West Slopes Central

Avalanche problems

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  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  1–2

  Another round of snowfall will build new storm slabs even as the current crop becomes dormant. Forecasted snow amounts and wind speeds alone would be enough to see some avalanches on Monday. An additional factor is a sharp rise in snow levels that could create prominent strong over weak layering as heavy, wet snow falls on colder and drier snow below. Note changes in texture, depth, and layering for the whole of the day - not just when you first get on the snow. Approach steeper terrain features with caution and plan on scaling back to simpler, lower angle, as the storm slabs become touchy and easy to trigger. If there is more snow than forecast and you start seeing widespread human triggered and even natural avalanche activity, assume a higher level of danger and simply avoid avalanche terrain. As usual, you are more likely to trigger an avalanche in areas of recent wind loading.

  

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  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  1–2

  Expect wet avalanche activity with a transition from snow to rain in the afternoon. Rain on a cold and dry snowpack like we currently have is a favored recipe for wet loose avalanches. If the rain comes sooner or there is more than forecast wet slab avalanches are possible as well. When you start seeing signs of instability like rollerballs, pinwheels, and very small wet loose avalanches it’s time to reign it in as wet avalanches will likely grow in size and frequency. Move off and away from steep slopes when you observe the beginnings of wet avalanche activity and pay particular attention to terrain overhead. Don’t get committed to places that could be difficult to escape if conditions change suddenly.

  

• 

  Deep Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  3

  Three very large (D3) avalanches were reported on Wednesday around Baker - two naturals and one from avalanche control work. Observations since the last storm are sparse due to poor visibility - we can’t say either way if more avalanches of the same character did or didn’t occur with Saturday’s storm.  

  The reported avalanches likely released in a layer of weak facets buried on March 8th. As the layer in question gets buried deeper, triggering one of these avalanches is more difficult. With the end of heavy snowfall, it's less likely one will release naturally - but it could still happen. A large load like a cornice fall, smaller avalanche initiating in higher terrain, or a group of people on a slope could trigger one where a single person might not. This isn’t really a “manageable” avalanche problem that can be figured out and mitigated with snowpits and other assessment tools. You are either in the terrain where it could happen or you are not. If you chose to travel these areas you are simply accepting a slightly higher risk of triggering or being overrun by a very large avalanche.