Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

You are more likely to trigger an avalanche on Saturday at upper elevations in wind-loaded terrain or on steep slopes that are seeing direct sunshine. Evaluate the snow carefully before stepping into consequential terrain, even small avalanches have the ability to knock you off your feet.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    The amount of sunshine making it through the clouds should once again drive the Wet Loose avalanche hazard on Saturday. The more sun in the area you are traveling, the higher the potential for these avalanches to occur. A warm and sticky snow surface combined with rollerballs, pinwheels, or snow shedding from trees and rocks will be your first indication that these avalanches are possible. Wet Loose avalanches often start at a point and can entrain snow, fan-out, or even trigger slabs as they descend downhill. You can minimize your exposure to these avalanches by heading toward lower angled or shaded slopes and ensuring that the slopes above you are not in the sunshine.

    (3/23/2021) Wet Loose avalanches like this one could occur when periods of sunshine cause the snow surface to become wet and unstable.

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Keep an eye out for potential Wind Slabs as you ascend in elevation on Saturday. You should use test slopes, uptrack tests, or visual clues such as freshly built cornices or textured snow surfaces to help you determine the existence and reactivity of potential Wind Slabs. Convex rollovers, terrain features over 35 degrees, or rocky terrain including confined gullies or the base of cliffs are the more likely locations for you to trigger one of these slabs. If you find a poor bond during your testing or notice cracking in the recent snow as you travel, look to avoid these features.

    Some areas of the zone may have freshly built cornices which may be sensitive. Be sure to give cornices a wide berth by not traveling on or below them.

    (3/8/2021) Look for lingering Wind Slabs near ridgelines and rocky features on Saturday. This Wind Slab formed at the base of the cliff and the large cornice above is a visual clue for its existence. Photo: Trevor Kostanich]

Avalanche Discussion

There should be one more day of mostly cloudy skies with sun breaks before precipitation returns to the zone on Sunday. Saturday should be the warmest day of the week and the clouds may not be quite as thick as the past few days, opening the door for more Wet Loose activity or other springtime avalanche hazards such as cornice failure. Don't rule out the possibility that the highest peaks could be sticking out of the lower level clouds, basking in the sunshine, and possibly producing avalanches on the slopes above you. 

This week’s storms left the pass with around 25” of snow above the 3/18 interface at middle to upper elevations, and considerably less below treeline. A second interface (3/24) was formed with the most recent round of snow on Wednesday, and both the 3/18 and 3/24 are easily identified on slopes that see direct sunshine. On slopes with a more northerly tilt, you should be able to still find them, but they could be a bit more subtle. We believe that all avalanche activity should occur above the 3/18 interface, with most focused above the 3/24. 

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

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