Avalanche Forecast

Issued: Jan 31st, 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 astclair, Avalanche Canada

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Carefully assess wind-affected terrain before committing to a feature. It may be possible to trigger wind slabs near ridge-crests and steep roll-overs. 

Summary

Confidence

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

Weather Forecast

Monday night: Mostly clear, moderate northwest winds, treeline low temperatures near -6 C, freezing level dropping to 400 m. 

Tuesday: Mostly clear, light northwest winds, treeline high temperatures near -4 C, freezing level rising to 500 m.

Wednesday: Cloudy, scattered flurries in the afternoon with up to 5 cm of snow, light west winds, treeline high temperatures near -5 C, freezing level around 200 m.

Thursday: Cloudy, scattered flurries with up to 5 cm of snow, moderate west winds, treeline high temperatures rising to -1 C in the afternoon, freezing level rising to 1000 m. 

Avalanche Summary

It may be possible to trigger avalanches in wind-drifted terrain at upper elevations on Tuesday.

On Sunday, operators on the North Shore reported numerous small (size 1) wet loose avalanches. In the backcountry, observers reported small (up to size 1.5) slab avalanches releasing in the storm snow near Tim Jones Peak, Pump Peak, and Mt Strachan

Snowpack Summary

25-50 cm of fresh snow has returned to the mountains above 1100-1300 m. Below these elevations, the recent snow has cycled through a melt-freeze cycle (see this MIN report from Hollyburn). 

Strong southwest winds during Sunday's storm have since become moderate from the northwest and have redistributed the recent snow into wind slabs across a range of aspects at upper elevations. Monitor for changing slab conditions as you move into wind-exposed terrain.

Where fresh snow remains, it is settling and stabilizing. However, there is lingering uncertainty as to whether a layer of surface hoar may be preserved above a crust in areas further north and east in the region at upper elevations. If you are increasing your exposure to avalanche terrain, carefully evaluate the bond of the new snow to the crust.

Below the recent snow, a thick and supportive crust extends to mountain top. The middle and base of the snowpack are well settled and strong. In isolated areas north in the region, a layer of faceted grains on a crust may be found 150-200 cm deep; however, observations suggest that this layer has become unreactive. 

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.
  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.

Problems

Wind Slabs

An icon showing Wind Slabs

25-50 cm of recent snow has been redistributed into wind slabs at upper elevations. Strong to moderate winds have shifted from the southwest to the northwest making it possible to trigger these wind slabs on a range of aspects. 

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 1st, 2022 4:00PM