Avalanche Forecast

Issued: Mar 14th, 2016 8:06AM

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

percy woods, Parks Canada

Glacier.

SW Wind and new snow have formed thin sensitive windslab at and above treeline.

Summary

Weather Forecast

Alpine temps will remain cool with freezing level of 1200m. Scattered flurries will bring another 4cm and moderate to strong SW winds will redistribute the storm snow onto lee slopes up high. Light precipitation, moderate west winds and cool temps expected to mid-week.

Snowpack Summary

Wind effected snow at and above treeline, with windslab on lee features. Near surface crusts will be lurking under 10cm+/- snow below 1700m. Feb 27th layer down 70cm has been most reactive on solar slopes. Feb 10th interface down 120cm+/- may react in a step down type slide where the extra load wakes it up. Cornices are large, fragile and failing.

Avalanche Summary

Three skier accidental thin surface slabs were triggered in the Balu Pass area yesterday on easterly aspect. These slides were composed of the surface slab, 10-15cm deep, 50-60m wide and ran 50m+. 4 slides in the size 1.5 range observed in the highway corridor.

Confidence

Due to the number of field observations

Problems

Wind Slabs

Windslabs are widespread and continue to be reactive to human triggering given the right terrain feature. 3 size 1.5 slides were triggered at Balu Pass yesterday.

Use caution in lee areas. Recent wind loading has created wind slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

Feb 27 interface is down 80cm+ and continues to give sudden planar results in field tests. The layer consists of crusts on solar aspects and decomposing surface hoar in isolated locations.

Avoid steep convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Cornices

Ripe cornices have been failing over the past several days resulting in some large slides. Avoid exposure to this overhead hazard.

Give cornices a wide berth when travelling on or below ridges.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Mar 15th, 2016 8:00AM