Avalanche Forecast

Issued: Mar 13th, 2012 10:51AM

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

Jlammers, Avalanche Canada

Northwest Coastal.

Summary

Confidence

Fair - Intensity of incoming weather is uncertain on Thursday

Weather Forecast

Wednesday: light snowfall - moderate to strong southeast winds - freezing level at 600m Thursday: moderate snowfall - moderate and variable winds - freezing level at 900m Friday: light snowfall - moderate southwest winds - freezing level at 600m

Avalanche Summary

Recently loaded wind pockets to size 1 were reportedly ski cut in the region. A size 1.5 cornice failure was also reported.

Snowpack Summary

Continued strong and variable winds have redistributed light amounts of recent storm snow into thin wind slabs that most commonly exist at treeline and in the alpine. In the northern part of the region two persistent weak layers are on the radar of some operators: Surface hoar buried at the beginning of March is as much as 70cm deep. The early February persistent weak layers (surface hoar, facets, crusts) are over a metre down. Although triggering persistent weaknesses has become less likely, persistent slabs would be destructive in nature, particularly below treeline on isolated and sheltered steep terrain where buried surface hoar may be preserved. Cornices in the region are reported to be very large and unstable.

Problems

Wind Slabs

Variable strong winds have formed thin wind slabs in unusual places, but generally below ridgecrests and in gullies.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Cornices

Cornices are reported to be very large at this time. A cornice fall could be destructive by itself, and may also act as a trigger for the slope below.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 6

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