Avalanche Forecast
Issued: Jan 1st, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Persistent Slabs and Loose Dry.
William Lawson,
A combination of strong to extreme winds and new snow will likely increase the sensitivity of wind slabs and initiate loose dry avalanche in steep terrain.
Summary
Weather Forecast
As the BC low moves into Alberta, strong to extreme winds will dominate through the forecast region. By Saturday night we will begin to see snow fall, forecasted accumulation amount very from 10 to 25cm by Monday. Thankfully temperatures will continue to climb through till Monday with valley bottom highs near -10.
Snowpack Summary
Strong winds are transporting faceted surface snow at upper elevations, forming hard slabs on lee slopes. There is 50-70cm over the Dec 2 crust/facet combo which exists below 2200m and appears to be waking up as a persistent weak layer. Shallow areas (<100cm) have weaker basal facets which also present cause for concern as temperatures rise.
Avalanche Summary
There was a skier triggered size 2 avalanche in Kootenay NP Thursday. This appears to have been on the Dec. 2nd crust/facets. A few other avalanche obs in Kootenay appear to have released on the same interface. Strong winds today have likely increase the natural avalanche activity at upper elevations.
Confidence
Problems
Wind Slabs
Last week's snow and winds have created wind slabs in the alpine. As strong to extreme winds and new continue through Sunday, we expect natural activity in the alpine and slab development at treeline.
- Minimize overhead exposure during periods of heavy loading from new snow, wind.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
The Dec. 2 crust/facet layer down 50-70cm has not presented as a widespread problem, but a skier triggered avalanche in Kootenay Thursday shows it has started to wake up. We are concerned with the potential for further slab development this weekend.
- Be very cautious if you notice slab development at treeline and below..
- Be cautious with steep or unsupported slopes.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Loose Dry
A long period of cold has lead to faceting of the upper snowpack. This weak snow will be more sensitive to triggering and will also allow avalanches to run further and faster. We expect the wind to generate a significant amount of loose dry activity.
- Be careful of loose dry sluffing in steep, confined or exposed terrain.
- Loose dry avalanches could easily trigger Wind Slab or Persistent Slab avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 2nd, 2022 4:00PM
