Avalanche Forecast

Issued: Mar 14th, 2012 10:40AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. 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

Thursday: moderate snowfall starting Wednesday evening and continuing through Thursday - moderate to strong southeast winds switching to southwest throughout the day - freezing level @ 600m Friday: light snowfall - light to moderate southwest winds - freezing level @ 600m Saturday: trace amounts of snow with possible clearing skies - light and variable winds - freezing level @ 600m

Avalanche Summary

A size 3 natural cornice failure was observed in the region on Wednesday. A size 1 skier triggered soft wind slab was also reported.

Snowpack Summary

Sporadic 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 potentially unstable.

Problems

Wind Slabs

Forecast strong winds and new snow will form fresh wind slabs on lee slopes.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Cornices

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

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 6

Valid until: Mar 15th, 2012 9:00AM