Avalanche Forecast

Issued: Nov 27th, 2020 4:00PM

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

Avalanche Canada JSmith, Avalanche Canada

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 Recent storm totals could exceed 50 cm by Saturday morning. Human triggered avalanches will be very likely and travel in avalanche terrain is not recommended. There may be less new snow and one-step lower hazard in the southern portion of the region.

Summary

Confidence

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

Weather Forecast

  

FRIDAY NIGHT: Snow, 15-25 cm / Strong, southwest wind / alpine low temperature -14 / Freezing level valley bottom.

SATURDAY: Mix of sun and cloud / Light, west wind / alpine high temperature -7 / Freezing level valley bottom SUNDAY: Mix of sun and cloud / Moderate, south wind / alpine high temperature -6 / Freezing level 1200 m.

MONDAY: Snow, 5-10 cm / Moderate, south wind / alpine high temperature -6 / Freezing level 1200 m.

Avalanche Summary

  

Human triggered avalanches will be very likely and travel in avalanche terrain is not recommended on Saturday.

Snowpack Summary

15-30 cm of new snow on Friday morning with another 15-25 cm expected by Saturday morning could bring 48hr storm totals to as much 50+ cm in the northern portion of the region. Human triggered avalanches will be very likely and travel in avalanche terrain is not recommended on Saturday. There is a crust from early November now down approximately 75-125 cm. This crust has been observed with sugary facets above and below it. There are limited observations on this layer, but some test results indicate that it has the potential to be reactive to human triggering. Total snowpack depths are an average of 100-200 cm at upper elevations, tapering quickly at lower elevations. 

Terrain and Travel

  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Avoid exposure to overhead avalanche terrain, avalanches may run surprisingly far.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.

Problems

Storm Slabs

An icon showing Storm Slabs

30-50+ cm of recent storm snow with strong, southwest winds are expected by Saturday morning.  

Human triggered avalanches will be very likely and travel in avalanche terrain is not recommended on Saturday.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1.5 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

A crust from early November exists down about 75-125 cm, and may have weak sugary facets above and below it. Storm slab avalanches may step down and trigger this layer, resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Nov 28th, 2020 4:00PM