Avalanche forecast

Kootenay Boundary

Dec 20 – 21, 2013Avalanche Canada
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Avalanche danger

Sun
Mon
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Highlights

The avalanche hazard could bump up a notch if more snow than expected arrives.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2
    Strong westerly winds at ridge tops have produced pockets of dense wind slab in exposed lee terrain and cross-loaded features. Rider triggering is possible, particularly in steep unsupported terrain.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–4

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Saturday: Mainly cloudy with a chance of flurries and sunny breaks. The freezing level could jump to 700 m and moderate gusty northwest winds continue. Sunday: Possible sunny breaks and flurries. The freezing level could climb to 1500 m  in parts of the forecast area. The upper flow continues to be northwesterly. Monday:  5 to 10 cm of snow at upper elevations,  freezing level to remain at valley bottom for most of the area.

Avalanche Summary

No avalanches have been reported in the last few days.

Snowpack Summary

It's been an exceptionally dry December so far. The total monthly precipitation in Nelson is 40 mm, and 30 mm of that fell in one storm at the beginning of the month. Hopefully the weather pattern changes soon!Recent light snowfall and strong westerly winds formed pockets of soft wind slab on lee slopes and scoured windward slopes in exposed terrain. Between 35 and 50cm below the surface you may find a weak layer of surface hoar on sheltered slopes or a melt-freeze crust on steep solar aspects. Most reports indicate this layer is "stubborn" to trigger, or there may not be a deep enough overlying slab to create a significant hazard. That said, I'd remain curious about this interface, especially as the snow load above gradually increases.In general, snowpack depths are below seasonal average and many slopes below treeline are reported to be below threshold for avalanche activity. Deeper snow is likely in the northern part of the region.

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