Avalanche Forecast

Issued: Feb 10th, 2020 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 jfloyer, Avalanche Canada

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Generally favourable avalanche conditions but watch for wind slabs on steep, wind-affected slopes.

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: Dry but windy with strong westerly winds.

Tuesday: Light snow up to 5 cm. Ridgetop winds around 40 km/h. Freezing level around 1300 m.

Wednesday: Dry with some sunny breaks. Light southwesterly winds. Freezing level around 1100 m.

Thursday: Light snow, up to 5 cm. Moderate southwesterly winds. Freezing level around 1000 m.

Avalanche Summary

A natural size 2 wind slab avalanches was reported on a north aspect at 2000 m. A cornice-triggered wind slab was also noted on an east aspect at similar elevation.

In the neighbouring Sea to Sky region, a very large (size 3.5) avalanche occurred on Saturday near Whistler on a steep north face at 2400 m. It is suspected to have failed on a layer of facets on a crust from late November. This very large event demonstrates the ongoing need for caution in aggressive alpine terrain, particularly in areas where deep instabilities remain.

Snowpack Summary

Relatively warm recent weather has made recent new snow feel dense and has been described in one report as a "storm snow" like slab. Strong southerly wind during the storm shifted to northerly wind and created wind slabs on all aspects. The snow surface is wind affected at treeline and in the alpine. The recent storm snow sits on a rain crust below 1900 m.

In the north part of the region (ie. Goldbridge/Duffey/Hurley), a few deep instabilities exist in the snowpack, including a weak basal facet crust complex. There has not been recent avalanche activity on these layers but they remain a concern and are on our radar. 

The south of the region, including the Coquihalla and Manning areas, we currently have no concerns about deeply buried weak layers.

Terrain and Travel

  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Be careful as you transition into wind affected terrain.
  • Avoid areas where the snow feels stiff and/or slabby.

Problems

Wind Slabs

An icon showing Wind Slabs

Friday's storm delivered 20-30 cm in the south of the region and 10-15 cm in the north. The wind changed direction during the storm from southwest to northerly and created wind slabs on all aspects at treeline and in the alpine. These wind slabs might still be sensitive to human triggers. 

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 11th, 2020 5:00PM