Avalanche Forecast

Issued: Dec 7th, 2012 4:00PM

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

steve blake, Parks Canada

Jasper.

Ski quality is good especially at sheltered locations, but remember that early season variability suggests the need for careful evaluation of large terrain features.

Summary

Weather Forecast

Cooler temps are forecast for the weekend with a chance of light flurries. A significant warming trend should start to set in early next week.

Snowpack Summary

Light and variable winds have had little influence on recent storm snow. The skiing is good but snow depths on lee features is now well above minimum thresholds values and several large slides have been observed in the past week. These avalanches have occurred on serious terrain but serve as a reminder to consider consequences before jumping in.

Avalanche Summary

No new natural avalanches were observed today. Explosive work along Parker slabs with produced one size 2.5 slab avalanche from a wind loaded location on rock slab on Thursday.

Confidence

Problems

Wind Slabs

Variable and winds created this slab condition on lee aspects particularly at ridge tops.

Caution in lee and cross-loaded terrain near ridge crests.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Persistent Slabs

A persistent facetted weakness can be found around a mid-pack crust.

Avoid unsupported slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Deep Persistent Slabs

This layer seems to be developing in relatively shallow snowpack areas do to a classic Rockies temperature gradient process.

Be aware of thin areas that may propogate to deeper instabilites.Carefully evaluate and use caution around thin snowpack areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Dec 8th, 2012 4:00PM