Lawinenlagebericht

Snoqualmie Pass

Northwest Avalanche Center
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Lawinengefahr

Wed
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
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Kernpunkte

Avalanche activity should mostly be confined to the recent storm snow. Wind-loaded, convex, or unsupported features will be more likely to house slabs, while steep sun-exposed slopes could destabilize and shed their winter coat. We're only a few days out from a major storm, so ease back into terrain slowly. 

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    Look for slabs to fail more easily in wind-loaded terrain on Tuesday. Slab depth should increase as you ascend in elevation into more wind-prone areas. Large drifts, textured surfaces, and fresh cornices can all help you identify wind-loaded aspects. Then, you'll want to look for areas that "look fat" to avoid. Locations such as leeward ridgelines, the base of rocks, confined chutes/gullies, convex features, or unsupported slopes are likely locations to trigger a slab. To complicate matters, some slabs may be hidden under a few inches of fresh snow. If the snow feels denser than the surrounding area, you may have found a wind slab. Carefully retreat back the way you came and look for a new route that avoids this hazard. 

    With so much recent storm snow, any steep slope may be capable of producing a loose avalanche. Slabs in wind-sheltered terrain are less likely but not out of the question in isolated locations. 

    (3/16/2025)

    An intentionally triggered shallow slab avalanche near Snow Lake. This one is near a ridgeline and could have been slightly wind-loaded.

    Photo: Aaron Richards

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    We expect enough sunshine on Tuesday that wet loose gets the nod as an official problem. However, there will be competing weather factors like clouds and breezy winds. You'll have to see how the weather is panning out wherever you are recreating to see if this problem manifests. Wet avalanches could occur if the sun is winning the battle and the snow surface is getting moist and sticky. Rollerballs, pinwheels, or new fan-shaped avalanche debris are all good indications that you need to head for shadier aspects, keeping aware of slopes above you. 

    (3/14/2025)

    A natural avalanche in the Alpental Valley that failed once the sun came out and destabilized fresh snow. Look out for solar induced activity on Tuesday if the sun is out for a prolonged period.

    Photo: Kuba

Avalanche Discussion

After several stormy days, there’s a lot of recent snow, complete with subtle layers, changes in density, and even a few crusts on sunny aspects. The upper snowpack will look different depending on aspect, elevation, and how far east/west you are in the zone. Generally speaking, these layers should be on the mend, and observations report mostly right-side-up snowpack conditions.

Looking ahead to Tuesday, the Pass is in the crosshairs for a convergence zone, so it should pick up a fresh coat of white paint, creating another interface. With springtime weather, convective showers are always a threat to deliver rimed precipitation particles/graupel, creating short-lived slab issues. Most avalanches should be confined to this weekend's storm snow, but we can't rule out an isolated slab breaking deeper, possibly down to the atmospheric river (AR) crust.

Avalanche activity over the weekend mainly consisted of small storm slab avalanches on convex or wind-loaded features and multiple reports of dry loose avalanches in very steep terrain. An outlier was a remotely triggered slab avalanche in Great Scott Bowl. While slightly wind-affected, it’s a common travel corridor, and several local professionals commented that a remote trigger on this slope is rare. 

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