Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
4 · High
Treeline
4 · High
Below
3 · Considerable
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Highlights

This is not a time to try and outsmart the mountains. A major winter storm will create very dangerous avalanche conditions all across the West South zone Monday. Stay away from places avalanches can start, run, and stop, especially at mid and upper elevations.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    1.5–2.5

    This storm checks all the boxes for large natural slides and very dangerous avalanche conditions. We’re expecting prolonged periods of strong and gust winds, heavy snowfall, and fluctuating temperatures. There could be several rounds of natural avalanche activity. So, don’t overthink it, stay off of and out from under all steep open slopes, especially at mid and upper elevations. While avalanches will be the largest and most deadly in terrain where the wind drifts the snow deeper, you could trigger a slide on any steep slope not scoured down to the old crust. 

    At lower elevations, it will take a bit of snow, before a hazard truly starts to grow. That could be very dependent on your location in the zone and elevation. Either way, with such strong wind speeds, avalanches will become most likely in terrain where the wind affects the snow. Look for textured surfaces and firmer drifts to figure out which areas you want to avoid. You could even see these features in the trees.

    (2/24/2022) Evidence of wind transported snow can help anticipate possible wind slabs. Photo: Dallas Glass

Avalanche Discussion

Locations across the West South zone could see 2-3 feet of snow by Monday afternoon. This will be a very big change from the more modest systems and spring-like weather we’ve seen over the past few weeks. At mid and upper elevations the new snow will likely accumulate on two common surfaces; a firm melt-freeze crust and recent storm snow (with the same crust beneath). How the new snow bonds to this old surface will likely depend on elevation. In both instances we expect the Early April Crust to prevent avalanches from involving deeper old snow layers. However, it could also act as a slick surface allowing slides to travel quickly. 

While we don’t expect avalanches to involve deeper snow layers, two observations from this past week (Mt St Helens 4/1 and Tatoosh Range 3/30) continue to keep the 3/8 weak layer and Early March Crust on our minds. It would likely take a very large trigger like a cornice or other avalanche to cause this deeper layer to fail, but with natural slides expected, this just gives you one more reason not to go into avalanche terrain.

Regions covered