Avalanche forecast

Stevens Pass

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
4 · High
Treeline
3 · Considerable
Below
3 · Considerable
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Very dangerous conditions are expected to develop on Sunday with heavy snowfall and strong winds. Danger will increase during the course of the day, and with elevation. Stay off of and out from underneath large slopes, and watch out for even small ones as slides could break in the new snow, or on deeper buried weak layers.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    1–2.5

    As snowfall increases during the daytime, storm slabs should become more reactive. These could break within the storm snow, at the old snow interface, or even deeper on a number of weaker layers. The new snow is covering up a previous surface of facets and surface hoar. As such, slides may fracture widely or be triggered from adjacent slopes. They could be even be triggered in sheltered terrain once enough new snow piles up. Above 5,000ft slides could run on more deeply buried weak layers including weak snow and a crust from early February, and they could be over 2.5ft deep in places.

    With these dangerous conditions and snowpack complexity, it'll be a day to keep it simple with your terrain if you decide to venture out. Avalanche danger is expected to continue increasing into the overnight period, so it won't be a day to hang it out there. 

    Example storm slab in terrain below treeline.

Avalanche Discussion

Expect a very stormy day with strong winds and heavy snowfall on Sunday. The new snow may initially bond well to lower elevations with warmer temperatures, but as snowfall rates pick up and snow amounts add up, we're likely to see stability decrease. Higher elevations will quickly become very dangerous during the day with the very strong winds, and slides could run down to mid elevations from ridgeline terrain.

The intermittent dry spells we've had so far in February have created a number of potential weak layers, leading to a complex set up going into a prolonged storm week. We expect these will begin to get stressed and break at some point, the question is when. These layers mainly exist above 5,000ft and on aspects besides due south. Check out the obs from forecasters on Jim Hill on the 19th and see the profile and images of the weak grains in the gallery below. In the East Central zone, backcountry travelers have triggered a number of avalanches just above the early February Crust, the most was on the 22nd and was up to 1.5ft deep.

If you get out, you can submit an observation here.

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