Lawinenlagebericht

East Slopes South

Northwest Avalanche Center
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Lawinengefahr

Tue
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
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Kernpunkte

Wet snow instabilities will become more widespread as snow levels push above ridgelines on Monday. Move off of steep terrain if you notice rollerballs peeling off or if you're sinking past your boot-top in wet, mushy snow. There's enough new snow resting over a crust that some wet loose avalanches could grow large - so don't linger above terrain traps if the surface snow is feeling wet and unsupportable. 

Lawinenprobleme

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    Wet loose instabilities will continue to arrive at a gradual pace in the East South mountains. We suspect these likely started shedding off sunny slopes on Sunday, but with warmer temperatures and some light rain, watch for these wet snow instabilities to become more widespread on other aspects, including some northerlies. 

    Fortunately, this problem is pretty straightforward to anticipate. Watch for rollerballs, deep boot penetration, and layers of snow fanning out below your machine or feet as obvious clues that the snow surface is wet and weak. Have options so you can easily escape steep terrain if you don’t like what you’re seeing. We have enough new snow over a crust that some wet loose avalanches could grow large in specific terrain. Don’t underestimate this problem, especially if there are terrain traps present such as creeks, trees, or deep depressions in the run-out of the avalanche path.

    (4/3/2025)

    Rollerballs and pinwheels like this are clues that the surface is becoming wet and weak. 

    Photo: Andy Harrington

Avalanche Discussion

On Friday, January 9th, four backcountry skiers were caught and carried by a large avalanche while descending near Longs Pass in the Teanaway River drainage. The slide occurred on an S to SE facing slope at approximately 6200ft. One member of the party was not buried. Another teammate was partially buried but injured. The other two individuals were fully buried. During the initial rescue, the team located one of the buried victims, who did not survive. Despite the group's best efforts, they could not pinpoint the fourth member of their team. The party contacted 911 via a satellite device, and Kittitas County Search and Rescue responded to the area on Friday evening. Additional rescue efforts were postponed until daylight. Search and Rescue then returned to the site on Saturday and were joined by NWAC forecasters. The teams were able to locate the remaining victim. Unfortunately, neither of the fully buried skier survived. Our deepest condolences to the family, friends, and community of those involved in this avalanche accident. S-SE aspect, 6200ft, Avg Depth 2ft, HS-AS-R3-D2.5-O

Discussion:

The East South zone is really beginning to warm up on Monday. Freezing levels will start pushing up to 11,000 ft as warm air continues to flood into the region as a high-pressure ridge begins to take grip. There should be clouds and possibly light rainfall near and west of Bumping Lake. Much of the zone should escape impactful rains. 

If the eastern mountains do escape high-elevation rain, still consider wind slabs at upper elevations. These are generally stubborn trending unreactive, however not impossible to trigger. The most likely place to get in trouble with one of these would be steep, unsupported terrain at upper elevations that have stiff, wind textured surfaces. Shooting cracks or hollow sounding slabs are obvious signs telling you to not ride or ski steep, wind loaded features. 

This past week brought 1-2 inches of snow water equvialnet to the East South mountains. This equates to 1-2 ft of recent snow over a crust that was buried on January 3rd. 

The snowpack is heavily wind-affected and generally strong in most areas. The exception would be wind sheltered open slopes between Ahtanum Meadows and the South Fork of the Tieton where a layer of buried surface was found. I found this layer on a NE aspect near the Superbowl on January 9th. You can check out my observation here.  This layer of buried surface hoar may have also been the culprit of one widely propagating natural avalanche near Dome Peak (observation here). This problem seems isolated, but the resulting avalanche could be wide. The best strategy is to dig down and look for weak layer 1-2’ below the surface before engaging in steep terrain. 

Despite the new snow, the snowpack remains thin. In choosing terrain, consider the consequences of a slide. Look for slopes with a clean runout free of bone-breaking trees, creeks, and rocks. 

 

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