Lawinenlagebericht

Stevens Pass

Northwest Avalanche Center
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Lawinengefahr

Fri
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
2 · Mässig
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Kernpunkte

Warm temperatures will continue and maintain a chance for very large wet avalanches. Avoid steep slopes and stay well out from under areas where slides could come from above. On the heels of a major rain event, temperatures will be slow to cool.

Lawinenprobleme

  • Wet Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    2–3

    Very large slides could start at upper elevations and run to valley bottoms. You may even be able to trigger avalanches at lower elevations that could be big enough to bury or kill you. Stay well away from and out from under slopes that are 35 degrees and steeper.  Don't linger or stop in runout zones of big avalanche paths. The natural activity is likely tapering off but we're uncertain exactly how easy it will be to trigger slides on Thursday.

    Temperatures will stay warm after close to 1.5" of rain fell at Stevens Pass through Wednesday. This will keep the snowpack wet and weak for the near future. It's been over a week since any of our staff has had access to the Stevens Pass zone. Information is limited and uncertainty is high.

    (1/12/2022)

    The lower track of a very large D3 avalanche. This ran sometime around January 10th in a path known as East Camp near Highway 2 Stevens Pass. Rock Mountain, south aspect.

    Photo: WSDOT Harlan Shepard

Avalanche Discussion

On Wednesday, WSDOT forecasters reported multiple very large (D3) wet avalanches in the Highway 2, Stevens Pass corridor. They reported another D3 in the East Camp path that ran to the valley floor on a south aspect of Rock Mtn, likely on Monday (see photos). Other very large and deep avalanches have recently occurred in the neighboring Snoqualmie Pass and East Central zones. We have limited information and access to the Stevens Pass area. Rain began in the early hours of the 11th, wetting a previously dry snowpack including significant new snow from the past week. Forecasters at Stevens Pass Mountain Resort measured 82" of snow accumulation in 72 hours between January 5 and 7th.

There is minimal access to most of the zone, weather stations have been down, and information is limited. Infrastructure and highway crews are still recovering from the historic storm last week. On the 7th, WSDOT crews reported triggering D3.5 avalanches on the pass with control work, which left debris 60ft high over the road. On the 6th, they reported multiple natural avalanches D2.5-D3 in size that hit the closed highway west of the pass. Once the storm ended, WSDOT reported over 208 debris piles up to 15 feet deep on Highway 2 in Tumwater Canyon alone. Several slides ran into the river and ten of them were very large. Prior to the storm on the 6-8th, observers noted a couple of buried layers of large, faceted stellars and surface hoar. These layers are probably 4-5ft below the surface now and could be weak layers for slab avalanches.

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