Avalanche Forecast

Issued: Nov 27th, 2020 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Deep Persistent Slabs.

Avalanche Canada JSmith, Avalanche Canada

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Recent strong southwest winds have created fresh wind slabs on lee features at treeline and above. Use caution when transitioning into wind affected terrain.

Summary

Confidence

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

Weather Forecast

  

FRIDAY NIGHT: Cloudy w/ flurries; 3-5 cm. / Moderate to strong, southwest wind / alpine low temperature -7 / Freezing level 800 m.

 SATURDAY: Mix of sun and cloud / Light, south wind / alpine high temperature -6 / Freezing level 1000 m.

 SUNDAY: Mix of sun and cloud / Light, south wind / alpine high temperature -6 / Freezing level 800 m.

 MONDAY: Snow, 5-10 cm / Moderate, south wind / alpine high temperature -3 / Freezing level 1200 m.

Avalanche Summary

  

Recent strong southwest winds have created fresh wind slabs on lee features at treeline and above.  

There have been very few reports of avalanches in the region, however observations are limited at this time. 

In the past week there have been a few size 2-3 avalanches reported on the early November crust in both the South Columbia and neighbouring Glacier National Park region.  

If you get out into the mountains, please consider sharing your observations on the Mountain Information Network!

Snowpack Summary

  

Recent strong southwest winds have created fresh wind slabs on lee features at treeline and above. There are a couple of crusts in the mid snowpack, from mid and early November. The most prominent of these is from early November, and it has been reported that there are weak, sugary facets above and below this crust. It is down approximately 70-100 cm, and recent observations indicate that this layer has the potential to be triggered by humans. Several reports indicate that it is likely the most reactive on south facing slopes.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

  

Recent strong southwest winds have created fresh wind slabs on lee features at treeline and above.  

Aspects: North, North East, East, South East, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

A crust from early November exists down about 70-100 cm. This layer has weak, sugary facets above and below it. There are limited observations on this layer right now, however some recent test results suggest that it has the potential to be human triggered. Recent observations have also indicated that this layer may be the most reactive on south facing slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

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