Avalanche Forecast

Issued: Mar 17th, 2019 3:00PM

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

matt.mueller, Alberta Parks

Kananaskis.

Heat during the day, poor over night re-freezes & an abnormally weak snowpack make for stressful times. Why be stressed all day? Why not just avoid avalanche terrain? Seems simple. Right?

Summary

Confidence

High -

Weather Forecast

Tomorrow's high will +4, but it will be there by 10am and last until late evening. The alpine winds will be around 25km/hr from the north. Skies will be cloudy in the AM, and clear a bit for the PM. No snow is expected.

Avalanche Summary

There was a widespread natural cycle (up to sz2.5) today. Solar aspects had loose wet avalanches at all elevations. The alpine & treeline had windslabs and deeper slabs fail on all aspects.

Snowpack Summary

As we quickly enter spring, the alpine snowpack is changing...FAST! The sudden spike in temperatures and solar exposure are making crusts more of a widespread layer. Expect them on any slope that sees the sun. On the shaded aspects, we have those lingering windslabs to worry about. All evidence points to these windslabs being very sensitive to temperature changes. The lack of support within the snowpack is preventing any sort of anchoring. Treeline has a similar issue, only the windslabs are thinner and not as widespread. The treeline slabs may be even touchier because of their thin nature and shorter recover (re-freeze) time at night.To share an opinion, this year's snowpack has a character that we haven't seen before. We have a long history with facets and depth hoar, but this year's crop is off the charts. As such, we feel it's necessary to acknowledge the uncertainty by avoiding large terrain right now. The snowpack has no trustworthy qualities right now.

Problems

Wind Slabs

Windslabs are being found in Alpine terrain and isolated areas at TL up to 20cm thick.

Be careful with wind loaded pockets while approaching and climbing ice routes.Caution in lee and cross-loaded terrain near ridge crests.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Wet

Watch for loose wet slides on solar aspects as temps warm up. Steep thin areas will be more vulnerable to this type of activity. They may trigger slabs as they gain mass.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.

Aspects: East, South East, South, South West, West.

Elevations: All elevations.

Likelihood

Very Likely - Certain

Expected Size

1 - 2

Deep Persistent Slabs

This layer is still concerning and could be woken up by a skier/rider in a thin shallow snowpack area, warmer temps with some solar radiation or a cornice failure. This problem deserves respect as any resulting avalanche will be full depth.

Be aware of the potential for wide propagations due to the presence of hard windslabs.Be aware of the potential for full depth avalanches due to deeply buried weak layers.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Mar 18th, 2019 2:00PM