Avalanche Forecast

Issued: Dec 10th, 2015 4:04PM

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

Max Darrah, Parks Canada

Jasper.

Great skiing can be found in sheltered locations at treeline and into the alpine. Conservative terrain choices are still recommended while the recent storm snow has a chance to settle in.

Summary

Weather Forecast

Snowfall amounts are tapering off, but a series of scattered flurries is expected to bring an additional 15cm by Saturday. Temperatures remaining cool, with daytime highs near -5C. Freezing level to remain below 1500m. Winds light and variable through to the weekend.

Snowpack Summary

70 cm of snow in the past week is settling rapidly and appears to be bonding well. The main concern is where this snow sits on the Dec3 surface hoar, most likely between 1700-2000m on sheltered North aspects. A touchy 15cm windslab can be found in lee areas at treeline. The midpack is supportive above 1700m and there is a new raincrust below 1200m.Â Â

Avalanche Summary

Numerous natural slab avalanches in the alpine up to size 3 were observed in the Columbia Icefield area as well as the lands adjacent to Marmot Basin. Several of these slides started as a storm slab, which stepped down to trigger basal weaknesses and caused large full depth avalanches. Loose dry point release were noted out of steep rocky terrain.

Confidence

Problems

Wind Slabs

A touchy 15cm windslab can be found in lee areas at treeline and into the alpine. Several natural avalanches started with this slab and then stepped down to full depth releases in the alpine.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Be aware of thin areas that may propogate to deeper instabilites.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Storm Slabs

Recent snowfall has been a great addition to the snowpack, and should help set the stage for the winter. The bonding of this new snow at the Dec 3 interface down 60cm is the condition to monitor right now.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 11th, 2015 4:00PM