Avalanche forecast

Northwest Inland

Feb 2 – 3, 2022Avalanche Canada
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Avalanche danger

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

New snow and strong winds are driving the avalanche danger to CONSIDERABLE. Wind slabs may be touchy and easily triggered due to the old weak snow surfaces they have formed on. 

Avalanche problems

  • Wind Slabs

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

    Fresh wind slabs will likely be reactive due to the surfaces they are forming on. Avoid features where even a small avalanche could be consequential. 

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1.5–2.5

    The mid-January surface hoar layer is a developing problem that could start to produce more avalanches in the future with increased load and slab development above. Use extra caution in sheltered terrain at treeline where preserved surface hoar is more likely to exist.

    The early January facet layer is now down as deep as 80cm and might require a large load such as a cornice fall or a smaller avalanche in the layers above in order to be triggered. This problem is likely most concerning on high north and east facing terrain.

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Tuesday Night: 5-10 cm of new snow with strong northwest winds at ridgetop. Alpine temperatures near -15 and freezing levels valley bottom.

Wednesday: Another 5-10 cm of snow with continued strong winds switching from the northwest to the west- southwest. Alpine temperatures near -10. Freezing levels valley bottom.

Thursday/ Friday: Mix of sun, clouds, and flurries near 10 cm with strong southwest wind at ridgetop. Average alpine temperature near -5 and freezing levels 1000 to 1600 m. 

Avalanche Summary

A natural wind slab avalanche cycle occurred on Monday up to size one. No new reports by Tuesday afternoon. 

New snow and strong wind from the NW then SW will likely build fresh and reactive wind slabs on Wednesday.

Snowpack Summary

Another 10-15 cm of new snow is forecast by Wednesday afternoon. This will add to the recent 15 cm that has fallen over a variety of surfaces including facets, surface hoar, and old wind slab. The new snow will likely not bond well to these surfaces. In the southern part of the region, it is possible to find a rain crust up to 1500 m.

Below this we have two persistent weak layers, the first is a surface hoar layer from mid-January buried down 20 to 30cm. The second is a layer of facets from early January which is now down 50 to 80cm, it has been most reactive where wind slab has formed above it and will now likely require a large load to trigger.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.

Regions covered