Bulletin d’avalanche

Jasper

Jan 29 – 30, 2019Parks Canada
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Archivé · expiré 8 years ago

Danger d’avalanche

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

A modest recent snowfall with wind was enough to cause notable new avalanches. Avoid obvious windslabs on steep slopes, and critically assess the the terrain you enter - if you trigger a Deep Persistent slab, what will the consequences be?

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2
    New snow on Sunday arrived with Strong winds (ranging from SW to N) creating windslabs over a variety of surfaces, including suncrust, surface hoar, and wind pressed areas. While natural activity has tapered, human triggering remains possible.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1.5–3.5
    A natural avalanche Monday on this layer shows that only minor changes may wake this generally dormant dragon. Triggering is most likely in thin areas, with variable snowpack depth. Use terrain choice and safe practices to minimize consequences.

Weather Forecast

Tuesday will be clear, Treeline Low -10, Hi -5, with Light NW winds. An inversion is possible, with cold air pooling in valley bottoms.Wednesday-Thursday: temperatures slowly rise, with sporadic cloud cover, and light snowfall possible. Light W winds may rise to Moderate.A detailed mountain weather forecast is available from Avalanche Canada.

Snowpack Summary

5-10cm of snowfall on Sunday with SW - NW winds created wind slabs in lee and cross-loaded terrain. Surfaces became moist on solar slopes at treeline Monday. A layer of weak surface hoar is now buried 10-20cm deep. Below, a strong mid-pack sits over depth-hoar in the lower third of the snowpack (giving sudden results in snowpack testing Saturday).

Avalanche Summary

A natural Size 3 Deep Persistent slab was observed Monday on a steep (35+ degrees) Alpine South-West facing slope. Triggered by a smaller windslab, it stepped down to depth hoar and the ground. Several windslabs to Size 2 were also observed (Alpine S and E aspects). Help forecast - share observations HERE, on the Mountain Information Network!

Confidence

Due to the number of field observations on Monday

Régions couvertes