Avalanche Forecast

Issued: Dec 22nd, 2018 3:00PM

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

matt.mueller, Alberta Parks

Kananaskis.

More natural avalanches were seen today. The snowpack is very slow to adjust to the new snow. Give it more time than usual and be patient.

Summary

Confidence

High -

Weather Forecast

Another evening of cold temps tonight. Tomorrow will see a slight warming trend that will carry on into next week. Overnight low of -17. Mostly clear skies and no snow tonight and tomorrow. Moderate winds at treeline from the SW.

Avalanche Summary

Numerous avalanches were seen, or witnessed directly today. They were all in the alpine on eastern aspects. Notables from the last 24hrs are:-sz3 , alpine bowl on Mt Murray. Initiated at ridgeline and cleared out the entire bowl but also crossed onto the face adjacent to the bowl.-sz2-3 on Snow Peak. 3 individual slides were noted on the same piece of terrain. Individually they were sz2's, but there is a chance they all started and ran together, which would make it a sz3.-several sz2's on different mountains. All these started at treeline with wide propagations.

Snowpack Summary

Wind continues to have the most influence on our snow pack right now. Wind slabs are widespread in the alpine, and are likely dense (1 finger). Gullies are noticeably crossloaded and most are fat with new deposited snow. Treeline is similar, but the windslabs are a softer(4 finger). The amount of avalanche activity seen today suggests the Feb 10 layer is more pronounced at this elevation band. Windslab thickness also varies. Fresh avalanche crowns tell us these slabs can be up to 1m thick.

Problems

Persistent Slabs

Forecasters are still experiencing whumpfs and cracking on the Dec 10th interface down 60-70cm at treeline. Cold temps will stiffen up the slab and make it easier to trigger.

Avoid freshly wind loaded features.Use conservative route selection, choose moderate angled and supported terrain with low consequence.Avoid areas with overhead hazard.

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

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

Some of the recent larger avalanches may have involved this layer. Keep an eye on it and use your probe to help find and assess it often.

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

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Dec 23rd, 2018 2:00PM