Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 8 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Rain will eventually change back to snow, and strong winds will help build new slabs. Expect wind features - and any avalanches you trigger- to become larger as you ascend above 6000 ft, particularly on the downwind sides of ridges or in the alpine. You can significantly reduce your exposure by sticking to ridgelines and slopes under 35 degrees. 

Avalanche problems

  • Wind Slabs

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

    High-elevation rain will eventually change back to snow during the overnight hours and easily drift into slabs across the middle and upper elevations in the East South. Expect the slab size and distribution to increase as you ascend into upper elevation terrain. These wind slabs will likely be thinner near treeline, but look for these slabs to pack a bigger punch above 6500 ft, particularly as you crest into larger, more connected alpine terrain.

    Wind slabs will likely build on wet snow surfaces or a newly formed crust, causing slab reactivity to vary from slope to slope. Friday will be a good day to use small test slopes and quick snowpack tests to gauge sensitivity, while watching for signs of recent loading, cornice growth, and freshly wind-textured snow surfaces. Avoid steep and unsupported slopes that show signs of recent wind loading or if you notice under your machine or boards. 

    (12/18/2025)

    Actively blowing snow is an easy sign to interpret. Wind slabs form on the downwind side of exposed features like this. 

    Photo: Dallas Glass

Avalanche Discussion

Thursday was a wet and windy day across the southern Cascades thanks to another atmospheric river. This one, however, delivered larger gains in overall snowpack heights across the zone. The Green Lake and Bumping Lake area received roughly 8-12 inches of new snow, with higher amounts likely near the Cascade Crest. Unfortunately, this storm also came up with a warm-up with higher telemetry reporting temperatures over 32, so expect a newly formed rain crust that likely extends into the upper elevations on Friday. An NWAC forecaster traveling at nearby White Pass verified this and found upside-down layering and rain extending to 6000 ft. You can check out the photo gallery for more information. 

The snowpack remains shallow, and observations are sparse. Despite the new snow accumulations, continue to give yourself extra time to access and exit the mountains. Early season hazards continue to plague the eastern cascades and could easily exacerbate the consequence of a small avalanche. 

The weather over the past few weeks has been extraordinary, with torrential rains, extreme winds, flooding, and landslides. Many communities are dealing with damage to homes, infrastructure, and businesses, stretching resources thin. These events have limited access to the mountains for all of us. State and local resources are working diligently to reduce the worst of these impacts. We can help by being respectful of local communities, obeying road closures, and heeding ski area uphill travel policies.

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