Conditions are variable across the region. The Coquihalla has received the deepest amounts of storm snow and conditions are likely to be touchier there than elsewhere. Danger ratings reflect the Coquihalla area conditions.
Confidence
Fair - Due to variable weather conditions
Weather Forecast
Wednesday: Strong to gale S winds. Alpine temp -10. Moderate snow (~20 cm).Thursday: Moderate S winds. Alpine temp -9. Light snow.Friday: Cloudy and cool. Very light snow possible.
Avalanche Summary
Size 1-2 sluffs were running in steep terrain on Sunday and Monday. On Sunday, skiers were also triggering numerous size 1 soft wind slabs. Near the Coquihalla summit, skiers triggered a slab at treeline which was at least 100 m wide and ran about 150 m downhill before stopping in the trees. One soft slab at treeline in the Duffey Lake area failed on a layer of stellars and surface hoar down 30 cm.
Snowpack Summary
Expect new storm slabs and wind slabs to form on Wednesday. Previous low density storm snow has been shifted by variable winds into soft slabs in the alpine and at treeline. A layer of surface hoar and stellars buried on Dec 10 exists at treeline in the Duffey Lake area and may be more widespread. Recent snowpack tests produced hard to no results on a deeper surface hoar layer from late November, buried down 70-100 cm. A consolidated mid-pack overlies the deeply buried November crust/facet layer, which continues to give occasional sudden planar compression test results. This layer has not been observed in the Coquihalla area.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.