Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

A slight cooling is expected Tuesday night, but we'll continue with warm, wet weather on Wednesday. You could encounter either wet or dry snow avalanche problems depending on the elevations you travel through. Avoid all steep slopes, and if you see any natural avalanche activity, avoid traveling beneath steep large paths as well. 

Avalanche problems

  • Storm Slabs

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

    Human-triggered slab avalanches are likely at mid to upper elevations. Avalanche danger will increase as snowfall amounts grow throughout the day. We're forecasted to get about 4- 6 inches of snow at higher elevations. Most avalanche activity will probably be limited to newly fallen snow, less than a foot deep.   However, we've been in a fairly steady storm cycle since Saturday, and avalanches could happen in older storm layers, up to around 2 feet.

    Expect thicker slabs and more reactivity in wind-loaded areas. Obvious clues such as long shooting cracks from your weight, whumphing, or intense periods of snowfall and wind, are all strong indicators of instability in the snowpack. A lot of uncertainty exists with the current conditions, so remain conservative during your outing.

    This isn't a day to test steep slopes. Avoid all terrain greater than 35°.  If you identify any recent natural avalanches, steer around lower-angle terrain beneath steep slopes as well.  

     

    Slab avalanches, similar to this one, are likely for a human to trigger on Wednesday. 

    Photo: Irene Henninger

  • Wet Slabs

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

    Neighboring zones all reported wet avalanche activity on Tuesday. We suspect the same happened in the West Central zone. Temperatures may cool a bit Tuesday night, but we still won't see a good freeze. Freezing levels will then rise a little on Wednesday, so wet avalanche activity may continue.

    Avalanches could range from shallow, wet loose in the new snow to ones a little deeper, entraining the last few days' snow, especially as temperatures rise. Wet slab avalanches might occur, failing up to a couple of feet deep. And finally, glide avalanches on steep, smooth rock faces could happen. Avoid travel beneath large gaping cracks in the snow to avoid getting caught in a glide avalanche. 

    If you travel onto steep slopes, and if the snow is wet and sticky, you might be able to trigger a loose avalanche, which is probably what you'd see more of on Wednseday. Wet slabs tend to release at unexpected times naturally, or may be triggered by a smaller loose avalanche. As before, this is definitely a day to avoid slopes greater than 35°, but if you're sinking past your ankles in wet, heavy snow, or notice any natural avalanche activity, avoid travel beneath steep slopes also. 

     

    Example photo: Wet slabs similar to this one may occur without warning on Wednesday. Note the runnelled surface, like what you'll find during your outing on Wednesday. 

Avalanche Discussion

We suspect that there has already been so much rain at lower elevations that avalanche activity is reduced at those elevations. Mid elevations, where the dry snow/rain interface exists, are where we expect the most wet activity.

Information is very limited in the West Central zone. Up high, you can expect to find dry snow, much of which is probably wind-affected. Lower down, travel, no matter the form, is probably unpleasant in wet, sticky, and punchy snow. Plan on making constant evaluations as you're out, and if in doubt, use lower-angle terrain to travel more conservatively in the backcountry. 

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