Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

Wed
Alta quota
4 · Forte
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
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In sintesi

Heavy snow and wind will create large avalanches, especially at upper elevations. Use extra caution on all slopes over 35 degrees and avoid steep slopes where the wind drifts the new snow into deeper slabs. Even in wind-sheltered terrain, it may be easy to trigger dangerous avalanches in the new snow.

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Very Likely
    Dimensione
    1–2

    Avoid traveling in or under wind-loaded avalanche terrain. The most dangerous areas will be leeward sides of ridges and wind-exposed features 35 degrees and steeper. Avalanches in these areas could be deep and large. Look for plumes of blowing snow to indicate where the wind is forming fresh slabs. The easiest way to stay safe is to stick to slopes under 35 degrees. If you see recent avalanches or cracks shooting through the snow stay on well-protected, low-angle slopes.

    Even at lower elevations, it's critical that you carefully assess the new snow as you move through the mountains. Expect that it may be easy to trigger avalanches on any slopes over 35 degrees. You may find stiffer snow over softer snow as an indicator that you can trigger storm slab avalanches. Use safe and smaller test slopes to check how easily the snow slides. Making many quick tests as you move through the terrain can help you assess the chances of triggering an avalanche. Take some time to dig down about 2 feet to look at the interface that was buried at the beginning of this storm, on Friday. If you find sudden or propagating test results on older, weak snow, stick to lower-angled slopes.

    (12/20/2022) An example from December of cracks extending from a small skier-triggered slab avalanche. 5,100ft, NNW, Stevens Pass Photo: Josh Hirshberg

Avalanche Discussion

Tuesday will be the peak of snow, wind, and avalanche activity. You may see wet snow and rain well-below treeline however, there's little recent snow accumulation at these elevations. It's a good idea to watch for wet avalanches below 4,000ft but I don't expect them to present much danger. 

Weak snow (near-surface facets) was buried at the beginning of this storm on February 3rd. It's yet to be seen if avalanches will run on this interface and involve all of the recent snow. The recent cold and dry weather formed weaker snow around crusts in the upper snowpack. One, from January 27th, found at mid-elevations, is thinner and more brittle and buried just over 2 feet below the surface. A more stout, clear ice lens that formed around the MLK holiday weekend, is buried about 3 ft below the surface. We haven't seen truly alarming results on these layers in pit tests, but we'll continue to keep an eye on these weaker older layers during this storm, as there is a chance they could wake up with a large load on top. 

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