Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Continue to be leery of wind-affected open slopes where triggering an avalanche is more likely. Recent very large avalanches in this type of terrain should give you pause. Warming temperatures and periods of sunshine should create the potential for wet avalanches in many areas of the zone. If you find yourself in a sunny location and snow is easily shedding from trees and rocks, head for shadier slopes.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–2.5

    Wind-loaded terrain at middle and upper elevations should continue to be the most likely location for you to trigger an avalanche on Sunday. These Wind Slabs may be a bit stiffer than you are used to and straddle a line between soft slab and hard slab. Look for freshly built cornices, textured snow surfaces, and wind-stiffened snow that may feel hollow as indicators of wind-loaded terrain to avoid. With so much recent snow and strong winds, these slabs could be several feet thick in high alpine terrain and produce very large avalanches. Freshly built cornices getting baked by Sunday’s warm weather could fall and act as a larger trigger for these Wind Slabs. Take care on open slopes near ridgelines and give cornices a wide berth by not getting too close to them or traveling under them. They notoriously break further back than expected.

    (12/28/2021)

    Example: This very large avalanche was likely triggered by a cornice fall in steep wind loaded alpine terrain earlier this winter. You could see similar avalanches Sunday.  NE-E aspcet, 5800'. SS-NC-R2-D2.5-U

    Photo: Dallas Glass

  • Loose Wet

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

    Sunshine and increasing temperatures are expected around the zone on Sunday. The warm-up will look a little different depending on your location, with some areas staying cooler due to east flow or low-level clouds. These slides could be more likely on sunny, wind-sheltered slopes above the recent rain/snow line of ~4000 feet. If you find yourself in the sunshine and the snow surface is starting to get wet and sticky, you should have wet avalanches on your mind. Keep in mind that slopes well above you could be in the sun and destabilizing while you are in the clouds or feeling a cool breeze. Look for snow shedding from trees and rocks or pinwheels and rollerballs as precursors to wet avalanches. Wet Loose avalanches often start at a point, can entrain significant snow or trigger slabs, and will fan out as they descend downhill. If you notice these signs, head for shadier slopes keeping aware of the slopes above you.

    With warming temperatures and recent rainfall, keep Glide avalanches in the back of your mind. These slides are notoriously unpredictable and can fail days after the rain has stopped. Give hanging blocks of snow on rock ledges plenty of space by not traveling under them to help minimize your risk.

    (1/8/2022)

    A natural Glide avalanche occurred within the Alpental Ski Resort on the night of 1/7. This wet slide contained the entire season's snowpack as evident by the exposed rock.

    Photo: Alpental Pro Patrol

Avalanche Discussion

We are starting to get some information coming in from the pass, but are still very much in the dark about conditions in the majority of the zone. Automated weather stations are now back online, and our professional partners at WSDOT and Alpental have relayed important information. Both groups report that 6-8” of snow sits atop a freezing rain crust below the rain/snow line of ~4000 feet. Multiple large to very large natural avalanches have occurred during the recent storm cycle, with many paths running multiple times and with different avalanche characteristics (wet vs dry avalanches). Alpental has reported that cornices grew large during the storm and that Glide avalanches occurred during the cycle (Rockface appears to have climax avalanched on the night of 1/7). A very large debris pile at the base of Alta Mountain was briefly spotted by WSDOT crews and Alpental Patrollers reported catching a glimpse of a very large avalanche the width of Kendall Peak with a crown estimated to be up to 5 feet deep.

A sharp cooling trend at the tail end of the storm, combined with a lack of weather inputs has helped to stabilize the upper snowpack from the top down in many areas, allowing us to quickly drop the avalanche danger only a few short days after widespread very large avalanches and us issuing consecutive avalanche warnings. As mentioned above, we still have a high degree of uncertainty, and conditions may range throughout the zone, so Sunday may not be the day to step directly into consequential terrain. 

If you are out and about in the nice weather and notice recent avalanche crowns or debris piles, please take a picture and share it with us as we try to track and document this cycle. The evidence of these avalanches may be hidden by some fresh snow sitting atop them, but we’d appreciate a picture of anything you suspect as an avalanche. Other useful information to accompany a picture is the location of the avalanche, along with aspect and elevation if possible. You can submit this information on our observation platform either privately or publicly. 

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