Avalanche forecast

Stevens Pass

Northwest Avalanche Center
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Avalanche danger

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

You could trigger slab avalanches well over 1ft deep at upper elevations. Look for signs of instability such as shooting cracks, recent avalanches, and steer around slopes steeper than 35 degrees above treeline. Loose wet avalanches may run on steep slopes that face the sun with daytime warming.

Avalanche problems

  • Storm Slabs

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

    With around 1ft of new snow and moderate wind drifting at upper elevations, storm slabs may continue to be reactive on Thursday. The likelihood and potential size of slabs will increase with elevation, and slabs may be most reactive during the first half of the day. In some areas the new snow may be resting on buried surface hoar or surface facets, which may also lead to lack of bonding to previous surfaces. Avoid steep and unsupported slopes that appear wind loaded at upper elevation, or if finding signs of instability such as shooting cracks.

    You can do quick hand shears, switchback ski tests, and use small test slopes to check how well new snow is bonding. Shooting cracks and fresh, slab avalanches are direct signs of instability and point to staying off of slopes steeper than 35 degrees.

    Example small storm slab on Tye Peak.

  • Loose Wet

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

    Warming temperatures and partial sun will initiate a round of loose wet avalanches on very steep slopes facing the sun. If the sun comes out, expect these to run. If it stays thickly cloudy, they may not happen.Look for signs of loose wet activity such as rollerballs, and other small fan-shaped avalanches as the daytime warms.  Don't let these predictable avalanches catch you by surprise in or around terrain traps or extreme terrain.

    Loose dry avalanches are possible on very steep slopes in the shade. Ride cautiously in steeper terrain knowing that you could initiate sluffs that may entrain loose snow and grow larger.

    Example of natural loose wet avalanches from Snoqualmie Pass on March 23.

Avalanche Discussion

Around 1ft of snow fell through the day on Wednesday. Temperatures warmed up during the snowfall, and observers reported touchy storm slabs around 8" deep even below treeline later in the day. Slabs were failing on the recently buried melt freeze crust. Near ridgetops and on exposed features, the wind was strong enough to drift the newly fallen snow into thicker slabs in those areas. 

Give cornices plenty of room when traveling on ridges and stay out from under them. Cornices could be touchy to triggering and they could trigger slab avalanches below. Several large glide cracks and a few glide avalanches were observed recently as well. If you notice crevasse-like cracks in the snowpack, avoid areas below the cracks. 

Deep persistent slab avalanches were a concern into early March, although at this point they appear dormant and unlikely. A layer of facets on a crust from Mid-January was responsible for these, and is now buried 8-9 feet deep. The last known deep slab avalanche in this zone was on March 1, and one was suspected in the West South zone on March 3. Major warming events later in spring and summer could trigger further rounds of avalanches on this layer. 

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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