Avalanche Forecast

Issued: Feb 5th, 2022 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is below threshold. Known problems include Wind Slabs and Loose Wet.

Avalanche Canada astclair, Avalanche Canada

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Strong winds and rising freezing levels are keeping the danger elevated. Start simple and avoid wind-drifted areas. Continually monitor the effect of warming on the recent snow. 

Summary

Confidence

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

Weather Forecast

Saturday night: Cloudy, 5-10 cm of snow, strong south wind with extreme gusts in the alpine, alpine temperatures near -4 C, freezing level rising to 200 m.

Sunday: Cloudy, 5-15 cm of snow, strong south wind with extreme gusts in the alpine, alpine high temperature near -3 C, freezing levels vary through region from 500-1000 m. 

Monday: Cloudy with sunny breaks, 5-15 cm of snow, strong southwest winds, alpine temperatures dropping from -5 C to -8 C, freezing level dropping to valley bottom m.

Tuesday: Cloudy with sunny breaks, 10-20 cm of snow, strong southwest winds, alpine high temperatures near -4 C, freezing level rising to 1000 m. 

Avalanche Summary

Recent reports have been limited. Earlier in the week, there were reports of numerous small (size 1) dry loose and soft slab avalanches. These ran naturally and we easy to trigger with ski cuts. On the Alaska side, strong outflow winds made for touchy avalanche conditions, with large natural releases running to the road. We expect that similar conditions exist on White Pass as the wind has picked up.

Snowpack Summary

Strong south winds picked up on Saturday, re-distributing 50 cm of low-density snow into reactive wind slabs on lee terrain features. These wind slabs will remain likely to trigger on Sunday. These slabs formed above surface hoar on sheltered northerly aspects and hard slab in wind-affected areas. Investigate these underlying surfaces for a poor bond. 

Treeline temperatures have warmed rapidly over the past 48 hours, which is likely to destabilize the new snow. Freezing levels are forecast to vary but may reach 1000 m in the eastern half of the region. Use extra caution in areas experiencing above freezing temperatures for the first time. 

In shallow snowpack areas, a layer of loose facets can be found at the bottom of the snowpack.

Terrain and Travel

  • Avoid freshly wind loaded terrain features.
  • Expect slab conditions to change drastically as you move into wind exposed terrain.
  • Avoid exposure to overhead avalanche terrain, avalanches may run surprisingly far.
  • Extra caution for areas experiencing rapidly warming temperatures for the first time.
  • As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.

Problems

Wind Slabs

An icon showing Wind Slabs

Strong winds are transporting upwards of 45 cm of recent low density snow into wind slabs in leeward terrain features. These slabs are expected to be highly reactive due to a poor bond to underlying surfaces.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Loose Wet

An icon showing Loose Wet

A substantial and rapid rise in temperature is expected to destabilize the recent snow on steep slopes. Back off terrain as the surface snow loses cohesion due to warming. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Feb 6th, 2022 4:00PM

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