Bulletin d’avalanche

South Rockies

Apr 13 – 14, 2014Avalanche Canada
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Archivé · expiré 12 years ago

Danger d’avalanche

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

Avalanche danger can rise very quickly with warming and solar radiation. Be aware of changing conditions and overhead hazards. Terrain choices and timing can be critical.

Problèmes avalancheux

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–4
    Daytime heating makes cornices droop and become unstable. Also, if anything is still able to trigger a deep persistent weak layer, it's a cornice release.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–3
    Periods of intense solar radiation or pronounced warming could result in some loose wet activity, especially on steep slopes.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–5
    The forecasted intense solar and warm temperatures could trigger the deeply buried weak layer especially on the slopes that have not seen such a heat shock yet. 

Confidence

Fair - Due to the number of field observations

Weather Forecast

Tonight and Monday: The ridge of high pressure bringing clear and warm conditions remains over the province. Clouds will start building as a low pressure system approaches later in the day. Expect freezing levels to be near 2500 m and light to moderate North West winds.Tuesday:  A trace of precipitation is forecasted with light North West winds, freezing levels going from 1200 m at night and rising to 1500 m during the day.  Wednesday: Mainly cloudy, a possibility of light precipitation, freezing levels around 1700 m.

Avalanche Summary

Natural loose dry avalanches up to size 2 were reported in Waterton Lakes area. These would have initiated in the new snow sluffing on the underlying crust on shaded aspects in the alpine.  Small wet loose avalanches were also reported on the solar aspects in the same region.

Snowpack Summary

Yesterdays light accumulation (~15 cm) is sitting on a crust in most places. Todays above freezing temperatures up to ~2000 m and intense solar radiation would have contributed to the creation of another melt-freeze crust on all aspects below this elevation and higher up on solar aspects. Snow stability is expected to decrease as the day progresses tomorrow, weakening the fresh windslabs and cornices in the alpine. The deep facet/crust persistent weakness buried at the beginning of February (now down up to 80-100 cm) should stay on your radar, especially on all alpine slopes that will see the intense sun tomorrow. Any activity at this interface would be large and destructive.

Régions couvertes