Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Steady winds drifted snow into stiff slabs where you could trigger avalanches. Look for pillowlike drifts and feel for hollow-sounding snow to identify and avoid steep slopes where unstable wind-drifted snow collects. It's springtime, so if the skies clear for any length of time, watch for wet avalanches on steep, sunny slopes.

Avalanche problems

  • Wind Slabs

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

    The East South received 8-12" of spring snow over the weekend. Since then, continuous moderate winds are redistributing the new snow into wind slabs on lee slopes. You will likely find wind slabs of various ages and depths. Older wind slabs may be stubborn and obscured by a dusting of new snow, but more recent shallow wind slabs formed on Monday may be easier to trigger. Steep slopes below corniced ridges, confined gullies, and the base of cliffs are the most likely places to get caught up in one of these avalanches. Look for pillowlike drifts and feel for stiff over soft snow layers to identify potential wind slab locations. If you suspect a steep slope to be wind-loaded or see obvious signs of unstable snow, such as shooting cracks, travel on lower angle slopes, ridge tops, or scoured wind-ward aspects instead. 

    Steer around pockets of drifted snow that appear textured or 'fat' like in this photo. 

    Photo: Joe Dellaporta

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    It's a tricky spring cloud forecast, but there is a chance the sun will make a prolonged appearance. Winds on Monday helped to keep surfaces cool, but Tuesday will be a much calmer day, so sunny slopes will have a better chance of warming up. Look for rollerballs and pinwheels as warning signs that the snow surface is becoming wet and weak. These avalanches often initiate from rocks or trees shedding snow onto steep slopes, so be aware of any overhead hazards as you travel. If the snow becomes moist and heavy, it might be time to move to shadier slopes or choose lower-angle routes.

    (3/18/2023)

    Wet loose avalanches often start when rocks or trees shed snow onto steep sunny slopes, like in this example.

    Photo: Pat Riffie

Avalanche Discussion

NWAC Forecasters and observers noted windy conditions and multiple triggered wind slabs near White Pass on Monday. We expect similar conditions further into the East South zone as well. Winds may die down by early on Tuesday, but it will take a while for the new snow instabilities to settle out. The recent snow fell over various surfaces, including thick melt-freeze crusts, which may act as a good bed surface. Whether it is a wet or dry snow avalanche, this slippery bed surface may allow the slide to travel further than expected. So, if you are venturing out to enjoy a spring-like day on Tuesday, keep all this in mind and enter new terrain slowly. You can use quick hand pits or test slopes to assess stability before committing to steeper terrain. Lower trailheads are melting out, and bare patches exist on some groomed trails, all signs that spring is near. The weather, however, is still set on winter. Winter storms in the early spring tend to bring complex and overlapping avalanche problems. You may experience dry slab avalanches and a rapid transition to wet snow avalanches with even a brief period of sunshine. The rapidly changing weather often makes for a tricky avalanche forecast. Stay tuned to the changing snowpack conditions and look for signs of instability. Recent avalanches, rapidly melting snow surfaces, shooting cracks, or actively drifting snow are all signs of deteriorating snow stability. Monitor the snow as you travel and be prepared with options to travel on less consequential terrain with lower angle slopes if you find questionable snowpack conditions. 

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