Avalanche Forecast

Issued: Feb 24th, 2012 3:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

10-15cm of new snow is forecast over the next 24hrs with moderate to strong SW winds. Dangerous avalanche conditions persist as forecasters encountered shooting cracks failing down 40-50cm as the traveled in open areas on Friday.

Summary

Confidence

Good

Weather Forecast

Up to 15cm of new snow is expected over the next 24hrs with the majority of this new snow forecast to fall throughout the evening on Friday. Winds are expected to also increase into the moderate to strong range out of the SW as the upper trough pushes through the forecast area.

Avalanche Summary

Lots of loose sluffing up to size 1 out of steep unskiable terrain. 1 Skier controlled avalanche sz 1 on an E aspect at 2200m. Slab was 5m wide, ran 25m and failed on the 0213SH interface.

Snowpack Summary

0213SH layer down 40-50cm at treeline. In the Fishermans ridge area, SH was 10mm big and standing up tall. CTE(2)SP down 40cm on this interface. Mid pack well settled. Lots of cracking and settlements while traveling along ridge crest. Total HS at this area was 160cm.

Problems

Wind Slabs

Soft slabs are widespread in all open wind affected areas. Lots of cracking down 40-50cm on the surface hoar layer as forecasters traveled throughout the area. This cracking is a RED FLAG indicating the human triggering of avalanches is very likely.

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

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 5

Storm Slabs

Storm slabs have formed in open wind affected terrain that are reactive to light loads such as a skier. Thinner slabs will likely step down to the 0213 Valentines day layer triggerring an avalanche size 2 or greater.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Cornices

New snow, warm temps and moderate to strong winds at higher elevations have caused cornices to grow large and fail in some areas. Failures have triggered avalanches up to size 2.5 on the underlying slopes.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

2 - 5

Deep Persistent Slabs

Weak facets and depth hoar linger at the base of the snowpack. Thin steep areas are the most likely trigger points. This problem is still a low probability issue, but with high potential consequences.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Feb 25th, 2012 8:00AM