Watch for wind loaded pockets below ridge crests and steep roll-overs. Small human-triggered wind slab avalanches have surprised a few skiers recently.
A continuing supply of light snowfall will sustain wind slab development. Recent wind direction has varied from northwest to southwest, creating wind slabs on a variety of aspects in exposed alpine and treeline terrain. Where wind slabs sit over a crust, they may be more sensitive to triggering.
Thursday night: Up to 10 cm new snow. Winds moderate west. Freezing level 1000 m.
Friday: Up to 10 cm new snow. Winds moderate northwest. Freezing level 1200 m.
Saturday: Flurries. Winds moderate west. Freezing level 1000 m.
Sunday: Up to 10 cm new snow. Winds moderate northwest. Freezing level 1200 m.
Explosive work Wednesday produced size 1.5-2 wind slab and cornice avalanches. Several small (size 1) natural and skier-triggered wind slab avalanches have been reported on east/northeast aspects in the alpine over the past few days. At least one of these occurred near treeline and was reported to have slid on a crust buried around 20 cm below the surface.
A bit of new snow and wind will further wind slab development in lee features at alpine and upper treeline elevations. Recent winds have varied in direction so wind slabs can be found on a variety of aspects. A thick rain crust as high as 2000 m sits below 25-45 cm of recent storm snow in the east of the region and 40-100 cm in the west. Recent avalanches slid on the crust or released within the storm snow. However, recent information indicates the bond at the crust is improving.
Weak facet/crust layers near the base of the snowpack have not been an active avalanche problem recently.
