Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

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

After a chilly start to the morning, Friday looks like a warm sunny day. Don’t be surprised when you see plenty of rollerballs and maybe even natural loose avalanches. While these slides should stay small, they can hurt you if they push you over rocks or into a creek.

Avalanche problems

  • Loose Wet

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

    Even though our last storm ended on Sunday, the extremely cold weather this week maintained a very cold and dry surface. So, it’s easy to imagine that Friday’s warm and sunny weather will produce some natural loose avalanches on steep southerly slopes. Fortunately, many areas saw at least some sunshine already this week and formed a thin crust on these aspects. This should help reduce the number and size of natural avalanches. As the snow surface warms, expect to see piles of new rollerballs and natural slides on steep sunny slopes. While these avalanches should remain small, they can still harm you if they push you over a cliff or into a deep gully. Don’t linger on or under this terrain when once you start to see signs the snow is becoming wet and sticky. While you may see loose avalanches at any elevation, they will likely be more prevalent near treeline where the perfect balance of ample recent snow and less wind effect exists.

    (1/16/2022)

    Example: You may see natural loose wet avalanches like this Friday on steep sunny slopes, especially near rocks and trees. Photo: Public Observation

  • Wind Slabs

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

    Winds this past week reshaped the snow on exposed features near and above treeline. Textured surfaces, scoured slopes, and sharp drifts abound. Because the winds came from several different directions (including E), you may find wind-loaded pockets in some unusual locations. This wind slab problem isn’t very widespread and these drifts are now a few days old. So, you’ll need to look feature by feature to see if the slope in front of you might hold a possible wind slab. When you find firm pillow-like drifts, steer around them and seek out lower angled or less wind-affected routes. On Thursday, wind drifted pockets still cracked and produced very small slab avalanches. While these slides alone couldn’t hurt you, don’t let them catch you off guard in high consequence terrain.

    (2/24/2022) A long (10') shooting crack in a firm pillow-like wind drift. These are the exact types of features where you may trigger a wind slab. Photo: Dallas Glass

Avalanche Discussion

It’s been downright frigid around the West South zone this week. This helped persevere the recent storm snow in many areas, but despite the cold, the snow surface began to change and become aspect and elevation dependent. In exposed areas higher on the mountains, the winds significantly reshaped the snow, sculpting the surface, and creating variable travel.

Southerly: Outside of the wind, on southerly aspects, a thin breakable crust formed in some locations. Below this new crust dry storm snow remains. On these same slopes, last weekend’s storm fell on a very strong and spring-like snowpack that melded together several crust and layers which you may find elsewhere.

Northerly: In more shaded terrain 10-20” of storm snow buried a much drier and more complex snow structure. Below the storm snow a thin crust (2/19) sits 1-2” above the more prominent Valentine’s day layer. Weak snow has been observed around and between these crusts. While we don’t currently expect avalanches on these possible weaklayers, that may change as we go forward.

Regions covered