Avalanche Forecast

Issued: Jan 2nd, 2017 4:00PM

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

garth lemke, Parks Canada

Jasper.

Ice-climbers need to be vigilant this week particularly if climbing in the Mt. Cirrus area. A couple of slabs were noted above the climbs but they did not crest the wall.

Summary

Weather Forecast

Temperatures and winds remain arctic like. Expect light N winds, no new snow, and clear skies for the next three days.

Snowpack Summary

Surface snow is facetting with the arctic temps and loosing internal cohesion. Southerly slopes in the alpine have been stripped by previous SW winds with hard slab on lee features. At treeline, the snow is faceted that is barely supportive and weak in shallow areas.

Avalanche Summary

Good visibility Jan 2 highway patrol. Several loose dry avalanches up to size 2 on steep alpine rocky terrain all aspects. 4 slabs up to size 2.5 noted on Mt. Cirrus above polar circus ice climb. They did not crest the wall but critical for ice climbers to take these into consideration. 1 icefall on Athabasca glacier did not initiate a slab below.

Confidence

The weather pattern is stable

Problems

Loose Dry

Arctic temperatures faceting the surface snow causing it to loose cohesion and release loose dry avalanches in steep alpine rocky terrain. Some have enough mass to be concern particularly to ice-climbers in confined terrain.

Be very cautious with gully features.Use caution above cliffs where small avalanches may have severe consequences.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

Cold temperatures and hard slab conditions make triggering less likely. Triggering from shallow spots remains a possibility.

Watch for areas of hard wind slab in steep alpine features.Caution in lee and cross-loaded terrain near ridge crests.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

This layer will weaken with cold temperatures. Weak facets continue to develop above and below the November crust found 20-40cm above the ground.

Be cautious in shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Jan 3rd, 2017 4:00PM