Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

Prolonged warm weather continues, with freezing levels expected to reach 9,500ft on Friday. With sustained and increasing warm temperatures expect more wet snow avalanches to come down. When you notice snow becoming soft and punchy retreat to firmer slopes, low angle terrain without overhead hazards, or consider heading back to the car.

Avalanche problems

  • Loose Wet

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

    Less of an overnight freeze, less wind, and warmer temperatures is enough of a concern to elevate the avalanche danger to Considerable. Wet loose avalanches may gouge deeper into the snowpack rather than just the surface snow, creating larger avalanches. Conditions will vary extensively based on your aspect, elevation, and time of day.  Early in the morning only easterly slopes may be affected, but as the day progresses and sun rises higher in the sky a much larger span of terrain could be affected. Upper elevation direct north slopes may no longer have cold, dry snow and wet loose avalanches may occur there. 

    Uncertainty exists as to when a larger avalanche cycle will happen, but now several days into this warming trend, we expect to see a spike in the amount and size of avalanches soon. As you travel keep close tabs on the changing snow conditions. Keep your return routes in mind - slopes you crossed safely early in the day may become wet, weak, and dangerous by afternoon. Don’t wait until it’s too late and avalanches start coming down all around you that you decide it’s time to retreat. When you start seeing signs of a weakening snowpack such as easily punching down several inches, or noticing any nearby avalanches, leave the area for lower angle terrain or firmer snow.

    Large wet loose avalanches from earlier this year, similar to what you might see on Friday. Photo: Matt Crisler

  • Glide Cracks

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    Expect glide avalanches to occur more frequently as prolonged warm temperatures continue to heat surfaces. Glide avalanches occur beneath glide cracks on steep slopes which are usually smooth bed surfaces, such as rocks, grass or low bushes. When these smooth surfaces are lubricated with water it may cause the overlying snow to easily slide. 

    Glide avalanches are very unpredictable, yet we do expect an uptick of them with the increased temperatures. Your best course of action is to identify glide cracks, usually found near the upper part of an open slope, and limit your time on the slopes beneath them. 

    (4/14/2021) A large glide avalanche starting on a steep rock face, seen in the Mountain Loop Highway area 4/15. Photo: George Coiner

Avalanche Discussion

A large wet loose avalanche was observed on Mt Persis near Index, visible from Highway 2.  It probably occurred Wednesday or Thursday. As temperatures increase frequency and size of avalanches increase. With several days of increasing temperatures conditions are continuing to become more unstable. 

Cornices are ripe for failure. Stand far back from the edges, and limit your time on slopes beneath them. Shedding on and beneath large features is happening more as temperatures increase, so travel judiciously in mellower terrain beneath areas with large overhead hazards. 

Daily avalanche forecasts will end on Sunday April 18th.

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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