Avalanche forecast

North Rockies

Mar 12 – 13, 2023Avalanche Canada
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Avalanche danger

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

Strong northeasterly winds have formed wind slabs on lee aspects at treeline and above.

Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Strong northeasterly winds have formed fresh wind slabs on lee aspects at treeline and above.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    2.5–4

    A weak layer of facets exists near the base of the snowpack. The likelihood of human triggering is low given the layer's depth, but large triggers such as cornice failures or smaller avalanches in motion have the potential to produce very large avalanches with surprisingly wide propagation. Suspect terrain for human triggering includes steep, shallow, and rocky terrain where the snowpack transitions from thin to thick.

Confidence

Moderate

Avalanche Summary

A couple small (size 1.5) naturally triggered wind slabs on steep west aspects in the alpine were reported on Friday.

A notable very large avalanche triggered by a cornice fall was reported in the pine pass area last weekend. See MIN.

Snowpack Summary

Strong northeast have formed fresh wind slabs on lee aspects at treeline and above.

Thin sun crust can be found a steep, sunny slopes. Soft snow can be found in areas sheltered from wind and sun.

The middle of the snowpack is generally well settled and strong.

A weak layer of large and weak facets is found near the base of the snowpack. This layer is of greatest concern in shallow snowpack areas in the north and east of the region.

Weather Summary

Saturday Night

Partly cloudy with isolated flurries; 0-3 cm / Light south ridgetop wind / Low temperature at treeline around -20 C

Sunday

Mix of sun and cloud / Light south ridgetop wind / High temperature at treeline around -7 C

Monday

Mix of sun and cloud with isolated flurries; 3-5 cm / Strong south ridgetop wind / High temperature at treeline around -7 C

Tuesday

Mix of sun and cloud with isolated flurries; 3-5 cm / Strong southwest ridgetop wind / High temperature at treeline around -4 C

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
  • Sheltered low elevation terrain will likely offer the best and safest riding today.

Regions covered