Avalanche Forecast

Issued: Mar 13th, 2012 9:00AM

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

danyelle magnan, Parks Canada

Glacier.

Widespread avalanche activity is occurring and will continue today. The weekend avalanche cycle had large avalanches on all aspects, at all elevations, and involved all of the layers of concern. Many paths repeatedly produced large avalanches.

Summary

Problems

Storm Slabs

More load and a new slab with 15cm overnight, more forecast today, and SW winds loading lee slopes. This will bond poorly to a rain crust below 1500m, and will be reactive at all elevations potentially stepping down to deeper layers.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 3

Persistent Slabs

Weak layers from Feb (combinations of surface hoar, sun crusts and/or facets) continue to produce impressively large avalanches. These layers are down 1.5 to 2m and may be triggered by skiers, wind loading or cornice fall, or stepping down.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

3 - 4

Wind Slabs

Southerly winds are transporting snow, building cornices, loading slopes and forming windslabs on exposed slopes at treeline and above. Avalanches continue to be triggered by windloading, with the largest avalanches occurring on fat loaded slopes.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Valid until: Mar 14th, 2012 9:00AM