Bollettino valanghe

East Slopes North

Northwest Avalanche Center
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Pericolo valanghe

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

Dangerous avalanche conditions will persist from continued warming. Wet avalanches are likely to be the most widespread, but avalanches in wind-drifted snow, cornice failures, or even widely propagating deep avalanches are all in the cards. Choose conservative terrain on low-angle slopes with minimal overhead hazards.

Problemi valanghivi

  • Loose Wet

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

    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 as temperatures push warming further around the compass. 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. 

    Cornices may be likely to fail in the warming temperatures. While these are a hazard on their own, they could trigger a wind slab on the slope below. 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. 

    Wet loose avalanches south aspect of Cutthroat from last March. 

    Photo: Willie Webster

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–3

    Tread carefully and put a large buffer between where you travel and large open slopes over 35 degrees suspect for these persistent slab avalanches. On Wednesday, a snowmobiler near Harts pass was caught, carried, and buried from a remotely triggered persistent slab. Thankfully, they were rescued and are okay. But we suspect the warming temperatures are increasing the likelihood of these large and deadly avalanches. Smaller avalanches in the recent snow can also initiate an avalanche on deeper weak layers.  Overlapping problems require you to plan conservatively and consider overhead exposure.  

    Expect that avalanches could run into runouts and valley bottoms. With the January Drought Layer (JDL) nearly 3ft deep now, you may not receive warning signs of whumpfs or collapses in flatter terrain.  

    (2/26/2025)

    On Wednesday, a snowmobiler was caught, carried, and buried in this remotely triggered persistent slab avalanche. Thankfully, they were uninjured. 

    SS-R3-D2.5-AMr-O

  • Wind Slabs

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

    Since Saturday, 1-2 feet of storm snow has fallen for areas above 5000-6000' and closer to the Cascade crest. Strong winds have formed deeper drifts on lee slopes at higher and mid-elevations.  On Wednesday, clear skies gave us views of large wind slab avalanches that had failed in the last 24 to 48 hours. Give these slabs additional time to settle by seeking out simple terrain or steeper slopes that are well-supported and limit overhead hazard.  Triggering a storm or wind slab avalanche could trigger a much larger avalanche on older, weak snow.  Wind slabs on these deeper layers may be more likely from large triggers such as cornice falls. 

    Don't let a small avalanche at lower elevations or in thinner snowpack areas catch you off guard at lower elevations.  We've seen small wet slabs, storm slabs potentially breaking on recently buried weak layers, and wet loose avalanches at lower elevations in sagebrush country over the last few days.  

    (2/6/2025)

    This large (D2) slab avalanche was likely triggered by cornice fall. Estimated crown depth is 1.5-2ft. Liberty Bowl, NNW, 7,200ft

    Photo: NCMG

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. 

Professionals reported several natural storm/wind slab avalanches and 2 very large persistent slab avalanches in the Harts Pass area on Monday.  The persistent slab avalanches likely failed on the January Drought Layer (JDL), now 2-3' below the surface.  On  Sunday, travelers near Cutthroat Creek felt several collapses and confirmed natural very large avalanches in the Harts Pass area. 

Heavy, dense snow layering over weak faceted snow in the foothills near the Methow Valley led to reports of whumfping and small avalanches the last 2 days.  We expect the prolonged warm temperatures will eventually help strengthen this weak snowpack structure, but this problem should still be on your radar until we get a solid cold night with a good re-freeze of the snowpack.

You can help us gather more data by submitting an observation HERE or via the Avy App. 

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