Regions
Banff Yoho Kootenay.
Conditions are generally good. In bigger alpine terrain, watch out for thin wind slabs that can be triggered in steep terrain. If the sun pokes out Saturday, watch for increasing hazard on solar slopes. SH
Weather Forecast
Moderate W-NW winds Saturday with cooling temperatures and freezing levels staying near valley bottom. Light snow Friday night into Saturday. Sunday through Monday expect cooling temperatures and light N winds.
Snowpack Summary
A weak freeze this morning with freezing levels up to 2000m. There are areas of wind effect in the alpine and isolated wind slabs can be expected in lee areas above 2400 m which can be triggered in steep terrain.
Avalanche Summary
A field team on the South side of Mt. Patterson ski cut a size 1 thin avalanche out of 45 degree terrain at 3100m today. A size 2 avalanche was also triggered yesterday which was 50cm thick and 80cm wide, which apparently slid on a crust on a SE aspect. This was on Mt. Unity in the Lake Louise backcountry at 2500m.
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.