Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Out of date — this forecast expired 6 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

The beautiful, sunny weather will come with a hidden danger on Sunday. A complex and atypical weak upper snowpack may result in surprising avalanche activity. Make trip plans that limit or eliminate your exposure to open slopes steeper than 30 degrees.

Avalanche problems

  • Persistent Slabs

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

    The threat of persistent weak layers in the upper snowpack failing should be shaping your travel plans on Sunday. While the likelihood of triggering these layers is a point of discussion, there is no disagreement among anyone who has taken the time to look - they are there, and they are weak. This snowpack setup is atypical for us here in the Cascades, so you can't just roll out your normal playbook and assume that you'll get the same results as you always do. Take the time to discuss your acceptable level of risk with your partners. Then make careful trip plans that give you the option to avoid open avalanche terrain over 30 degrees. 

    This problem is difficult to diagnose in the field, so you likely won't receive much feedback before an avalanche occurs. Maybe you'll get a whumpfing collapse or a shooting crack, but that's not a guarantee. Even using test slopes or uptrack tests won't help you identify where this problem could rear its ugly head. If a persistent slab avalanche occurs, it could break widely or even be triggered remotely (from a distance). The only mitigation tool you have is terrain avoidance. 

    (2/28/2026)

    A very large natural avalanche occurred near Mount Baker Ski Area on Saturday afternoon. This slide was likely triggered due to a full day of solar input and illustrates how finicky persistent slab issues can be.

    Photo: Zack McGill - Cascade Mtn Ascents

  • Loose Wet

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

    Is March 1st too early to talk about spring? Maybe... but you'll likely find some springlike weather in the mountains on Sunday, leading to the possibility of wet avalanches. 

    If the surface is getting warm and sticky or you see snow shedding from trees and rocks, you'll know that wet avalanche activity could soon follow. That will be your cue to head for shaded, low-angle terrain, staying aware of slopes above you.

    This avalanche problem is typically easy to manage, but with persistent weak layers lurking below the surface, it becomes more complex. In addition to fanning out and growing in size as they descend, the threat now exists that they will trigger larger and more dangerous persistent slab avalanches. 

    (2/28/2026)

    Roller balls off Draft Dodge Ridge in the Alpental Valley. A precursor to wet avalanches.

    Photo: Joe Hoch/ Pro Guiding Service AIARE 1

Avalanche Discussion

On Thursday, February 26th, a skier was fully buried in an avalanche at Stevens Pass Resort. Despite a long burial time, the skier was successfully rescued by Stevens Pass Patrol and treated for non-life-threatening injuries. The avalanche occurred on a wind-loaded northwest aspect near 5,3000ft and likely ran on a persistent weak layer over a crust, 15-20" deep.

Saturday was a beautiful, mostly sunny day in the mountains. Although temperatures were on the rise, multiple avalanche professionals reported that conditions stayed relatively cool in the Alpental Valley, with only some rollerballs and pinwheels observed. As we look forward to Sunday, expect a similar day in terms of sky cover, but those warm temperatures should start to creep in and make their presence felt a little more. This could lead to an uptick in wet avalanche activity. To get there, the March sun and temps will likely need to break down a surface crust that forms overnight. This likely won't take long, but you could find some slick travel conditions first thing in the morning.

The real question on everyone's mind is how our persistent weak layers will respond as this warm-up continues. The 2/13 and 2/7 layers contain surface hoar and facets and can generally be found in the top couple of feet of the snowpack. These layers have produced widely breaking avalanches in neighboring zones all week, such as Stevens Pass (see above) and the West South. We've been in a bit of a lull in terms of activity at Snoqualmie Pass, with our last reported avalanche on these layers suspected to have occurred last weekend.

That doesn't mean this problem is dead, however. These sorts of avalanches typically come in waves, and when the time is right, they can happen quickly. On Saturday afternoon, a very large natural avalanche occurred near Mount Baker, likely triggered by a full day of sunny weather. Maybe the warmth will reinvigorate these layers at Snoqualmie on Sunday? Or maybe they're just waiting for you to come along and find a shallow point in the snowpack.  Either way, persistent weak layers are inherently difficult to predict, so there is naturally a large degree of uncertainty in how they will respond in the coming days. Plan your trips accordingly, knowing that the setup exists and that the consequences if these layers fail will likely be dire.

We threw this in Friday's forecast, but for those of you who missed it and are curious. Chair Peak has produced very large and destructive avalanches twice in recent years, both on March 1st. In both cases, we were dealing with persistent weak layers, albeit deeper in the snowpack and with more significant recent weather inputs. If you're superstitious, maybe this Sunday is a cursed date? But just to be clear, the odds of a catastrophic avalanche coming off Chair Peak on Sunday are not very high.

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