Avalanche Forecast

Issued: Mar 14th, 2012 4:00PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Storm Slabs, Persistent Slabs, Deep Persistent Slabs and Cornices.

mike.koppang, Alberta Parks

Kananaskis.

Another system will bring more storm snow to the area over the next 24 hours - forecasted amounts are down to approx 30cm now but strong to extreme winds mean new windslabs will be quick to form and they will be sensitive to human triggering. BD

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain on Thursday

Weather Forecast

Up to 30cm of new snow expected by Thursday night with a moderate to strong SW flow continuing. Temps on a slow rising trend with daytime highs -6 to1-12 and winds extreme at 3000m.

Avalanche Summary

Very limited visibility in the Smith-Dorrien area so no new observations. Avalanche control work on the East End of Rundle produced several Size 2 soft slab releases which averaged approx 40cm in depth and did not run full path.

Snowpack Summary

10cm of new snow overnight with only a trace of new through the day. Increasing winds later in the morning with considerable redistribution of storm snow occurring.

Problems

Storm Slabs

With up to 45cm of recent snow over the past 48 hours and strong winds, wind slabs have formed at treeline and above in lee and cross loaded terrain. These slabs are very touchy and will be highly susceptible to human triggering for a couple of days

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

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 6

Persistent Slabs

Surface hoar buried up to 130cm continues to be a major concern in the snowpack. A dense slab now sits on top of this layer. Remote triggering is a real possibility. Many avalanches have stepped down to this layer.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 7

Deep Persistent Slabs

The weak basal facets and depth hoar have re-awakened. Large terrain features are areas of concern where a smaller slide could step down and trigger a very large avalanche with deep and wide propagation.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

3 - 8

Cornices

Cornices have grown significantly in the alpine. Failures continue to occur and have triggered avalanches up to size 3 on the underlying slopes. Give cornices a wide berth and stay well back from corniced ridge crests.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

2 - 7

Valid until: Mar 15th, 2012 9:00AM