Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

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

You could trigger avalanches on steep slopes at mid to upper elevations, especially in thicker wind-drifted areas, so avoid these locations on Sunday. Expect avalanche danger to increase throughout the day as more snow continues to fall. Avalanche danger will continue to rise as a storm deposits snow through Tuesday. 

Avalanche problems

  • Storm Slabs

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

    Snowfall intensity is expected to increase throughout the day, with up to a foot of snow falling by evening. This means a rise in avalanche danger as the day progresses. Continue to pay close attention to the snow as the day progresses, as conditions will continue to evolve. You may encounter avalanches where you did not find them earlier in the day. The thick layer of snow at near and above treeline elevations is likely to avalanche with a human trigger, especially as snowfall amounts grow. Subtle daytime warming could result in slightly heavier snow sitting on cooler and lighter underlying snow, creating more unstable conditions. It's tough to tell whether the more unstable conditions will happen with any subtle changes in the snow that falls throughout the day.  The new/old snow interface might be strong, but there is the possibility of the underlying 3/31 crust making a good sliding surface. 

    You can expect more reactivity in wind-loaded areas, and strong wind will redistribute snow on Sunday. Pay attention to surfaces beneath you as you travel. In areas where snow gets thicker, or if you notice rippled surfaces or wind lips, wind slabs are close by.  You're most likely to find slabs around rocky outcroppings, in gullies and on leeward sides of features. Avoid slopes greater than 35 degrees where you find these characteristics. Anywhere that you travel, if you encounter red flags such as recent avalanches, cracking or whumphing, stay off steep nearby slopes, as these are solid indicators that the snowpack is unstable.  

     

    Cracking is a strong indicator that you'll see an avalanche on a steep nearby slopes. Stick to lower angle terrain if you encounter this. 

Avalanche Discussion

A deep persistent slab avalanche concern previously listed as a problem is remaining on our radar. We don't expect that a human could trigger an avalanche on the layer, located on upper elevation northerly aspects.  There's a chance that a large cornice falling on it, or another avalanche, could trigger this layer buried 4-8 feet down, which would result in a very large avalanche.  For now, remain aware of the problem, and consider not lingering for long periods on or beneath large slopes where it may exist, especially if gargantuan overhead cornices are present.

I took a quick morning trip to the Baker backcountry on Saturday. There initially was minimal avalanche hazard where I traveled. I was surprised by sun breaks, which quickly led to rollerballs and it was easy to trigger swaths of wet loose avalanches, running 4 inches deep on the underlying crust on south-facing slopes. We probably won't see this on Sunday with thicker cloud cover, but it's a reminder of the strength of the springtime sun and how quickly conditions can change. 

Sunday starts a period of unsettled weather which will continue through Tuesday. Large amounts of snow will fall Sunday night, and avalanche danger will rapidly rise. If you're planning on getting into the backcountry in the next few days, make sure to factor in the copious amounts of snowfall we're getting in the coming days.  

 

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