The recent storm snow sits on a weak layer and touchy conditions may persist for a few days. The deep mid-Dec layer remains a concern and isolated avalanches continue to step down to this layer.
Summary
Confidence
Fair
Weather Forecast
A ridge of high pressure should keep the region dry and mostly sunny for Tuesday-Thursday. On Tuesday and Wednesday, freezing levels should reach around 1000m during the day and fall to valley bottom overnight. On Thursday, an inversion is forecast and above-freezing air in the alpine is possible. Alpine winds are expected to remain light for Tuesday and Wednesday but are forecast to increase to moderate on Thursday.
Avalanche Summary
On Sunday, a skier remotely triggered a size 2 avalanche on the mid-Dec weak layer down around 50cm on an east aspect at treeline. A ski cut produce a size 1 avalanche on the mid-Jan weak layer down around 25cm. Explosives triggered several storm slabs up to size 2 on all aspects. On Saturday, a skier remotely triggered a size 1 avalanche on the mid-Dec layer down around 40cm. Natural avalanche activity is generally not expected on Tuesday but remains possible in isolated areas. Human-triggering is likely in wind loaded areas and steep terrain features, especially where surface hoar underlies the recent storm snow.
Snowpack Summary
30-40cm of recent storm snow sits on the mid-Jan surface hoar layer. In many places the surface hoar sits above a thin crust that can be found up to about 1900m on north aspects and all the way to ridgeline on south aspects. A deeper crust/surface hoar combo buried in mid-December continues to be a concern. This layer can typically be found down 70-100cm. The reactivity of this persistent weak layer appears to have become isolated but still has the potential for large, destructive avalanches in some areas. The layer appears has been the most reactive at and just below treeline.
rbuhler,
Avalanche Canada
