Bulletin d’avalanche

Northwest Inland

Mar 24 – 25, 2022Avalanche Canada
Voir sur la carte
Archivé · expiré 5 years ago

Danger d’avalanche

Sat
Sun
Alpin
2 · Modéré
Limite forestière
1 · Faible
Sous la limite
1 · Faible

Points saillants

Evaluate your line for wind slabs and cornice exposure before committing to consequential terrain.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    Wind slabs likely remain triggerable at elevations where the snow has remained dry. Watch for drifted or wind loaded snow in leeward terrain features with sharp changes in slope angle like ridge crests, ribs and convexities.

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1.5–2.5

    Cornices have undergone rapid growth. Recently reported cornice failures have triggered wind slabs on slopes below.

Confidence

High -

Weather Forecast

Wednesday night: Mostly cloudy. Moderate to strong southeast wind. Alpine low around -7 °C. Freezing level dropping to 800 m. 

Thursday: A mix of sun and cloud. Light southeast wind. Alpine high around -5 °C. Freezing level 1200 m.

Friday: Cloudy with sunny periods. Light to moderate south wind. Alpine high around -6 °C. Freezing level 1100 m.

Saturday: Clouds clearing. Light wind. Alpine high around -5 °C. Freezing level 1200 m.

Avalanche Summary

Several natural wind slab avalanches have been observed this week size 1.5-3, some of them triggered by cornice failures. During the rain event on Tuesday, loose wet avalanches were reported up to size 1.5 at 1800 m and lower. 

Snowpack Summary

Wet snow or crusty conditions can be found at least as high as 1700 m. Wind slabs may be found at high elevations that have remained dry.

A couple of layers of weak crystals in the upper snowpack appear to be bonding according to recent snowpack tests. Additionally, we suspect that the surface crust will help bridge these layers, further decreasing their likelihood of triggering.

A thick crust 50-80 cm deep which formed in mid-February effectively bridges any underlying instabilities in the lower snowpack.

Terrain and Travel

  • A crust on the surface will help bind the snow together, but may make for tough travel conditions.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.

Régions couvertes