Avalanche Forecast

Issued: Dec 22nd, 2011 9:17AM

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.

mpeter, Avalanche Canada

South Rockies.

Summary

Confidence

Fair - Due to variable snopack conditions

Weather Forecast

Friday: Mostly sunny with gusty (up to 80km/h) westerly winds. Expect temps to -7. Saturday & Sunday: A mix of sun and cloud, with a chance of localized flurries. Continued westerly winds with highs near 0 each afternoon.

Avalanche Summary

No new avalanches

Snowpack Summary

Westerly winds continue, creating windslabs on lee locations in the alpine and open treeline. A buried layer of surface hoar lies approximately 20 cm below the snow surface. Reports indicate this layer was blown around before it was buried and can only be found in isolated, sheltered locations at and below treeline. A well settled mid pack bridges over the basal weaknesses at the ground. This layer was responsible for some large releases earlier on in the season. However, there hasn't been any activity on this layer since early December and confidence is growing that it is gaining strength.

Problems

Wind Slabs

Shifting winds have set up windslabs on a variety of aspects, particularly north through southeast.Cross-loading is also possible on open slopes oriented parallel to the wind, which contain features and gullies to catch wind-drifted snow.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

Thin slabs may be reactive on the mid-December surface hoar/facet combo. Low mass events, but running far.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 23rd, 2011 8:00AM