Avalanche Forecast

Issued: Dec 6th, 2012 5:05PM

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

garth lemke, Parks Canada

Jasper.

Good skiing can be located in sheltered treeline locations.

Summary

Weather Forecast

8mm of precipitation in the form of light flurries will move through now until Sunday. A weak ridge of high pressure may set up beginning on Saturday bringing the first cold temperatures of the season in the -20 range. Winds will continue to gust moderate Southwest at alpine ridgetops.

Snowpack Summary

Light to moderate variable winds at ridgetop are redistributing recent storm snow onto a variety of lee aspects. Watch for pockets of specific terrain features that may have developed into a slab condition.

Avalanche Summary

No New significant natural avalanches were observed today. Explosive work along parkers slabs with 14 avalauncher shots only produced one size 2 slab avalanche from a windloaded location on rock slab.

Confidence

Due to the number and quality of field observations on Thursday

Problems

Wind Slabs

Variable and localized winds will continue to transport storm snow onto lee aspects particularly at ridgetops. Triggering a windslab is possible in immediate lee alpine features.

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

Unlikely - Possible

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 recently.

Avoid freshly wind loaded features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 7th, 2012 4:00PM