Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

Avalanche danger will increase as you climb higher in the terrain, especially on the volcanoes where significantly more snow fell on Sunday. Watch out for smooth pillow-like drifts. Given the recent wind patterns, you may see these in weird spots and even well below ridgelines.

Avalanche problems

  • Wind Slabs

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

    You might find a wind slab higher in the terrain anywhere in the zone, but they’ll be more common, larger, and more dangerous on the volcanoes. Monday’s new snow and stronger winds could drift into a fresh crop of slabs. These will add to the patchwork of older wind-loaded pockets from Friday. Given the E-SE wind direction, you might find slabs on strange aspects, along gullies, or even well below the ridgetops. 

    New slabs might be shallow and easier to manage, but if one releases deeper, it could break above you or propagate widely. Since Friday, there have been at least 10 unintentionally triggered wind slabs in the WA Cascades. These occurred in nearly every zone, including the West South. This might speak to the atypical loading patterns. Watch for blowing snow, textured surfaces, and drifts to point toward potentially loaded terrain. 

    At middle elevations, mild weather on Sunday likely helped old wind slabs heal. Avalanches could still occur on unsupported slopes or where weak facets underlie these wind slabs. It will be impossible to determine the latter. Avoiding steep, wind-loaded terrain might be the only option.

    (2/16/2024)

    Visual observations help you anticipate wind loaded slopes.

    Photo: Dallas Glass

Avalanche Discussion

This storm pattern continues to favor the volcanoes. On Sunday, Mt St Helens and Mt Rainier received 0.3-0.6 inches of water. This likely translated to 4-6 inches of snow at middle and upper elevations. They could receive another 2-3 inches by Monday afternoon. 

Closer to the crest, much less snow fell. You will likely experience lower avalanche danger near Govenor’s Meadow, Crystal Mt, and White Pass. 

The warm air made its way into the Zone Sunday. Milder temperatures and filtered sunshine resulted in rollerballs and a few small wet loose slides. This warmup should help limit additional wet snow issues on Monday. However, rain or sunshine could cause steeper slopes to get wet and sticky. If you see new rollerballs or point-release avalanches, steer clear of nearby steep slopes. 

Other recently human-triggered avalanches occurred on Friday and Saturday at Paradise and Crystal. Some of these slides propagated widely and failed on a firm crust. 

The upper snowpack consists of 12-30 inches of recent snow over the very firm Early February Crust (EFC). Various layers of settled snow, facets, and thin crusts exist above the EFC. Some snowpack tests failed on these various weak layers; others didn’t. In general, you’ll find surface crusts on southerly and wind-exposed slopes. Shaded, sheltered aspects might just continue to hold on to a bit of soft, cold snow. 

Thin coverage at lower elevations has plagued the zone all winter. While it makes travel difficult, the open creeks, holes, and obstacles make it more dangerous. 

Regions covered