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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Avoid wind loaded features especially in areas where snowpack depths vary and a persistent weak layer is present.

Summary

Confidence

Moderate -

Weather Forecast

Tuesday night: light alpine winds from the west with some light flurries. Low of -9 at 1600m.

Wednesday: Trace amounts of new snow with moderate Southwest winds. High of -7 at 1600m.

Thursday: Up to 5cm of new snow with a high of -7 at 1600m. Winds becoming strong from the Northwest.

Friday: no new snow expected. Moderate winds from the Northwest shifting to the Southwest. High of -11 at 1600m.

Avalanche Summary

Several skier triggered and natural wind slabs up to size 2 were observed in the region on Monday. These avalanches were in the upper treeline and alpine elevation and on North and East aspects.

Snowpack Summary

Up too 20cm of recent new snow has formed wind slab in isolated features in exposed treeline and alpine terrain. 

The defining feature of the snowpack is a prominent and widespread crust that reaches as high as 2400 m in the alpine and now sits 40-80 cm below the surface. In many places, overlying snow is well-bonded to the crust but in others weak faceted grains have been observed growing above it.

Average snowpack depth at treeline is 200cm.

Terrain and Travel

  • Be careful 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

Isolated wind slab can still be found in exposed treeline and alpine features.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

40-70 cm of snow sits over a weak layer on a thick crust. While only a handful of avalanches have been reported to have run on this layer, they have been large. Avalanches on this layer may be triggered by humans or vehicles from thin spots or by large loads like wind slab avalanches.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

2 - 3

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