Avalanche Forecast

Issued: Dec 19th, 2014 4:00PM

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

a.l. horton, Parks Canada

Jasper.

New snow will be landing on a large surface hoar layer. This will be a weak layer and freshly wind loaded slopes should be avoided.

Summary

Weather Forecast

Light precipitation through the weekend with a little more on Sunday. Light SW winds at treeline increasing to moderate in the alpine. Mild temperatures with freezing levels staying well below treeline.

Snowpack Summary

Surface Hoar continues to form. A strong mid-pack overlies approximately 20-40cm of facets. Isolated wind slabs still exist in open areas at tree line and alpine elevations. The interface between the mid-pack and facets is most susceptible to human triggering from shallow areas.

Avalanche Summary

No observations in the Marmot area today. No other avalanches reported. There is past evidence of large deep slides in wind loaded features that released in the last cycle.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Sunday

Problems

Deep Persistent Slabs

These deep persistent slabs at tree line and sheltered alpine slopes may be triggered from shallow areas within the snowpack.

Carefully evaluate and use caution around thin snowpack areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Wind Slabs

Approach loaded, cross-loaded and re-loaded lee features with caution.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Be careful with wind loaded pockets while approaching and climbing ice routes.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 20th, 2014 4:00PM