Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
4 · High
Treeline
4 · High
Below
3 · Considerable
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Out of date — this forecast expired 2 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Very dangerous avalanche conditions will exist at Snoqualmie Pass on Wednesday. High snowfall rates, strong to extreme winds, rising temperatures, and known layers of concern will likely result in natural avalanches that could run toward valley bottoms. Do not try to tiptoe around the danger - avoid all locations where avalanches can start, run, or stop. 

Avalanche problems

  • Storm Slabs

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

    Expect several feet of snow to fall above the rain/snow line Tuesday night and Wednesday. Rising temperatures throughout this event means the snow will likely be heavy. With soft powder snow already in place above known crusts and potential weak layers, you have the perfect recipe for slab avalanches large enough to bury and kill you. If they break down into older snow layers, they could grow very large and run close to full path on a firm crust. Wednesday is not the day to wander in the mountains anywhere an avalanche can start, run, or stop. 

    (2/4/2024)

    Very large avalanches capable of running to valley bottoms are expected on Wednesday. Travel in avalanche terrain is not recommended.

    Photo: Jonathon Spitzer

  • Loose Wet

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

    Below the rain/snow line, rain will likely destabilize the snow surface and produce natural avalanches. Wet avalanche potential will peak shortly after rain begins falling on dry snow. That could be on Tuesday night. Don’t try to thread the needle; these slides could occur anywhere the snow surface is wet. Even if the height of instability for these avalanches has passed, the threat of very large avalanches coming down on you from upper elevations should have you avoiding all avalanche terrain. 

    (1/29/2024)

    Example: Wet avalanches near the Waterfall Cliff on the main approach to Kendall. Expect similar slides on Wednesday.

    Photo: Dallas Glass

Avalanche Discussion

After a relative lull in the action on Tuesday, we’re heading back into a very stormy period for the next few days. The warmup has already begun at Snoqualmie Pass - temperatures slowly crept up throughout the day on Tuesday. On Wednesday, peak warming will coincide with the heaviest precipitation and strong to extreme winds during the daylight hours. It will be a very dangerous day to be in the mountains. Avoid all terrain where avalanches can start, run, or stop - including well down in the forest.

On Monday, a cold winter storm dropped several feet of low-density snow at mid to upper elevations, creating the 2/24 interface. Deeper in the snowpack, a series of crusts and pockets of weak snow exist above the Early February Crust (EFC). With 2+ feet of heavy snow expected during this next storm, avalanches could fail 5-6 feet deep down to the EFC. In isolated locations, they could span far distances or wrap terrain features. These are not avalanches you’re going to want to be anywhere near.

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