Avalanche Forecast

Issued: Dec 23rd, 2011 9:05AM

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

Saturday: Expect mixed skies with strong westerly ridgetop winds. Some localized flurries are possible, especially towards the Crowsnest Pass and in northern parts of the region. Highs near 0. Sunday & Monday: Mostly clear, with occasional cloudy periods. Moderate to strong winds from the west-southwest with temperatures reaching -2 in the afternoons.

Avalanche Summary

No new avalanches. Nearby (in the Lizard Range) there were 2 incidents reported yesterday. Check out the incidents through these links: http://bit.ly/uBRvLX http://bit.ly/rE20wh

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 lower layer was responsible for some large releases earlier in the season but we haven't seen any action on it lately. Worth keeping in the back of your mind around shallow snowpack areas where the bridging could be weaker.

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

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 24th, 2011 8:00AM