Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Warm temperatures and sunny skies make wet loose avalanches likely on Thursday. Look for fresh avalanches, rollerballs, pinwheels, and sinking in past your boot tops into wet or moist snow, and switch to a shady or lower-angle slope if you see these signs. These avalanches will be most likely on steep sunlit slopes, but at the lower elevations they could occur in the shade as well.  

Avalanche problems

  • Loose Wet

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

    Wet loose avalanches will be sensitive to human triggers on Thursday and will likely release naturally. On slopes that saw sun on Wednesday, a surface crust will need to break down before this problem develops. However, many west-facing slopes may not have a crust at all, allowing wet loose avalanches to initiate quickly once the sun hits. While most avalanches should remain small, an isolated large wet loose slide is possible, especially on slopes that lacked a crust and in the low-elevations. Stay aware of what’s above you, as snow may shed off rocky faces before the surface you’re on shows signs of moistening. Additionally, wet loose avalanches could trigger deeper slab avalanches.

    Below the recent storm snow, much of the upper snowpack is still sopping wet. Continued warming will add more meltwater to an already saturated snowpack, keeping wet slab avalanches on the radar, even if they remain unlikely. Think twice before committing to a steep, sunlit slope if you see signs of wet snow on the surface.

    Finally, cornices are large and could fail during this warming trend. Stand far back and ensure you are on solid ground.

    (2/26/2025)

    Wet loose avalanches on a sunlit mid-elevation slope at in the White Pass backcountry on Wednesday.

    Photo: Dallas Glass

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–2.5

    You may be able to trigger a lingering wind slab in steep and complex terrain, especially where slopes are confined and/or unsupported. Think rocky faces, tops of couloirs and chutes, above a rollover, and below cliff bands. You can identify wind slabs by looking for textured surfaces, dunes, or pillow-like deposits. It's hard to safely assess representative snow from an adjacent slope when you are considering a piece of complex terrain, so consider the consequences before committing. Lingering slabs could be hard, many feet deep, and may let you well out onto the slope before breaking above you. Heed them if you see them, but don’t expect to find obvious signs of instability like shooting cracks on Thursday. Better riding and safer conditions can be found on non-wind loaded slopes.

    (2/25/2025)

    A widely propagating hard wind slab avalanche at Crystal on Monday. This slide was triggered by a ski patroller from the ridge and was up to 3 1/2' deep. Complex terrrain like this rocky and steep face could still hold lingering instabilities on Thursday.

    Photo: Andy Harrington

Avalanche Discussion

The sun came out in the West South on Wednesday before clouds rolled in later in the day, shutting down some of the nascent wet loose activity and likely leaving more in store for Thursday. NWAC forecasters near Crystal and White Pass reported no obvious signs of slab instability, while Crystal Pro Patrol was able to explosively trigger some smaller lingering wind slabs with larger shots during AM control work. A large natural avalanche on Tahoma as well as a smaller natural near White Pass highlighted some of the storm instabilities from Tuesday. Snow near Crystal was described as caked in and much less sensitive than the day prior.

Expect a bump in the warming on Thursday with little help from the breeze except at the highest of elevations. Use your senses and give a wide berth when things start to get wet. Down low, less snow rests over a wet and saturated snowpack that could allow wet avalanches to gouge deeper and gain more mass. Crusts are forming in the wet snow, but they will take some time to fully harden and refreeze. 

 

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