Bollettino valanghe

Northwest Inland

Dec 24 – 25, 2016Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 10 years ago

Pericolo valanghe

Sun
Mon
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
Apri la mappa completa

In sintesi

Use extra caution this holiday weekend as weak layers near the bottom of the snowpack have been very touchy. Stick to mellow terrain and avoid steep and convex slopes.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2
    Triggering wind slabs remains possible in exposed lee areas, as last week's storm delivered up to 50 cm of new snow with strong winds.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–3
    A substantial amount of recent snow has loaded two layers of weak, faceted snow: one is buried around 50 cm and the other near the base of the snowpack. Likely trigger points are unsupported (convex) slopes in shallower snowpack areas.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

SUNDAY: Increasing cloud with afternoon flurries, southwest winds picking up throughout the day reaching 40 km/h by the afternoon and reaching 80 km/h overnight, temperatures around -15C.MONDAY: Stormy with accumulations of 5-15 cm, strong southwest winds, temperatures around -10C.TUESDAY: Flurries with trace accumulations, moderate west winds, temperatures around -10C.

Avalanche Summary

Persistent slabs have been very touchy in areas with thin snowpacks, as several size 1.5-2 avalanches have been remotely triggered the past few days. The avalanches have released on weak facets near the ground in steep shallow start zones. Remote triggering is a sign of a serious weakness deep in the snowpack and indicates that persistent slab avalanches may be triggered with very light loads. Also, strong winds with new snow will continue to develop wind slabs throughout the region on Sunday. Overall, human triggering remains likely, especially in terrain that has not been heavily ridden.

Snowpack Summary

Clear cold weather has limited the settlement of recent storm snow and resulted in the formation of new surface hoar and surface facets. Last week, extreme winds formed hard wind slabs behind exposed terrain features. Elsewhere, up to 50 cm of low density snow sits over a highly variable interface comprised of wind-scoured surfaces, hard wind slabs, faceted (sugary) snow, and feathery surface hoar in sheltered areas. The new snow appears to have bonded poorly to this interface. The snowpack is still shallow throughout the region and widespread faceting of the entire snowpack is likely in most areas. A thick rain crust that formed in early November is probably near the bottom of the snowpack and is likely surrounded by sugary facets. Basal facets and depth hoar (more sugary crystals) right at the bottom of the snowpack are reportedly widespread.

Regioni coperte