Bulletin d’avalanche

Sea To Sky

Feb 18 – 19, 2024Avalanche Canada
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Archivé · expiré 3 years ago

Danger d’avalanche

Tue
Wed
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible

Points saillants

Distinguishing between old wind effect and still-triggerable wind slab can be tricky. Seek out sheltered snow for better, safer riding and lower slope angles if your search comes up short.

Problèmes avalancheux

  • Wind Slabs

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

    Outflow wind has impacted open terrain on various aspects. This formed wind slabs that are bonding poorly to underlying surface hoar and facets on the early February crust.

Confidence

High

Avalanche Summary

A combination of transportable snow, elevated winds, and weak grains sitting on the hard early February crust has led to a steady stream of small (size 1 to 1.5) and a few large (size 2) wind slab avalanche reports over the past few days. Natural avalanches have triggered on leeward slopes by wind transport but human-triggered avalanches have occurred on a range of aspects. Slabs have been averaging 20 - 30 cm thick, with some failing on buried surface hoar.

Snowpack Summary

Sun and wind have created variable surface conditions. Exposed terrain is scoured by northeast wind has formed wind slabs on south and west facing slopes.

Roughly 30 cm of snow sits above large surface hoar and/or faceted crystals at treeline and above. This is most problematic in places where wind slabs have formed over it. A widespread, supportive crust exists 30 to 40 cm below the surface. It is an excellent bed surface for slabs run on.

The snowpack well bonded and strong below this crust.

Weather Summary

Saturday night

Cloudy. Southeast alpine winds 10 - 20 km/h, easing. Freezing level remaining near 1700 m.

Sunday

Cloudy with isolated wet flurries, light rain as high as 1300 m. Southeast alpine winds 5-10 km/h. Treeline temperature -2 °C with freezing level around 1400 m.

Monday

Cloudy with isolated wet flurries, light rain as high as 1500 m. Southeast or east alpine wind 10 - 15 km/h. Treeline temperature 0 °C with freezing level around 1600 m.

Tuesday

Cloudy with isolated wet flurries, light rain as high as 1400 m. South alpine wind 5-10 km/h. Treeline temperature -1 °C with freezing level around 1500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Wind slabs may be poorly bonded to the underlying crust.

Régions couvertes