Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

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

We've got around a foot of snow arriving,  which is very different from our recent weather, and it's time to think differently. Avalanche danger will increase throughout the day as more snow falls and moderate to strong winds blow. Focus on identifying  thicker and firmer-feeling wind-drifted slabs and steer around them on steep slopes when the drifts grow deeper than about 6 inches.

Avalanche problems

  • Wind Slabs

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

    Early in the morning avalanche danger may be low, but danger will quickly increase as new snow depths increase. Precipitation will start as rain, but should quickly shift to snow. We're forecasted to receive about a foot of snow, possibly more. Moderate to strong winds will redistribute snow into thick drifts, which will likely react to a human trigger. Even at the upper reaches of the lower elevation band, there might be enough new snow over a consistent old snow surface that human triggered avalanches are possible. 

    Conditions will change and become more dangerous throughout the day, so keep your focus on new snowfall amounts and drift depths during your outing. You may find these drifts in gullies, around rocky outcroppings, or along ridgelines.  Identify features that may be wind-rippled, or possibly smooth.  Identify hollow-sounding or firmer-feeling snow. These indicate wind-affected snow, which you can expect to be more reactive. Search for other obvious signs of instability like long, shooting cracks from your feet or sled.  Avoid slopes steeper than 30° when drifts are around 6" or deeper and especially when you see any obvious signs.

    Example photo: Signs of wind transport like this can help you identify where slabs likely exist. Photo: Dallas Glass

Avalanche Discussion

Snow is falling on mainly firm old snow surfaces, which means the new snow may slide easily on the old surface. You wouldn't want to trigger and be caught in an avalanche now, because even if it's a small one, you'll be taken for a rough ride over hard and possibly very irregular surfaces. Over the last few days, observers made note of how much snow we've lost. This is the case on all aspects, but it's most obvious on south-facing terrain. There are a lot of rocks and trees exposed. Open creeks are present everywhere. A lot of obstacles will subtly be hidden under the new snow. This also includes hard, chunky avalanche debris piles. 

We haven't gone below freezing for days, and most of the snowpack is wet, especially at mid and lower elevations. The surface is semi-supportable.  In the last few days observers have seen very small glide avalanches running in thin patches of snow on steep rocks. In isolated steep, rocky locations, avalanches in the new snow may entrain some underlying wet snow. 

If you make it into the backcountry please send us an observation. Also keep in mind that conditions will be very different on Friday from many of the days we've had so far this year. 

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