Bulletin d’avalanche

Lizard-Flathead

Apr 4 – 5, 2021Avalanche Canada
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Archivé · expiré 5 years ago

Danger d’avalanche

Tue
Wed
Alpin
2 · Modéré
Limite forestière
1 · Faible
Sous la limite
1 · Faible

Points saillants

Watch for cornices and wind slabs near ridgetops and be cautious on sun-exposed slopes. 

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–1.5

    Convective flurries and southwesterly winds on Sunday may have formed small wind slabs on lee features below alpine ridgetops.

  • Cornices

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

    Cornices are large and looming along many ridgelines. They are capable of triggering large avalanches when they fail.

Confidence

High -

Weather Forecast

SUNDAY NIGHT: Cloudy with isolated flurries bringing 2-5 cm of snow, light northeast wind, freezing level dropping to valley bottom with treeline temperatures dropping to -5 C.

MONDAY: Sunny with a few clouds, light west wind, treeline temperatures reach 0 C with freezing level climbing to 2000 m.

TUESDAY: Sunny, light southwest wind, treeline temperatures reach +2 C with freezing level climbing to 2200 m.

WEDNESDAY: Increasing cloud and some light afternoon flurries, 40 km/h southwest wind, freezing level around 2000 m.

Avalanche Summary

No avalanches were reported on Saturday at the time of publishing. On Friday, naturally triggered wet loose avalanches up to size 1.5 were reported on steep solar aspects in the alpine.

Snowpack Summary

5-15 cm of heavy powder is sitting above crusts on all but north facing terrain at upper elevations. Some small wind slabs may be found on lee features below alpine ridgetops. Cornices are large, looming, and capable of triggering avalanches when they fail.

The mid-pack is firm and well settled. Some faceted snow and a decomposing melt-freeze crust can be found near the base of the snowpack. 

Glide cracks releasing as full depth glide slab avalanches become more common in the spring and are extremely difficult to predict. Best practice is to avoid slopes with glide cracks.

Terrain and Travel

  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Carefully evaluate steep lines for wind slabs.
  • Be alert to conditions that change with elevation and sun exposure.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.

Régions couvertes