Avalanche forecast

West 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Out of date — this forecast expired 8 months ago.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

Triggering an avalanche is most likely on mid and upper-elevation slopes, particularly on leeward slopes beneath exposed ridges and open areas where fresh wind drifts continue to grow. Larger slabs may still linger at the uppermost elevations of the volcanoes. Stick to wind-sheltered terrain or slopes less than 35 degrees to reduce your risk.

Avalanche problems

  • Wind Slabs

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

    Sensitive wind slabs will develop into Friday, increasing in size with higher elevation. You could trigger an avalanche at mid and upper elevations, in areas of freshly wind loaded snow, primarily downwind of open slopes and ridges. Approach upper elevations with caution, as very little information exists from these areas. On the volcanoes, where the rain may not have reached, larger slabs could continue to grow through Friday.

    Use small test slopes to identify dense, wind-compacted snow, cracking, or slab failure. Sticking to wind-sheltered terrain will help limit your exposure. Hazard will decrease at lower elevations.

    (12/18/2025)

    A 6-8 inch wind slab intentionally triggered elsewhere in the zone. 

    Photo: Joe Dellaporta

Avalanche Discussion

Good news — we are finally building up our snow coverage! The much-needed snowfall has provided a fresh coat across the West South Zone. Here are a few observations from today:

  • Weather stations: White Pass recorded 10 inches, and Paradise recorded 10 inches of snow in the past 24 hours.
  • Public on Mount Adams: 18 inches of new snow since earlier in the week.
  • Forecasters near the Cascade Crest: 15–20 inches of heavy snow observed since earlier in the week. Though the morning started cold and wintry, heavy rain quickly followed. At lower elevations, a natural wet avalanche cycle occurred on very steep slopes, failing up to 4 inches deep and entraining a significant amount of snow.

Snow transitioned to rain at lower and mid-elevations late Thursday afternoon, while upper elevations are unlikely to have seen much, if any, rain. Thursday night, precipitation will switch back to lower-density snow, with cold conditions expected through Friday. A crust is likely to form Thursday night prior to any new snowfall, at least as high as mid-elevations. 

Forecast uncertainty at upper elevations has been a major concern this season. Recent extreme weather has caused power outages at weather stations, limited mountain access, and greatly reduced field observations. If you’re headed into upper-elevation terrain, be aware that very little information has been collected from these areas. Larger, more sensitive slabs may continue to develop through Friday, posing a greater risk than the surrounding forecast zone.

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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