Regions
Banff Yoho Kootenay.
It is still wintery in the high alpine. Isolated wind slabs can be expected, and may be hidden by the new, light dusting we are currently receiving.
Weather Forecast
An upslope flow will bring cloudy conditions and light snow to the region tomorrow. Ridge-top winds will be light/moderate from the N/NE and freezing levels will remain in the valley bottom.
Snowpack Summary
Cooler conditions for the next few days should create a solid, supportive crust in the morning, softening with day-time warming. There are areas of wind effect in the alpine and isolated wind slabs can be expected in lee areas above 2400 m. These slabs can be triggered on steep, unsupported slopes.
Avalanche Summary
Yesterday, 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. On Thursday near Unity Peak in the Lake Louise backcountry, a size 1.5-2 skier-triggered avalanche near 2500m was reported. The slide was 50cm thick and 80m wide, which apparently slid on a crust on a SE aspect.
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.