Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
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Out of date — this forecast expired 8 months ago.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

As warming intensifies, your odds of triggering a wet avalanche will increase. Once the snow turns moist and sticky, move to shadier aspects or lower-angle terrain. Old unstable wind slabs may still exist in steep rocky terrain at upper elevations, especially on the volcanoes.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Loose wet avalanches will become a concern on Monday as temperatures climb another notch higher. A temperature inversion will trap colder air in the valleys and help limit significant warming at lower elevations. However, mid and upper elevations will see much less cooling overnight. As you ascend, expect to climb into warmer conditions and an increasing avalanche problem.

    Short daylight hours and potential cloud cover could help mitigate warming, but it's no guarantee. Either way, pay close attention to the snow around you. If you start noticing trees and rocks shedding, or snow sticking to your skins/ski poles/sled track, move to shadier aspects.

    (12/28/2025)

    Small roller balls observed on a southerly slope in Cement Basin. Early signs of wet snow instability like this often appear near rock bands and on solar aspects.

    Photo: Andy Harrington

  • Wind Slabs

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

    Triggering a wind slab avalanche remains a risk, albeit difficult to trigger, and harder to find. These slabs are most likely in very steep terrain such as chutes, rock faces, and large rollovers. Upper elevations of the volcanoes are likely the easiest place to find lingering slabs.

    They may be difficult to identify aside from unusually stiff surface snow. Steep, unsupported slopes remain suspect. Simpler, less wind-affected terrain offer safer travel. 

    (12/28/2025)

    A crown spotted in the Platinum Peak area around the Crystal Mountain backcountry. This could be the crown from a close call on 12/27. 

    Photo: Northwest Avalanche Center

Avalanche Discussion

The West South has seen a solid refresh, with Friday night's storm depositing 10–14" of snow across the zone. Avalanche activity has been limited to shallow wind slabs near ridgelines and cliff bands. No significant activity has been observed on the 12/24 or 12/18 crusts. Exposed mid and upper elevation slopes have been strongly affected by wind, with some areas scoured and others densely wind-compacted.

Sunday was generally calm and quiet across the western Cascades. Skies started blue turning cloudy later in the day. Peak temperatures hovered just below freezing for most areas, including low elevations. Sunday also provided the first real warm-up since the recent snowfall, though very little wet avalanche activity was reported. Observers in the Cement Basin and Norse areas noted roller balls on sunny slopes and a thin solar crust forming late in the day. As temperatures rise on Monday, wet avalanches may become more of a concern, though short daylight hours should help limit their extent.

Regions covered