Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Wet snow avalanche problems remain our largest concern, with a low likelihood but high consequence scenario as temperatures stay warm and we get another inch of rain Thursday night. Avoid traveling beneath gaping glide cracks or other snow patches that are suspended in precarious locations like on rock slabs over steep slopes. If you make it to upper elevations and find several inches of new snow, it's possible you could trigger an avalanche on steep slopes. 

Avalanche problems

  • Glide Cracks

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

    We've received 3.5inches of water in the last few days, most of which has fallen as rain. We're getting another inch or so on Thursday night. Most wet avalanches ran their course Tuesday night, when temperatures and incoming water amounts first spiked. However, prolonged warm, wet weather gives us enough concern that we don't quite feel good about letting the danger drop to low. 

    Lingering wet avalanche concerns are most likely to present as glide avalanches. These exist as a low probability, yet high consequence scenario. Friday probably isn't a good day to travel beneath any gaping glide cracks. You never know when one of these cracks may release and avalanche, and after several days of warm, wet weather this isn't the time to push your luck. 

    Search for other overhead hazards as you travel, such as cornices and other snow deposits perched in precarious, unsupported locations above you. These also might randomly come down, and could possibly entrain more snow or even trigger an avalanche on steep slopes beneath. Avoid these areas. If you're ever in a situation where you're punching well past your ankles into wet snow, consider avoiding slopes greater than 35°.

    Example photo: A glide avalanche like one you might see on Friday. 

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    The inch of rain at lower elevations might equate to a foot of snow near the top of our upper elevation band. If you make it up that high, prepare to encounter dry slab avalanches. In between, snow may be heavier and wet, before all of a sudden you might notice it's lighter and fluffier. If new snow amounts over the firmer old snow layer grow to depths of 4-6 inches or deeper, change your mindset to new snow avalanche problems. 

    Start on small test slopes to see if the snow reacts to your impact on the slope. If any small avalanches results, or if you experience any long, shooting cracks or "upside down" snow, where a heavier layer of snow is over lighter, fluffier snow, then steer clear of larger slopes steeper than 35°.  Any new or recently wind-transported snow could avalanche with a human trigger, so avoid wind drifted features. Search for actively blowing snow or pillowlike or wind textured features and avoid those locations on steep slopes. 

    Example photo: Slab avalanches like this one may fail in the new snow at upper elevations on steep slopes. 

Avalanche Discussion

We've had a rollercoaster of a week (and season!) with a few deep powder days and now a sudden shift to warm temperatures that have made most of our dry snow disappear. Our intense period of rainfall that ended Wednesday morning left us with a moist snowpack and many avalanches. I traveled into the Baker backcountry on Wednesday and found a lot of new avalanches, and you can check out my observation HERE.

The recent rain left us with moist snow down to the 12/7 crust, which is 2-4ft below the surface. Beneath the 12/7 crust the snowpack was already moist from the previous rain that fell in most areas. There may be some spots near the top of our upper elevation band where dry snow exists somewhere in the snowpack. Once we get another good freeze these layers will provide a great base for additional snowfall that we'll hopefully be getting soon enough. 

We're now seeing rain runnels at the snow surface. Snow is likely supportable for most forms of travel. However, snow may be sticky, and a breakable crust could exist in some areas, making travel more challenging. 

If you make it into the backcountry, whether you see avalanches or not, we'd love to hear from you. Please share with us so that we can write better avalanche forecasts for you and other backcountry users in the zone. You can submit an observation HERE, or by using our app, Avy. 

 

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