Avalanche Forecast

Issued: Apr 20th, 2012 4:00PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Loose Wet, Wind Slabs and Deep Persistent Slabs.

mike.koppang, Alberta Parks

Kananaskis.

A clear weekend is forecast so expect stability to decrease due to solar radiation and temperatures rising throughout the day. These decreaes will be most apparent on thin rocky solar aspects so start eaaarrrllllyyyy!

Summary

Confidence

Good - Timing or intensity of solar radiation is uncertain on Saturday

Weather Forecast

Clear conditions overnight and clear skies on Saturday will give us two things. A good freeze overnight, and a rapid decrease in stability when the sun starts to come out. No new snow is expected and freezing levels will be around 1900m. Winds are expected to decrease into the light range out of the SW.

Avalanche Summary

No new avalanche observations.

Snowpack Summary

A few new cm of snow fell overnight that was settling rapidly due to the warm temps. Expect up to 8cm of new snow overlying a crust on all aspects but true north. Dry snow can still be found on N aspects down to about 2300m.

Problems

Loose Wet

Crusts will break down early on Saturday as the temperature warms up. Decreases in stability will first appear on Solar aspects then spread to all aspects as temperatures climb. Keep an eye on overhead terrain that is already in the sun.

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 4

Wind Slabs

A few cm of new snow over the past 24hrs is adding to the pockets of windslabs that have developed in lee features at treeline and above. Field observations are showing that tehse slabs do not extend far downslope.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Deep Persistent Slabs

A few warm days may re-awaken some of the deeply buried weak layers lingering at the base of the snowpack. There has been no activity on this layer in the past few days but that could change will the big pulse of heat forecasted for the weekend.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

4 - 7

Valid until: Apr 21st, 2012 9:00AM