Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

You may see the wind building new slabs throughout the day especially as the storm ramps up in the afternoon. Watch for blowing snow and textured surfaces to help figure out where these wind-loaded pockets are forming.

Avalanche problems

  • Wind Slabs

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

    You may not find any wind slabs to start the day, but once the storm drops a few inches of new snow, they should start to build. So, once you start to see pockets of wind-loaded snow, expect them to only get deeper and more widespread as the day continues. Since some of these slabs may form over a crust, they could trigger easily and run quickly. Fortunately, the stormy weather should give you the key clues you need to anticipate and avoid this problem. 

    While we don’t expect these avalanches to grow very big, by the end of the day there could be enough new snow on the ground for one of these slides to take you for a nasty ride.

    (3/21/2023) Clear signs of wind loaded slopes can help you anticipate slabs. Photo: Dallas Glass

Avalanche Discussion

Right off the bat in the morning, you may not find much in the way of avalanche hazard. But, as the storm gets rolling, the danger should start to increase, especially at upper elevations. While not a huge storm, many locations could see 4-6 inches of snow by the end of the day. Some areas, like White Pass, may see less snow and locally lower danger. 

To start the day you may find punchy wet snow, breakable crust, icy slopes, and frozen old avalanche debris. Rain at lower elevations may help to soften the surface, but we don’t think it will be enough to develop much of a wet avalanche problem. If you encounter wet mushy snow, you may be able to push a small avalanche in steep terrain. You’re most likely to find these conditions near rocky slopes where any overnight freeze should be the weakest. 

The spring weather this past week definitely had an impact on the upper foot or so of the snowpack. An avalanche professional in the Crystal area Saturday reported very firm conditions that softened some in the afternoon. Below this layer of melt-forms, the snowpack remains very winter-like. As it continues to transition to spring, you could see isolated “shed” style avalanches (glide, cornices, wet slab). These types of slides seem very unlikely on Sunday, but even still, don’t hang out in the runouts of larger avalanche paths. A huge natural avalanche that was found near White Pass on Friday is a good reminder that these types of events can happen and are nearly impossible to predict. (see image below). 

This is the last avalanche forecast for the 22/23 season. NWAC will continue issuing mountain weather forecasts each afternoon at 2:30 pm through April. We’d like to thank each of you for reading and using these forecasts to make informed safe decisions and for contributing to your community by submitting observations. Please continue to help support your backcountry friends by letting others know what you find in the mountains. Have a wonderful spring and summer! ~Dallas and Andy

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