Avalanche Forecast

Issued: Feb 2nd, 2021 4:00PM

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

Avalanche Canada kdevine, Avalanche Canada

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Although the storm has subsided, human triggered avalanches remain likely, especially in wind loaded areas. 

Keep in mind that a persistent weak layer is now buried up to 60 cm. Avalanches on this layer will become harder to predict, so a conservative approach is important.

Summary

Confidence

Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength. Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

Weather Forecast

TUESDAY NIGHT - Mainly cloudy with a few flurries / moderate southwest wind, switching to light northwest wind overnight / alpine low temperature near -11 

WEDNESDAY - Sunny with cloudy periods / light north wind / alpine high temperature near -10

THURSDAY - Mainly cloudy with a few flurries, 5-10 cm / strong west wind / alpine high temperature near -7 

FRIDAY - A mix of sun and cloud / moderate northwest wind / alpine high temperature near -6

Avalanche Summary

Human triggered avalanches will remain likely on Wednesday, especially in wind loaded areas at higher elevations. 

There were several reports of size 1-2.5 natural, human and explosives triggered avalanches in the region on Monday. It is suspected that some of these failed on the recently buried persistent weak layer.

There were several reports of size 1-1.5 natural and human triggered avalanches in the region on Sunday.

Snowpack Summary

30-60 cm of recent fresh snow sits on a persistent weak layer that consists of facets at upper elevations, surface hoar in sheltered areas, a melt-freeze crust below 1600 m, and a sun crust on south-facing slopes. 

In the south, the underlying snowpack is well consolidated. In the north, a melt-freeze crust from early December may be found 100 to 200 cm deep. Recent reports suggest that this layer is gaining strength and it has been unreactive in recent weeks.

Terrain and Travel

  • Keep in mind that human triggering potential persists as natural avalanching tapers off.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Avoid freshly wind loaded terrain features.
  • Be aware of the potential for large avalanches due to the presence of a persistent slab.

Problems

Storm Slabs

An icon showing Storm Slabs

Storm slabs will likely continue to be reactive, especially in wind loaded areas. 

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

30-60 cm sits on a buried weak layer that consists of facets, surface hoar, or a crust, depending on location. Avalanches on this layer may propagate widely.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Feb 3rd, 2021 4:00PM