Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired 8 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

It's likely that you can trigger an avalanche in newly wind-drifted snow on Friday. Search for active wind transport of snow as you're out, feel for heavier snow beneath you, and look for textured or pillowlike surfaces. If you identify any newly drifted snow, or experience long shooting cracks from your weight or recent avalanches, steer around steep slopes. 

Avalanche problems

  • Wind Slabs

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

    Newly formed wind slabs are where you can expect most avalanche activity to occur on Friday. As you climb higher, more wind-effect will result in larger and more reactive avalanches. Drifts, especially by the end of the day, could be a foot or more deep. 

    A crust formed due to rain on Christmas Eve at least through mid elevations, but subsequently froze. We're not sure if snow is well-bonded to the crust everywhere. You can check with pole or hand pits to see how well the snow sticks to the underlying crust as you travel. If snow slides easily on the crust, you'll want to take a more conservative approach if you're near steep terrain. 

    It's working in our favor that temperature trends are dropping, so snow should remain "right side up" in non wind-loaded areas, unless the layer doesn't stick to the underlying crust. Use small test slopes and search for drifted snow around terrain features, in gullies, and along ridgelines. Steer around these areas in steep terrain. 

    Example photo: Wind transport creates obvious cornices. It may not be as easy to see new wind slabs building up on slopes beneath the cornice, but expect them to be there. 

Avalanche Discussion

We may receive a couple inches of snow to pad the crust by Friday morning. During the day, we should receive 6 inches or more of snow. Wind will be strongest in the morning, redistributing new snow. As more snow falls throughout the day, the slabs may be hidden by non wind-affected snow. 

On Christmas Eve we had rain reaching up to nearly the top of the mid-elevation band. This resulted in a crust on Christmas Day, and continuously cooling temperatures since then has only further frozen any previously wet snow. When rain fell down low, heavy snow likely fell at upper elevations and was subsequently highly wind-affected. We expect most of these slabs would have stabilized over the last few days, but it's not out of the question that an avalanche might fail deeper than expected, or step down to a deeper layer if you trigger a smaller slab. 

Snowfall and snow depths vary widely across the zone. If you make it out, prepare to evaluate conditions for yourself during your journey. Several road washouts and closures exist from the flooding we experienced a couple of weeks ago. In some locations in the West Central zone, there may be access challenges that have not yet been discovered. Consider carrying emergency supplies and a chainsaw in your vehicle, and expect that you may not be able to drive on roads that were once usable. 

State and local resources are working diligently to reduce the impacts of destructive storms that occurred earlier this month. We can help by respecting affected communities, complying with road closures, and adhering to ski area uphill travel policies.

Regions covered