Avalanche forecast

North Rockies

Mar 17 – 18, 2023Avalanche Canada
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Avalanche danger

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

Lingering wind slabs may remain reactive to human triggers in isolated locations at upper elevations.

Avoid shallow, rocky areas or where the snowpack transitions from thin to thick.

Avalanche problems

  • Wind Slabs

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

    Lingering wind slabs may remain reactive to human triggers in isolated locations at upper elevations.

  • 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 cornice triggered wind slabs up to size 2.5 were reported on steep, northerly aspects in the alpine on Thursday.

Snowpack Summary

Southerly winds continue to redistribute the 15 to 25 cm of recent snow. Higher-elevation wind slabs may remain reactive. March sun and warm daytime temperatures may begin to have an effect on the snowpack. Crusts may form on steep solar slopes and at low elevations.

The new snow is sitting on generally hard surfaces from extensive wind effects or a thin sun crust on steep, sunny slopes.

The middle of the snowpack is generally well-settled and consolidated.

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

Weather Summary

Friday Night

Partly cloudy / 20 km/h southwest ridgetop wind / Temperature at treeline around -8 C / Freezing level valley bottom

Saturday

Mix of sun and cloud / 10 km/h southwest ridgetop wind / Temperature at treeline around -2 C / Freezing level 1700 m

Sunday

Sunny / 20 km/h southeast ridgetop wind / Temperature at treeline around -1 C / Freezing level 1800 m

Monday

Mix of sun and cloud / 40 km/h southeast ridgetop wind / Temperature at treeline around -2 C / Freezing level 1700 m

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
  • 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.

Regions covered