Avalog Join
Archived

Avalanche Forecast

Feb 7th, 2012–Feb 8th, 2012
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: South Rockies.

Confidence

Good - -1

Weather Forecast

Mainly cloudy with a chance of flurries for the forecast period. Freezing levels are expected to remain in valley bottoms. Winds could get quite gusty, but generally moderate from the southwest.

Avalanche Summary

Over the weekend widespread natural deep slab avalanche activity to Size 3 was reported. The avalanches occurred in response to a warming pattern that affected much of BC. Avalanche activity has decreased dramatically with the current cooling trend.

Snowpack Summary

The current snow surface is well on its way in becoming a dangerous weak layer once a sufficiently cohesive slab develops. Surface hoar is continuing to develop on sheltered slopes at all elevations combined with near-surface facets at lower elevations and surface crusts on sun-exposed slopes. At the base of the snowpack basal facets and depth hoar seem fairly widespread in the region. Basal facets recently became active again with warm temperatures, and remain a concern with heavy triggers, such as airborne sled impacts and cornice falls, on steep unsupported alpine slopes. In Elk Valley North and the Crowsnest, the average snowpack depth at treeline is 150 cms. In Elk Valley S and the Flathead the snowpack depth is closer to 2 m.

Avalanche Problems

Wind Slabs

Fresh wind slabs are expected to develop below ridge crests and behind terrain breaks in lee and cross-loaded terrain.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3

Cornices

Cornices are large, unsupported and may be a trigger for a large avalanche on the slope below.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 3 - 6

Deep Persistent Slabs

Deep and destructive persistent slabs have become less likely, but may be triggered with a large trigger (cornice fall, trenching sled); especially in unsupported, rocky terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 3 - 6