Avalanche Forecast

Issued: Mar 18th, 2019 3:00PM

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

Alberta Parks jeremy.mackenzie, Alberta Parks

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Avoid avalanche terrain. The snowpack is not adjusting well to the rapid change to warm temperatures and intense solar radiation.

Summary

Confidence

High -

Weather Forecast

This week's weather looks sunny and hot for the duration. Tuesday should see high temperatures near +6 at ridge-top and freezing levels climbing to 3100m. Winds will be light from the North. Wednesday and Thursday look similar, if not a bit warmer.

Avalanche Summary

More avalanche activity again today, with slides up to size 2.5. Numerous loose wet avalanches occurred at all elevations. At Treeline and Alpine elevations wind slabs and deep persistent slabs were again active 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 wind slabs to worry about. All evidence points to these wind slabs 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 wind slabs 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

An icon showing Wind Slabs
Wind slabs have become active with the recent heat, and recent avalanches have occurred on all aspects.
Caution in lee and cross-loaded terrain near ridge crests.Be careful with wind loaded pockets while approaching and climbing ice routes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet
Loose wet slides will occur on solar aspects at all elevations as temps warm up. Steep thin areas will be more vulnerable to this type of activity. They may trigger slabs as they gain mass.
If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

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

Elevations: All elevations.

Likelihood

Very Likely - Certain

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
Warmer temps have woken up this layer. Shallow snowpack areas and cornice triggers are of particular concern. This problem deserves respect as any resulting avalanche will be full depth.
Be aware of thin areas that may propogate to deeper instabilites.Be aware of the potential for full depth avalanches due to deeply buried weak layers.Be aware of the potential for wide propagations due to the presence of hard windslabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

2 - 3

Valid until: Mar 19th, 2019 2:00PM