Avalanche forecast

East Slopes Central

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

Dangerous conditions continue as significant snowfall and wind this weekend stressed older layers of weak snow.  Stay far away from and well out from under large open slopes 35 degrees and steeper. Consider avoiding all large avalanche terrain where you can trigger very large and destructive avalanches that could break widely across slopes.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–3

    A fatal persistent slab avalanche occurred on February 8th in the Salmon La Sac area. Our condolences go to the friends and families of those involved. Read further for more details and how you can avoid these dangerous avalanches.

    Recent snow and strong wind have made it easy to trigger avalanches 2-4ft deep. Persistent slabs can propagate widely across terrain features and can result in very large and deadly avalanches. Stay well out from under any large open slopes steeper than 35 degrees, as they can be triggered from a long distance away or from below. Be alert to signs of instability such as shooting cracks, and whumphing collapses.

    You can trigger avalanches on a weak layer of facets around and sandwiched by crusts formed in mid-January. You can find the soft, weaker snow and icy crusts 2-4 feet below the snow surface. Snowpack tests that fail suddenly or show propagating cracks, are all indicators that you could trigger these deadly avalanches. When the snowpack is weak and complex, it's easiest to keep your decisions simple and avoid avalanche terrain.

    (2/9/2021) Persistent slab avalanches may have run naturally on an east aspect at around 4900ft in the Knox Creek drainage above Cle Elum Lake. These are suspected to have run on the mid-January crust later in the storm cycle of Feb 5-9th.

  • Wind Slabs

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

    Strong west winds transported the snow in open and wind-exposed terrain. Feel for wind stiffened or hollow sounding snow as you enter open terrain, and change aspects.  Any avalanche in the new snow could step down to deeper weaker layers and result in a very large and deadly avalanche above 5,000ft. Consider the terrain you're connected to and avoid steep, open wind loaded slopes. Stay alert to indicators of wind slab such as heavy snow drifting, shooting cracks and whumphing collapses.

    (2/1/2021) From White Pass on Monday: Example of a small wind slab avalanche stepping down to weaker deeper layers.

Avalanche Discussion

Preliminary avalanche accident, Monday, February 8th, 2021: Two snow bike riders were caught and buried by a very large avalanche in the mountains west of Salmon la Sac Sno-Park along Cle Elum Lake. One snow biker was partially buried and was able to dig himself out. The other rider was fully buried and killed by the avalanche. The avalanche occurred on a north aspect at 4400 ft in the Knox Creek drainage. This terrain lies in NWAC’s East Central forecast zone. Avalanche classification: HS-AV-R3-D3-O. 

All of us at NWAC want to extend our condolences to family, friends, and the local community following this tragic event.  

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The Salmon la Sac, Teanaway, Icicle, and other drainages on the southern and western edges of the zone have been favored for snowfall and now hold the most dangerous conditions. While slabs are thinner and the danger may be less elevated in the Wenatchee Mountains, the avalanches will be similar. Dangerous conditions have produced many very large natural avalanches and avalanche involvements over the past week including the following:

Widely propagating avalanches ran over the weekend on an east aspect of Sixtysix Hundred (6600ft) ridge in the Icicle drainage. On Sunday, backcountry skiers were caught but uninjured in a very large avalanche on Jim Hill in the neighboring Stevens Pass zone. On Saturday, observers reported a D2 natural avalanche near Van Epps Pass and a D3 sized avalanche that resulted in a burial with no injuries near the Easton Sno-Park. Observers reported a natural D2 avalanche on an east aspect at 5,500ft west of Blewett Pass on Friday. On Thursday, a snowboarder was caught in a wind slab avalanche at Mission Ridge on a Northwest aspect in the Near Treeline elevation band. Luckily they escaped unharmed. An observer reported a number of large (up to D2.5) avalanches with the recent storm from February 1 or 2 near Holden Village. 

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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