Avalanche Forecast
Regions: Banff Yoho Kootenay.
Another bitterly cold, clear, calm day on Friday before winds pick up for the weekend. The moderate rating at treeline and below is due steep, unsupported terrain where the Dec. 2 crust and facets may be triggered.
Weather Forecast
Expect temperatures Friday AM to be around -30C with clear skies and light winds. On Saturday winds will really pick up midday and last for the weekend with some warming temperatures. Temperatures and winds drop again for next week.
Snowpack Summary
10-40 cm of snow last week and recent wind from various directions has developed wind slabs in the alpine. There is 50-70 cm over the Dec. 2 crust/facet combo which exists below 2200m, which we are monitoring closely. Shallow areas (<100 cm) have weaker basal facets.
Avalanche Summary
There was a skier triggered size 2 avalanche below treeline in Kootenay today. This may have been on the Dec. 2nd crust/facets. Sunshine ski hill saw a natural wind slab avalanche (size 2) possibly triggered by a cornice. Lake Louise triggered a few size 1.5 and a 2 with explosives that were new wind slabs from winds Wednesday night.
Confidence
Due to the number and quality of field observations on Thursday
Avalanche Problems
Wind Slabs
Last weeks snow and winds from a variety of directions have created wind slabs in the alpine. Predominantly these are located in the alpine.
- Watch for surface cracking and stiffer surface layers of snow. Avoid wind loaded terrain.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 2
Persistent Slabs
The Dec. 2 crust/facet layer down 50-70cm is not yet a widespread problem, but a skier triggered avalanche in Kootenay Thursday shows it has started to wake up in some steep, unsupported locations (see avalanche activity).
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood: Possible
Expected Size: 1 - 2