Avalanche forecast

North Rockies

Mar 21 – 22, 2023Avalanche Canada
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Avalanche danger

Thu
Fri
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 steep, rocky, and wind effected areas where triggering slabs is more likely.

Avalanche problems

  • Wind Slabs

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

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

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Strong solar radiation will increase the likelihood of wet loose avalanches on sunny aspects in the alpine.

  • 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

High

Avalanche Summary

Numerous size 1-1.5 wet loose avalanches triggered by solar radiation were reported on sunny aspects at upper elevations on Monday.

Snowpack Summary

Expect to find a melt-freeze crust on the surface of all aspects at treeline and below and on sunny aspects in the alpine. Solar radiation will break down the crust on sunny slopes throughout the day.

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

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

A weak layer of large 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. The most likely areas to trigger this layer are shallow, rocky areas or where the snowpack transitions from thin to thick.

Weather Summary

Tuesday Night

Clear skies / 30 km/h west ridgetop wind / Temperature at treeline around -7 C / Freezing level valley bottom

Wednesday

Mostly sunny / 30 km/h southwest ridgetop wind / Temperature at treeline around -3 C / Freezing level 1700 m

Thursday

Mix of sun and cloud / 20 km/h south ridgetop wind / Temperature at treeline around -3 C / Freezing level 1700 m

Friday

Cloudy with isolated flurries; 0-3 cm / 10 km/h east ridgetop wind / Temperature at treeline around -7 C / Freezing level 800 m

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Cornice failure may trigger large avalanches.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

Regions covered