Avalanche Forecast

Issued: Apr 9th, 2023 4:00PM

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

Avalanche Canada Mikey, Avalanche Canada

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Snow and strong winds are expected to increase the avalanche hazard. Approach avalanche terrain with caution.

Summary

Confidence

Moderate

Avalanche Summary

Some small loose wet avalanches have been observed on the Canmore Hill.

Snowpack Summary

The warmer weather has penetrated the snowpack and is continuing to weaken it. There have been little night recovery over the last few nights and it look like Sunday night will only reach 0c at 2200m. This means that any kind of heating will only deteriorate the snowpack even more and possibly waken up the deeper layers. Expect to find widespread wind slab developing with the forecast snow and high winds. How this new load will affect the weaker layers underneath is the big question??? In a nut shell, there is lots going on, a lot of inputs on the snowpack and a lot of uncertainty. It is advisable to approach avalanche terrain with caution.

Weather Summary

Interesting weather. Weather models are showing precipitation for Monday to be between 12-30cm and anywhere from 30-50cm by Wednesday. Freezing levels are forecast to be at 2200m with extreme winds from the SW.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Up to now this layer has been somewhat shielded by a mediocre mid-pack. As this mid-pack warms up it will not have a bridging effect anymore. This layer will become more touchy as heat gets absorbed into the snowpack. This weakening applies to ALL terrain. Even polar terrain or slopes with recent tracks on them. Tread cautiously and avoid overhead exposure.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3.5

Persistent Slabs

An icon showing Persistent Slabs

There are two layers of concern here: 1) a buried sun crust (on solar) and facets (on polar) down 20-40cm, and 2) a facet/depth hoar layer down 80-100cm that was buried mid season. The sensitivity of these layers is highly variable so take the time to dig down and evaluate the snowpack. These avalanche problems are more prone to triggering during periods of intense solar radiation.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Wind Slabs

An icon showing Wind Slabs

Extreme winds over the last couple of days and more wind with the coming snow.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 10th, 2023 4:00PM