Bollettino valanghe

East Slopes Central

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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We are about to turn up the temperature and turn our concerns to wet avalanches. The recent dry snow may become wet and heavy in the sunshine, large cornices could fail, and slabs of snow may release from rocks. 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
    1–1.5

    Continued warming 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 some larger avalanches are possible closer to the Cascade Crest with higher recent snow totals. 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 (D1) in Tumwater Canyon

    Photo: Josh Hirshberg

Avalanche Discussion

The East slopes of the Cascades warmed up on Wednesday, and there was an initial round of wet loose avalanches. Southerly slopes will likely form a crust on the surface overnight. However, continued warming is expected, with freezing levels going well above our upper elevation band. So we expect surface crusts to break down, and even shady terrain may see increased wet avalanche activity on Thursday. 

On Tuesday, the East Central Zone picked up between 5 and 10 inches of snow above 4000ft, with higher snow totals closer to the Cascade Crest. Strong to extreme winds accompanied this storm, and Mission Ridge Summit Weather Station recorded gusts to 115mph. Moving into Wednesday, recently formed wind and storm slabs were stubborn, but you may find lingering instabilities in very steep, unsupported alpine terrain. Make frequent assessments and consider the consequences of triggering even a small avalanche in this type of terrain. 

Tuesday's snow and wind created sensitive wind and storm slabs throughout the area. A large natural wind slab in the Icicle Creek Drainage released in a wet snow layer below the recent snow. In this heavily wind-loaded area the avalanche was 2-3 feet deep. At Mission Ridge Ski Area, ski patrol reported sensitive 6-8inch, widely propagating avalanches during avalanche mitigation work. Over the weekend, a widespread wet, loose avalanche cycle occurred on Blewett Pass, closing the highway for a few hours on Sunday. A similar cycle occurred, closing Tumwater Canyon on Monday. On the 23rd, observers from the Holden area reported widespread natural slab and wet loose avalanches. Some were very large and may have run on the January Drought layer.

We suspect that after this big warm-up, with rain to over 6600ft, those deeper, weak layers may no longer be an issue for avalanches. But if you're traveling to more obscure places in the zone or at elevations above the rain/snow line (approximately 7000ft), this layering should still factor into your uncertainty and travel decisions. 

Submit an observation to help NWAC Forecasters reduce uncertainty. It can be short, simple, and even anonymous. 

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