Bollettino valanghe

Northwest Coastal

Dec 28 – 29, 2013Avalanche Canada
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Archiviato · scaduto 13 years ago

Pericolo valanghe

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

In sintesi

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–6
    Primarily a concern in Northern sections. A recently buried surface hoar layer, now down 50-60 cm, could be triggered by additional loading from snow or wind or by the weight of a rider. Also, a weak facet/crust combo lurks near the ground.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    1–4
    More snow is on the way. Some areas could see another 25 cm through Sunday. Expect touchy wind slabs to form in exposed N-E facing terrain and cross-loaded features.

Confidence

Fair - Due to the number of field observations

Weather Forecast

Tonight and Sunday: Periods of snow, heaviest overnight – 10-25 cm. The freezing level could climb to 1200-1500 m in the south, but remain near valley bottom in the north. Winds are moderate to strong from the W-SW. Monday: Periods of snow – 15-20 cm. The freezing level lowers to around 800-1000 m. Winds remain moderate to strong from the SW. Tuesday: Cloudy with flurries. The freezing level is near 1000 m.

Avalanche Summary

Numerous loose wet avalanches up to size 2.5 were observed on Friday at lower elevations, primarily in the southern half of the region. Fresh deposits were also observed in the Shames backcountry, with some paths running all the way to the valley bottom.

Snowpack Summary

Southern Sections: The latest storm dumped 50-80 cm under mild temperatures and strong SW-NW winds. Much of the low elevation snowpack was washed away by heavy rain, as freezing levels peaked close to 2000 m in some areas. In the wake of the system there was brief clearing and cooling. This may have created a surface crust at lower elevations. Recently buried weaknesses of surface hoar and/or facets are now well over 1 m deep and were likely flushed out or squashed by the heavy snowfall. Northern Sections: Storm snow totals are closer to 30-40 cm. Fresh dense wind slabs are likely in exposed lee terrain and cross-loaded features. A recently buried surface hoar layer is now down around 50-60 cm and is likely primed for rider triggering. A facet/crust layer exists near the base of the snowpack, primarily on higher NW through E facing slopes. Triggering this layer may be unlikely, but if triggered the resulting avalanche would be very large and dangerous.

Regioni coperte