Avalanche forecast

Northwest Coastal

Feb 2 – 3, 2022Avalanche Canada
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Avalanche danger

Fri
Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Storm slabs will build through the day and likely be touchier by early afternoon. Deeper and stiffer slabs will exist on leeward slopes and behind terrain features. If less than 25 cm of snow falls the hazard may stay MODERATE.

Avalanche problems

  • Storm Slabs

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

    Up to 25 cm of new snow is forecast by Wednesday afternoon. Fresh and reactive storm slabs will build with deeper and stiffer slabs on leeward slopes (N-NE-E) due to increased ridgetop wind. Sensitivity could be greater in areas where storm and wind slab has formed over a crust, facets, or surface hoar. 

    Dry loose avalanches and sloughing will likely be seen on steeper terrain features, especially at lower elevations where the new snow falls on a crust. 

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Tuesday Night: 10-15 cm of new snow with strong southwest winds at ridgetop. Freezing levels valley bottom.

Wednesday: Another 10 cm of snow with strong southwest wind at ridgetop. Alpine temperatures near -4. Freezing levels 800 m.

Thursday/ Friday: More snow 10-15 cm on Thursday and up to 20 cm on Friday with strong southwest wind at ridgetop. Average alpine temperature near -5 and freezing levels 1200 m. 

Avalanche Summary

Evidence of several wind slabs and natural cornice failures up to size 1.5 in the past 24 hours. No new avalanche observations by Tuesday afternoon. 

With new snow and wind forecast, storm slabs and wind slabs will build through the day and likely be reactive. 

Snowpack Summary

Forecast new snow and wind will build fresh storm slabs at upper elevations adding to the 20-30 cm that currently overlies a variety of surfaces that formed during the end of January. This interface is made up of a crust, facets, and surface hoar. The crust can be found at or below treeline as well as on south-facing terrain in the alpine. In isolated sheltered terrain at treeline surface hoar has formed along with facets above this crust. Where a crust did not form facets will likely be found.

The January 19th surface hoar layer can still be found down 30 to 50 at treeline and above in sheltered terrain. Recent reports indicate that it is becoming less of a concern. 

Terrain and Travel

  • Minimize exposure during periods of heavy loading from new snow and wind.
  • Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
  • Wind slabs may be poorly bonded to the underlying crust.

Regions covered