Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
4 · High
Treeline
4 · High
Below
4 · High
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Highlights

When very dangerous avalanche conditions like we are currently experiencing persist, the answer is simple. Stay away from anything that resembles avalanche terrain. That includes avoiding areas down in the forest where avalanches can run and stop.

Avalanche problems

  • Storm Slabs

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

    The storm continues to rage at Snoqualmie Pass. On Thursday the DOT reported numerous triggered and natural storm slab avalanches along the I90 corridor. A few of these slides grew very large (D3) and traveled to near valley bottoms. Recent avalanches, continued heavy precipitation, and strong ridgeline winds all point toward one thing: very dangerous avalanche conditions. With several feet of snow already on the ground and more to come, all of these avalanches will be large enough to kill you, and some may even grow very large and destructive. Don’t try to outsmart this avalanche hazard. Let the storm play out well away from any slope where an avalanche can start run and stop. As more snow piles up, we could begin to see startzones between 30 and 35 degrees fail and produce avalanches in more unusual locations.

    (1/6/2022)

    This deep natural avalanche has a 1-1.5m crown and occurred in the I90 corridor Thrusday. 

    Photo: WSDOT SCR

  • Wet Slabs

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

    Heavy rain at and above Pass level saturated the surface snow. Many wet snow avalanches occurred on Thursday, some of them running in paths that had previously slid during this storm. As more rain falls, this problem will continue. You will see large loose wet, wet slab, and glide avalanches. These slides could occur well below treeline as the snow sheds from any open slopes. All steep open terrain should remain suspect during this storm. Stay off of and out from under these possible avalanche slopes. 

     

    (1/6/2022)

    A snow profile at 3000' at Snoqualmie Pass. Note the pooling water well below the surface. This could result in wet slab or glide avalanches. 

    Photo: Alyssa Young

Avalanche Discussion

Avalanche professionals reported 2-2.5’ of snow Pass level before the precipitation changed to rain Thursday afternoon. This heavy wet snow fell with eye-popping rates of 2-3” per hour during the day. Not surprisingly, many natural avalanches (D1.5-3) released. As temperatures warmed another round of natural avalanches occurred as snow changed to rain. Expect this trend to continue. We could see several more cycles of natural avalanches particularly during periods of heavy precipitation and when wind speeds increase on Friday. 

It may take a while for the rain to change back to snow at Pass level. As it does so, you may see the avalanche danger very slowly decrease at lower elevations. However, remember the storm is continuing above your head, and significant wind loading at upper elevations could still cause very large natural avalanches that descend down to lower elevations. 

Roof avalanches and tree bombs continue to be a very real threat to anyone venturing outside. Similarly, expect arduous travel conditions with deep heavy snow. Snow Immersion Suffocation (SIS) and treewell hazards only add to the very dangerous conditions. This may be a great day to spend anywhere but the backcountry.

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