Avalanche forecast

Olympics

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

The longest period of hot weather seen all winter continues to impact the snow and increase the possibility for large loose wet avalanches. Pay attention to the slopes above you. Avoid lingering underneath any steep and rocky terrain especially receiving direct sunshine during the heat of the day.

Avalanche problems

  • Glide Cracks

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    With several warm days in a row, water will begin to move through the snowpack and may reach the ground in some areas. As it does so, you could see snow shedding from rocky faces and glide avalanches on steep smooth slopes. This low-likelihood/high-consequence problem is best managed through avoidance. Limit any time you spend below slopes where you see crevasse-like glide cracks. These avalanches can fail without warning at any time of day.

    (4/15/2021) Example: Glide cracks and a glide avalanche on the NW side of Granite Mt. NW, 4700'

  • Loose Wet

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

    It won’t take long for the sun and very warm temperatures to break down any surface crust. Once they do, conditions will change rapidly. This will occur in the morning on easterly slopes before quickly spreading to other aspects as the day continues to warm. You may see large natural loose wet avalanches entraining wet snow and even gouging into older snow layers. They may not be your normal easy-to-manage loose wet slides. If you see signs of new larger avalanches, dial it back and stay out from under similar slopes. 

    While our primary loose wet concern stems from natural slides caused by warming, you could trigger these same avalanches once the surface becomes wet and unsupportable. If you see new rollerballs or sink into the snow past your ankle seek out more frozen or lower angled slopes. If one of these avalanches catches you, the heavy wet slides can easily carry you over a cliff or into a gully.

    (4/11/2021) Example: Pay attention to the terrain above your head. Steep rocky slopes could produce large natural avalanches Friday.

Avalanche Discussion

Thursday night will be the third night in a row without a solid freeze at the snow surface. On Friday, temperatures may climb into the 60’s. This is by far the warmest weather the snowpack has experienced all winter. As we pass some of these critical thresholds, our concern about a springtime shed avalanche cycle grows. Predicting the exact timing of these events is incredibly challenging, but Friday could be the day. You could encounter any number of wet/spring avalanches: loose wet, wet slab, glides, and cornices. While the avalanche danger and problems may seem common, the conditions you could encounter are not. Give the snowpack time and space to adapt to this big change in the weather. If you head out to the mountains, go early before the sun and warm temperatures develop substantial wet and unstable snow. Pay attention to the slopes above you. They may bask in the sun and warm faster than where you travel. And, anticipate which slopes you’ll want to avoid as you return towards the trailhead.The terrain you cross in the morning may respond much differently later in the day. 

Daily avalanche forecasts will end on Sunday, April 18th.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

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