Avalanche Forecast

Issued: Nov 12th, 2023 3:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is below threshold. Known problems include Wind Slabs and Loose Dry.

Avalanche Canada JMackenzie, Avalanche Canada

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A fatal avalanche incident occurred Saturday involving ice climbers in the Ranger Creek area. Lee and cross-loaded features in the Alpine should be avoided.

Summary

Confidence

Low

Avalanche Summary

Numerous wind slabs and loose dry avalanches occurred Saturday up to size 2.0. Many slopes avalanched, then quickly reloaded and slid again. While natural activity tapered on Sunday, avalanche control in an alpine basin with N and E aspects produced numerous size 2.0 avalanches.

A fatal avalanche occurred on Saturday involving ice climbers on the Spray Road. A size 2.0 naturally trigged slab avalanche failed in alpine terrain, ran over a cliff and caught two people in a terrain trap. Unfortunately one person did not survive. Avoid exposure to avalanche terrain as another rapid loading event is possible Monday afternoon.

Snowpack Summary

We now have a persistent weak layer (Nov 10) that is down about 20-40cm in the alpine, 10cm at treeline. Very little is known about this Nov 10th temperature crust, but it appears to be spotty aspect wise, very reactive(slippery) and estimated to be up to 2400m. Wind slabs built very quickly Saturday with lots of visible wind transport. Overall snowpack depth and character is largely unknown as it is early season. From what we have seen and heard total snow depth varies from 10-60cm. Coverage is very inconsistent with LOTS of hidden hazards.

Weather Summary

Monday will be a mix of sun and cloud with a storm rolling through in the afternoon. Strong to extreme winds are expected midday, followed by about 5cm of snow. Temperatures should be near -1C as a high.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid lee and cross-loaded terrain.
  • Be carefull with sluffing in steep terrain, especially above cliffs and terrain traps.
  • Avoid terrain traps where the consequence of any avalanche could be serious.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs in lee and cross-loaded terrain are found in Alpine features. These slabs are resting on a crust from a recent warm spell. There is still some uncertainty around this layer's distribution and character, but for now assume it's widespread and slippery. Slabs won't bond well to this layer.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Loose Dry

An icon showing Loose Dry

Winds will continue to load gully features. Avoid steep, confined terrain. Expect these to run far.

Aspects: North, North East, East, South East, South.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Nov 13th, 2023 3:00PM

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