Avalanche Forecast

Issued: Mar 20th, 2012 4:00PM

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

pmarshall, Avalanche Canada

Northwest Coastal.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Wednesday: Light convective snowfall - 5-15cm. The freezing level rises to 400-500m during the day. Winds are moderate from the SW. Thursday: Isolated flurries with possible sunny breaks in the afternoon. Freezing level rising to 600m. Winds are light from the SE. Friday: A mix of sun and cloud. Freezing level rising to 600-800m during the day.

Avalanche Summary

There has been very little recent avalanche activity aside from a few cornice failures, most of which did not trigger a slab below. Expect to find small pockets of wind slab in steep exposed terrain that could be triggered.

Snowpack Summary

5-15cm of new snow sits on the previous snow surface which included a sun crust on southerly aspects, surface facets or surface hoar in cool shady areas, and pockets of wind slab in exposed terrain. A variety of potential weak layers exist between 60 and 120cm deep. These include surface hoar or facets. There has been no recent activity on these layers but they could wake up with heavy triggers like a large cornice chunk or a snowmobile digging its track in. Cornices in the region are reported to be very large and potentially unstable.

Problems

Wind Slabs

New wind slabs may form in exposed lee and cross-loaded terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very 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, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 6

Valid until: Mar 21st, 2012 9:00AM