Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

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

Avoid traveling on or under steep slopes if you encounter wet, sloppy snow under your feet or sled. Snowpack stability can worsen as crusts break down through the day. On slopes that hold dry snow, triggering large avalanches, 2-4 feet deep remains possible. 

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    In places that stayed cold and dry, you may be able to still trigger wide avalanches breaking on persistent weak layers buried 2-4 feet deep. We have a bit of uncertainty regarding this problem, but we suspect it lingers on shaded aspects above 6000 ft. Steep, rocky, wind swept terrain on the north side of the compass is most concerning. These avalanches can act surprisingly, often propagating widely or being triggered from a distance. You may or may not receive feedback before triggering this type of avalanche. Continue to be patient and conservative with your terrain selection. 

    (3/16/2024)

    A very large slab avalanche that likely occurred 3/15.Chiwaukum Range, 6,600ft, NW

    Photo: Stevens Pass Patrol

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    Wet slabs are notoriously complicated to forecast and manage. The cooling trend is slowly helping the snowpack stabilize, however, it still remains possible to trigger wet avalanches in areas that you find wet, unsupportable snow. A thin surface crust doesnt always eliminate the chances of triggering one of these beasts. Slopes can remain unstable while water percolates down through the snowpack. Wet avalanches may run naturally, or you could trigger a widely propagating wet slab on deeply buried weak layers from Early February. 

    You can reduce your exposure to these wet avalanches by traveling on slopes that are supportable and firm. Be suspect of slopes greater than 30 degrees that feel wet and sloppy. Stay off of and out from large or consequential avalanche paths where you're sinking past your

    (3/16/2024)

    Snowmobilers triggered this avalanche on a southern aspect in the Ahtanum on Saturday, March 16th. It likely failed and ran on the Early February Crust. 

Avalanche Discussion

The cooling trend is slowly helping the snowpack stabilize. In places with a thick, supportable crust, you can generally expect safe avalanche conditions. However, keep in mind that a weak snowpack structure did exist prior to this warm-up.

NWAC Forecaster Katie Warren was out in the Ahtanum/Darland Mt area on Tuesday. The prolonged period of sun and warm temperatures had done a number on the lower elevation snowpack and steeper southerly slopes. The snowpack on southerly aspects was wet and moist to the ground, but more supportable than other sunny aspects where you could punch through wet snow to your waist. Northerly aspects held a colder, more layered snowpack and the early February crust was easy to find about 4' down on a N aspect @ 6700'. 

On Saturday, there was a close call where snowmobilers triggered an avalanche in Ahtanum that failed on deeply buried weak layers. While we haven't seen any new avalanches on this layer, the structure is there. The potential for large and destructive avalanches will linger during this extended period of warmth as meltwater moves through the snowpack. Before this warm-up, we had a widespread, persistent slab problem. There was a fatality three weeks ago in Ahtanum Meadows area, and in the neighboring East Central, we saw multiple large human-triggered persistent slab releases last week.  

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