Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Wet avalanches will likely be difficult to predict, sporadic, and larger as poor overnight refreezes continue. Shed-style and glide avalanches on smooth bedrock slopes increase in likelihood as the day progresses. Keep an eye on your travel route and another on the slopes above you.

Avalanche problems

  • Loose Wet

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

    As the wet avalanche cycle continues, the avalanche size distribution changes. The larger, less predictable, and scarier type of wet loose slide should be your focus after several nights without a good refreeze. These avalanches occur in more isolated areas. You will primarily see them release naturally near and below cliffs on E-S-W aspects, but they start to entrain onto N aspects if the snow becomes heavy and wet. With 1-2 ft of snow above the 3/21 crust to potentially entrain, these avalanches could be large. Travel early and reduce your exposure to larger terrain features once the crusts break down.

    Some aspects are further along in their spring transition and are trending toward homogeneity. In these areas, you may trigger the smaller and more predictable wet loose avalanches once the surface crust softens and the wet snow becomes deeper than your ankle. When you find wet, saturated snow, head to more shaded aspects or lower-angled slopes. These avalanches are most likely in areas receiving direct sunshine.

    Example: A large natural avalanche from the Byrant Peak Couloir. This slide likely released as a spring shed from the looker's righthand cliffs. E, 5000'.

    Photo: Dallas Glass

  • Glide Cracks

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    During longer warm periods such as this, shed-style avalanches (cornice falls, glides, and wet slabs) could also occur.  The longer a warm period extends, the more higher the uncertainty grows. And we're in the late stages of this one. Meltwater continues to increase in the snowpack, lubricating bedrock slabs or pooling on crust interfaces. These types of avalanches can release any time of day. Manage your overhead hazard by minimizing or eliminating any time you spend on or under snow-covered rocky faces and looming cornices. Look for routes that minimize or even eliminate any time you spend under snow-covered rocks, looming cornices, or other very steep snow places.

    (1/29/2024)

    Example: Glide cracks in the Red/Kendall Basin. 

    Photo: Dallas Glass

Avalanche Discussion

Preliminary Report: NWAC is saddened to report an avalanche fatality as a result of a cornice fall on Mount St. Helens. On Friday, March 29, 2024, a snowboarder summited the peak. While standing near the top, he triggered a cornice and fell into the crater triggering a large slab avalanche on the slope below. NWAC is working with Skamania Co Sheriff’s office and SAR to compile a report. Our deepest condolences to the family, friends, and community.

Discussion:

A warm stretch keeps getting warmer, with peak temperatures likely on Tuesday. Avalanches will grow as we enter the second day without a good overnight refreeze (at any elevation).  The snow surface should still cool, but you may be able to easily punch through any shallow refreeze. Expect plenty of sunshine once again on Tuesday morning before clouds increase in the afternoon. Temperatures will be in the 40s and even 50s.

During this warm-up, we’re primarily worried about the snow over the 3/21 crust. You may not be able to identify this structure on more southerly slopes, but in shaded terrain, it’s often 1-2ft below the surface. 

Middle and upper-elevation snowpacks in the Snoqualmie pass region have plenty of colder, drier snow beneath the spring-like surfaces. Surprises linger, so it's a good time to keep an extra margin for error. Within this recent warm spell, numerous travelers unintentionally triggered avalanches; a few were caught, some were buried, and one was killed. 

Observations from Friday through Sunday indicated a fairly widespread wet loose avalanche cycle on E-S-W aspects. These slides were small (D1-1.5) and were pushing toward the large size range around Kendall Peak on Sunday. At this time we don't know how much dry snow lingers on upper elevation shaded aspects, but expect it to shed if it starts to melt.

Regions covered