Avalanche forecast

Little Yoho

Feb 2 – 3, 2022
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Avalanche danger

Thu
Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Touchy storm slabs that sit on a well preserved surface hoar layer are the biggest concern right now.

Avalanche problems

  • Wind Slabs

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

    New windslabs have formed in the immediate lees of features and are up to 40 cm deep.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–3

    This problem represents both the Dec. 2nd crust/ facet layer (treeline and below) and the late December facet layer. Lots of variation in the sensitivity ranging from reactive sudden collapse to no results depending on location, aspect and elevation.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    1–1.5

    There is a touchy storm snow interface, down 15-35 cm, on surface hoar/crust/facets buried on Jan 30. Steep rolls with >20 cm of snow are most reactive, if they have not already slid.

Weather Forecast

Cold air will continue through Wednesday and then start to warm up on Thursday. Valley bottom temps on Wednesday in Lake Louise will be -15. Flurries forecast for Thursday, but little accumulation. Ridgetop winds will pick up Wed afternoon into the mod to strong range.

Snowpack Summary

15-35 cm storm snow has created fresh windslabs in the alpine. Storm slabs exist at tree-line and below treeline elevations where storm snow sits on a touchy surface hoar layer. This was very apparent on Mt Field on Monday but this problem is expected to exist in other areas within the forecast region. Expect easy triggering of these soft slabs.

Avalanche Summary

Field team to Mt Field on Monday experienced numerous ski-cut and natural avalanches on the storm snow interface down 25-35 cm. The storm snow was sitting on a 3-5 mm well preserved surface hoar layer. Ski hills reported several small natural and explosive triggered windslabs in the alpine.

Confidence

Wind speed and direction is uncertain on Thursday

Regions covered