Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

You can trigger thick wind slab avalanches on wind loaded slopes on Thursday.  Increasing snowfall and strong winds will increase the avalanche danger throughout the day. Avoid wind loaded slopes greater than 35 degrees, and the areas beneath large avalanche paths as well. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2

    Dangerous wind slabs will develop Wednesday night and Thursday.  Failures might occur in Thursday’s snow, or they could fail deeper, as we’ve received more than 3 feet of snow since Friday and winds are actively redistributing it. Pay attention as you transition into wind-affected terrain, and look and feel for sudden changes in snow surface texture and hardness.  Look for plumes of snow depositing onto steep slopes.  These wind loaded areas are more likely to slide, if steep enough.

    The most dangerous conditions exist in wind-loaded terrain at higher elevations. The avalanche danger will increase into Friday as snowfall intensifies and wind continues.  Steer away from wind loaded slopes, and avoid travelling through lower angle areas beneath large, steep wind loaded slopes.  Pay attention as snow continues to fall and consider sticking to even more conservative terrain as the danger increases with additional snowfall and wind. 

    (2/24/2021) Silica Peak area in the West Central zone. Small slabs stepping down to deeper slabs, with new loose dry avalanches on top.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    2–3

    The deep persistent slab avalanche problem is still a concern in the West Central zone. Many deep avalanches which occurred during the last storm cycle were seen in the area on Wednesday.  Intense periods of loading with wind and snow during a storm is when this avalanche may occur.  Additionally, a  human trigger when the snowpack is most reactive in the midst of a storm could be enough to tip the balance, although unlikely.  The likelihood pf an avalanche occurring on this layer is low, however the consequences if you are involved are high.  Despite the low likelihood of this type of avalanche occurring, as the storm adds more snow and wind rapidly loads slopes at upper elevations, consider staying out of upper elevation avalanche terrain, and the runouts of large avalanche paths even at lower elevations.

    (2/24/2021) Evergreen Mountain southwest face. This avalanche stepped down possibly to the mid Jan weak layer.

Avalanche Discussion

Several avalanches up to D3 occurred in the West Central zone during the widespread avalanche cycle Sunday through Tuesday.  Check out the media gallery below for photos of the avalanches. Numerous other very large avalanches were reported throughout the Stevens Pass, Snoqualmie, and West North zones. The amount of recent and wind-blown snow is concerning enough, and the mid-January persistent weak layer may still be capable of producing very large and surprising avalanches. After our short break in the weather on Wednesday the unsettled weather has returned, so travel very carefully in the backcountry as the storm continues. 

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

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