Avalanche Danger
Alpine: Moderate through Friday
Treeline: Moderate through Friday
Below Treeline: Moderate through Friday
The avalanche danger may increase on some slopes exposed to the effects of the sun.
Travel Advisory: Our primary concern continues to be possibility of large destructive avalanches being triggered at weak spots, or by large sudden loads such as cornice fall. The December weakness that has been dormant for several weeks is beginning to come to life again in some areas with shallow snow cover with the addition of a new load. Below treeline, large surface hoar has now been buried by Sunday night's snow. This layer could also become very active as we continue to receive more snowfall and the load increases. Caution is advised on any slopes exposed to the effects of the sun.
Avalanche Activity: Sunday night's new snow formed a slab that initially did not bond well to the variety of old surfaces. Explosive testing and ski cutting produced numerous results to size 2 that for the most part involved the storm snow only, propagating easily and over a wide distance. We did see one deeper result on a NW facing roll at 1,850 metres elevation. The failure initiated in the storm snow, stepping down to a layer of buried facets. Although the shears at the recent storm snow interface appear to be gaining strength, the soft slab may remain reactive to ski testing on some wind-loaded slopes.
Snowpack: The crust/facet combination that formed with prolonged cold temperatures in early December is now buried up to 200 cm below a stiff more coastal snowpack. During this period areas of depth hoar also formed in shallow rocky terrain. Recent stability tests within the basal weakness continue to be variable and inconsistent. The mid-pack has been gaining strength while some surface weaknesses have begun to form. Sunday night's snowfall was accompanied by moderate to strong SE winds and rising temperatures. The resulting slab did not bond well initially, but with the warming temperatures it should settle in, given some time. The aforementioned slab that failed on the facets above the December crust is likely only a hint of what is yet to come, so be very cautious when travelling through terrain where the snowpack is shallow. The buried surface hoar layer at treeline and below is also a concern, but has yet to receive a critical load.
Weather: We should see mainly sunny skies today and tomorrow with above freezing temperatures in the alpine with an inversion. A series of weak systems arriving Thursday night will bring light snowfall through the weekend.
Conditions may vary and can change rapidly. Check for the most current conditions before heading out into the backcountry. Daily updates for the areas adjacent to Whistler Blackcomb are available at 604-938-7676, or surf to www.whistler-blackcomb.com/weather where there is also a link to the CAA public avalanche bulletin, or call 1-800-667-1105.
- Whistler Mtn Snow Safety
