Archived

Avalanche Forecast

Mar 5th, 2012–Mar 6th, 2012

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

4: High

The avalanche danger rating below treeline will be high

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Regions: 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

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.

Avalanche 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