Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

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

The snowpack is slowly stabilizing after 10 inches of water fell in the last four days. A large natural avalanche cycle Monday slowly transitioned to human triggered avalanches being the more likely cause of avalanches later on Tuesday. Continue to avoid areas steeper than 35 degrees as the snowpack slowly adjusts from this large load.

Avalanche problems

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1.5–2.5

    Wet slab, wet loose, we’ve seen plenty of wet snow avalanches in the last few days. There is a lot of wet snow in below and near treeline areas. Chances of encountering a natural avalanche are reducing, but you could still trigger one. It may be a wet loose avalanche, which is more predictable, and easier to manage from the top of a slope. It is harder to determine whether you might trigger a wet slab avalanche, but you’d most likely to trigger one on a large, unsupported slope, a location to consider steering around in areas greater than 35 degrees on Wednesday.

    (2/28/2022)

    A human triggered wet slab avalanche which occurred Monday in the West North Zone during the peak of instability. 

    Photo: Public Ob

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1.5–2.5

    Upper elevations may have managed to avoid the rain, and thick storm slabs exist in these locations. The new snow formed into a heavy, dense blanket coating the old snow surface. These deposits are probably well over 3 feet deep. Avalanches might occur as deep as the old snow layer, as there could be weak snow near the top of the old snow surface.  

    If you plan to head out on Wednesday, consider letting the snowpack adjust for one more day, and same as above, avoid steep slopes. Don’t ignore obvious signs of instability like shooting cracks, whumphs, or recent avalanche activity.  Approach any steep slope with caution and remain aware of terrain above you.

    (3/1/2022)

    A widely propagating unusual crown, typical of the unusual avalanche conditions which were present in the last few days. This probably consisted of a mix of wet surface snow and drier snow beneath.  E, 5000ft.

    Photo: Lee Lazzara

Avalanche Discussion

Avalanche activity will slow in the coming days. Likelihood may shift towards Possible for both problems on Wednesday, as there is uncertainty with how long the problems will linger. Nevertheless, consider letting the snowpack adjust for one more day before heading into steep terrain. 

The faucet slowly squeezed shut, and we’re left with many large avalanche debris piles that ran into below treeline areas in neighboring zones. About 10 inches of water fell through much of the West Central Zone since Saturday evening. The snowline mainly hovered between 4,000 and 5,000ft, but probably ended higher Monday night into Tuesday. Large avalanche cycles occurred in neighboring zones Monday, and we suspect there was a large avalanche cycle in the West Central Zone as well. Wet loose and wet slab avalanches ran, with a mix of drier storm slab avalanches in above treeline areas. Crowns 3 feet or larger were sighted in the poor visibility on Tuesday. As skies clear more we’ll probably have an impressive sight of the large avalanche cycle that just took place. 

Regions covered