Avalanche Forecast

Tuesday night: Cloudy with isolated flurries bringing a trace to 3 cm of new snow.. Light southwest winds. 

Wednesday: A mix of sun and cloud with cloud decreasing over the day. Calm or light variable winds. Alpine high temperatures around -7.

Thursday: Cloudy with light flurries developing late in the day, bringing a trace to 5 cm and continuing overnight. Light to moderate southwest winds increasing over the day and becoming strong at ridgetop. Alpine high temperatures around -8.

Friday: Cloudy with new snow totals of 10-15 cm. Light to moderate southwest winds. Alpine high temperatures around -7.

Reports from Monday show more observations of the widespread large to very large (size 2-3) natural avalanches that have run recently, along with numerous other explosives-triggered size 2-3 releases, targeted in the Whistler area.

Many more size 2-3 avalanches were triggered by explosives and by skiers on Saturday and Sunday. 

Many of the avalanches mentioned above failed on the mid-November weak layer described in our Snowpack Summary. Many of the larger examples scoured the lower snowpack away to reveal ground. Some of the avalanches were remotely triggered, meaning the weak layer was triggered from one spot and propagated through the snowpack to reach the steeper terrain where the avalanche released. See here for some photos of one of them.

Human-triggering of large avalanches remains likely at higher elevations. Very cautious route-finding and conservative decision making is currently required for safe travel in higher elevation avalanche terrain.

Large new surface hoar is beginning to be reported on the snow surface in sheltered areas. Below the surface, the upper snowpack now consists of around 70 to 120 cm of recent snow. This fell at the end of last week with very strong southwest winds. 

All this snow overlies a weak layer of surface hoar as well as a deeper weak layer of sugary faceted grains and a hard melt-freeze crust buried in mid-November. This unstable structure has been producing large and destructive avalanches, often with light triggers and even remote (from a distance) triggers over the past several days. The above mentioned weak layers may be found anywhere from about 80 to 150 cm deep.

This weak and touchy snowpack is highly atypical for the region and is expected to persist for some time. Conservative terrain choices along with selective avoidance of avalanche terrain will be imperative to manage your risk until the snowpack gains strength.

• Don't let the desire for deep powder pull you into high consequence terrain.
• Persistent slabs have potential to pull back to lower angle terrain.
• Make conservative terrain choices and avoid overhead hazard.