Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Wed
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

A springtime storm will bring mixed precipitation, fluctuating freezing levels, and strong winds to the West South zone. Be prepared to manage both wet and dry avalanche problems. When in doubt, avoid slopes over 35 degrees where avalanches are more likely.

Avalanche problems

  • Loose Wet

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

    This should be a relatively warm storm. Mixed precipitation, a poor overnight freeze, and other springtime factors will combine to create a weak and wet snow surface capable of producing avalanches. These slides typically start near a point and fan out as they move downhill, possibly growing large in the process. With a crust just below the surface, slides could run far or even fail in a more slab-like manner than you might anticipate. Wide swaths of moist snow could move downhill in a way that's not quite loose but not quite slab. Regardless of how you want to label these avalanches, they'll be more likely on slopes over 35 degrees. If the sun pops out in the afternoon, their distribution could expand onto upper-elevation slopes.

    (4/7/2024)

    Wet avalanche activity in the Crystal Mountain area. Expect rollerballs, pinwheels, and wet avalanches anywhere you find moist surfaces.

  • Storm Slabs

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

    As you ascend above the rain/snow line, you'll hit a messy transition zone and then start to encounter a more winter-like scene. Heavy new snow, gusty winds, and fluctuating freezing levels will result in new snow problems to manage. They may not be your classic storm slabs or wind slabs, but some mutant child formed with wet snow. Use quick hand pits to examine the snow over the Early April Crust (4/2). Take note if you find heavy snow over weak snow or poor bonding. Use uptrack tests and small slopes as you travel to gain information about how the new snow is reacting to your weight as a traveler. If you see cracking of the surface, blocks of snow failing in your tests, or observe signs of wind-loading, avoid slopes over 35 degrees where triggering a slab is more likely. Slabs will likely be thicker on the volcanoes or in wind-loaded terrain.

    (4/7/2024)

    A skier-trigger avalanche in recent storm snow. This one blurs the lines between wet and dry, loose and slab. [Tatoosh Range]

Avalanche Discussion

Monday night should be stormy in the West South zone, particularly on the volcanoes. By Tuesday morning, the storm will likely be subsiding. You may need to contend with the highest avalanche potential first thing in the morning. We have a large and diverse zone, so use the snow surface and depth over the Early April Crust as a gauge to determine how much hazard there is. Later in the day, sun breaks could reinvigorate wet avalanche activity.

As you ascend in elevation, avalanche problems should transition from wet to dry, with a messy zone where you could find both right in the middle. Some may even obscure the boundaries between wet and dry, loose and slab. Regardless of moisture content, the majority of avalanches should be confined to the snow above the Early April Crust (4/2). This interface should be easy to find when digging with your hand or shovel. A handful of reported avalanches from over the weekend failed in snow above this melt-freeze crust.

With spring weather, the threat of shed-style avalanches is a constant. Keep an eye on the terrain above you and limit your time spent below hanging blocks of snow, sagging cornices, or slopes with large cracks. That snow all has to come down at some point.

Lower elevations contain relatively low snow coverage. But where adequate snow exists, small avalanches are possible. More likely, you'll need to manage travel hazards. Open holes/creeks, shallowly buried rocks, and refrozen avalanche debris are more prevalent down low, but they litter the landscape at all elevations. This storm will only exacerbate these problems. Give yourself extra time and bring the tools required to travel safely.

Regions covered