Avalanche forecast

East Slopes North

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Highlights

Warming temperatures and strong sun will maintain concern for falling cornices. You may be able to trigger loose avalanches on very steep northerly slopes as well as on sun-exposed slopes.

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

     Cornices top many ridgelines and steep features above treeline and have been occasionally falling.  Avoid lingering on or under large cornices. They could easily be big enough to injure you. If you're traveling on a ridge, check that you're standing above part of the mountain and not on unsupported snow. Clues like exposed rocks and vegetation can tell you where you can travel without being on an overhung cornice. Give cornices a wide margin as they can break further back onto the ridge than you may expect.

    Warm temperatures and sun could be enough to bring down more cornices from where they're overhung and unsupported. Observers have reported ongoing cornice fall in the Washington Pass area in the past 10 days. I watched one fall in Copper Creek on Monday. Some of these have resulted in avalanches that wouldn't have occurred otherwise.

    (3/8/2021) Large cornices sagging high above the Hairpin Valley.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    A warming trend with strong sun will continue this week. Watch for triggering small, loose wet avalanches on steep solar slopes. Time your travel to be off of these slopes before the surface snow becomes weak and unstable. Use caution around terrain traps such as gullies and cliffs where small avalanches could be dangerous. You may also be able to trigger dry loose avalanches on slopes steeper than 40 degrees. 

    (3/11/2021) An example of loose wet avalanches from the Stevens Pass zone. These ran on either March 9th or 10th. Rock Mtn, SE, 6,400ft.

Avalanche Discussion

On Monday, I checked out multiple a variety of slopes at Washington Pass in the Hairpin Valley and beyond. We triggered small loose dry avalanches, a very small wind slab, and watched a natural cornice fall. You may find some similar conditions on Friday. Shallow wind slabs that built early in the week are now isolated and difficult to trigger. The snowpack is generally strong, deep, and without any layers of concern. In the top 2 feet of the snowpack, I did find a couple of interfaces with strong-over-weak layering. Investigating these interfaces revealed no signs of instability or reasons for concern at the time.  A widespread avalanche cycle occurred in the zone around February 22nd and many crowns and debris piles are still visible. Further east, the snowpack is more shallow and could potentially harbor persistent weak layers.

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