Avalanche Forecast

Issued: Dec 18th, 2011 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Wind Slabs, Deep Persistent Slabs and Loose Dry.

snow safety, Parks Canada

Banff Yoho Kootenay.

15-30cm fell Sunday, which is making conditions touchy at higher elevations. Skiers had a close call today, causing a size 2.5 avalanche in the Lake Louise backcountry today on basal facets. Click the Facebook link below to see pictures.

Summary

Weather Forecast

Snowpack Summary

Avalanche Summary

Confidence

Wind speed and direction is uncertain on Monday

Problems

Wind Slabs

Many soft wind slabs 15-30cm will be developing in lee areas that will be touchy to human triggering with increased forecast alpine winds on Monday afternoon.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Deep Persistent Slabs

The new snow load is adding stress to the snowpack that sits over basal depth hoar and facets. This will be easiest to trigger from thin areas. The Lake Louise avalanche slid on this layer to ground.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Loose Dry

Lots of loose snow at all elevations that will spindrift heavily with any wind input, especially in gullies and climbing terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 19th, 2011 4:00PM