Bulletin d’avalanche

North Rockies

Mar 16 – 17, 2024Avalanche Canada
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Archivé · expiré 3 years ago

Danger d’avalanche

Mon
Tue
Alpin
4 · Fort
Limite forestière
4 · Fort
Sous la limite
4 · Fort

Points saillants

⚠️ Avoid all avalanche terrain ⚠️A widespread natural avalanche cycle will occur over the next few days.

Check out our latest blog about the forecasted warming.

Problèmes avalancheux

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1.5–3

    Cornices are becoming weak with above-freezing temperatures in the alpine. Cornice failure could trigger very large destructive avalanches. Avoid exposure to slopes that have cornices overhead.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1.5–3

    A weak layer of facets rests above a hard-melt freeze crust that formed early February. We expect to see a widespread avalanche cycle on this layer with intense warming through the weekend.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1–2.5

    Warming and periods of sun will produce widespread wet loose avalanches, especially on steep sun-exposed slopes. These may step-down and trigger deeper slab avalanches.

Confidence

High

Avalanche Summary

On Friday, several natural persistent slab avalanches were observed, primarily on solar aspects, up to size 2.5. Cornice failure, solar input and/or warm temperatures were the triggers for these avalanches. Several natural loose wet avalanches were reported up to size 2.

Widespread natural avalanche activity will continue over the next few days. Avoid all avalanche terrain and exposure from overhead hazards as avalanches could run full path.

Snowpack Summary

Moist snow surfaces extend into the alpine on all aspects. The exception may be the high, shaded north-facing terrain where the surface remained dry.

At treeline and above, 40 cm of storm snow was redistributed by previous winds, leaving widespread wind-affected surfaces in exposed terrain.

A thick and hard widespread crust that formed in early February is buried about 50 to 110 cm deep. This crust has a layer of facets above it in many areas.

The eastern portion of this region is much shallower with a highly variable and wind-affected snowpack.

Weather Summary

Saturday Night

Clear skies. 20 increasing to 40 km/h southwest ridgetop wind. Alpine temperature remains around +6°C. Freezing level between 3200 and 3500 m.

Sunday

Sunny. 20 to 30 km/h southwest ridgetop wind occasionally gusting to 50 km/h. Alpine temperature high +5°C, low +1°C. Freezing level drops through the day from 3200 to 2500 m.

Monday

Mainly sunny. 20 to 30 km/h west ridgetop wind. Alpine temperatures high of +2°C. Freezing level between 1800 and 2500 m.

Tuesday

Mainly cloudy. 10 to 30 km/h southeast ridgetop wind. Alpine temperatures high of -1°C. Freezing level 1500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid runout zones of avalanche paths on solar aspects, avalanches could run full-path if triggered.
  • Choose gentle slopes without steep terrain above.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.

Régions couvertes