Bollettino valanghe

Kootenay Boundary

Feb 17, 2018Avalanche Canada
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Archiviato · scaduto 9 years ago

Pericolo valanghe

Sun
Mon
Alta quota
4 · Forte
Limite del bosco
4 · Forte
Sotto il limite
4 · Forte
Apri la mappa completa

In sintesi

Intense snowfall will elevate the danger. Travel in avalanche terrain is not recommended on Saturday.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2.5–4
    Several deeply buried weak layers exist in the snowpack. Although the likelihood of triggering a persistent slab is gradually decreasing, the consequences remain very high.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Very Likely - Certain
    Dimensione
    1–2.5
    Storm slabs will become very reactive with another 20-40 cm of snow expected on Saturday. Natural and human-triggered avalanches are very likely.

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

SATURDAY: Heavy snow with 20-40 cm by the end of the day, moderate west wind, alpine high temperatures around -8 C.SUNDAY: Lingering flurries with light east wind and alpine high temperatures around -15 C.MONDAY: Mix of sun and cloud with light northeast wind and alpine high temperatures around -17 C.

Avalanche Summary

A few small slabs were reactive to skier and explosive triggers as storm snow accumulated on Wednesday-Friday. They were primarily small (size 1) and in wind-affected terrain at treeline and alpine elevations.Last weekend, three large persistent slab avalanches (size 3) were reported on northeast aspects in the Valhallas. Two were triggered with explosive and the third was naturally triggered.By Saturday, storm slabs will be much larger and more reactive while deeper weak layers may be getting stressed by the weight of the new snow.

Snowpack Summary

Storm snow has been accumulating for a few days. Saturday's storm is expected to deliver 20-40 cm on top of the 20-30 cm from the past few days. All this new snow is sitting above an interface that could favour wide propagations in the storm snow. The interfaces include sun crusts on steep south-facing slopes, a rain crust below 1800 m and small surface hoar in isolated areas.We now have 1-2 m of settled snow sitting on three significant surface hoar/crust layers that were formed early to mid-January, and back in December. Near the base of the snowpack a crust/facet interface exists that will likely haunt us all season. These layers produced large destructive avalanches on a regular basis up until last weekend. Avalanche activity on these layers has gradually diminished, but the persistent slab problem still demands respect and diligence.

Regioni coperte