Avalanche Forecast

Issued: Mar 20th, 2024 4:00PM

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

Avalanche Canada lbaker, Avalanche Canada

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Avalanche hazard may have improved, but be mindful that deep instabilities are still present and remain possible to human trigger.

Summary

Confidence

Moderate

Avalanche Summary

On Tuesday, explosives control targeting cornices produced a few size 2 avalanches.

Through the prolonged warming event, avalanche activity in the region was observed up to size 4. Steep rocky terrain and direct solar slopes were the most impacted. Evidence of this natural avalanche cycle will still be visible to backcountry users who head into the mountains on Thursday.

Snowpack Summary

A dusting of snow overlies a melt-freeze crust that covers the snow surface at all elevations. The exception is on direct north-facing terrain above 2000 m where the surface remained dry through the prolonged warming. Below the crust is 50 to 80 cm of moist snow.

100 to 250 cm down is a weak layer of facets overlying a crust. This layer was the culprit in many very large avalanches through the extended warm period. Uncertainty remains around how long this layer will persist with cooler temperatures.

Below the crust, the snowpack is well settled.

Weather Summary

Wednesday Night

Mainly cloudy with 0 to 4 cm of snow. 10 to 20 km/h southwest ridgetop wind. Treeline temperature -3°C. Freezing levels fall to 1300 m.

Thursday

Cloudy. 5 to 15 km/h west ridgetop wind. Treeline temperature -2°C. Freezing level 1500m.

Friday

Cloudy with 2 to 5 cm of snow. 10 to 25 km/h southeast ridgetop wind. Treeline temperature -2°C. Freezing level 1500m.

Saturday

Partly cloudy with 1 to 4 cm of snow. 10 to 25 km/h northeast ridgetop wind. Treeline temperature -2°C. Freezing level 1500m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Keep in mind that human triggering potential persists as natural avalanching tapers off.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
  • A crust on the surface will help bind the snow together, but may make for tough travel conditions.

Problems

Persistent Slabs

An icon showing Persistent Slabs

Concern remains for human-triggering the persistent weak layer on sheltered north aspects above 2000 m. If triggered avalanches will be large and destructive. Avoid shallow snowpack areas where triggering is more likely.

Aspects: North, North East, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 3.5

Valid until: Mar 21st, 2024 4:00PM