Avalanche forecast

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Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Slabs of wind-drifted snow below ridgelines and confined features are the most likely places to trigger an avalanche on Monday. Steer around steep slopes with stiff or wind-textured snow. In the northern and eastern areas of the zone, an unlikely potential for very large avalanches on old snow layers exists on northern aspects.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Strong winds and a few inches of recent snow may have formed shallow wind slabs over the past 48 hours. Wind slabs that rest on slick crusts might be quite reactive. You're most likely to encounter wind slabs below corniced ridgelines or in confined alpine features at upper elevations. We expect most of these avalanches would be small, but even a small avalanche can ruin your day. 

    Track the depth of new snow over the old crust and watch for shooting cracks to indicate unstable snow. Small but steep wind-affected test slopes are also a good way to gauge the reactivity of wind-drifted snow. The best way to avoid these avalanches is to choose lower angle or wind-sheltered slopes. 

    (3/29/2025)

    Skiers triggered shallow wind slab avalanches on the 29th at upper elevations.

    Photo: NCH

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    2–3

    If you're venturing into upper elevations east of the Cascade crest, take time to dig and look for potential weak layers in the top 3-4 feet of the snowpack. Stiff snow over softer snow layers deep in the pack is a key indicator of the potential for these consequential avalanches. When in doubt, choose more conservative, simpler terrain. 

    There is uncertainty surrounding older, weaker layers of snow. Upper elevations and areas far east of the Cascade crest may not have stout crusts overlying older weak layers. There may still be a chance of triggering persistent slab avalanches east of Mazama and Harts Pass, where a shallower, weaker snowpack structure exists. 

    (3/17/2025)

    A widely propagating avalanche near Tiffany Mtn.

    Photo: Willie Webster

Avalanche Discussion

Most surfaces have supportable crusts with 5-6" of snow over them, and wet avalanche activity has decreased significantly with the cooler temperatures. Still, diurnal temperature swings are significant this time of the year, and if we get a few additional inches of snow overnight, you might see small, wet loose avalanches as the day warms up. Pinwheels, rollerballs, and deep, wet snow are all signs that wet avalanches are possible. Overhead hazards from snow falling off rock slabs or cornices are also something to keep in mind.

On Wednesday, WSDOT forecasters in the Highway 20 corridor reported a widespread cycle of wet avalanches. The cycle likely started on the 24th and continued at least through the afternoon of the 26th. Many wet slides ran on a range of slopes, and some deeper slab avalanches were reported up to D3.

Before warming and rain, the January Drought Layer was buried 2–3.5 ft and shallower east of Mazama. Near Rainy and Easy Passes, the JDL was over 4 feet deep and capped with a thick melt-freeze crust. On March 17, an observer near Tiffany Mountain reported widely propagating recent natural avalanches and rolling collapses on a weak layer in the middle to lower half of the snowpack. As observations have become limited, our uncertainty about the snowpack has increased.

Submit an observation to the website or the Avy App to help NWAC Forecasters reduce uncertainty. It can be short, simple, and even anonymous. 

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