Avalanche Forecast

Issued: Jan 7th, 2025 4:00PM

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

Avalanche Canada Avalanche Canada, Avalanche Canada

Email

It's a good day to make conservative choices.

Stick to low-angle below treeline slopes, with no overhead hazard from big avalanche terrain.

Summary

Confidence

Moderate

Avalanche Summary

On Monday, north of Stewart, a vehicle triggered a size 1.5 slab on the persistent weak layer. It failed on a northwest slope in the alpine. A few wind slabs size 1 to 2 were also observed across the region.

We expect a widespread natural avalanche cycle to be ongoing, and to continue overnight and into Wednesday. The potential for human-triggered avalanches is expected to be almost certain during this stormy period.

Snowpack Summary

15 to 30 cm of snow fell throughout the day Tuesday. An additional 10 to 20 cm accompanied by moderate to strong westerly ridgetop winds is forecast to fall overnight. This combination is expected to form fresh storm slabs and deep wind-deposits on leeward slopes.

We expect the accumulated storm slabs to be especially touchy wherethey are sitting on a layer of buried surface hoar, facets, or a thin crust, in some areas.

A persistent weak layer of surface hoar and facets overlying a crust. It is buried 60 to 120 cm deep in the southern parts of the region, and up to 200 cm deep in areas north of Stewart.

The snow surface may be moist, wet or crusty below 1100m.

Weather Summary

Tuesday Night

Cloudy with 10 to 20 cm of snow near Terrace, 0 to 5 cm near Stewart. 40 km/h west ridgetop wind. Treeline temperature -2 °C. Freezing level ~ 1100m.

Wednesday

Cloudy, with 0 to 3 cm of snow. 35 to 45 km/h west ridgetop wind. Treeline temperature -2°C. Freezing level ~ 1100m.

Thursday

Cloudy with 15 to 25 cm of snow. 80 to 100 km/h south ridgetop wind. Treeline temperature -1 °C. Freezing level rising to ~1400 m near Terrace.

Friday

Cloudy with 2 to 10 cm of snow. 50 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level rising to ~1000 m.

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.
  • Avoid exposure to overhead avalanche terrain; avalanches may run surprisingly far.
  • Don't let the desire for deep powder pull you into high consequence terrain.

Problems

Storm Slabs

An icon showing Storm Slabs

New snow and strong west winds are expected to build reactive new storm slabs. The highest danger will be on steep, leeward slopes below ridgetops.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

This weak layer has demonstrated extensive propagation across terrain features following the last big storm. With the incoming weather, it has the potential to trigger very large natural and human-initiated avalanches again.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3.5

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

Login