Avalanche forecast

Kootenay Boundary

Feb 11, 2018Avalanche Canada
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Archived · expired 9 years ago

Avalanche danger

Mon
Tue
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

Heads up! Large avalanches have the potential to reach run-out zones. Be aware what, or who, may be above you.Special Avalanche Warning in effect for the interior ranges. Copy this address to view details: http://bit.ly/2nSOUyX

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5
    Storm slabs are reactive. Natural avalanche activity may taper off, but slopes are primed for human triggers. Be aware that a slab or loose snow release near the surface could also step down to deeper layers in the snowpack.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–4
    The snowpack is complex and continues to produce very large avalanches on weak layers now deeply buried below the surface.

Confidence

Moderate -

Weather Forecast

SUNDAY: Mix of sun and cloud. Ridge wind light to moderate, east. Temperature -10. Freezing level valley bottom.MONDAY: Mostly sunny. Ridge wind light, north. Temperature -8. Freezing level valley bottom.TUESDAY: Cloudy, light flurries. Accumulation trace. Ridge wind light to moderate, southwest. Temperature -8. Freezing level 800 m.

Avalanche Summary

There are no confirmed reports of avalanches from Friday, however is SAR responding in an incident involving a snowmobiler in the southern Slocan Valley that appears to be avalanche related.On Thursday, several large and destructive natural slab avalanches occurred through the region up to size 2.5 on all aspects and elevations. Avalanche control using explosives triggered numerous loose wet avalanches up to size 2 and a significant size 3 storm slab avalanche. These were reported from SE-SW slopes above 1900 m. Earlier in the week, two very large destructive avalanches up to size 3.5 were triggered remotely (from a distance) with crown depths up to 200 cm. At least one of these avalanches ran full-path, destroying mature trees.Natural avalanche activity will likely taper off through the weekend with colder temps; however, slopes will remain primed for human triggers.

Snowpack Summary

Storm snow accumulations from the past week vary from 10-45cm across the region at upper elevations. In the alpine this new snow has been redistributed to leeward slopes from strong northwest winds. Below 1800 m, up to 5 cm of low density snow covers a thin crust. This now brings 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 and will likely haunt us all season. These persistent weak layers that lurk within the snowpack are reactive, producing large and destructive avalanches. The snowpack is extremely complex and requires respect and diligence at this time.

Regions covered