Bulletin d’avalanche

Yukon

Avalanche Canada
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Danger d’avalanche

Sat
Sun
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
Sans niveau
Périmé — ce bulletin a expiré 4 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

New snow and strong winds forecasted for White Pass could increase the avalanche danger. Scale back to mellow, sheltered terrain.

Further inland the danger may be one step lower.

Problèmes avalancheux

  • Wind Slabs

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

    In White Pass, up to 10 cm of new snow may fall by the end of the day on Friday with strong southwest wind, creating fresh, reactive wind slabs. A small wind slab avalanche may step down to the surface hoar layer below.

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1.5–2.5

    With the spring sun packing a punch, be especially aware of your exposure to slopes below cornices during the heat of the afternoon.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1.5–2.5

    This problem represents older wind slabs that are sitting over surface hoar in sheltered, shaded terrain.

Confidence

Moderate

  • We are uncertain due to a highly variable snowpack.

Avalanche Summary

On Wednesday, near White Pass, numerous avalanches were reported on steep slopes facing the sun, mostly small (size 1.5), but a few large (max size 3).

With cloudier weather forecasted for Friday, this sort avalanche activity is not expected.

On Tuesday, dry snow sluffing was reported in steep terrain

Snowpack Summary

A variety of surfaces exist across aspects and elevations. Firm, supportive crusts are present at lower elevations and on sun-exposed slopes.

In higher-elevation terrain sheltered from sun and wind, 10-15 cm of recent snow overlies a mix of older, wind-affected surfaces.

A weak layer of surface hoar may persist 30 to 60 cm below the surface in northerly alpine terrain.

The lower snowpack remains faceted and generally weak, especially in shallow snowpack areas.

Weather Summary

Thursday Night

Mostly cloudy. 4 cm of snow expected near the American border, with amounts dropping off quickly as you move inland from White Pass. 40 km/h southwest ridgetop wind, increasing to 60 km/h through the night. Treeline temperature -4 °C.

Friday

Cloudy. 5 cm of snow expected near the American border, with amounts dropping off quickly as you move inland from White Pass. 55 km/h southwest ridgetop wind. Treeline temperature -4 °C.

Saturday

Mostly cloudy. 1 to 5 cm of snow. 50 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 800 m.

Sunday

Mix of sun and clouds. 1 to 2 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -3 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid steep, rocky, and wind-affected areas where triggering slabs is more likely.
  • Avoid freshly wind-loaded terrain features.
  • Be aware of the potential for remote triggering and large avalanches due to buried surface hoar.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.

Régions couvertes