Bulletin d’avalanche

Northwest Inland

Apr 9 – 10, 2013Avalanche Canada
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Archivé · expiré 13 years ago

Danger d’avalanche

Thu
Fri
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
1 · Faible

Points saillants

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–4
    Thin new wind slabs are likely in exposed lee terrain and cross-loaded features. Triggering may be possible in steep terrain.
  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–6
    Large cornices may be weak and fall off naturally during warm temperatures or from increased loading.
  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–4
    Loose wet avalanches are possible at lower elevations where precipitation may fall as rain or wet snow.

Confidence

Poor - Due to limited field observations

Weather Forecast

Synopsis:  Precip should taper off by Wednesday morning.  The trailing cold front brings freezing levels down to Valley Bottom with no significant precipitation expected.  Colder temps and broken cloud cover should persist through Thursday evening before a weakening low makes landfall Thursday night, persisting through Friday.Wednesday: Freezing Level: Near valley bottom. Precip: Isolated convective flurries. Wind: Mod, SW.Thursday: Freezing Level: Valley bottom. 1800m Precip: Nil Wind: Mod, SWFriday: Freezing Level: 500m Precip: 5/10mm – 8 – 15cm Wind: Strong, SE.

Avalanche Summary

No new avalanche activity reported Monday.  Natural and skier triggered loose wet sluffs were reported in steep sun-exposed terrain on Sunday. On Saturday, widespread loose dry sluffing was reported in steep terrain running on a recently buried crust.

Snowpack Summary

15-25 cm of new snow sits on a melt-freeze crust at most elevations. Warm temperature and solar radiation resulted in moist snow on solar aspects and lower elevations. A new surface crust may form before the next system arrives on Tuesday night. Pockets of wind slab have developed in exposed lee terrain and cross-loaded gullies. 30 - 60 cm of snow overlies a crust, old wind slabs or surface hoar layer buried on March 9th. The distribution of the surface hoar is also highly variable and it does not exist in every drainage. I would still remain cautious and continue to dig and test before diving into my line. Deeper in the snowpack, basal facets may resurface as a concern with continued mild temperatures.Cornices have become well-developed and could easily become unstable during periods of warm weather or direct solar radiation.

Régions couvertes