Bulletin d’avalanche

Microwave-Sinclair

Mar 4 – 5, 2025Avalanche Canada
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Archivé · expiré 2 years ago

Danger d’avalanche

Thu
Fri
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Points saillants

Weak layers exist in the snowpack, and conditions are primed for human triggering.

Wind-loaded slopes at ridgecrest will be the most likely place to trigger an avalanche.

Problèmes avalancheux

  • Wind Slabs

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

    Fresh and reactive wind slabs are likely. Wind slabs will be the most sensitive where they overlie facets.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2.5

    Reactive weak layers from January and February exist in the upper 80 cm of the snowpack. New snow, wind, sun, and warming could all add stress to these layers, and human triggering remains a concern.

Confidence

Moderate

Avalanche Summary

On Friday, a natural wind slab was observed in a zone called the Onion. This released on a north aspect at 1650 m.

Wind-loaded slopes at upper elevations are most suspect and may be primed for human-triggering.

Snowpack Summary

Wind-transported snow has likely built deeper slabs on northerly aspects at upper elevations. South-facing slopes have formed a crust and lower elevation snow may be crusty as freezing levels fall.

The upper metre of the snowpack is complicated. This snow sits above several significant weak layers that formed during the January and February dry spells. These include facets, surface hoar (in sheltered terrain), and crust on solar aspects.

A layer of facets on top of a crust from early December is buried 100 to 200 cm deep. This layer is generally not a concern in this region.

Weather Summary

Monday Night

Partly cloudy. 10 to 20 km/h northwest ridgetop wind. Treeline temperature -6 °C. Freezing level dropping to valley bottom overnight.

Tuesday

Mix of sun and clouds. 20 to 30 km/h east ridgetop wind. Treeline temperature -5 °C.

Wednesday

Mostly sunny. 10 to 20 km/h west wind. Treeline temperatures -1. Freezing level 1200 m.

Thursday

A mix of sun and cloud. 10 to 25 km/h south ridgetop wind. Treeline temperatures 0. Freezing level 1400 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid freshly wind-loaded features, especially near ridge crests, rollovers, and in steep terrain.

Régions couvertes