Avalanche Forecast

Issued: Dec 2nd, 2020 4:00PM

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

Avalanche Canada swerner, Avalanche Canada

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The snowpack doesn't like rapid change. The avalanche danger remains elevated due to sustained warm temperatures. Watch for signs of instability and be very conservative with your terrain selection. 

Summary

Confidence

Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.

Weather Forecast

Summer in December?

Thursday: Mainly cloudy. Treeline temperatures near +5 and ridgetop wind 20-30 km/hr from the South. Freezing levels 2900 m. 

Friday: A mix of sun and cloud. Treeline temperatures near +7 and ridgetop wind light from the southeast. Freezing levels 2900 m.

Saturday: Cloudy with sunny periods and light rain. Treeline temperatures near +9 and ridgetop wind moderate to strong from the southeast. Freezing levels 3200 m. 

Avalanche Summary

No new avalanche observations were reported but I suspect some natural avalanche activity occurred on Wednesday.

On Thursday I suspect loose wet avalanches to continue with sustained warming. They can gain mass and push you into ugly terrain like gully features which can be hard to escape. Once temperatures start to drop the snowpack will likely strengthen.

Have you been out and about in the mountains? If so please submit to the Mountain Information Network (MIN). It doesn't have to be technical it can be as simple as a photo. Photos are especially helpful! Sending out a big thank you to the already submitted MIN's this season. Thanks everyone!

Snowpack Summary

Recent sun and very warm alpine temperatures have had the greatest impact on the snowpack. This rapid warming likely increased slab development above 1300 m. Deep pockets of wind slab may linger on leeward slopes at upper elevations. 

Below 1200 m a soggy snowpack may exist. Cooler temperatures overnight may form a crust on all aspects and elevations but I suspect with the continued warming that crust will disappear quickly.

Snowpack depth rapidly changes with elevation and the snow line currently sits at around 900 m. Its near 100 cm around 1000 m between 150 to 200 cm near the mountain tops.

Terrain and Travel

  • Be careful as you transition into wind affected terrain.
  • Avoid steep slopes when air temperatures are warm, or solar radiation is strong.
  • Loose avalanches may start small but they can grow and push you into dangerous terrain.

Problems

Wind Slabs

An icon showing Wind Slabs

Northerly aspects in the alpine may see deeper pockets of wind slab where the old storm snow was redistributed. A sharp rise in temperature coupled with solar radiation will promote rapid settlement and accelerated slab development on all aspects at treeline and above. Be especially wary of steep south aspects at upper elevations, where recent snow sitting on a crust.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

A rapidly warming snow surface may release loose wet avalanches. Pinwheeling is a good indicator of this type of instability.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Dec 3rd, 2020 4:00PM