Bulletin d’avalanche

Lizard-Flathead

Dec 31, 2020 – Jan 1, 2021Avalanche Canada
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Archivé · expiré 6 years ago

Danger d’avalanche

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

Points saillants

The new snow may be easy for riders to trigger on Thursday, particularly in steep and committing terrain. The possibility also remains of triggering buried weak layers, where they exist.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1.5–3

    Weak layers of feathery surface hoar and/or sugary faceted grains above a hard melt-freeze crust remain buried in the snowpack around 50 to 100 cm deep. Although avalanche activity hasn't been reported on these weak layers for over a week, the possibility remains that a rider could trigger them, where they exist.

  • Storm Slabs

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

    The new snow may form small slabs, particularly in exposed terrain where the wind could stiffen it. Steep terrain will be the most suspect. If triggered, the snow could catch riders in committing terrain.

Confidence

Moderate - Forecast precipitation (either snow or rain) amounts are uncertain.

Weather Forecast

WEDNESDAY NIGHT: Cloudy with snowfall, accumulation 5 to 10 cm, 30 km/h west wind, alpine temperature -7 C.

THURSDAY: Partly cloudy, 20 km/h southwest wind, alpine temperature -6 C.

FRIDAY: Cloudy with snowfall, accumulation 5 cm, 20 to 30 km/h southwest wind, alpine temperature -5 C.

SATURDAY: Cloudy with snowfall, accumulation 10 to 20 cm, 40 km/h southwest wind, alpine temperature -5 C.

Avalanche Summary

The 5 cm of new snow was reported as being easy to trigger on Wednesday. As this new snow accumulates overnight, the likelihood of triggering it will increase.

Snowpack Summary

Around 5 to 10 cm is expected to accumulate by Thursday morning. This snow may slide easily, particularly in steep and committing terrain. The slabs may be a bit thicker and touchy in lee terrain features near ridges due to northwest to southwest wind.

In the Lizard Range, a few reports indicate a potential weakness in the snow around 20 to 40 cm deep, potentially on sugary faceted grains around a melt-freeze crust up to an elevation of approximately 1800 m and hard surface above.

Around 50 to 100 cm deep, weak layers of feathery surface hoar and/or faceted grains overly a hard melt-freeze crust. This layer appears to be 

Terrain and Travel

  • Approach lee and cross-loaded slopes with caution.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Régions couvertes