Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

An atmospheric river will continue to impact Snoqualmie Pass on Friday, bringing high elevation rain and generally stormy conditions. It likely won’t be a very fun day to be in the mountains and dangerous avalanche conditions are expected. The snowpack will need time to adjust to this load so stay out of avalanche terrain until the rain has stopped.

Avalanche problems

  • Wet Slabs

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

    Continued rain to the tops of the peaks around the Snoqualmie Pass zone should result in snow ripe for wet avalanches on Friday. You could see loose avalanches failing from a point and fanning out as they descend, or slabs failing as water percolates the snowpack. Larger chunks of snow could break off sagging cornices or shed from rocky ledges. These sporadic and difficult to forecast avalanche problems aren’t the type to try to tiptoe around. Your best mitigation tool is to avoid anywhere an avalanche can start, run, or stop until this atmospheric river wraps up.

    (12/26/2022)

    Some larger Glide avalanches occurred as a result of our previous atmospheric river event over Christmas. You could see plenty of wet avalanches on Friday as the rain continues.

    Photo: Alpental Pro Patrol

Avalanche Discussion

On Friday, it still won’t be a particularly enjoyable time to be in the mountains around Snoqualmie Pass. We’ll keep rollin’ on the atmospheric river, with freezing levels predicted to be about 7000 feet. We dropped the hazard level since the initial onset of rain on snow has already occurred. This means that the first wave of natural avalanches has likely passed. However, conditions are still considered dangerous, with the snowpack now primed for more human-triggered slides and less widespread natural activity. At lower elevations, limited snow above the Christmas Crust prior to the storm and plenty of rain on Thursday likely has played out the majority of the avalanche cycle. That doesn't mean slides can't impact you from above or that avalanches are impossible.

As of Thursday afternoon, the Pass has already received about 1.00” of water and we expect that number to about double by the end of Friday. While the precipitation did start as snow on Thursday, temperatures slowly crept up and rain was likely reaching the higher peaks by day’s end. Observations have obviously been limited due to the undesirable nature of this storm, but Alpental Pro Patrol did report very sensitive Storm Slabs first thing in the morning before precipitation changed into a more liquid variety mix. They also reported possibly seeing some natural activity, but visibility was extremely poor. 

With a few layers of interest found in the snowpack prior to this storm, we could continue to peel back the snowpack onion layer by layer as we strip down toward the Christmas Crust. Again, even though the hazard has dropped due to natural avalanche likelihood, it will still be a dangerous day to be in the mountains and likely an unpleasant one at that. There's a chance that we haven't seen the worst of it yet. You may want to consider waiting this storm out. But if you decide to enter the mountains, it’s been said that people on the river are happy to give. So give us some observations and pictures of what you’re seeing out there and make conservative terrain choices. 

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