Avalanche forecast

West Slopes South

Northwest Avalanche Center
View on map

Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map
Out of date — this forecast expired 5 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Beautiful spring weather will grace the mountains of the West South this weekend. But just because it's sunny and warm doesn't mean you can turn off your avalanche brain. Wet slides will be commonplace on steep, sun-exposed slopes, while lingering storm instabilities may be found in shaded upper-elevation terrain.

Avalanche problems

  • Loose Wet

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

    It's going to be a scorcher of a day on Saturday, putting wet avalanches front and center as your main avalanche concern. The combination of April sunshine along with skyrocketing freezing levels means you could find these avalanches on any aspect except for the truly dark and shaded slopes at upper elevations. That also means our usual tip to avoid this problem by changing aspects may not be as applicable. Instead, you'll either need to seek out permanently shaded terrain or lower-angled slopes far from the runout of any potential avalanche. 

    Keep in mind that although you may be walking around in valley clouds or possibly traveling in a shaded chute, slopes far above you are likely basking in the sunshine. Make travel plans that account for overhead slopes, including cornices, and don't get caught by one of these slides near a terrain trap. Although they often start small, they can fan out and grow large as they descend, possibly even triggering slabs in the process.

    (4/3/2026)

    A wet loose slide in the neighboring Snoqualmie Pass zone from Friday. Similar slides will occur throughout the West South zone on Saturday.

    Photo: Craig Muderlack

  • Wind Slabs

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

    The wind slab problem is now a few days old, and the warmth should help it heal quickly. But we may not be done with this problem quite yet. Numerous slides were reported on Thursday and Friday, meaning it's worth keeping them on your radar heading into the weekend, especially at upper elevations or in extreme terrain.

    You're more likely to encounter one of these slabs on shaded or partially shaded slopes. The usual trigger locations, such as confined chutes or convex rollovers, still apply, so approach these features with caution. 

    In the Crystal Mountain area, they could fail on weak faceted snow a few inches above the 3/25 crust. Meaning they may trigger more easily or break more widely than in other parts of the zone.

    (4/3/2026)

    A wind slab avalanche in Sheep Lake Couloir near Crystal Mountain. Confined gullies and rocky terrain are common locations for wind slabs to form.

    Photo: Jeremy Allyn

Avalanche Discussion

Get ready for a hot and sunny weekend in the West South zone. No surprises here, wet avalanches will be your main concern throughout this warm spell. While that includes the wet loose and cornice falls mentioned above, our zone has some other unique challenges that may come into play. Namely, the volcanoes. Remember that the NWAC forecast tops out at 8,000 feet, and above this elevation, you could encounter very different conditions. With such warm weather in the forecast, icefall may be a concern on the volcanoes.

After the last few days were marked by both human-triggered and natural wind slab avalanches, wet loose activity began to increase on Friday. On Saturday, you should expect to dodge natural wet slides as rocks heat up and shed their snow. And if you find yourself on a steep, sun-exposed slope, you'll likely be able to push a wet avalanche of your own. Be cognizant of terrain above you and whether people might be traveling below you.  

All triggered avalanche activity should be confined to the snow above the easily-identifiable 3/25 crust. Other interfaces exist within the upper snowpack, such as the 3/29 and the 4/1, and could produce failures, but we'll largely be moving toward heavy, wet snow problems. In isolated locations, these wet slides could gouge down and run far distances on the underlying 3/25.

This week's storm helped improve travel at lower elevations for the time being. But there still isn't enough snow to pose much avalanche hazard. You will likely see wet avalanche activity in the lower elevation band, but the majority of it won't be large enough to reach the threshold to be called consequential avalanches. Instead, you'll need to continue to manage holes, creeks, bare ground, or shallowly buried hazards as you make your way into the mountains. These hazards will become more pronounced throughout our weekend of hot weather.

Regions covered