For the areas adjacent to the Whistler Blackcomb ski areas
The avalanche danger rating on Dec. 8 is CONSIDERABLE. The hazard will likely increase with the warm precipitation event that is forecast for Friday.
Avalanche start zones at treeline and below treeline elevations have filled in significantly during the past week. In the alpine terrain rocky areas still retain many exposed anchors, and the glaciers are full of open crevasses and bergschrunds.
The snowpack is gradually increasing, measuring up to 200 cm in the alpine and 130 cm at 1,650 metres. The critical layers of concern remain the Nov. 26 raincrust (below 2,100 metres) and the Dec. 3 surface hoar layer that can be found in sheltered areas. The crust is now sitting about 60 cm below the surface and is surrounded and sometimes laminated by small facetted crystals. The surface hoar is not too far above the crust. As can be expected, any shallow snowpack areas have been totally weakened this becomes very evident if your line of travel involves any traversing through the rocks.
Throughout the week we have been seeing the usual storm snow avalanches in the alpine start zones. More importantly though is the action that is occurring at the treeline and below treeline elevations. Soft slabs are failing easily on both the surface hoar and the crust layers. You can expect to see continuing activity on these layers as the overlying slab increases in depth and density.
The forecast weather system on Friday is predicted to bring heavy amounts of precipitation and a sharp spike in the freezing level. Behind it a ridge of high pressure will usher in cooler and dryer air. Depending on where the snow level sits during Fridays storm, the lower elevation snowpack weaknesses could be wiped out when the temperatures drop during the weekend. Call 604-938-7676 for the daily avalanche hazard ratings.
A note for folks accessing the backcountry from Whistler Mountain: avalanche control will be commencing shortly in the Flute area. During times of a building high avalanche hazard, access to the park may be limited to the lower route via the Burntstew runout. If you are planning a multi-day trip and intend to take the high route home through Flute Basin, be aware that explosive testing could be in progress.