Bulletin d’avalanche

North Rockies

Mar 10 – 11, 2022Avalanche Canada
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Archivé · expiré 5 years ago

Danger d’avalanche

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

Points saillants

 Recently formed wind slabs may remain reactive to human triggers on steep and/or convex slopes.

Cornices are very large in many areas. Cornice failures may trigger large avalanches on the slopes below.

Problèmes avalancheux

  • Wind Slabs

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

    Recently formed wind slabs may remain reactive to human triggers on steep and/or convex slopes; especially where they are sitting on a slippery sun crust or a weak layer of surface hoar.

    Cornices are very large in many areas. Cornice failures may trigger large avalanches on the slopes below.

Confidence

High -

Weather Forecast

WEDNESDAY NIGHT: Increasing cloudiness / Strong northwest winds / Low of -17 / Freezing level surface.

THURSDAY: Mostly cloudy / Light northwest wind / High of -7 / Freezing level surface.

FRIDAY: Cloudy with isolated flurries; 0-5 cm / Strong west wind / High of -2 / Freezing level rising to 1200 m.

SATURDAY: Snow; 5-15 cm / Strong northwest wind / High of -2 / Freezing level 1200 m.

Avalanche Summary

No new avalanches were reported on Tuesday.

A skier triggered size 1.5 wind slab was reported on a east aspect below a treeline ridgetop on Monday. The wind slab was sitting on a layer of recently buried surface hoar which resulted in wide propagation of the slab.

Riders may get surprised by widely propagating wind slabs that are sitting on crusts and/or surface hoar.

Snowpack Summary

10-15 cm of recent snow and west/northwest winds have formed wind slabs on lee features at treeline and above. These slabs may remain more reactive on south facing slopes where they are sitting on a slippery sun crust. Below the recent snow, there may be a layer of small surface hoar that is likely most pronounced on northerly aspects or sheltered locations.

Lower elevations have seen warm temperatures last week and have a melt freeze crust on the surface. 

The mid and lower snowpack is generally well-settled and strong in most areas, with multiple crusts throughout. No recent persistent slab avalanches have been reported on these layers.

Terrain and Travel

  • Cornice failure may trigger large avalanches.
  • Minimize your exposure time below cornices.
  • Carefully evaluate steep lines for wind slabs.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Use ridges or ribs to avoid areas of wind loaded snow.

Régions couvertes