Avalanche Forecast

Issued: Feb 21st, 2022 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 jcoulter, Avalanche Canada

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Watch for pockets of wind slab on various aspects in exposed terrain and around ridge lines. Northeast winds may cause reverse loading and build slabs in unexpected features.

Summary

Confidence

Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.

Weather Forecast

MONDAY NIGHT: Clear skies with moderate northeast wind. Lows around -17. 

TUESDAY: Mostly sunny with moderate northeast winds. Alpine high of -13. 

WEDNESDAY: Sunny with increasing cloud late in the day, light to moderate northwest winds. Alpine high of -11. 

THURSDAY: Mix of sun and cloud, light northerly winds and alpine high of -7.

Avalanche Summary

On Sunday there were several small dry loose natural and skier triggered avalanches reported. Explosives control produced results in the 1-1.5 range. This recent MIN from Black Queen/5 Mile area reported seeing no new avalanches.

Snowpack Summary

The most recent 15 cm of storm snow is being redistributed by variable winds. The storm came in with westerly wind, but with the intrusion of arctic air and moderate northeast winds, wind slabs could be forming on usual aspects. There is likely around 25 cm of snow over the old February drought layer interface that consists of melt-freeze crust on solar aspects at all elevations, and firm wind-affected surfaces in exposed terrain.

Two layers of buried surface hoar sit in the upper snowpack, most likely to be found and triggered in sheltered areas at treeline. These are now down around 30-50 cm and 60-80 cm deep. Though improving, these layers remain reactive in some snowpack tests and could be triggered by large loads such as a cornice fall or step down avalanches. 

The lower snowpack is well consolidated, with a crust/facet layer found 100 to 200 cm deep. It is currently considered dormant, but could become active later this season. Check out the forecaster blog for more information. 

Terrain and Travel

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

Problems

Wind Slabs

An icon showing Wind Slabs

Watch for pockets of wind slab on various aspects in exposed terrain and around ridgelines. The storm initially came in with southwest winds, but with the intrusion of arctic air, winds switched to the northeast potentially building slabs in less common locations.

These slabs may have formed on top of old crusts and hard wind-pressed snow and there is uncertainty about how quickly they will bond to old surfaces. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 22nd, 2022 4:00PM