Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
4 · High
Treeline
4 · High
Below
4 · High
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Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Thursday will be a very dangerous day to be out in the mountains. This is not the day to try to tiptoe around avalanche terrain. Stay well away from any area where an avalanche can start, run, or stop, including open areas well below treeline. We expect widespread natural avalanches easily big enough to bury and kill you.

Avalanche problems

  • Storm Slabs

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

    You don’t need to have a PhD in avalanches to figure this one out. Very heavy precipitation, rapidly warming temperatures, and strong winds will all combine Thursday morning at the Pass to create very dangerous conditions. We expect lots of large natural avalanches big enough to kill you at all elevations. In some locations, these slides may entrain significant snow, break into older snow layers, and grow very large and destructive. Stay away from all avalanche terrain including areas where slides can run and stop.

    You may encounter some of the most widespread storm slab avalanches below treeline. With all the low elevation snow, you could find avalanches in some unusual locations. Just because you haven’t seen it slide before doesn’t mean it’s safe. Avoid all slopes over 30 degrees and any open areas below them.

    (12/25/2021)

    Example: You could see large storm slabs even in treed terrain Thursday. 

  • Wet Slabs

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

    At some point on Thursday, the warming temperatures will win and bring rain to above Pass level. This could happen very quickly. When it does so, expect widespread wet avalanches. While some of these could be loose, many could be wet slabs. Truly it doesn’t matter, loose or slab, wet or storm… this isn’t a problem you want to play with. Keep away from all avalanche terrain until this storm plays out.

Avalanche Discussion

Normally we point to a trend and a peak in avalanche danger. That is not the case this time. Due to the ongoing and dynamic nature of this storm, you could see several rounds of natural avalanche activity. We are expecting several feet of snow at mid and upper elevations. As the snow stacks up avalanches could grow larger and more destructive. While numerous avalanches have been reported at the Pass this year, this will by far be the largest and most widespread avalanche cycle of the season to date. Best to sit this one out well away from anything that resembles avalanche terrain. 

If the storm and resulting avalanche danger weren’t enough, roof avalanches, tree bombs, deep snow immersion, and treewells all pose a danger Thursday. Be very cautious if you choose to venture into the mountains.

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