Avalanche forecast

Microwave-Sinclair

Apr 18 – 19, 2025Avalanche Canada
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Avalanche danger

Sun
Mon
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Highlights

Lingering concern remains for buried weak layers in the snowpack. A cautious approach is recommended during times of uncertainty.

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–2.5

    Use extra caution around cornices. A cornice fall would be the most likely trigger for a persistent slab avalanche.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–3

    Uncertainty remains about the reactivity of weak layers in the snowpack, and they continue to produce concerning, but isolated, results in snowpack tests. It's worth remaining cautious until we gain more confidence in these layers.

Confidence

Low

Avalanche Summary

On Thursday, a skier triggered a size 2 wind slab on a NE aspect at 2350 m, which was 10-20 cm thick. Natural wet loose avalanches up to size 2.5 and natural cornice releases were also observed.

On Wednesday, a natural cornice fall triggered a size 2.5 wind slab in the west of the region. This occurred on a NW aspect at 2300 m, and the slab was 100 cm thick.

Snowpack Summary

A widespread surface crust is expected to have formed following Thursday's warming event.

Two layers currently exist in the mid-snowpack and remain an isolated concern:

  • A layer of surface hoar that formed in early March can be found at a depth of 40 to 70 cm.

  • A layer of facets, surface hoar, and/or a crust from mid-February is buried 60 to 120 cm deep.

Weather Summary

Friday Night

Cloudy with snowfall up to 3 cm. 30 to 40 km/h west ridgetop wind. Treeline temperature -5 °C. Freezing level valley bottom.

Saturday

Cloudy with snowfall up to 6 cm. 20-30 km/h northwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1100 m.

Sunday

A mix of sun and cloud with lingering flurries in the morning. 10 to 20 km/h northwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1400 m.

Monday

Mostly sunny. 10 to 20 km/h northwest ridgetop wind. Treeline temperature +1 °C. Freezing level 1600 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be aware of the potential for large avalanches due to buried weak layers.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
  • If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.

Regions covered