Avalanche Forecast

Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

Another powerful storm is expected to move in late Friday afternoon

Thursday night: Clearing overnight, a trace of snow possible, light west winds, low treeline temperatures near -6 C, freezing level dropping to 300 m.

Friday: Increasing cloudiness, light flurries possible in the late afternoon, light winds becoming southwest, high treeline temperatures near -4 C, freezing level around 500 m.

Saturday: Overcast, 50-80 mm of precipitation is expected by the end of the day, strong southwest winds with extreme gusts, treeline temperatures rising to near +1 C, freezing level rising to around 1200 m.

Sunday: Cloudy, 15-25 mm of precipitation, southwest winds decreasing from moderate to light, high treeline temperatures dropping from 0 C to -3 C, freezing level around 700 m.

In the neighbouring Sea-to-Sky region on Wednesday, we received reports of two large (size 2-3) human-triggered avalanches that released on a persistent weak layer between elevations of 1700-1900 m on southerly aspects. Notably, these avalanches were remote-triggered while party members were traveling uphill. Several small sympathetic avalanches also released during these close calls. We have heightened concern that this problem may extend into the south coast region at upper elevations. In specific areas, large avalanches may be possible to human trigger.

On Thursday, sunny skies likely promoted rapid settlement in the recent snow and may have formed a thin crust on steep south-facing slopes. 

The region picked up another 15-25 cm of light snow on Wednesday. Winds have varied in speed and direction with ample snow for transport. This has likely created sensitive wind slabs on a wide range of aspects in wind-exposed areas. 

Below substantial accumulations of snow from the past week (90-140 cm), two crust layers can be found that formed in early December. Small facets (loose, sugary snow) have been reported above and between these crusts that may be transitioning into a persistent slab problem. On Tuesday, observers near Ski Pilot reported whumphing at upper elevations (see this MIN report). It may be possible to human trigger this persistent slab in thinner areas near ridge tops, where the facets are more developed and where the crust layers are more accessible to the weight of a person or machine.

Below these crust layers, the snowpack is generally well-settled. Early season hazards such as rocks, stumps, and open creeks remain at lower elevations. 

• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Recent wind has varied in direction so watch for wind slabs on all aspects.
• Be aware of the potential for large avalanches due to the presence of a persistent slab.
• Remote triggering is a concern, avoid terrain where triggering slopes from below is possible
• Uncertainty is best managed through conservative terrain choices at this time.