Avalanche Forecast

Low - Uncertainty is due to the limited number of field observations.

  

FRIDAY NIGHT: Clear / Light, northwest ridgetop wind / alpine low temperature -12 / Freezing level valley bottom.

SATURDAY: Sunny / Light, southwest ridgetop wind / alpine high temperature -8 / Freezing level valley bottom.

SUNDAY: Cloudy with isolated flurries; 0-3 cm. / Strong, south ridgetop wind / alpine high temperature -10 / Freezing level valley bottom.

MONDAY: Cloudy with flurries; 3-5 cm. / Moderate, southwest ridgetop wind / alpine high temperature -8 / Freezing level valley bottom.

  

Large avalanches earlier this week provided evidence that a buried crust formed in early December and November combined with weak, sugary snow at the ground are reactive to large loads and stress to the snowpack. This problematic snowpack structure may be more prevalent in colder, shallower areas in the north and east of the region.

Cornice falls or smaller avalanches in motion may have the potential to step-down to these deeper layers, producing very large and destructive avalanches.

Have you been out riding in the mountains? We would love to hear about it and it doesn't need to be technical. Photos can be extremely helpful; please share your observations on the Mountain Information Network (MIN). Thanks!

  

Recent winds from a variety of directions have reverse loaded some slopes, creating wind slabs on typically windward features at treeline and above. 

The storm earlier in the week brought over a metre of snow accompanied by strong southwest winds to alpine elevations. Treeline elevations saw quite the mix of snow and rain depending on where the freezing level sat (mostly around 1200 m. during the storm). Below treeline the snowpack has likely refrozen into a firm crust. Cornices have likely grown large along ridgelines. 

The early December crust is now down 100 cm plus in the alpine and just below the surface at treeline. The early November crust is even deeper in the alpine and down 70-120 cm at treeline. Sugary facets near the bottom of the snowpack have produced large full depth avalanches pre-storm and during the storm. The extent of this problematic snowpack structure in the region is not well-known, but it likely exists in colder, shallower snowpack areas.

Snowpack depths are highly variable across aspects and elevations as a product of wind scouring, above-freezing temperatures, and rain. Snow has melted fast at lower elevations, and snowpack depths have seen rapid settlement.

• 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.
• If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
• Avoid lee and cross-loaded terrain.