Avalanche Forecast

Issued: Dec 24th, 2011 9:46AM

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

Avalanche Canada jlammers, Avalanche Canada

Summary

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Sunday: 13cm of new snow - moderate southwest winds - alpine temperatures of -8.0Monday: 15cm of new snow - moderate to strong southwest winds - alpine temperatures of -9.0Tuesday: 30cm of new snow - moderate southwest winds - alpine temperatures at -7.0

Avalanche Summary

Multiple size 1 and 1.5 slab avalanches were observed on lee aspects at treeline and in the alpine on saturday. Conditions have been described as touchy with the new snow and wind.

Snowpack Summary

The region received 20cm of new snow on friday night and throughout saturday. Alpine winds were moderate to strong from the southwest during this period. Touchy windslabs up to 50cm deep now exist on lee aspects.Below this new snow a weak rain crust exists up to treeline. This crust may over-ride buried surface hoar and/or facets may persist 10-20cm below. Watch this layer as it gets more load and a thick cohesive slab develops, particularly below treeline where the buried surface hoar would be especially large. A strong mid pack overlies basal facets that have also gained considerable strength.Snow depths are at approximately 140cm at treeline in the Spearhead area and 180cm at treeline in the Branywine area.

Problems

Wind Slabs

An icon showing Wind Slabs
Fresh windslabs exist below ridge crests, behind lee terrain features and in cross-loaded gullies.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Storm Slabs

An icon showing Storm Slabs
Expect storm slab development on all aspects and elevations as the new snow creates a consistent veil of snow on old surfaces.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 26th, 2011 8:00AM