Avalanche forecast

Northwest Coastal

Jan 12 – 13, 2025Avalanche Canada
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Avalanche danger

Tue
Wed
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Continue to make conservative terrain choices while the storm snow settles and bonds to underlying layers

Careful route selection and avoiding overhead hazard is recommended

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–3.5

    While the likelihood of triggering a persistent slab has dropped following the storm, the consequences remain very serious.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    Storm slabs have shown wide propagation where they sit over weak surface hoar crystals. Potential remains for storm slabs to step-down down to deeper persistent weak layers.

Confidence

Moderate

Avalanche Summary

Numerous large and very large storm slabs up to size 3, occurred across the region over the last few days of stormy weather. Notably, only a few cases failed on the persistent weak layer.

Skiers have also reported widespread whumpfing and shooting cracks.

Looking forward, we expect natural avalanche activity to taper off, but for human triggering to remain likely at upper elevations.

Snowpack Summary

40 to 80 cm of recent storm snow has accumulated in the alpine, and is now settling rapidly with the mild temperatures. Some of this new snow fell as rain, with the rain/snow line around 900 -1200 m. A crust or wet snow may exist below those elevations.

The storm snow may be slow to bond because it sits on surface hoar, facets, or a thin crust.

Strong winds from various directions have been redistributing the new snow, building deeper and more reactive deposits on lee slopes.

A persistent weak layer of surface hoar and facets overlying a crust is buried 90 to 140 cm deep in the southern parts of the region, and up to 240 cm deep in areas north of Stewart. Avalanches failing on this layer will be very large and destructive.

Weather Summary

Saturday Night

Cloudy with 0 to 3 cm of snow. 50 km/h west ridgetop wind. Treeline temperature -2 °C.

Sunday

Partly cloudy. 25 to 35 km/h west ridgetop wind. Treeline temperature -2 °C.

Monday

Cloudy with 5 to 15 cm of snow. 55 km/h southwest ridgetop wind. Treeline temperature -1 °C.

Tuesday

Cloudy with 20 to 40 cm of snow. 80 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1300 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be aware of the potential for remote triggering and large avalanches due to buried surface hoar.
  • Be especially cautious as you transition into wind-affected terrain.
  • Keep in mind that human triggering may persist as natural avalanches taper off.
  • Be mindful that deep instabilities are still present and have produced recent large avalanches.

Regions covered