Avalanche Forecast
Issued: Dec 29th, 2011 10:10AM
The alpine rating is Wind Slabs and Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Intensity of incoming weather is uncertain on Friday
Weather Forecast
Thursday night: 10-15cm snow. Freezing level 900m.Friday: 5-10cm snow. Freezing level rising briefly to around 1300m near the coast, then falling back to 900m. Strong westerly winds.Saturday: A cool sunny day. Sunday: Dry but mild, with cloudy periods possible.
Avalanche Summary
Highways avalanche control triggered size 3 slabs up to 1m deep. A skier was carried some distance by an avalanche in the Duffey Lake area on Thursday afternoon. I expect avalanche activity to continue, with less naturally-triggered and more human-triggered events occurring over the next couple of days.
Snowpack Summary
Up to 50cm of recent snow has been shifted by southerly winds into wind slabs on lee slopes in the alpine and at treeline.Below the recent storm snow, three weaknesses exist in the upper snowpack. A surface hoar layer formed in early December overlies facets and is down about 60cm. It is giving easy-very easy, sudden collapse results in snowpack tests.A second surface hoar layer buried around Christmas is also giving easy, sudden planar results.A crust which exists to around treeline, buried on December 17th, adds to the complexity of the snowpack.Persistent weaknesses seem to be more of a concern around the Duffey Lake area than in the Cascades (Coquihalla and Allison Pass).The mid and lower snowpack are generally well-settled and strong.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 30th, 2011 8:00AM