Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

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

Sunday's winds will continue to drift snow over ridges and build stiff slabs of snow in steep ridgeline terrain. Avoid steep slopes with actively blowing snow and feel for hard snow over soft snow layers before committing to steep terrain. In adjacent zones, weak snow layers deep in the snowpack are producing large avalanches. Heed warning signs such as large whumphing collapses and gather information before committing to steep, open, alpine terrain. 

Avalanche problems

  • Wind Slabs

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

    Winds shifted from west to east on Saturday, and while wind speeds haven't been impressive, the cold, light snow easily drifted around. This pattern will continue on Sunday and create new shallow slabs. With these easterly winds, slabs may form in areas you don't typically see. Look for actively blowing snow, small drifts, and observe the wind direction. Before you commit to steep slopes, use your probe or pole to feel for stiffer snow over softer snow. If you plan to travel in open wind affected terrain, use small, inconsequential terrain features like convex rolls to test if these slabs will break.We expect most of these avalanches to be small, but they could also take you for a ride through rocks or over a cliff. In East Central, large avalanches on deeply buried weak snow layers are occurring. I was out near Clover Flats yesterday, and while I could identify similar layers, I did not find these layers to be as touchy as conditions in East Central. However, this is our only data point, and other locations may harbor these deep instabilities. An avalanche on this layer could be quite large and run on the ground. Make sure to listen and feel for signs of instability, such as large collapses or shooting cracks. These are certain signs you should stick to low angle routes. Even without these loud signals of instability, it is worthwhile to dig down and identify any weak, sugary snow in the snowpack before committing to new steep terrain.

    (12/1/2022) Rime and wind drifts can help you anticipate wind loaded slopes. Photo: Dallas Glass

Avalanche Discussion

I was out enjoying some early season riding conditions near Darland Mountain on Friday. Grooming operations have not yet begun in Ahtanum State Forest, but travel was smooth. About 10 inches of snow exists at the trailhead, and the recent storm snow from 11/29 is the entirety of the snowpack until you travel above 5600ft. I found around 3 feet of snow at 6250ft in the sheltered terrain at Clover Flats. The upper snowpack consists of primarily low density storm snow. However, I did find a thin layer of small facets about 1.5ft down. It was unreactive in stability tests, but I could easily slide the column off on this layer smoothly in repeated tests, so it may prove to be a sliding surface for avalanches in steep terrain. The base of the snowpack is a mixed bag of strong crusts and increasingly dense snow. At the base of the snowpack, I identified weak, sugary snow. This is the same layer that is causing persistent slab problems in the East Central zone. At this site, the layering did not appear as much of a problem, but we're still suspect of higher elevation terrain especially facing northwest through northeast. This week's storm brought up to 2ft of snow to some locations of the East South zone. This storm doubled the snow depth for many locations and dramatically increased recreation opportunities. While coverage is much better, it's still early season, so one should expect rocks and bushes to be just under the surface. With so many things to hit, even a small avalanche could hurt you by carrying you through or into these terrain traps.

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