Avalanche Forecast

Issued: Nov 21st, 2012 4:22PM

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

mike eder, Parks Canada

Jasper.

Early season hazards may be hidden directly under the snow surface.

Summary

Weather Forecast

5 - 10cm of snow are expected overnight with light winds. Another light snowfall is expected on Friday with increasing SW winds.

Snowpack Summary

Snowpack on a South aspect at treeline is 60cm with facets between two crusts and a moist layer at the ground.Â Moderate tests showed a weakness in the facets just above the november 6th crust.

Avalanche Summary

no new avalanches observed in the past 24 hrs.

Confidence

Wind speed and direction is uncertain

Problems

Wind Slabs

This layer produced several avalanches to size 2.5 on Tuesday, limited to lee and cross loaded features but a wide range of aspects in the alpine. No new avalanches were observed on Weds.

Avoid lee and cross-loaded terrain near ridge crests.Avoid unsupported slopes.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

A variety of old surface layer shears can be found in field tests. No avalanches have been observed on these layers. A test profile on Parker south showed moderate sudden planar results.

Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Nov 22nd, 2012 4:00PM