Avalanche Forecast

Issued: Mar 6th, 2022 4:00PM

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

Avalanche Canada ldreier, Avalanche Canada

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Strong wind from the south and west formed wind slabs. The recent snow sits on firm old surfaces and might need more time to stabilize. Assess the snowpack carefully when transitioning into wind affected terrain.

Summary

Confidence

High -

Weather Forecast

Sunday night: Clear, trace of new snow, moderate north wind, alpine low -12 °C, freezing level at valley bottom. 

Monday: Mainly sunny with a few clouds, moderate northeast wind, alpine high -10 °C, freezing level at valley bottom.

Tuesday: Sunny, moderate northeast wind, alpine high -8 °C, freezing level at valley bottom. 

Wednesday: Mix of sun and clouds, moderate west wind, alpine high -5 °C, freezing level at valley bottom.

Avalanche Summary

Skiers were surprised by wind slab avalanches on north and northeast aspects in the White Pass area on Friday. The slabs were about 20 cm thick and the avalanches reached up to size 2. Slabs were still reactive to skier traffic on Saturday.

Snowpack Summary

30-40 cm of recent snow are sitting on old firm surfaces. Strong wind from the south and west transported the snow and formed fresh wind slabs. The bond between the recent snow and the old firm surfaces was reactive to skier traffic in the last couple days. On steep, south aspects at treeline and below, there is potential for the existence of a thin sun crust. 

The lower snowpack is well bridged by the layers above, and it is unlikely that avalanches will be triggered on weak, sugary crystals near the ground at this time. 

Terrain and Travel

  • Be aware of highly variable recent wind loading patterns.
  • Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
  • Caution around slopes that are exposed to cornices overhead.

Problems

Wind Slabs

An icon showing Wind Slabs

Strong south and westerly wind formed fresh wind slabs on Sunday. Wind slabs will be found below ridge crests and in lee terrain features. The strong wind might have built slabs farther down slope than expected. 

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 7th, 2022 4:00PM

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