Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
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Highlights

Pay attention as snow surfaces thaw with another round of warming and sunshine on MLK Day. You may be able to trigger small wet loose avalanches on the steepest, sun-exposed slopes. While these slides won't likely hurt you on their own, don't let them push you over rocks or into a deep gully. 

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Any avalanche danger you encounter will likely stem from the impact of warm temperatures and sunshine on the snow surface. First thing in the morning, the snow should be very firm and maybe even icy. As temperatures warm and the sun has a chance to shine directly on some slopes, expect the surface to soften. This will occur first on SE-SW aspects, especially near-treeline where temperatures may be warmest. Step off your skis, board, or sled to see exactly how soft the surface is getting. If you sink in past your ankle or you find very wet and punchy snow, it’s time to head for lower angled or more frozen slopes. New rollerballs are also a great clue that the surface is becoming wet and possibly unstable. Crusts in the upper snowpack should help keep any potential loose wet avalanche small.

    (1/15/2022)

    Plenty of small rollerballs on steep sunny slopes Saturday demonstrated the effect of warm temperatures and sunshine on the snow surface. 

    Photo: NPS Rangers

Avalanche Discussion

These long dark winter nights and mostly clear skies should allow the snow surface to again freeze despite continued warm temperatures. This strong crust combined with two recent very widespread natural avalanche cycles (Jan 6-7 and 11-12) gives us the confidence that the snowpack has become generally stable. However, low danger doesn't mean every slope is safe. Most of our weather station sites haven’t dipped below freezing in 5 days. Take a moment to talk about these possible sources of uncertainty with your team before you commit to bigger and more consequential alpine objectives. 

The most notable observations from Sunday came from Mt Rainier where a sizeable wet loose avalanche occurred in the Nisqually Chute, and a few cornices fell during the heat of the day (photos below). NWAC forecasters at White Pass and Crystal reported no new avalanches. On Saturday, a skier triggered a large wind slab high on Mt St Helens. The skier was able to ride off the debris and fortunately, no one was injured or buried (photo below). It was a good reminder you may still find isolated areas of wind drifted snow at the highest elevations, especially on the southernmost volcanoes that were favored by the most recent storms.

The upper snowpack contains alternating layers of firm crusts, weak wet snow, and strong rounded grains. Right now there aren’t any specific layers we’re tracking and any unstable snow should be limited to the surface. With the ongoing warm weather, it wouldn’t be a surprise to hear of additional cornice falls Monday. Fortunately, these waves of snow are relatively small and not very overhung by Cascade standards. That said, keep an eye out for cornices capping ridgelines above you, and find routes that minimize the amount of time you spend underneath these possible hazards.

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