Avalanche Forecast

Issued: Dec 5th, 2012 4:07PM

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

mike eder, Parks Canada

Jasper.

Periodic road closures may be in affect on Thursday for avalanche control in the Icefields area with delays of up to 2 hours. Check the AMA road report after 0900 hours to confirm if control actions are taking place.

Summary

Weather Forecast

Winds and snow are tapering off overnight. Temperatures are expected to get cooler. A clearing trend is expected to arrive in time for the weekend.

Snowpack Summary

Twenty cms of new snow overnight. Moderate Southwest winds at ridgetop this afternoon are redistributing recent storm snow to lee aspects. This may provide the load to cause natural avalanches on the midpack facet layers around the November 01 crust.

Avalanche Summary

No New avalanche observations due to obscured visibility.

Confidence

Due to the number of field observations

Problems

Wind Slabs

Gusting Southwest winds are moving 20cm of storm snow onto Northeast aspect ridgetops and lee terrain features. Triggering a windslab may provide the energy for an avalanche to step down to the persistent weakness described below.

Avoid lee and cross-loaded terrain near ridge crests.Be careful with wind loaded pockets while approaching and climbing ice routes.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

A persistent facetted weakness can be found around a mid-pack crust. Saturday, an isolated size 3 slab avalanche on a steep Northerly slope in the Hilda Creek area likely ran on this layer. No other avalanches have been observed on this layer.

Avoid freshly wind loaded features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 6th, 2012 4:00PM