Avalanche Forecast

Issued: Apr 5th, 2012 4:00PM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs, Loose Dry and Persistent Slabs.

mike.koppang, Alberta Parks

Kananaskis.

40cm of snow has fallen over the past 24hrs with warm temps and light winds. This new snow is rapidly settling into a storm slab that is overlying a widespread crust. Use caution and watch for concerns with daytime warming decreasing stability.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain on Friday

Weather Forecast

A few additional cm of new snow may fall over the next 24hrs. Winds are forecast to be calm but this will be a critical weather factor to play close attention to over the next 24hrs. Lots of snow is available for transport. Skies will be a mix of sun and cloud but its important to remember, when the sun does come out, stability can rapidly deteriorate so keep an eye on the sky...

Avalanche Summary

Extensive sluffing up to size 1.5 on all aspects.

Snowpack Summary

A new crust layer is now prevalent within the snowpack. The recent storm snow is now overlying the 0403 melt freeze crust (down 40) that can be found on all aspects except true north up to 2100m and on solar aspects up to 3000. The new snow was sluffing easily on this crust entraining significant mass as it traveled. The 0229 melt freeze crust was found down 80cm today at treeline areas. Easy sheers were being noted within the storm snow and at the 0403 interface. Moist snow was being encountered by 13:00 on all aspects except true north. This warm temps was settling the recent snow into a soft slab that will only become more reactive with time. Reports of large whumpfs near the Haig glacier.

Problems

Storm Slabs

The new snow combined with warm temps are creating settlement slabs in open terrain. Rapid settlement of the upper snowpack into a 30-40cm slab was being observed near black prince on Thursday.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Loose Dry

Widespread loose dry sluffing was observed on all aspects over the past 24hrs. The bed surface for many of these slides was the recently buried April 3rd temperature crust.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 3

Persistent Slabs

The February surface hoar is buried 120-150cm at treeline. This interface is still hard to trigger, but it has come back alive in recent cornice triggered avalanches. The spring transition could see more avalanches stepping down to this layer.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 6

Valid until: Apr 6th, 2012 9:00AM