Avalanche Forecast
Issued: Dec 20th, 2012 9:55AM
The alpine rating is Wind Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Due to limited field observations
Weather Forecast
Overnight Thursday and Friday: Very light snowfall / Light to moderate southeast winds / Temperature inversion with ridgetop temperatures of -18.0Saturday: Mostly clear with trace amounts of new snow / Light southeast winds / Temperature inversion with ridgetop temperatures of -12.0Sunday: Trace amounts of snowfall / Light east winds / Ridgetop temperatures of -17.0
Avalanche Summary
No recent avalanches have been reported. On Wednesday last week, a snowmobiler triggered a hard wind slab at the Sinclair riding area. It failed on the November crust/facet layer 30 cm above the ground while side-hilling. Check out this incident report for more details. This deep crust/facet layer has been the failure plane for a number of large avalanches further to the west and was suspected to have failed at the Hankin-Evelyn area.
Snowpack Summary
Light amounts of new snow overlie older storm and windslab instabilities which are likely settling and gaining strength. Spotty surface hoar was buried in the upper snowpack, particularly in sheltered treeline areas. Of key concern is a November facet/crust layer which can be found near the base of the snowpack. This layer, which is widespread, can be triggered from thin-spot trigger points, or with a heavy load, such as storm slabs stepping down, a cornice fall or a snowmobile track digging a trench. It has the potential for large, destructive avalanches. In general the snowpack depths, and therefore strength is highly variable due to windy conditions this season.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 21st, 2012 2:00PM