Avalanche Forecast

Issued: Dec 4th, 2020 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is below threshold. Known problems include Storm Slabs.

Avalanche Canada kdevine, Avalanche Canada

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Continued stormy weather with new snow and wind will keep hazard elevated. Choose conservative terrain as human triggered avalanches remain likely, especially in wind loaded areas. 

Summary

Confidence

Low - Uncertainty is due to the limited number of field observations. Forecast snowfall amounts are uncertain.

Weather Forecast

FRIDAY NIGHT - Flurries, 5-10 cm / southwest wind, 60-80 km/h / alpine low temperature near -5 

SATURDAY - Snow, 15-20 cm / southeast wind, 15-25 km/h / alpine high temperature near -7 

SUNDAY - Flurries, 5-15 cm / southeast wind, 50-80 km/h / alpine high temperature near -5 

MONDAY - Flurries, 5-10 cm / south wind, 60-80 km/h / alpine high temperature near -5 

Avalanche Summary

A widespread natural avalanche cycle with numerous avalanches up to size 3 was reported to have occurred in the White Pass area, mostly during the height of the storm (Monday-Wednesday) Check out this MIN report detailing these observations.

With more snow and wind on the way, it is expected that avalanches may still be easy for humans to trigger on Saturday, especially in wind loaded areas.

Snowpack Summary

The White Pass area received over 100 cm of new snow earlier in the week with strong southwest winds. Another 20-30 cm is expected between Friday night and Saturday afternoon with strong southwest winds that finally begin to taper off on Saturday. Total snowpack depth is around 175 cm in sheltered areas around White Pass.

In drier areas such as the Wheaton Valley, total snowpack depths are likely in the 50-100 cm range and are probably quite variable due to wind transport. The base of the snowpack in this area may consist of some weak, sugary facets

Both storm slabs and wind slabs are likely widespread in the region and may be easily triggered by humans. Storm slabs may be more prevalent in the White Pass area, while wind slabs may be more prominent in areas like the Wheaton Valley.

Terrain and Travel

  • Watch for fresh storm slabs building throughout the day.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Recent new snow may be hiding windslabs that were easily visible before the snow fell.

Problems

Storm Slabs

An icon showing Storm Slabs

Continued stormy weather means that storm slabs will likely continue to be reactive, especially in wind loaded areas. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 2.5

Valid until: Dec 5th, 2020 4:00PM