Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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In sintesi

With continued warming, wet avalanches are the primary concern, particularly on steep slopes warming in the sun. The recent dry snow may become wet and heavy, large cornices could fail, and slabs of snow may release from rocks in the sunshine. If the snow feels wet and sticky, move to lower-angle terrain. 

Problemi valanghivi

  • Loose Wet

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

    Continued warming with decreasing easterly winds will make Thursday a notch warmer than Wednesday. You are likely to trigger wet avalanches where recent snow gets wet and heavy. We expect most avalanches will be small, but as the wet avalanche activity wraps further around the compass, large wet avalanches are also possible where the snowpack is still dry.  Move to lower-angle terrain if you feel the surface snow becoming wet, heavy, or sticking to your equipment. Wet avalanches may run naturally from trees or rocks shedding snow above you, so be aware of overhead terrain. Consider finding shady terrain for recreation in dry snow with a lower likelihood of avalanches. 

    Liquid water is still draining through the snow, so a rogue glide or wet slab avalanche off steep rocky terrain or grassy slopes is also a consideration. Avoid lingering underneath glide cracks, cliffs, or overhung cornices. These overhead hazards may fail naturally as things heat up and are hazards all on their own. However, a large trigger, such as a cornice fall, may also trigger a slab avalanche on the slope below.

    (2/24/2025)

    Loose wet avalanche (D2) on Nason Ridge

    Photo: Josh Hirshberg

Avalanche Discussion

The warming will continue on Thursday, with freezing levels soaring well into our upper elevation band. Add in sunny skies and plenty of dry snow, and we have a perfect setup for widespread wet avalanches. Wednesday saw significant wet avalanche activity, and many southerly aspects likely have a crust on the surface. We expect this crust to break down on Thursday and the warmer temperatures to drive wet avalanches on shady terrain as well. 

Since Friday, Feb. 21st, the Stevens Pass zone has received over 5 inches of water, 1.5 inches of which was snow above 4000ft on Tuesday. There is now about 2 feet of snow over the 2/24 melt-freeze crust. 

On Wednesday, an NWAC forecaster near Stevens Pass got the first post-storm look at upper elevation terrain and observed very large crowns and cornice failures above 6000ft on Rock Mountain and Nason Ridge. They also reported a widespread wet loose avalanche cycle during the day. The reactive storm interfaces from Tuesday were strengthening, but there may be lingering instabilities in very steep, unsupported slopes and confined alpine features. If you use this warm sunny weather to get into the upper elevations, enter more complex terrain cautiously and make frequent assessments before committing to more consequential routes in wind-affected terrain. 

Older observations highlight the widespread wet avalanche cycle that began on Saturday during the atmospheric river. We suspect the rain/snow line over the weekend hovered between 5000 and 6000ft. Many large and very large wet avalanches were reported along the HWY 2 corridor and outside of the Stevens Pass Ski Area.  We are still cataloging this avalanche cycle, so let us know what you see by submitting an observation!

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