Avalanche Forecast

Issued: Dec 5th, 2019 4:00PM

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

Avalanche Canada astclair, Avalanche Canada

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Caution as you transition into wind-exposed terrain. Avalanches are possible where wind slabs have formed in the alpine.

Summary

Confidence

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

Weather Forecast

Thursday night: Cloudy, isolated flurries with a trace of accumulation, moderate southwest winds, alpine temperature -3 C, freezing level around 1000 m.

Friday: Mix of sun and cloud, isolated flurries with a trace of accumulation, moderate southwest winds, alpine high temperature near 0 C, freezing level around 1700 m.

Saturday: Cloudy with periods of sun and snow with 2-5 cm possible, moderate southwest winds, alpine high temperature -2 C, freezing level dropping from around 1500 m

Sunday: Decreasing cloud cover, 5-15 cm of snow, light northerly winds, alpine high temperature -8 C

Avalanche Summary

There have been few recent avalanches reported in the region. A couple of small wind slabs triggered by explosives have been observed. 

Large explosives in early season control work triggered several large avalanches stepping down to deeper weak layers. While human triggering these larger avalanches remains unlikely in the short term, these results are indicative of a persistent weak layer lingering in the snowpack that may become reactive with additional loading. 

Snowpack Summary

Ongoing strong westerly winds have likely been creating wind slabs at upper elevations on lee terrain features. Snowpack depths are highly variable this early in the season with amounts ranging between 50-100 cm at higher elevations, and tapering rapidly below treeline (check out this MIN report from Imperial Ridge). A crust has been reported in the middle of the snowpack.

If you are getting out into the mountains, let us know what you see by posting to the Mountain Information Network!

Problems

Wind Slabs

An icon showing Wind Slabs

Use caution in wind-affected areas. Recent snow and strong westerly winds have formed wind slabs on lee terrain features in the alpine that may be reactive to human triggering.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 6th, 2019 5:00PM

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