Avalanche Forecast

Issued: Jan 21st, 2012 9:51AM

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

triley, Avalanche Canada

Northwest Coastal.

Summary

Confidence

Fair - Freezing levels are uncertain on Tuesday

Weather Forecast

Snow and wind from the southwest is expected to accumulate 15-20 cm by Sunday morning. A weak ridge of high pressure will cause some broken skies and generally drier conditions during the day on Sunday. Snow should begin again Sunday evening combined with gusting westerly winds, bringing about 20 cm by Monday morning. Flurries are forecast for Monday, becoming heavy snowfall with rapid warming on Monday night and continuing heavy snowfall on Tuesday.

Avalanche Summary

Reports of widespread whumpfing at treeline and above on hard windslabs. Skier accidental reported to size 2.0 from a south aspect on a convex roll. Natural activity reported from the Bear Pass area in the highway corridor.

Snowpack Summary

The deep snowpack is considered to be well settled with no persistent layers of concern. There is now 20-30 cm of dry cold snow above windslabs that have developed due to strong NE outflow winds which have not bonded to the January 8th surface. These pockets of hard windslab can be triggered by light loads such as a single skier or rider. Some areas have developed surface hoar or surface facetting on sheltered slopes in the alpine and at treeline, that are now getting buried by new snow and shifting winds.

Problems

Wind Slabs

Old stiff windslabs have developed on South through West aspects due to strong northeast winds in the alpine and at treeline. New soft windslabs are expected to develop with the approaching strong southerly winds and new snow.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

2 - 5

Storm Slabs

Forecast strong southerly winds combined with moderate precipitation may develop a storm slab. If temperatures remain cool the new snow may continue to be loose and dry causing widespread sluffing.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 5

Valid until: Jan 22nd, 2012 8:00AM