Bulletin d’avalanche

Lizard-Flathead

Mar 31 – Apr 1, 2017Avalanche Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

Sun
Mon
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Avalanche Danger is slowly trending down. The snowpack has seen a lot of change in the last few days, and it may need another day to adjust. Conservative terrain choices are recommended.

Problèmes avalancheux

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    2–3
    Cornices may continue to be weak and naturally shed the recent cornice growth. Cornice falls may release storm slab avalanches on the slopes below.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–3
    Recent storm slabs may continue to be reactive to human triggering. This is most likely in shaded alpine areas where the snow may be drier.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2
    The snow may become moist or wet early in the day if there is not a good re-freeze overnight.

Confidence

Moderate - Freezing levels are uncertain on Saturday

Weather Forecast

Overnight: Cloud developing overnight that will keep the freezing level close to 2000 metres. Saturday: Overcast with flurries or light snow combined with moderate westerly winds and daytime freezing around 2100 metres. Sunday: A cooler day with a mix of sun and cloud. Moderate westerly winds and freezing around 1500 metres. Monday: Re-freeze to valley bottom expected. Chance of snow developing from the northeast.

Avalanche Summary

Numerous storm slab avalanches up to size 2.5 reported from explosives control on Friday, as well as loose wet avalanches released by ski cuts up to size 1.5. Numerous storm slab and loose wet avalanches were reported from the Fernie area on Thursday. One natural cornice fall was size 3.0, and pulled a storm slab from the slope below. There is concern for storm slabs to continue to be reactive to human triggering if there is little or no re-freeze before another warm day on Saturday.

Snowpack Summary

Storm slabs in the alpine received a big punch of solar radiation on Friday. Sheltered slopes may continue to be dry and may not be well bonded to the old surface. At treeline and below the snow is moist or wet, and may not get a good re-freeze overnight before another forecast warm day with high freezing levels. The deep persistent weak layer of facets and crust that was buried early in the winter may "wake-up" due to this prolonged warming and recent loading. This deep problem is difficult to forecast, and the best strategy may be to avoid large terrain features until the snowpack cools and adjusts to the recent inputs (ie loading, sun, wind, and temperature fluctuations).

Régions couvertes