Avalanche Forecast

Issued: Feb 14th, 2015 3:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

Isothermal snowpack and warm temps are wreaking havoc on the snowpack. Cold temps will need to penetrate the snowpack for a day before stability begins to improve. Avoid the bigger terrain features.

Summary

Confidence

Good

Weather Forecast

Freezing levels are forecast to start dropping overnight back down to the valley floors by tomorrow. It will take some time for the heat to be squeezed out of the snowpack by the cooler temperatures so danger levels will still remain elevated for Sunday.

Avalanche Summary

No new observations were seen on Saturday but field teams were out of the field by 13:00hrs. Prior to this time, skies were obscured and visibility was limited.

Snowpack Summary

The snowpack is isothermal up to 1950m. Above this there is a crust from the recent heat on all aspects up to 2200m then only on solar aspects up to 2600-2700m. Easy to moderate sheers persist within the upper snowpack down 30-40cm. Extended column tests also indicate that this layer is prone to wide propagations. The Jan 31st interface is down 70-80cm but the bond at this interface seems to be improving. The basal layers in the snowpack area still weak and any avalanche that is triggerred will likely step down to these basal layers. THroughout the past 24hrs, 10-15cmof new snow has fallen via convective flurries.

Problems

Wind Slabs

Any wind affected area in alpine terrain and gullied, and crossloaded features at treeline.

Resist venturing out into complex terrain, even if you observe no obvious signs of unstable snow.>Dig down to find and test weak layers before committing to a line.>Choose well supported terrain without convexities.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 5

Deep Persistent Slabs

Avalanches in the upper snowpack are stepping down and waking up the deeper basal layers.

Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>Be wary of slopes that did not previously avalanche>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

3 - 6

Cornices

Cornices have grown over the past week. Many have collapsed and caused large avalanches on the underlying slopes.

Cornices become weak with daytime heating. >Avoid steep slopes below cornices.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 15th, 2015 2:00PM