Avalanche Forecast

Issued: Mar 19th, 2024 4:00PM

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

Avalanche Canada lbaker, Avalanche Canada

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

Summary

Confidence

Moderate

Avalanche Summary

On Monday, evidence of previous widespread natural avalanche cycle from the prolonged heat continued to be reported. It is suspected most of these avalanches are 24 to 72 hours old. Through the weekend loose wet, wet slab and persistent slab avalanche activity was observed on every aspect up to size 3. Steep rocky terrain and direct solar slopes were the most impacted.

On Sunday, a size 1.5, skier remote, persistent slab avalanche was reported on a northwest aspect at 2200 m.

Snowpack Summary

As temperatures slowly cool expect to find a melt-freeze crust that covers the snow surface at all elevations. Daytime heating may soften the crust in some places making surfaces moist. The exception is on direct north-facing terrain above 1900 m where the surface remained dry through the week.

The top 30 cm of the snowpack is moist snow. 60 to 170 cm down is a layer of facets overlying a crust. This layer has been the culprit for many recent large avalanches through the extended warm period. It remains a concern on northerly aspects above 1800 m, where the layer may still be reactive to human triggering.

Below the crust, the snowpack is well settled.

Weather Summary

Tuesday Night

Partly cloudy. 20 to 40 km/h southwest ridgetop wind. Treeline temperature +1 °C with freezing levels falling from 2200 to 1800m by morning.

Wednesday

Partly cloudy. 10 to 25 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing levels 1800m.

Thursday

Cloudy with 1 to 5 cm of snow. 10 to 25 km/h northwest ridgetop wind. Treeline temperature -1 °C. Freezing levels rise from 1000 to 1600m in the afternoon.

Friday

Cloudy with 1 to 2 cm of snow. 10 to 20 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing levels rise from 500 to 1300m in the afternoon.

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.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Rocks will heat up with daytime warming and may become trigger points for loose wet avalanches

Problems

Persistent Slabs

An icon showing Persistent Slabs

Concern remains for human-triggering the persistent weak layer on sheltered north aspects above 1800 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

Loose Wet

An icon showing Loose Wet

Where the upper snowpack remains moist, wet loose avalanches may still be reactive to human triggering in steep terrain. Be especially cautious on slopes seeing direct sun and near rock outcrops.

Aspects: All aspects.

Elevations: Below Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Mar 20th, 2024 4:00PM