Avalanche Forecast

Issued: Nov 20th, 2020 3:00PM

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

Avalanche Canada matt, Avalanche Canada

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Light snow and strong north winds have created pockets of reverse loaded windslabs. Recognizing the variable depth snowpack is critical right now. Both of our avalanche problems will be worse in thin areas. 

Summary

Confidence

Moderate -

Weather Forecast

A few scattered flurries tonight won't offer much for new snow. A bit of morning cloud will break up by 11am and hopefully offer some blue skies. Temperatures will be consistent at about -7. Alpine winds will be around 40-50km/hr from the west.

Avalanche Summary

One size 2 on an east facing, high alpine slope near Mt Lawson. It was about a meter deep and ran a couple hundred meters. 

Snowpack Summary

We continue to get small, but continuous new snow fall. At the moment there is about 10cm of new snow from the last few days. The north winds today have redistributed it into a more variable pattern. We are seeing anywhere from 20-50cm on top of the crust. With that, snow depth also varies dramatically. Rolls in the terrain are very thin, while concave areas are 90cm deep. The crust is very apparent, down 50 in today's profile. In some areas there is a slippery facet layer above it and in others it is well bonded with surface layers. Ground cover seems to be the link here. Rocky/gravel areas have a more pronounced facet layer. And it wouldn't be a snow pack structure summary without the mention of our ever-present wind slabs. These are concerning near ridges and immediate lee areas.

Terrain and Travel

  • Avoid areas with a thin or variable snowpack.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Problems

Wind Slabs

An icon showing Wind Slabs

Watch for windslabs in alpine areas in the upper snowpack. Gullies and ridgelines are common areas to find these issues. 

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

This is becoming an issue in variable depth areas, especially in the rocky alpine areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Nov 21st, 2020 3:00PM

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