The unusually low early season snowfall has created conditions that many coastal skiers will not be familiar with and the snowpack structure is a loaded gun waiting for the next storms.
A crust matrix formed in mid-November that is covered with a layer of faceted snow is widespread at treeline and above. This layer has been the failure layer for several persistent slab avalanches that have been both skier triggered or sympathetically released nearby slopes over the last few days in the Whistler uncontrolled terrain.These avalanches have been up to size 2.5 and are failing 40-80cm down on this November 23 facet/crust layer.
Snowpack tests on the November 23 layer have been showing good potential for avalanche propagation. (ECTP, PST 30/100 end ). Also large whoomps have been observed in many locations.
The recent storm was just enough incremental load to create dangerous conditions on only a few wind-loaded slopes. With more snow in the forecast, it is certain that this layer will become more likely to trigger and create widespread avalanche danger.
The supportive crust at the base of the shallow snowpack has created good travel conditions that have given many recreational users the confidence to ride on just about any feature that has snow over the last few days.
The sleeping avalanche dragon is about to wake up! With Christmas coming, combined with the pent up desire for backcountry travel due to the late arrival of winter this year, the recipe could not be worse for human triggering.
The upcoming period is a time to stick to conservative, low-angle terrain and be aware of the potential for overhead slopes or nearby steep slopes that may effect you. This condition will likely persist longer than normal Coastal instabilities.