Avalanche Forecast

Issued: Feb 8th, 2020 4:00PM

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

Avalanche Canada ldreier, Avalanche Canada

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Strong wind changed direction during the last storm from south to north and formed wind slabs on all aspects. Wind slabs might still be sensitive to human triggers especially when exposed to the sun.

Summary

Confidence

Moderate -

Weather Forecast

Saturday Night: Clear, light to moderate northwest wind, alpine high -12 C, freezing level 600 m.

Sunday: Mix of sun and cloud, light northwest wind, alpine high -6 C, freezing level 900 m.

Monday: Mostly sunny, light northerly wind, alpine high -3 C, freezing level 1300 m.

Tuesday: Mostly cloudy, light southwest wind, alpine high -3 C, freezing level 900 m.

Avalanche Summary

On Friday a few large (size 2) slab avalanches were triggered with explosives, one released naturally. Explosive control on cornices was successful and resulted in large (size 2-2.5) avalanches. Several small (size 1) slab avalanches were triggered by skiers.

On Thursday a few small (size 1) slab and loose dry avalanches were reported. 

On Wednesday several small (size 1) slab avalanches were triggered by explosives and skiers. Several small (size 1) and one large (size 2) loose dry avalanche were reported in the north of the region.

There was also a report of two size 3-3.5 naturally triggered deep persistent avalanches on a northwest aspect at 2600m. These would have run during or just after the storm on the weekend.

Snowpack Summary

Extreme southerly wind during the last storm shifted to strong northerly wind and created wind slabs on all aspects. The snow surface is heavily wind affected at treeline and in the alpine. The recent storm snow sits on a rain crust below 1900 m. It is uncertain how well the snow bonds to the crust. 

Weak faceted grains and crusts near the base of the snowpack have not been an active avalanche problem recently, despite significant new snow loads. They are still on our radar, especially in inland parts of the region.

Terrain and Travel

  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Be especially cautious as you transition into wind affected terrain.
  • Be alert to conditions that change with elevation.

Problems

Wind Slabs

An icon showing Wind Slabs

Extreme southerly wind during the last storm on Friday shifted to strong northerly wind Friday night and created wind slabs on all aspects. The snow surface is wind affected at treeline and in the alpine. Due to the shift of the wind direction it might be tricky to recognize previously formed wind slabs. Wind slabs might still be sensitive to human triggers especially when exposed to the sun.

The storm snow sits on a rain crust below 1900 m and it is uncertain how well the snow bonds to the crust. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 9th, 2020 5:00PM