Avalanche forecast

Stevens Pass

Northwest Avalanche Center
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Avalanche danger

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

Thicker wind-drifted snow deposits are where you're most likely to trigger an avalanche on Wednesday. Search for wind-textured surfaces, pay attention to signs of actively blowing snow, and feel for heavier snow. Steer around steep slopes where you identify these characteristics or any other unstable signs during your outing. 

Avalanche problems

  • Wind Slabs

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

    Low-density snow from this storm has been redistributed in many areas, especially at upper elevations, into thicker wind-drifted deposits of snow. These heavier wind slabs are where you're most likely to trigger an avalanche on Wednesday. Avalanches could break around a foot deep, possibly deeper. They could take you for a scary ride, or they could be big enough to bury you. Stay aware of active snow drifting during the day, as an indicator of locations to avoid. Pay attention to clues such as textured snow surfaces or wind-sculpted features. Feel for heavier, stiffer snow beneath you. If you find any of these characteristics or identify any other obvious clues of instability, steer around slopes greater than 35 degrees.  

    (2/18/2023) It's likely that you could trigger wind slabs like this in steep areas, or possibly deeper, during your outing on Wednesday.  Photo: Dallas Glass

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–3

    A thin, weak layer of snow resting on a slick crust from mid-January is anywhere from 3-5ft down in the snowpack. We've been continuing to find test results that indicate propagation potential could occur on this layer, and this layer of concern keeps getting deeper. The last activity we know of on it was from February 8-13th. Some of these were quite large and surprisingly wide. With the recent added snow and wind loading, we may see avalanches failing on this deeper weak layer. Be aware of the possibility of triggering an avalanche on this layer if you enter steep near and above treeline terrain. The resulting avalanches could be very large and destructive.  If you see any deep slides which ran naturally during the storm, please take a photo and share it with us. 

    (2/11/2023)

    Large slab avalanche that carried and buried a skier a week and a half ago. This layer may still be a problem. 

    Photo: Rob Fallon

Avalanche Discussion

AVALANCHE ACCIDENT COLCHUCK PK, EAST CENTRAL ZONE

We’ve received preliminary information of an avalanche incident on Colchuck Peak, SW of Leavenworth, WA. (East Central Zone) The accident occurred on Sunday, February 19 and involved a group of 6 backcountry travelers. Three members of the group are suspected to have been buried and perished in the event. Another sustained injuries and was evacuated by SAR.  Rescue efforts are ongoing. NWAC is working with Chelan County Sheriff’s office and will make updates as more information becomes available.

Forecast Discussion:

Dry loose avalanches could run naturally or with a human trigger on steep, non wind-loaded slopes. Be sure to pay attention to the possibility of triggering one if you enter steep terrain so it doesn't take you out from behind, or hit a partner. Also keep in mind that even if an avalanche is small, if it pushes you into a terrain trap it could have a deadly outcome. 

We received about 1.5 to 2 feet of snow out of this storm in the Stevens Pass zone. Snowfall amounts vary depending on elevation, since the storm started out quite warm and wet at lower elevations.  As the storm came to a close it cooled off and deposited a nice thick layer of low-density dry snow at the surface. The low-density snow on top with the heavier snow beneath generally made for "right side up" storm layers, with fewer avalanches and more pleasant surfaces to travel on. Wind-loaded areas are where these circumstances changed, however, and small and large wind slab avalanches were noted in the zone on Tuesday. Reactive wind slabs are expected to continue to be a problem on Wednesday.

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