Avalanche Forecast

Issued: Mar 11th, 2012 9:39AM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Storm Slabs, Persistent Slabs and Wind Slabs.

Grant Statham, Parks Canada

Glacier.

Another storm has resulted in a widespread avalanche cycle with avalanches to size 4 from all aspects running across valleys. Forecast inputs (10-20 cm snow, south winds, and afternoon sun) may trigger natural avalanches running full path. DM

Summary

Problems

Storm Slabs

Up to 60 cm of snow has fallen in the past 48 hrs. Temps rose to just above freezing at treeline with moist snow to 1600m. This cohesive slab overlies a layer that is reactive and may step down to deeper layers resulting in very large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

Persistent Slabs

Up to 60 cm of snow has overloaded the Feb surface hoar layers, which continue to produce impressively large avalanches. These layers are down 1.5-2 m. They may be triggered by skiers, loading by wind or cornice fall, or stepping down (problem 2).

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

3 - 4

Wind Slabs

Southerly winds during the storm transported snow, loading slopes, triggering avalanches and forming windslabs on exposed slopes at treeline and above. These windslabs overlie lower density snow and may be triggered by skiers.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Valid until: Mar 12th, 2012 9:00AM