no failures on the deep persistent problem. The majority of results were loose dry avalanches, which entrained the faceted snowpack and ran far down the paths. The largest avalanche was a size 3 on Mount Field.
Snowpack Summary
Recent strong winds and new snow have formed wind slabs on lee slopes in the alpine and at treeline . At treeline, the mid-pack consists of weak facets, over the breaking down October crust and depth hoar at the bottom. An average of 60-100cm of snow can be found at treeline elevations.
Weather Summary
An Arctic air mass has moved into the forecast region, bringing cold temperatures, clear skies, and light to moderate North winds. Temperatures are expected to drop as low as -25°C over the weekend.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
Avalanche Problems
Wind Slabs
Strong to extreme winds with light flurries on Thursday created wind slabs 10-30 cm thick in alpine and treeline lees. During the wind event, a field team observed active natural avalanche activity on this problem, though it has since subsided.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Deep Persistent Slabs
Weak facets exist at the base of the snowpack. Although we haven't seen much avalanche activity on this layer in a while, the snowpack structure is weak and large open slopes at treeline and in the alpine remain suspect.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 1.5 - 3