Bulletin d’avalanche

Yukon

Jan 22 – 23, 2025Avalanche Canada
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Archivé · expiré 2 years ago

Danger d’avalanche

Fri
Sat
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
Sans niveau

Points saillants

Stick to conservative terrain free from overhead hazards. A reactive weak layer in the region is best managed by choosing simple terrain, and avoiding freshly wind-loaded slopes.

Problèmes avalancheux

  • Wind Slabs

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

    Recently formed wind slabs are expected to remain reactive to human triggering. New snow with strong winds on Wednesday may further add to these slabs.

  • Persistent Slabs

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

    A weak layer of facets and a crust down 50 to 100 cm has produced very large avalanches over the past week. Remotely triggered avalanches and wide propagations remain possible.

Confidence

Low

Avalanche Summary

On Tuesday, the field team observed two old size 2 wind slabs from the highway. We expect that natural wind slab avalanches likely occurred on Sunday and Monday during periods of strong wind.

Last Wednesday, a snowmobile remotely triggered a size 3 persistent slab from 100 m away near Bryant Lake. It was triggered from flat terrain at the col on an ENE aspect at 1500 m (MIN report).

Snowpack Summary

30-50 cm of settling storm snow from the last week can be found in sheltered terrain. Exposed terrain has been heavily wind-affected.

A weak layer of facets and a crust from early December is buried 50 to 100 cm deep. This layer exists on all aspects up to around 1700 m. This layer has shown recent reactivity, and we expect it to remain sensitive to human triggering.

Check out this recent ACMG Mountain Conditions Report for more on the persistent weak layer problem.

Weather Summary

Tuesday Night

Cloudy with light snowfall 2-4 cm. 30 to 50 km/h south ridgetop wind. Treeline temperature -6 °C.

Wednesday

Cloudy with 4-8 cm of snowfall. 40 to 60 km/h southwest ridgetop wind. Treeline temperature -5 °C.

Thursday

Partly cloudy with flurries. 30 to 50 km/h west ridgetop wind. Treeline temperature -4 °C.

Friday

A mix of sun and cloud. 30 to 50 km/h west ridgetop wind. Treeline temperature -3 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be aware of the potential for large avalanches due to buried weak layers.
  • Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Remote triggering is a concern; avoid terrain where triggering overhead slopes is possible.

Régions couvertes