Bollettino valanghe

Purcells

Apr 15 – 16, 2013Avalanche Canada
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Archiviato · scaduto 13 years ago

Pericolo valanghe

Wed
Thu
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Apri la mappa completa

In sintesi

This bulletin was produced using limited data streams, and significant variations in snowpack structure are likely to exist. If you've been traveling in the backcountry, we'd love to hear from you. Observations can be sent to [email protected].

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    1–4
    Recent snowfall has been redistributed by changing winds. Wind slabs exist on a variety of aspects at treeline and above. Wind has also formed very large and potentially unstable cornices.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    1–6
    A weak interface buried in the upper metre of the snowpack can create surprisingly large avalanches. It`s been reactive in nearby regions, but there`s limited information about its reactivity in the Purcells. Be cautious in alpine terrain.

Confidence

Poor - Due to variable snowpack conditions

Weather Forecast

Tuesday: No snow. Moderate E winds. Freezing level near 1200 m, dropping to 200 m overnight.Wednesday: Light snow. Light W winds. Freezing level near 1500 m, dropping to 1100 m overnight.Thursday: Light snow. Light W winds. Freezing level near 1700 m, dropping to 1100 m overnight.

Avalanche Summary

On Sunday, a naturally triggered size 2.5 slab failed on a buried crust. Numerous small loose dry avalanches were also observed. In neighbouring Glacier National Park, skiers triggered a size 3 slab on a buried crust on an east aspect in the alpine on Monday. The slab above this interface may be reaching tipping point with incremental loading from snow and wind.

Snowpack Summary

Around 40 cm recent storm snow has been shifted by variable winds into wind slabs at treeline and above. In some areas, a trace of new snow overlies a refrozen surface on southerly aspects and below 2000 m on northerly aspects. A weak interface in the upper metre of the snowpack consists of a crust on solar aspects, and surface hoar on high-elevation northerly aspects. Recent activity in Glacier National Park and the North Columbia regions demonstrates that this interface has the potential for surprisingly large avalanches. Cornices in the region are potentially destructive. Periods of warming or solar radiation may increase the reactivity of cornices and storm slabs.

Regioni coperte