Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Continued warm weather and additional rain showers may be enough to keep wet avalanches on the table. Be leery of slopes where you're sinking into wet and sticky snow deeper than your ankle. Travel conditions may be difficult due to the recent weather exposing several natural hazards.

Avalanche problems

  • Loose Wet

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

    Wet avalanche activity should be grinding toward a halt after this week's atmospheric river event. But we just haven't cooled down quite enough for our comfort level. And we're going to add some more rain for good measure. Wet slides are always tricky to predict and sometimes occur long after the rain has stopped. If the snow surface is wet and punchy, keep them on your radar. On steep slopes, you may be able to push snow that gathers mass and fans out as it descends. 

    We suspect that most slab activity should be finished, but you could see cornices fail in the warm and wet weather or blocks of snow shed from rocks/cliffs.

    (12/18/2024)

    Wet avalanche debris coming out of a steep rocky area in the White Pass Backcountry.

    Photo: White Pass Pro Patrol

Avalanche Discussion

We're on the heels of an atmospheric river event that delivered anywhere from 3-6 inches of rain to the West South zone this week. This resulted in a major avalanche cycle with large to very large avalanches reported at Crystal, White Pass, Mt. Rainier, Mt. Adams, and Mount St. Helens. Due to high-elevation rain (above ridgecrest) falling on a previously cold and dry snowpack, it's safe to assume that avalanches likely occurred within most mountainous areas in our zone.

Reported avalanche activity since the storm has been minimal, but it can take time for water to work its way through the snowpack. Crystal Mountain Pro Patrol reported moist grains up to a foot and a half below the surface, wetting the 12/13 and 12/7 interfaces. Most avalanche activity likely occurred at these weak points during the storm. A poor overnight refreeze didn't take long to soften up on Thursday

Next up for the West South: continued warm weather and a few rain showers, heaviest on the volcanoes. There likely won't be enough input to tip many slopes over the edge after absorbing so much water earlier in the week. But we're not exactly cooling and locking things up, either. We're kind of just puttering along with moist to wet snow, poor overnight refreezes, and daytime warming (albeit December daytime warming). That all adds up to maintaining the potential for difficult-to-predict wet avalanches. 

What is easier to predict are the travel conditions. You may find that they've deteriorated greatly since you last entered the hills. Be prepared for firm crusts, rain runnels, frozen avalanche debris, swollen creeks, open holes, and exposed rocks/logs. If the surface is firm and slick, there’s a chance you could slip and go for a long uncontrolled slide. Travel with the appropriate gear and when in doubt, default to lower-angled slopes.

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