Watch for wind slabs in lee features like ridge crests and steep roll-overs at alpine and treeline elevations.
A bit of new snow and wind will further wind slab development in lee features at alpine and treeline elevations. Recent winds have varied in direction so wind slabs can be found on a variety of aspects. Where wind slabs sit over a crust, they may be more sensitive to triggering.
Wednesday night: Increasing cloud cover. Winds building to strong southwest. Freezing level 500 m.
Thursday: Up to 10 cm new snow. Winds strong southwest. Freezing level 1000 m.
Friday: Up to 10 cm new snow. Winds moderate southwest. Freezing level 1000 m.
Saturday: Flurries. Winds moderate southwest. Freezing level 1200 m.
Natural wind slab avalanches up to size 2 were observed on steep, north to east facing alpine terrain on Tuesday.
In the neighbouring Sea to Sky region, a very large (size 3.5) avalanche occurred on Saturday near Whistler on a steep north face at 2400 m. It is suspected to have failed on a layer of facets on a crust from late November. This very large event demonstrates the ongoing need for caution in aggressive alpine terrain, particularly in areas where deep instabilities remain.
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 rain crust sits below recent storm snow below 1900 m.
In the north part of the region (ie. Goldbridge/Duffey/Hurley), a few deep instabilities exist in the snowpack, including a weak basal facet crust complex. There has not been recent avalanche activity on these layers but they remain a concern and are on our radar.
The south of the region, including the Coquihalla and Manning areas, we currently have no concerns about deeply buried weak layers.
