Avalanche Forecast

Issued: Dec 14th, 2021 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 Persistent Slabs.

Avalanche Canada TRettie, Avalanche Canada

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Continually assess the wind effect as you move through terrain. Avoid slopes where slab properties exist above a persistent weak layer.

Summary

Confidence

Moderate -

Weather Forecast

Tuesday night: some light flurries bringing up to 5cm with light West winds. A low of -10 is expected for 1700m.

Wednesday: trace amounts of snow with light Southwest winds.High temperature at 1700m -6.

Thursday: Trace amounts of new snow with a high of -7 at 1700m. Winds becoming moderate from the Northwest. 

Friday: 5cm of new snow with moderate west winds and a high of -6 at 1700m.

Avalanche Summary

On Monday two natural wind slab avalanches up to size two were observed on a Northeast aspect at 2300m in the North part of the forecast region.

Snowpack Summary

Recent storm snow has been redistributed by Southeasterly winds, Look for new wind slab on reverse loaded features in upper elevations.

The defining feature of the snowpack is a prominent and widespread crust that now sits 30-70 cm below the surface. In many places, overlying snow is well-bonded to the crust but in others, including Kootenay Pass, weak faceted grains have been observed growing above it around treeline.  

Snow depths are roughly 140-180 cm at treeline throughout the region.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slab has been observed on North and east aspects on Monday. We suspect wind slab can also be found on Westerly aspects after recent Southeast winds.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

40-60 cm of snow sits over a weak layer on a thick crust. Over the weekend, avalanches were reported to have run on this layer.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1.5 - 2.5

Valid until: Dec 15th, 2021 4:00PM