Avalanche Forecast

Issued: Jan 6th, 2025 4:00PM

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

Avalanche Canada Avalanche Canada, Avalanche Canada

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Overnight snowfall and strong wind are increasing the avalanche hazard, especially in White Pass

Conservative terrain choices and avoiding overhead hazard is strongly recommended.

Summary

Confidence

Moderate

Avalanche Summary

The most recent avalanche reports are from last Wednesday, this MIN reported whumping and shooting cracks.

Last Tuesday, a large (size 2) avalanche failed on the persistent weak layer. Click on the photo below for details.

We expect the likelihood of both natural and human-triggered avalanches to increase in White Pass during this stormy period.

Snowpack Summary

5 to 25 cm of new snow accompanied by extreme southerly winds is expected to form fresh storm slabs overnight Monday. Due to the forecast winds, we expect the most reactive storm slabs will be on north-facing slopes. White Pass is expected to get the highest precipitation amounts, with drastically less snow falling further inland.

An additional concern is a persistent weak layer of a crust with overlying facets, and in some cases surface hoar. This interface is currently buried 20 to 30 cm deep and extends up to 1750 m.

Despite the presence of faceted grains in the lower snowpack, there are no current layers of concern below the crust. 

Snowpack depths range from about 70 to 180 cm.

Weather Summary

Monday Night

Cloudy with 5 to 25 cm of new snow. White Pass is expected to get the highest amounts, with drastically less snow further inland. Extreme south ridgetop winds: 75 to 85 km/h. Treeline temperature 0 °C.

Tuesday

Cloudy with 0 to 5 cm of snow. Extreme southwest ridgetop winds: 70 to 90 km/h. Treeline temperature -2 °C.

Wednesday

Cloudy with 0 to 5 cm of snow. 50 to 60 km/h southwest ridgetop wind. Treeline temperature -3 °C.

Thursday

Cloudy with 5 to 15 cm of snow. 60 to 80 km/h south ridgetop wind. Treeline temperature -2 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Be careful as you transition into wind-affected terrain.

Problems

Storm Slabs

An icon showing Storm Slabs

Snowfall and extreme winds are forecast to build storm slabs overnight Monday. The safest riding will be found on lower angle slopes with no overhead hazard.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A buried crust with weak crystals overtop may be overloaded by the new snow snow, triggering larger than expected avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 2.5

Valid until: Jan 7th, 2025 4:00PM

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