Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

Thu
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
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In sintesi

We're coming out of a significant storm cycle. Avalanche danger is trending downward, but conditions are still dangerous. You could easily trigger large avalanches in new and wind-drifted snow. Avoid steep slopes with deep, pillow-like drifts and stick to shady or low-angle terrain to avoid wet avalanches. 

Problemi valanghivi

  • Wind Slabs

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

    Avoid slopes over 35 degrees on steep lee slopes below ridgelines. Strong winds and heavy snowfall on Tuesday created sensitive wind and storm slabs. The most likely places to trigger large avalanches will be on the leeward sides of ridges at middle and upper elevations.  However, with heavier snow over softer snow, you could still trigger smaller storm slab avalanches in sheltered terrain. Choose well-supported lower-angle slopes or scoured aspects for travel in wind-exposed terrain. In sheltered areas, gravitate towards conservative terrain selection on well-supported, planar slopes or forested areas. 

    We expect these slabs are gaining strength, but the heavy over soft layering may take some time to become unreactive, especially in wind-loaded terrain. Cracking on test slopes or snow that slides easily in hand pit tests are signs the snow is still unstable, and you should avoid steep slopes. 

    (2/25/2025)

    On Tuesday, test slopes like this produced cracking, a solid indicator of unstable snow. 

    Photo: Katie Warren

  • Loose Wet

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

    You may encounter wet avalanches where recent snow gets warm and moist in the sun. Easterly flow and inverted temperatures may help middle and lower elevations east of the Cascade Crest stay cooler than upper elevations and further west in the zone. This makes for a complicated setup, you'll need to rely on your observations of the surface snow to avoid wet avalanches. If you feel the surface snow becoming wet, heavy, and sticking to your equipment, move to lower-angle terrain. 

    Keep in mind the higher consequence of an unlikely wet slab avalanche. While we don't expect these to be more than a very isolated problem, heavy over soft snow layering and warming should keep this problem in the back of your mind. Keep an eye out for glide cracks or large cornices or chunks of snow precariously hanging onto rocks. Don't linger under these features.

    (2/24/2025)

    Loose wet avalanche (D2) on Nason Ridge

    Photo: Josh Hirshberg

Avalanche Discussion

It's been a very active few days for weather and avalanches. Since Friday, Feb. 21st, the Stevens Pass zone has received over 5 inches of water. Over 1.5 inches of that fell as snow above 4000ft in the last 24 hours, totaling about 2ft of snow over the 2/24 melt-freeze crust. Moving into Wednesday, we'll unfortunately begin another warming trend, although it will come with sunshine and dry weather this time. Easterly flow and a few high clouds should help keep the snow a bit cooler through Wednesday before conditions really heat up toward the end of the week. 

Recent observations highlight the widespread wet avalanche cycle that began on Saturday during the atmospheric river. We have a lot of uncertainty at upper elevations, but we suspect the rain/snow line hovered between 5000 and 6000ft through the weekend. Many large and very large wet avalanches were reported along the HWY 2 corridor and outside of the Stevens Pass Ski Area.  Then, a welcome cool-down brought new snow, strong winds, and a dry snow avalanche cycle. I was out in the Stevens Pass area during this stormy weather on Tuesday and found reactive wind and storm slabs. Test slopes easily produced shooting cracks and mini avalanches on a mid-storm layer down 10 inches, from heavier snow falling on softer snow. Stevens Pass Ski Patrol reported sensitive conditions and avalanche control results that ran full path on the 2/24 melt-freeze crust. As the skies clear this week, we'll continue documenting this widespread avalanche cycle. 

Let us know what you see by submitting an observation!

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