Boletín de aludes

Olympics

Northwest Avalanche Center
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Alta montaña
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Límite del bosque
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Bajo el límite
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Desactualizado: este boletín caducó 5 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

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Winter storms in springtime create a mix of small dry and wet avalanche hazards. Wind slabs may form down to mid-slope terrain features on lee slopes. Wet avalanche conditions develop quickly if the sun comes out and creates wet or sticky snow.

Problemas de aludes

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1

    New snow and moderate ridgeline winds will create small wind slabs near the ridgeline and potentially extending down to mid-slope features. Look for areas with 6" or more of snow to identify recent deposits. Steer around lens-shaped pillows and areas of firm or textured snow. You can test the bond of the new snow to the old snow surface (likely a crust) on small test slopes. Increase your margin for error around high-consequence terrain features. Slabs may run efficiently on either the 4/9 to possibly the 4/7 crust. 

    Example: (3/26/2021) This shallow Wind Slab was triggered by a skier on Friday (3/26) near White Pass and likely ran on the 3/24 interface. It was 6-8" deep. [NE 6200']

  • Loose Wet

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1

    Wet loose avalanches will entrain the fresh storm snow if the sun makes an appearance on Saturday.  Expect rollerballs and then shallow 4-5" wet loose avalanches on slopes receiving direct sunshine. These avalanches start slowly from snow shedding off trees or rocks, but gain momentum on long steep slopes. Move from sunny to shaded aspects and reduce your exposure to steep slopes above. Extreme terrain or terrain traps such as gullies or cliffs will amplify these small avalanches.

    Example: (4/9/2021) Small wet loose avalanches ran on steep, east facing slopes at around 5,500ft in Whitepine Cirque.

Avalanche Discussion

We're expecting around 4" of snow to fall Friday night with another inch or so during the day on Saturday. Depending on the aspect, the fresh snow should sit on either an old snow interface or breakable melt-freeze crust formed during sunny weather on Thursday.  Below that crust, around 5-8" of dry snow should be consolidating above a crust (4/7) that exists on nearly all aspects and elevations. Each April storm forms well-defined layers, particularly crusts. We'll need to watch these crusts carefully once warmer weather returns, concentrating meltwater in specific layers.

Although the Hurricane Ridge area experienced a quiet week without significant reported avalanche activity, that has not been the case throughout the region. 

On Friday, multiple riders triggered avalanches, including an involvement where a skier was caught and carried. In one such occurrence,  the crown was 2 ft deep and the slide ran 600 vertical feet. This caps a week that saw multiple avalanche involvements and near-misses around the Cascades, including in the West South where a snowboarder was caught and carried by a large avalanche on Mount St. Helens. We continue to bring up that the snowpack has not made its full transition to a springtime snowpack, and this past week provides proof of that with both dry and wet avalanches driving these involvements. As we navigate our way through springtime weather, the transitions between dry and wet avalanche problems can be rapid and unpredictable, just like the weather. It can make decision-making and forecasting challenging since you can’t bring your winter mindset or spring mindset to the mountains to rely on for any given day. Perhaps the best advice is to learn from these recent incidents and dial back your terrain choices until more stable weather and snowpack patterns prevail.

The snowpack in the Olympics is in great shape for early April with significant depth and excellent coverage.  

Are you out in the Olympics?  Let us and the backcountry community know what you see and Submit an Observation. 

Spring Forecast Schedule:  NWAC will issue a danger rating every day for the Olympics beginning Friday, April 2nd  - Sunday, April 18th. 

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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