Avalanche Forecast

Issued: Apr 14th, 2018 3:32PM

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

mike.koppang, Alberta Parks

Kananaskis.

25cm of snow in the past 48hrs and more forecast to fall overnight. Watch for the windslabs to become more reactive on sunday. If the sun comes out, avoid solar aspects.

Summary

Confidence

Moderate -

Weather Forecast

A few more cm of snow is forecast to fall overnight with upper level winds still in the Moderate SW range. This new snow will add to the 15cm that fell throghout the day on Saturday. If we do get more that the 4cm is forecast, we may see avalanche danger push back into the considerable range in the alpine. The freezing level on sunday is forecast to be at 2300m so as conditions warm up expect stability to decrease and the new snow to rapidly settle.

Avalanche Summary

Report on the MIN of a skier accidental sz 2 avalanche below the Window Couloir on french creek. Otherwise no new natural avalanche activity.

Snowpack Summary

SW winds increased in alpine overnight and into the morning building windslabs 20-25cm thick in lee features in the Alpine and treeline. The recent snow (10-15cm at treeline and above on Saturday and 10cm on Friday) is overlying a supportive MFC that is 4-6cm thick up to 2200m and up to the peaks on solar aspects We are finding good "dust on crust" skiing on top of this crust. Corncies are LARGE right now and a few have collapsed recently with the warmer weather. Start early and be home early before the snow begins to melt and settle and loose stability in the warmer temps or the solar radiation.

Problems

Wind Slabs

Windslabs up to 25cm thick in lee and crossloaded features. Lots of snow is currently available for transport so pay attention to localized wind affect.

Avoid lee and cross-loaded terrain near ridge crests.Give cornices a wide berth when travelling on or below ridges.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

Cornices are large and looming and become weak with daytime heating. New snow on Saturday combined with warm temps on Sunday may make these features prone to collapse.

Cornices become weak with daytime heating, so travel early on exposed slopes.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1.5 - 3

Persistent Slabs

Lots of variability on this interface down 50-60cm on solar aspects. Stability tests have been improving but we still have limited confidence on these aspects until a full melt freeze cycle occurs.

Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Apr 15th, 2018 2:00PM