Avalanche Forecast

Issued: Mar 15th, 2024 4:00PM

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

Avalanche Canada JH, Avalanche Canada

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Temperatures are forecast to remain above freezing overnight well in to the alpine.

As the day warms Saturday, widespread natural avalanches are expected, and have the potential to step down to the Feb 3rd crust/facet combo.

Travel in avalanche terrain is not recommended.

Summary

Confidence

Moderate

Avalanche Summary

Natural avalanche activity picked up Friday afternoon, with ongoing warming. We observed several large loose and wet slab avalanches from solar aspects. There was a notable size 3 persistent slab avalanche beside the Grizzly couloir.

Expect natural avalanches to increase in size and frequency with continued warming.

Natural avalanches on the persistent weak layer (over 1m deep) are expected to become widespread as the warmth penetrates deeper into the snowpack.

Snowpack Summary

Radiant cooling during the clear night may create a weak surface crust. Above freezing temps into the alpine will quickly weaken the surface snow on all aspects as the day warms.

A previous suncrust, down 20-40cm, may make a sliding layer for wet slabs.

80-140cm of settled snow sits above a sugary facet layer. These facets are poorly bonded to the widespread, firm crust from Feb 3rd. This is a significant persistent weak layer and will be a concern for the foreseeable future.

Weather Summary

Temperatures continue to rise, with a mass of warm air driving freezing levels up above 3000m (mountain top) over the next couple days.

Tonight: Alpine low 2°C, with a temperature inversion. Light W ridgetop winds.

Sat: Mainly cloudy. Alpine high 3°C, Freezing level (FZL) 2900m. Light W winds.

Sun: Sun/cloud. Low 3°C, High 7°C. FZL 3300m. light SW winds.

Mon: Sun/cloud. Low 2°C, High 4°C. FZL 2500m. Light SW winds.

Terrain and Travel Advice

  • Avoid exposure to overhead avalanche terrain as temperatures increase.
  • If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
  • Avoid traveling in runout zones. Avalanches have the potential to run to the valley floor.

Problems

Persistent Slabs

An icon showing Persistent Slabs

This crust-facet combo (Feb 3rd) was created by a rain event followed by an extended cold, clear period without snow earlier this month. 80-140cm now sits on this persistent weak layer. Natural avalanche activity is expected on this layer as warm temps continue to penetrate the snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Loose Wet

An icon showing Loose Wet

With above freezing temps into the alpine, loose snow avalanches are expected to run on all aspects as the snowpack warms.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2.5

Wet Slabs

An icon showing Wet Slabs

If triggered, these slabs may provide enough mass to trigger the deeper Persistent Weak Layer.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 2.5

Valid until: Mar 16th, 2024 4:00PM