Finding areas where there is no significant wind effect and/or lingering wind slab will lead you to the safest and most enjoyable travel. As the cold continues to weaken the snowpack, skiers/riders in steeper terrain features report triggering sizable loose dry avalanches.
Lingering hard wind slabs exist on alpine lee features. Potential failure planes are old weak facet layers or the Jan 30 layer of facets, sun crusts, and isolated surface hoar beneath the recent snow.
On Thursday & Friday, Sunshine Village reported up to size 1.5 windslab avalanches with explosives and ski cuts. They were 30-50 cm deep hard slabs failing on a weak facet layer with propagations up to 25 m.
Also on Friday, sizable loose dry avalanches were skier triggered in steep terrain near Lake Louise.
On Tuesday we investigated the Quartz skier accidental wind slab avalanche, triggered from a shallow spot in 48° terrain.
Last week's storm snow has been redistributed into now aging wind slabs, which sit on top of the Jan 30 interface. Specific areas exposed to the wind may also have strastrugi. The mid-pack is generally weak with facets, while depth hoar over a crust forms on an even weaker base. The snowpack is the weakest in eastern areas where snow depths are low. In these areas, the basal weaknesses should be carefully considered. Here is a representative snow profile taken on Wednesday
Friday night: Cloudy periods with scattered flurries without much accumulation. Alpine temperature: Low -17 °C with Light westerly ridge wind.
Saturday: Mix of sun and cloud, scattered flurries without much accumulation. Alpine temperature: High -14 °C. Light ridge NW wind becoming SW.
Sunday: Cloudy with scattered flurries. Alpine temperature: Low -17°C, High -13 °C. Ridge wind light South.
