Bulletin d’avalanche

Banff Yoho Kootenay

Jan 13 – 14, 2022
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Archivé · expiré 5 years ago

Danger d’avalanche

Fri
Sat
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré

Points saillants

High freezing levels and lots of wind have created tricky conditions. The surface snow is dense and the persistent slab problem appears to be activating in new ways across the region. Note some new patterns in avalanche activity are emerging.

Problèmes avalancheux

  • Wind Slabs

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

    Windslab are all over the place in alpine terrain and they overlie weak facets formed during the Xmas cold snap. It would be easy to trigger a windslab right now, so avoid leeward loaded terrain. Stick to ridges or uniform, non-loaded slopes.

  • Persistent Slabs

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

    The problem is evolving and is expanding further into the entire BYK region (see avalanche activity table). Facets formed during the Xmas cold snap are failing easily below treeline. This seems to be activating with the warmer temps and wind.

Weather Forecast

The strong southwesterly flow continues for the next 24-hours with strong winds, freezing levels to 2000 m and another 10-20 cm of snow (rain low elevations). This changes at the end of the day Thursday following a cold front, when a ridge of high pressure builds, the skies clear and the temperatures drop by 10 degrees.

Snowpack Summary

Warm temperatures, winds, 10 cm of snow and light rain to ~2000 m have created dense windslabs that overlie facets from the Xmas cold snap and produce moderate test results. At lower elevations the middle of the snowpack is facetted and combined with the Dec 2 layer in Kootenay is now becoming active. This will continue through Thursday.

Avalanche Summary

A new pattern is emerging. SSV had a skier controlled size 2.5 starting at 2500m with a windslab over facets. It ran full path and dug deeper into facets low in the path. Lake Louise had repeated windslabs from alpine terrain that pulled deeper slabs on facets at the lower elevations. Skier accidental size 2 below TL ran full path at LL today also.

Confidence

Régions couvertes