Regions
Banff Yoho Kootenay.
Wind slabs are not widespread, but ice climbers should expect to find them in alpine gullies and steep, unsupported ridge top features. SH
Weather Forecast
Continued valley bottom freezing levels with only trace amounts of new snow for Friday through to the weekend. Gusty moderate Westerly alpine winds Friday will decrease on the weekend.
Snowpack Summary
Snow depths are variable across the terrain, and many areas at treeline and below are still below threshold for avalanches. In the alpine, a basal facet layer or melt/freeze crust from late Oct. can be found. Above, wind slabs 30-60cm thick, varying from soft to hard can are in isolated terrain features such as gullies and immediate lee terrain.
Avalanche Summary
Sunshine Village produced 2 size 1.5 avalanches in the alpine on N aspects with ski cutting. These were 40-60cm deep and ran on the Oct. melt/freeze crust. While small, one of the slides ran for 300m which would be a big concern on an ice climb. Lake Louise ski hill saw similar conditions.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.