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.

Avalanche Canada rbuhler, Avalanche Canada

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Wind slabs continue to be the main concern on Wednesday. Due to recently shifting wind directions, slabs should be expected on all aspects in exposed terrain. 

Summary

Confidence

High - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

An Arctic high pressure system remains the dominant feature for the forecast period bringing cold and dry conditions to the region.

Tuesday Overnight: A few clouds, light S winds, treeline temperature around -20 °C.

Wednesday: A mix of sun and cloud, light to moderate variable winds, treeline high around -15 °C. 

Thursday: Mostly sunny, moderate to strong NW winds, treeline high around -16 °C.

Friday: Mostly cloudy with a chance of flurries, light to moderate SW winds, treeline high around -16 °C.

Avalanche Summary

On Monday, the Avalanche Canada field team reported a few size 1 loose dry avalanches on steep alpine slopes. On Sunday, explosives were triggering wind slabs up to size 1.5 in the far south of the region. 

On Wednesday, wind slabs are expected to remain the primary concern in the region. Newer wind slabs which formed on Monday from the NE winds are expected to be most reactive but the older wind slabs from the weekend may still be reactive, especially in steep, unsupported terrain features. 

Snowpack Summary

Over the weekend, the region typically saw 10-20 cm of new snow. This new snow was accompanied by strong SW winds which formed reactive wind slabs in exposed terrain. On Monday, outflow (NE-E) winds are expected to have formed new wind slabs on the opposite aspects compared to the weekend storm and as a result, wind slabs should be expected on all aspects. 

An early season crust and facets can be found near the base of the snowpack. This layer now appears to have gone dormant through most of the region but could still be reactive in some shallow snowpack areas. 

Snowpack depth at treeline typically ranges from 150-200 cm, with higher values in the western part of the region and tapering to the east.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Be alert to conditions that change with elevation and wind exposure.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs are expected to be most reactive on south and west aspects as a result of the strong NE winds on Monday. However, north and east aspects also likely still have some reactive wind slabs from the storm on the weekend. As a result, wind slabs should be expected on all aspects in exposed terrain. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

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

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