Avalanche Forecast

Issued: Mar 11th, 2021 4:00PM

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

Avalanche Canada kdevine, Avalanche Canada

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Sunshine and rising freezing levels will increase the potential for solar-triggered avalanches and cornice failures throughout the day. Minimize your exposure to cornices and steep solar aspects during the heat of the day.

Lingering wind slabs remain a concern in the alpine.

Summary

Confidence

Moderate - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

THURSDAY NIGHT - Mainly clear / light to moderate west wind / alpine low temperature near -6 

FRIDAY - Mainly sunny / light to moderate west wind / alpine high temperature near -1 / freezing level 2000 m

SATURDAY - Mainly sunny / light southwest wind / alpine high temperature near 1 / freezing level 2700 m

SUNDAY - Mainly sunny / moderate south wind / alpine high temperature near 1 / freezing level 2500 m

Avalanche Summary

Reports from this week have mostly been limited to small wet loose avalanches on solar aspects, and small dry loose avalanches in steep, shaded terrain

During last week's warm weather, a large (size 2) slab avalanche released naturally on a weak layer of facets near the ground in a shallow snowpack area east of the region near Apex.

The most recent avalanche observed on the late January persistent weak layer was reported February 28th, when large explosives produced very large (size 2-3) results at Kootenay Pass.

Snowpack Summary

Wind slabs may be found in lee features at upper elevations. Soft, dry snow exists in sheltered, shaded areas, and solar aspects likely have a crust on the surface.

Deeper in the snowpack, a persistent weak layer from late January is buried 80-150 cm deep and is composed of a combination of surface hoar, crusts, and facets. There is some lingering uncertainty about whether this problem remains reactive on isolated upper elevation slopes in thin snowpack areas. 

As described in this MIN report, shallow snowpack areas in the east of the region may harbor a faceted basal snowpack. This structure can typically be managed by avoiding shallow rocky areas where the snowpack transitions from thick to thin. 

Terrain and Travel

  • Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
  • Minimize your exposure time below cornices.
  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Problems

Wind Slabs

An icon showing Wind Slabs

Shallow wind slabs in lee features at upper elevations may still be possible to trigger.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Mar 12th, 2021 4:00PM

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