Bollettino valanghe

North Columbia

Feb 27 – 28, 2024Avalanche Canada
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Archiviato · scaduto 3 years ago

Pericolo valanghe

Thu
Fri
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato

In sintesi

It remains likely for humans to trigger high-consequence avalanches. Conservative decision making is essential.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    2–3.5

    A weak layer of faceted grains above a melt-freeze crust buried 60 to 120 cm deep is a recipe for large, high-consequence avalanches. This snowpack setup will take some time to strengthen.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1.5–2.5

    Storm slabs remain reactive to human traffic. The slabs are particularly touchy where they sit on weak layers of facets or surface hoar. Expect deeper and touchier slabs in lee terrain features near ridges.

Confidence

Moderate

Avalanche Summary

Many avalanches were observed during the weekend's stormy weather. Many of them were small to large (size 1 to 2) storm slabs occurring on all aspects at treeline and alpine elevations. A few large to very large (size 2 to 4) persistent slab avalanches occurred on the facets above the melt-freeze crust described in the Snowpack Summary, being 60 to 100 cm deep on north to west aspects at treeline and alpine elevations.

Riders could trigger similar avalanches going forward.

Snowpack Summary

40 to 70 cm of recent snow sits on a variety of layers that it may not bond well to, including surface hoar in wind-sheltered terrain, weak facets, or a hard melt-freeze crust on sun-exposed south and west-facing slopes. The wind has likely formed thicker deposits in lee terrain features near ridges.

A thick and hard widespread crust that formed in early February is buried 60 to 120 cm deep and is found up to around 2400 m. This crust may have a layer of facets above it, which makes it a troublesome avalanche layer.

The remainder of the snowpack is settled.

Weather Summary

Monday Night

Mostly cloudy with 2 to 5 cm of snow. 10 to 20 km/h west ridgetop wind. Treeline temperature -15 °C.

Tuesday

Partly cloudy. 10 to 20 km/h west ridgetop wind. Treeline temperature -18 °C.

Wednesday

Cloudy with 15 to 30 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1500 m.

Thursday

Cloudy with 15 to 30 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -5 °C. Freezing level 1000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Use careful route-finding and stick to moderate slope angles with low consequences.
  • Remote triggering is a concern, watch out for adjacent and overhead slopes.
  • Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Carefully evaluate steep lines for wind slabs.

Regioni coperte