Bulletin d’avalanche

Waterton Lakes

Dec 24 – 27, 2015Parks Canada
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Archivé · expiré 11 years ago

Danger d’avalanche

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

Don't let powder euphoria override your judgement - think carefully before entering big slopes, or traveling above terrain traps.  Buried wind slabs and a weakening buried crust may both make slopes difficult to evaluate. 

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3
    The existing Wind Slabs are variable in size and distribution. Watch for new wind slab development if forecast periods of Moderate Westerly winds eventuate.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–3
    A large natural slab avalanche was observed today, that may have released at a buried crust from early December. For now, it is unclear if this will remain an isolated event, or if this layer is becoming more sensitive to loads.

  • Loose Dry

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

Weather Forecast

An Arctic front slowly slips over us tomorrow, bringing flurries tonight & tomorrow. Most models predict 3 - 5cm of snowfall. Some periods of Moderate W winds at ridges. Already cool temperatures will fall sharply late tomorrow. For Friday, expect an improvement in the weather, and temperatures in the -8 to -14 range. Saturday is looking clear.

Snowpack Summary

Up to 20cm of low density snow has fallen since Dec 20 with Light NE winds, before a period of Moderate NW wind yesterday evening. This has buried wind slabs formed by previous strong SW winds. Below this is the Dec 9th crust (down 40-80cm), which has become a concern as a potential weak layer. Two more crusts exist in a strong lower snowpack.

Avalanche Summary

One large slab avalanche failed naturally within the last 24 hours, on an open slope at Treeline elevation on the Eastern aspect of Mt Rowe. Also, several size 1 loose snow avalanches, both natural and human triggered have been observed over the past two days.

Confidence

Due to the number of field observations

Régions couvertes