Avalanche forecast

West Slopes South

Northwest Avalanche Center
View on map

Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map
Out of date — this forecast expired last year. You’re viewing past conditions, not the current bulletin.

Highlights

New snow and gusty winds could form shallow slabs on specific terrain features on Monday. Use visual clues, such as actively blowing snow, fresh cornices, or textured surfaces, to identify unstable slopes. You may want to limit the amount of time you spend traveling below overhead hazards such as cornices or glide cracks.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    We're headed back into a snowy pattern for the next few days. As new snow falls, it could be drifted around by the wind into shallow slabs on leeward slopes. Look for actively blowing snow, fresh cornices or new pillow-like drifts to help identify wind-loaded features to avoid. Sunday's wind came from the east, but on Monday, it will be primarily out of the west. Therefore, you may need to manage slabs on both sides of the ridge. Slabs should be resting on a newly forming crust, which could act as a good bed surface for avalanches to run far distances. You can use uptrack tests or small test slopes to gauge the reactivity and slab potential of the new snow.

    (3/29/2025)

    A recent wind slab avalanche on a relatively small slope in the Mount Adams area was spotted by sledders on 3/29. [SE 7800']

Avalanche Discussion

Sunday was a relative break in our stormy March weather in terms of precipitation. However, moderate to strong easterly winds made their presence felt in the zone as clouds increased ahead of our next weather system on Sunday evening. This next storm is expected to deliver a nice little shot of snow to our zone, increasing the potential for shallow avalanches on Monday. Slabs will likely be larger and potentially more reactive on the volcanoes. 

Last week's atmospheric river event was followed by unseasonably warm temperatures, resulting in a widespread wet avalanche cycle throughout the zone. We continue to receive reports of very large slides (up to D3) that occurred during this timeframe. Our last confirmed D3 avalanche was a naturally occurring wet slab on Wednesday evening at Crystal Mountain.

As we begin to distance ourselves from this cycle and enter a cooler period, a new surface crust is slowly forming. Reports have wavered on its thickness to date, but another night of relatively cool temperatures with partially clear skies on Sunday should help it gain strength. Once this crust becomes boot-supportable, thick, and strong, we should be able to put the threat of these very large and destructive wet avalanches to bed for the time being. Does that mean that they're impossible? Definitely not. We wouldn't be surprised to hear of one occurring. However, we don't think it's very likely at this point; otherwise, we'd still have it on the official problem list.

But take a look for yourself if you're out in the mountains. Take a moment to step out of your mode of transportation and see how deeply your foot sinks into the snow. If you're plunging through a weak surface crust into old, moist snow, put those very large and destructive slides back on your radar. Whether you think they're a concern or not, you should consider limiting the time you spend traveling below precariously hanging blocks of snow or sagging cornices. They're the most common, albeit unlikely, culprits to fail and create a very large avalanche.

Debris piles from this week's avalanche cycle are widespread. As are open creeks, holes, and patches of bare ground or rock. Some of these hazards may be hidden under some recent storm snow. Once the surface stiffens up, slick and difficult travel may develop. Allow yourself extra time to navigate these hazards. 

Regions covered