Avalanche Forecast

Issued: Mar 5th, 2012 9:44AM

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

mike.koppang, Alberta Parks

Kananaskis.

Up to 70cm of storm snow at treeline overnight is forming fresh windslabs. A cycle of large avalanches is occurring. The 'Canmore Hill' is closed due to avalanche activity - may reopen later Tuesday PM.BD/JM

Summary

Confidence

Good

Weather Forecast

Snowfall is forecast to taper off Tuesday evening .Increasing winds from the west and cool alpine temperatures.

Avalanche Summary

Visibility nil for most of the day but numerous large avalanches could be heard in the distance.

Snowpack Summary

36 cm of storm snow by 0900 on Monday AM with 70cm of storm snow at treeline by late afternoon!! Valentines Surface hoar layer now buried beneath as much as 125cm! Some cracking in surface layers observed.

Problems

Wind Slabs

Extreme SW winds have formed hard and soft slabs at all elevations on lee and cross loaded features. A failure in these slabs will likely step down and trigger the surface hoar or the basal facets. Avalanches are occurring on this layer.

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

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 8

Persistent Slabs

The Valentine's surface hoar and sun crust continue to be a problem The surface hoar is particularly touchy and is now buried over 125 cm's at treeline and above. Remote triggering, cracking and whumpfing are occurring.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 8

Deep Persistent Slabs

Weak facets and depth hoar linger at the base of the snowpack. Thin steep areas are the most likely trigger points. Avalanches are stepping down to this weakness.

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

Elevations: Alpine, Treeline.

Likelihood

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

Expected Size

2 - 6

Valid until: Mar 6th, 2012 8:00AM