Bulletin d’avalanche

Tumbler

Feb 16 – 17, 2023Avalanche Canada
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Archivé · expiré 4 years ago

Danger d’avalanche

Sat
Sun
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Points saillants

New snow with wind is on repeat lately with another pulse of new snow in the forecast. Approach wind-loaded features like ridges and ribs with caution and keep an eye out for shooting cracks as you transition into open terrain.

Problèmes avalancheux

  • Wind Slabs

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

    Another 5 to 10 cm of new snow will be coming in with moderate to strong southwest winds building new thin wind slabs in lee terrain and will add to the current wind slab problem that may still be triggered by large loads. Approach all lee and cross-loaded terrain with caution.

    Keep in mind that larger wind slab releases have the potential to step down to the weak basal snowpack, resulting in very large and consequential avalanches.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–3.5

    A layer of large and weak facets sits near the base of the snowpack. This layer is most prominent in upper treeline and alpine elevations. Riders are most likely to trigger an avalanche on this layer in steep terrain where the snowpack is shallow. Your best defence is to stay diligent in choosing low-consequence terrain away from overhead exposure.

Confidence

Moderate

Avalanche Summary

No new avalanches reported in the area. Please continue to submit your observations to the MIN.

Looking forward, wind slabs formed by the recent snow and variable winds are becoming stubborn and may catch riders off guard.

Snowpack Summary

Roughly 5 to 10 cm of new snow will be coming in with moderate to strong southwest winds that will build wind slabs at alpine and treeline elevations.

These new wind slabs add to the upper snowpack that is settling and bonding over previous surfaces of old wind slabs found at upper elevations and soft snow in sheltered locations. A melt-freeze crust can be found below 1000 m formed when temperatures dipped following a warm spell.

The mid-pack is consolidated but variable in depth depending on aspect and elevation.

The lower snowpack is composed of large and weak facets formed in November and most likely triggerable in steep, rocky alpine terrain.

Weather Summary

Wednesday night

Mainly cloudy clearing briefly overnight, 50 to 60 km/h southwest winds, treeline temperatures around -8 °C.

Thursday

Increasing cloud, 5 to 10 cm new snow, 40 to 50 km/h southwest winds, treeline temperatures around -7 °C

Friday

Increasing clouds, isolated flurries with trace accumulations, 40 to 50 km/h southwest winds, treeline temperatures -10 °C

Saturday

Mainly cloudy, isolated flurries with 2 to 5 cm of new snow, 40 to 50 km/h winds, treeline temperatures -10 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Avalanche hazard may have improved, but be mindful that deep instabilities are still present.

Régions couvertes