Finding areas where there is no significant wind effect and/or lingering wind slab will lead you to the safest and most enjoyable travel.
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, Sunshine Village reported numerous small size 1 windslab avalanches with explosive control. Otherwise, no new avalanches were reported.
On Tuesday we investigated the Quartz skier accidental avalanche, where the start zone was 48° and the failure plane was an old layer of weak facets down 50 cm. The avalanche was triggered from a very shallow, faceted location and the crack propagated into the thicker snowpack nearby and released the avalanche.
Last weeks 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
Thursday night: Cloudy with clear periods. Alpine temperature: Low -15 °C. Ridge wind east: 10 km/h. Alpine temperature inversion.
Friday Mainly cloudy. Alpine temperature: High -15 °C. Ridge wind east: 10 km/h.
Saturday Cloudy with sunny periods and isolated flurries. Alpine temperature: Low -17 °C, High -15 °C. Ridge wind west: 10 km/h.
