Bulletin d’avalanche

Northwest Inland

Mar 1 – 2, 2022Avalanche Canada
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Archivé · expiré 5 years ago

Danger d’avalanche

Thu
Fri
Alpin
2 · Modéré
Limite forestière
1 · Faible
Sous la limite
1 · Faible

Points saillants

Reactive wind slabs continue to form in upper treeline and high alpine leeward features. Continue to investigate the crust that was buried on February 9th as it now has a 50-70cm thick slab above it that could produce larger avalanches. 

Problèmes avalancheux

  • Wind Slabs

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

    The most likely place to trigger a wind slab is near ridge crest and on convex terrain features. Use extra caution when dropping into a run, highmarking, or travelling on ridges. 

  • Persistent Slabs

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

    A stout crust from mid-February is now buried 50-70cm below the surface. This interface has not been exhibiting reactivity but the recipe for avalanches is there so this layer should continue to be investigated and treated with respect.  

Confidence

Moderate -

Weather Forecast

Monday night: Mostly cloudy. 5cm of new snow overnight. Winds moderate from the southwest to southeast. -5°C.

Tuesday: Mostly cloudy. 5cm of new snow. Winds moderate from the south. -5°C.

Wednesday: A mix of sun and cloud. No precipitation. Winds light and variable. A low of -4°C and a high of 0°C.

Thursday: A ridge starts to build bringing a mix of sun and cloud. No precipitation. Winds light and variable. A low of -5°C and a high of 1°C. 

Avalanche Summary

No new avalanches were reported over the weekend. 

Snowpack Summary

Monday and Tuesday will bring 10-15cm of snow which will get blown into small wind slabs in upper treeline and alpine leeward features. Wind slabs continue to form on a variety of surfaces including wind effected slopes, facets, or weak feathery surface hoar crystals in sheltered areas. 

The upper snowpack appears to be bonding to a rain crust now buried 50-70cm. However, the field team did observe reactivity in test profiles on this layer (ECTP29) and the recipe for avalanches exists at this interface.

The lower snowpack is effectively capped, making human triggering of avalanches on deeper weak layers unlikely.

Terrain and Travel

  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • Highmark or enter your line well below ridge crests to avoid wind loaded pillows.
  • Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.
  • Keep in mind the crust offers an excellent bed surface for avalanches.

Régions couvertes