Avalanche forecast

Banff Yoho Kootenay

Dec 12 – 13, 2023Avalanche Canada
View on map
Archived · expired 3 years ago

Avalanche danger

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

Highlights

The natural avalanche cycle over but human triggered avalanches are still likely. Continue to practice conservative decision making.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Previous strong winds have created reactive windslabs in the alpine and treeline.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1.5–3

    A buried crust has bridged this problem at lower elevations but pay attention to where it disappears, if there is no crust there will be a higher likelihood of triggering the persistent weak layer.

Confidence

Moderate

Avalanche Summary

On Saturday a size 2 skier triggered avalanche failed as a deep persistent slab at treeline and ran 600m scrubbing to ground. One skier was caught and sustained injuries that required an overnight rescue.

Numerous Na slab avalanches up to size 2 have occurred in the alpine over the past few days.

Snowpack Summary

Last week's storm snow has settled to 20-50cm over the Dec 2 weak layer which consists of the basal facets and surface hoar. A rain crust (1 to 7cm thick) exists within the storm snow up to 2300m on all aspects. The thickness of the rain crust tapers with increasing elevation.

Weather Summary

Tuesday will be mainly sunny with light southwest ridgetop winds and a temperature inversion, alpine highs of -6°C to -3°C. Wednesday will be much the same with increased winds and slightly higher freezing level. The next potential for snow is Thursday.

For more information, click Mountain Weather Forecast.

Terrain and Travel Advice

  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Avoid exposure to overhead avalanche terrain, avalanches may run surprisingly far.

Regions covered