Lawinenlagebericht

West Slopes South

Northwest Avalanche Center
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Lawinengefahr

Thu
Hochgebirge
3 · Erheblich
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
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Kernpunkte

You’re likely to see natural wet avalanches near and above the rain-snow line as temperatures warm and the sun comes out. These slides will be large and more dangerous in areas that received more than 6 in of recent snow. Pay attention to the slopes above you and limit the time you spend below rocky faces.

Lawinenprobleme

  • Loose Wet

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

    You’re most likely to see wet loose avalanches where there is several inches of newer snow sitting on top of a crust. As conditions heat up on Wednesday, you may easily trigger “push-o-lanche” wet slides that run easily on the underlying frim layer. As snow starts falling off rocks and trees, it may trigger these avalanches on the slopes below. This will be most common on E-S-W aspects near and below rocky faces. 

    If these slides descend lower in the terrain where the snowpack is very wet and punchy, they could entrain lots of heavy snow and grow much larger. These “shed-style” wet loose avalanches are much more dangerous. Similarly, blocks of snow may fall off cliffs, cornices collapse, and glides release. With all of these spring slides, manage your overhead hazard by paying attention to the slopes above you and limiting any time you spend underneath large, rocky avalanche terrain.

    (3/16/2024)

    Example: Large natural wet avalanche below rocks and cliffs. 

    Photo: Crystal Mt Ski Patrol

  • Wind Slabs

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

    As you ascend, the snow should eventually become drier and more winter-like. At these upper elevations, strong winds during this storm likely affected nearly every slope. You could see scoured firm windward areas and deeper loaded aspects. Textured surfaces, fresh drifts, and sharp wind lips all point toward potential wind slabs. Avoid these firmer loaded slopes and give them time to heal. You may see wind slabs even well below ridgelines on convex rollovers or along the sides of gullies.

    Wind slabs will be the biggest and most dangerous on the volcanoes where more snow fell during the storm. In these locations, some slabs could easily be 1-2ft thick and very wide.

    (3/13/2024)

    Example: Visual  clues help highlight where wind slabs may occur.

    Photo: Dallas Glass

Avalanche Discussion

Wednesday looks like a dynamic spring day right on the heels of a storm. The danger won’t be the same throughout the zone. Places near the Crest, like Crystal, didn’t receive as much snow. They should see smaller avalanches and lower danger than areas closer to Paradise. 

With the changing weather, expect avalanche concerns to increase during the day as temperatures rise and the sun warms the surface. With light winds and thin clouds, it could get steamy and feel like a greenhouse. Frequently, these types of conditions correspond to significant natural wet avalanche activity. 

On Tuesday, a storm brought rain and high elevation snow to the zone. They rain-snow line seemed to hover between 5500 and 6000ft. On Mt Rainier, more than a foot of new snow likely fell above this elevation. Lesser amounts fell at Mt St Helens, White Pass, and Crystal Mt. 

During this period, we’re mainly worried about the recent snow over the Early April Crust (EAC). The depth varies greatly by location, elevation, and aspect. This is often the first significant firm layer below the surface. In some places, it could be 1.5ft deep. At lower elevations, the recent warm and wet weather took a massive toll on the snowpack. Expect thin coverage, areas of bare ground, open creeks, and significantly less avalanche danger.

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