Avalanche Forecast

Issued: Dec 28th, 2018 3:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

Good skiing is being found at upper elevations but it is heads up hockey for thin weak spots where a skier can trigger the weak basal layers. Mellow terrain is key.

Summary

Confidence

Moderate -

Weather Forecast

Winds will move out of the north to a more SW flow with flurries overnight and throughout the day on Saturday.Â Total snowfall amounts by end of the day on Saturday will be around 10cm.Â Temperatures will thankfully warm back up to the -10C range as the western flow returns.

Avalanche Summary

A sz 2 on a NE aspect on Heros bowl was observed below a cliff band which was a theme over the past week (below cliff bands).Â Likely due to the pronounced facetting around the thin rocky areas.Â Another sz 2 was observed on Mt Murray which failed on a re-loaded bed surface on a N aspects at 2400m.

Snowpack Summary

Well not much be a changing except the snowpack is getting weaker.Â The cold temps are facetting out the entire snowpack especially in thinner areas.Â The winds earlier in dec have made the snowpack highly variable.Â Areas that are normally "deep" at this time of year are very shallow.Â As the Dec 10th interface has improved in strength the basal facets have gotten worse.Â The alpine snowpack has settled while treeline areas are where forecasters are very cautious and hyper alert.Â Pockets of old windslabs are carefully perched over the underlying facets and with thin weak areas widespread, human triggerring is possible for sure.Â Stick to conservative terrain.Â The snowpack is below average for this time of year.Â

Problems

Persistent Slabs

Slabs are everywhere in lee and cross-loaded terrain in the Alpine and open areas at Treeline. These slabs are very sensitive to human-triggering in steep and unsupported terrain.

Remote triggering is a concern, watch out for adjacent slopes.Use conservative route selection, choose moderate angled and supported terrain with low consequence.Be cautious in shallow snowpack areas where triggering is more likely.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1.5 - 2.5

Deep Persistent Slabs

The basal layers are very weak. An avalanche initiated in the upper snowpack could step down to the bottom of the snowpack.

Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.Be cautious in shallow snowpack areas where triggering is more likely.Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Dec 29th, 2018 2:00PM