Avalanche Forecast

Issued: Feb 9th, 2020 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs.

Avalanche Canada ghelgeson, Avalanche Canada

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Natural avalanche activity has likely slowed, but human triggered storm slab avalanches remain possible, especially on features immediately lee of ridge crest. If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.

Summary

Confidence

Low - Uncertainty is due to how quickly the snowpack will recover and gain strength.

Weather Forecast

Aside from a few bouts of potentially strong wind, we’re moving into a rather benign weather pattern for the foreseeable future.

SUNDAY NIGHT: Freezing level at valley bottom, light to moderate northwest wind, no significant precipitation expected.

MONDAY: A few clouds, freezing level rising to 800 m in the afternoon, light wind generally out of the northwest, no significant precipitation expected.

TUESDAY: Scattered cloud cover, freezing level rising to around 1400 m in the afternoon, moderate to strong northwest wind, trace of precipitation possible.

WEDNESDAY: Scattered cloud cover, freezing level near valley bottom, light variable wind, trace of precipitation possible.

Avalanche Summary

Over the weekend numerous natural and human triggered avalanches to size 1.5 were observed, there is a great MIN that serves as an example of this kind of activity here.

A natural avalanche cycle during the first weekend in February included some large (size 2.5) deep persistent slab avalanches in the Elk Valley (see photos in this MIN report) that appear similar to avalanches in that area in mid-January, which suggests the deep persistent slab problem may resurface during stormy periods.

Snowpack Summary

5 to 15 cm of storm snow from Friday Night/Saturday adds to the variable amounts of wind affected snow that sits above a widespread rain crust that exists up to roughly 2100 m. The storm snow is being formed into slabs by wind from a variety of directions. The Elk Valley has 5-20 cm of snow above the crust and the eastern slopes have 15-35 cm above the crust. There have been observations of surface hoar forming in the Elk Valley previous to Friday Night's storm, check that out here. A well consolidated mid-pack overlies generally weak basal facets, that may be possible to trigger in isolated shallow rocky start zones.

Terrain and Travel

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
  • Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.

Problems

Storm Slabs

An icon showing Storm Slabs

Storm slabs have formed above a widespread crust, Natural activity has likely slowed down, but human triggering remains possible. Deeper wind-fueled storm slabs can likely be found near ridge crest.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 10th, 2020 5:00PM

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