Avalanche forecast

Banff Yoho Kootenay

Dec 5 – 6, 2019Parks Canada
View on map
Archived · expired 7 years ago

Avalanche danger

Fri
Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
1 · Low

Highlights

Higher then forecasted snow fall amounts and strong winds have resulted in a heightened avalanche danger for the region.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–2.5

    20-30 cm of recent storm snow accompanied by strong SW winds have created widespread wind slabs in alpine and tree-line regions. Slabs of 50cm thick have been reactive to skier traffic.

Weather Forecast

Snow ending Wednesday with a short reprieve Thursday before the next system hits Friday which could bring an additional 20cm to the region. Temperatures will rapidly cool Thursday with a forecasted low of -20. This will be short lived, as the next wave of precipe moves in freezing levels could climb up to 1400m.

Snowpack Summary

20 to 30cm of new snow accompanied by moderate to strong SW winds have created fresh wind slabs on lees slopes at treeline and above. The midpack consists of 25-35 cm of facetted snow overtop of the Nov 8 crust. The lower snowpack consists of facets and depth hoar. Snowpack depths at treeline vary from 60-100 cm with up to 140 cm in lee areas

Avalanche Summary

Reactive wind slabs on alpine and treeline lee slopes are producing avalanches to size 2 in the region. Little evidence of these slabs stepping down to deeper instability has been observed, though with the current snowpack structure it is something to consider. We will likely find more evidence of an avalanches cycle Thursday as things clear up.

Confidence

Regions covered