Avalanche Forecast

Issued: Jan 7th, 2025 4:00PM

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

Avalanche Canada Avalanche Canada, Avalanche Canada

Email

Storm slabs remain reactive to human triggers.Conservative terrain choices and avoiding overhead hazard is strongly recommended.

Summary

Confidence

Moderate

Avalanche Summary

The field team remotely triggered a large (size 2) storm slab that stepped down to the persistent weak layer on Tuesday by the Fraser Chutes. They also experienced signs of instability like whumpfing and shooting cracks in many steeper wind loaded pockets.

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

Snowpack Summary

Up to 30 cm of new snow accompanied by strong southerly winds built storm slabs on Monday night. The majority of the snow fell in White Pass, with drastically less snow falling further inland. An additional 2 to 10 cm is expected by end of day Wednesday.

Due to the forecast winds, we expect the most reactive storm slabs will be on north-facing slopes.

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

Tuesday Night

Cloudy with 0 to 5 cm of new snow. 50 km/h southwest ridgetop wind. Treeline temperature -4 °C.

Wednesday

Cloudy with 0 to 6 cm of snow. 50 to 60 km/h southwest ridgetop wind. Treeline temperature -3 °C.

Thursday

Cloudy with 10 to 20 cm of snow. 60 to 70 km/h southeast ridgetop wind. Treeline temperature -3 °C.

Friday

Cloudy with 3 to 10 cm of snow. 60 km/h southwest ridgetop wind. Treeline temperature 0 °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

Up to 30 cm of storm snow has build reactive slabs. The safest riding will be found on lower angle slopes with no overhead hazard.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A crust buried 40 to 70 cm with weak crystals overtop, could trigger larger than expected avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1.5 - 2.5

Valid until: Jan 8th, 2025 4:00PM

Login