Avalanche forecast

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Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

You are most likely to trigger avalanches where the wind drifts snow into stiff slabs. However, southern aspects may harbor a deeper weak layer where you could trigger a larger avalanche even in sheltered areas. Avoid steep wind-drifted slopes and choose low angle or small slopes before considering stepping out into more consequential terrain. 

Avalanche problems

  • Wind Slabs

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

    Winds overnight on Sunday will likely form fresh wind slabs at mid and upper elevations. The most dangerous areas will be at upper elevations and on leeward sides of ridges and wind-exposed features. Identify wind-loaded terrain with visual clues like cornice formations, textured surfaces, or cracking in stiff surface snow layers.  In wind-sheltered terrain, consider the potential for avalanches on deeper weak layers, particularly on southern aspects where a thick crust has formed a poor bond with the overlaying snowpack. You can identify these weak interfaces by digging in the top 3 feet of the snowpack and using snowpack tests with planar, sudden failures.

    Stick to well-supported, lower-angle slopes and wind-sheltered terrain. Steer around typical trigger points, such as convexities and unsupported features. Watch for recent avalanches, collapses, and cracks shooting through the snow to indicate tanger. Use small features and quick tests to see how easily the snow slides before traveling on larger slopes.

    (12/25/2024)

    A small skier-triggered wind slab on a convex feature, about 10" deep, size D1. Delancey Ridge, 6,500ft, S

    Photo: Will Govus

Avalanche Discussion

The next storm system, on Sunday night, is focused more on the southern and western Cascades. This will give the East North zone a bit of reprieve from precipitation, and winds will be the driving force for avalanche concerns on Monday rather than significant snow accumulations.

Information from this prolonged active period is trickling in but is limited due to the frequency of storms and poor visibility. This adds some significant uncertainty to the forecast. Most folks are stilling to lower-angle sheltered terrain and reported isolated soft storm slabs. However, several observations of deeper instabilities on Saturday stood out: A skier triggered an avalanche near Cutthroat Lake on a southerly, unsupported slope at upper elevations, not far from the ridgetop. This slide broke ~70cm deep on what we expect is the Solstice Crust. On Delancey Ridge, an observer reported signs of instability at lower to middle elevations on a southeast aspect. They reported a collapse at 4,800ft and then sudden results in multiple compression tests ~70cm below the surface on the Solstice Crust at 5,300-5,680ft. The height of the snow there was 168cm.

Snow totals throughout this week are between 2-4 feet above 4000ft. Below that, there has been significantly less accumulation, and the snowpack is moist from warm temperatures and light rain. Despite the recent warm temperatures, there's decent coverage at lower elevations and in the eastern mountains. On Thursday and Friday, observers in the Twisp River drainage found a relatively strong snowpack, though still shallower than at the Cascade crest. There was 70-100cm of snow on the ground near 3,000ft, and depths increased with elevation. In the foothills and eastern portion of the zone, you may find more weak layers than at the Cascade crest. Pay attention to red flag signs of instability, such as whumping collapses, and consider digging down to identify potential weak layers. The Loup Loup area has a relatively robust snowpack compared to many years, though still shallow compared to further west. 

You can contribute to the avalanche forecast. Please let us know what you see in the mountains by submitting an observation. 

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