Avalanche Forecast

Issued: Feb 27th, 2024 4:00PM

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

Avalanche Canada lbaker, Avalanche Canada

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Very dangerous avalanche conditions exist at higher elevations. Avoid all avalanche terrain.

Widespread natural avalanche activity is expected with heavy snowfall and strong winds.

Summary

Confidence

High

Avalanche Summary

On Monday, a size 2 skier accidental persistent slab was reported north of Pemberton. This avalanche occurred on a north aspect at 1800 m and failed on a weak layer of preserved surface hoar.

Several remotely triggered persistent avalanches were reported up to size two throughout the region. This is a clear sign the persistent weak layer is primed for human-triggering.

Evidence of a size 3, persistent slab avalanches was observed in the Duffey area.

Snowpack Summary

Storm snow accumulates over wind-affected surfaces and old wind slabs in exposed areas and settling snow in sheltered areas.

Multiple weak layers exist in the upper and mid snowpack. The most concerning weak layer is a widespread crust down 20 to 80 cm with a weak layer of facets or isolated surface hoar above this crust. This problematic layering is very concerning with recent large avalanche activity attributed to it.

Weather Summary

Tuesday Night

Partly cloudy with 2 to 8 cm of snow. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -10 °C. Freezing levels remain at valley bottom.

Wednesday

Cloudy with 20 to 35 cm of snow. 30 to 40 km/h southwest ridgetop wind. Treeline temperature rises to -4 °C. Freezing level rises to 1200 m throughout the day.

Thursday

Partly cloudy with 0 to 5 cm of snow. 10 to 25 km/h southwest ridgetop wind. Treeline temperature -8 °C. Freezing levels around 800 m.

Friday

A mix of sun and cloud with 1 to 3 cm of snow. 20 to 30 km/h south ridgetop wind. Treeline temperature -8 °C. Freezing levels around 800 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
  • Watch for fresh storm slabs building throughout the day.
  • Storm slab size and sensitivity to triggering will likely increase through the day.
  • If triggered, storm slabs in-motion may step down to deeper layers and result in very large avalanches.

Problems

Persistent Slabs

An icon showing Persistent Slabs

A problematic weak layer from early February, of facets overlying a crust, is becoming increasingly triggerable. This layer was the culprit of recent human-triggered avalanches in the region.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 3

Storm Slabs

An icon showing Storm Slabs

As snow accumulates through the day watch for storm snow becoming a cohesive slab and increasingly reactive to triggers. Deeper deposits are expected in north and east facing terrain around ridgelines.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2.5

Valid until: Feb 28th, 2024 4:00PM

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