Avalanche forecast

East Slopes Central

Northwest Avalanche Center
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Avalanche danger

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

We're in store for another warm day on Sunday, with mild overnight temperatures preventing surfaces from refreezing. Wet avalanches could be possible earlier in the day than you may expect. Move off of steep terrain where the snow feels wet and heavy. With spring warmups, the potential for cornice falls and large surprising avalanches is possible, so consider this additional uncertainty when choosing terrain. 

Avalanche problems

  • Loose Wet

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

    Temperatures will notch up again on Sunday, making it another day to avoid steep slopes with heavy, wet snow. A mild, cloudy night may only produce superficial surface crust in the morning, so wet loose avalanche activity may begin earlier in the day. If you're sinking deeply into heavy, wet snow, move to lower-angle slopes or northern aspects less exposed to the sun. Cloud cover may be thin in the morning, and southern aspects will likely be the first to heat up and produce wet avalanches. Wet loose avalanches tend to start from a single point and fan out, entraining more snow as they move downhill. They often initiate from steep cliffs, rocky terrain, and tree bombs, but you can also trigger them by skiing or riding in steep terrain. Rollerballs, pinwheels, and sticky snow are all signs that the likelihood of wet loose avalanches is increasing. These avalanches may be more predictable than slab avalanches, but they carry a lot of mass and can push you into terrain traps or over cliffs. Steep rock faces could release as wet slabs or glide avalanches and be quite large. These slides can be very unpredictable, so be aware of the overhead hazards from steep rocky terrain.

    Along with wet loose avalanches, large cornices may begin to fail with the warming temperatures. When they fail, these large overhanging blocks of snow are hazards on their own but pack enough weight that they could also trigger slab avalanches on the slopes below. There is a possibility that avalanches triggered by large cornices could be very large and carry fatal consequences, so best to avoid lingering under these overhead hazards. 

    (3/18/2023)

    Rollerballs on steep slopes like this are an indication wet loose avalanches are possible. 

    Photo: Pat Riffie

Avalanche Discussion

We have been in a stormy period for the last couple of weeks, and now that the sun is out and temperatures are creeping higher, we are beginning to see an initial spring shed cycle occurring throughout the Cascades. Very large natural and human-triggered avalanches have occurred over the last week. There isn't a consistent failure layer from zone to zone for these avalanches. But with continued warm temps and mild, cloudy nights, large and hard-to-predict avalanches may occur. As we ease into spring, take a conservative mindset for this transitional period to account for the uncertainty surrounding these larger slides. 

It's been about a week since significant snowfall, but the winds have been active, and there are likely lingering pockets of wind slabs at upper elevations. You're most likely to trigger one of these pockets in very steep alpine terrain. Confined couloirs and gullies are prime locations to find lingering pockets of unstable snow. Enter new terrain slowly, and assess conditions before committing to consequential terrain. 

The recent snow has piled deep over a couple of intermittent sun crusts and a pair of rain crusts from Valentine's Day, which are around 3-5ft deep. This crust extends to just below 7000ft with some weaker snow beneath it, and observations indicate wide variability in the structure and depth of this layer throughout the zone. The MLK crust is down 4-6ft and extends to higher elevations. Very large avalanches that occurred on the 10th on Cannon Mountain and Rock Mountain may have run on one of these crusts or some other deep layer, but we cannot say for sure.  

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