Bollettino valanghe

South Columbia

Dec 25 – 26, 2018Avalanche Canada
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Archiviato · scaduto 8 years ago

Pericolo valanghe

Thu
Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole

In sintesi

The persistent slab problem is best managed with patience and relatively conservative terrain choices. Read more in the new forecaster blog here.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    2–3
    The likelihood of persistent slab avalanches is gradually decreasing, but triggering a widespread weak layer buried 50 to 100 cm beneath the surface would have major consequences. This problem will likely linger through the holidays.

Confidence

Moderate -

Weather Forecast

The BC weather will take a holiday break over the next couple of days as the wild storm cycle of recent weeks eases in the Pacific.CHRISTMAS NIGHT: Freezing level at valley bottom, light variable wind, no significant precipitation expected. BOXING DAY: Overcast, freezing level at valley bottom, light south/southwest wind, trace of snow possible. THURSDAY: Broken cloud cover, freezing level at valley bottom, light northerly wind, no significant precipitation expected. FRIDAY: Scattered cloud cover, freezing level at valley bottom, light northerly wind with potential for moderate gusts in the afternoon at upper elevation, trace of snow possible.

Avalanche Summary

On Monday a few old size 2 natural avalanches were observed on south facing features between 1600 and 2300 m. The avalanche at 1600 m is notable as that is below treeline. As the sun made an appearance a few small loose avalanches were also observed.The most recent 10-30 cm of low density snow was reactive to skiers on steep and convex features on Sunday. Otherwise, natural and human triggered activity has started to taper off.However, as recent as last Friday, large (size 2-3) persistent slab avalanches were occurring naturally. There have also been a few notable persistent slab avalanches remotely triggered from skiers on adjacent slopes. Most recently, last Wednesday a few large (size 2-2.5) avalanches on north-facing slopes were remotely triggered by skiers in the Selkirks.

Snowpack Summary

10-20 cm of low density snow sits above wind slabs in the alpine, and in some isolated areas above small surface hoar (feathery crystals).A weak layer that formed during the dry spell in early December is now 50-100 cm deep. The layer is composed of weak facets, surface hoar, and a sun crust on steep south-facing slopes. This layer has been responsible for large persistent slab avalanches over the past two weeks, particularly on north and east facing slopes between 1900-2300 m and on steep south-facing slopes in the alpine.The lower snowpack is generally strong and settled, with a crust that formed in late October near the bottom of the snowpack.

Regioni coperte