Bollettino valanghe

Northwest Coastal

Mar 22 – 23, 2024Avalanche Canada
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Archiviato · scaduto 3 years ago

Pericolo valanghe

Sun
Mon
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole

In sintesi

Watch for changing surface conditions with sun and warm temperatures,

The search for dry snow may draw you to high north facing terrain, be aware buried weak layers may remain reactive here.

Problemi valanghivi

  • Persistent Slabs

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

    Human triggering remains a concern with buried weak layers. Minimize your exposure to large open slopes, especially on shallower terrain features at alpine and treeline.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    1–2.5

    The potential for wet avalanches will increase throughout the day with warm and sunny conditions, particularly on steep south-facing terrain. Avoid sun affected terrain as the surface crust breaks down.

Confidence

Moderate

Avalanche Summary

Loose wet avalanches were observed from steep solar slopes over the last 2 days. Avalanches ranged from size 1-2.5, with the larger avalanches scouring to ground.

On Wednesday, a few persistent slab avalanches were observed to size 3, on alpine south-facing slopes, liikely triggered by daytime warming. Skier-triggered avalanches (size 2) also occurred in shallow rocky areas which stepped down to the persistent slab.

Snowpack Summary

A widespread melt-freeze crust exists on the surface in most areas. The crust may soften throughout the day at lower elevations and on south-facing slopes. Dry snow can still found on true north-facing alpine slopes. At lower elevations below the surface crust, the snowpack is likely moist or wet to ground from recent warming.

A layer of weak, faceted crystals over a crust, or surface hoar, remains a concern for human triggering at treeline and alpine elevations, buried approximately 90-180 cm deep. This layer is harder to trigger as it becomes deeper, but has the potential to produce large avalanches.

Weather Summary

Friday Night

Clear skies. 20-30 km/h east ridgetop wind. Freezing level drops to valley bottom.

Saturday

Sunny. 20-30 km/h northeast ridgetop wind. Treeline temperature +4 °C. Freezing level rising to 2000 m. Overnight refreeze expected.

Sunday

Sunny. 20 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level remains around 1700 m.

Monday

Cloudy. 20 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level remains around 1200 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
  • Be aware that wet activity at low elevations is a classic situation for step-down failures in deeply buried persistent weak layers.

Regioni coperte