Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

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

Another sunny, warm day will renew wet avalanche concerns on steep, sunny slopes. Default to shadier terrain once you notice rollerballs shedding or sticky wet snow under your feet or machine. At upper elevations, use caution around wind-drifted slopes and assess for instability before committing to bigger terrain. 

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    The sun and warm temperatures will renew the wet avalanche problem once the surface crust breaks down. You'll initially see signs of warming and wet avalanches beneath rock bands or on steep slopes with direct sun exposure. As the day progresses, you may notice signs of warming on east and west aspects as well.

    Rollerballs, pinwheels, or sticky, sloppy snow surfaces usually indicate that surfaces are becoming wet and weak. Look for more shaded aspects once you start noticing these signs. 

    If you see slides breaking into slabs, gouging deeper, or growing larger, the scales have tipped, and you're dealing with a much more dangerous wet avalanche beast. Put space between you and these slopes.

    (1/28/2024)

    An example of a small wet loose under a cliffy area, which is a common place you may see these.  

    Photo: Katie Warren

  • Wind Slabs

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

    If you climb to upper elevations, you may still find some lingering stubborn wind slabs. An uptick in north winds may build a new generation of slabs, but these will be shallow, but still worth keeping on your radar in steeper, consequential terrain. 

    .Managing this problem is fairly straightforward. Be suspicious of any terrain features that promote drifting. You can typically find these on the downwind side of ridges, below cornices, and beneath rock and cliff bands. Using small test slopes or doing quick hand pits is a great way to gauge the reactivity of these slabs. If you notice blowing snow, textured rippled surfaces, hollow drum-like snow, or shooting cracks under your sled or feet, default to more sheltered lines. 

    (3/13/2024)

    Visual  clues help highlight where wind slabs may occur.

    Photo: Dallas Glass

Avalanche Discussion

Preliminary Report: NWAC is saddened to report an avalanche fatality as a result of a cornice fall on Mt St Helens. On Saturday, March 30, 2024 a snowboarder summited the peak. While standing near the top, he triggered a cornice and fell to his death. Our deepest condolences to the family, friends, and community.

Discussion:

Saturday was a beautiful day across the region. Temperatures pushed into the 40's at many East South weather stations. Sunday will bring more of the same, just with an uptick in north winds. This should help keep slopes at higher elevations dry and cold for one more day. Look for a more significant increase in freezing levels come Monday. 

 This past week, trickles of new snow freshened up surfaces across the zone. You'll typically find 1-1.5 ft of recent snow resting over the stout crust left from last week's warm-up. Fortunately, this stout crust helped reduce the likelihood of triggering deeper layers of concern. However, you'll want to shift your focus to surface instabilities such as wind slabs or wet avalanches in the coming days. 

On Wednesday, an NWAC forecaster in the Ahtanum area found around 6" of new snow above 6000ft. New snow depths at lower elevations were significantly less, with rain down at the Snopark. A profile at approximately 6600ft on a NE aspect showed a stout crust below the recent snow. Shovel tilt tests produced moderate results with clean shears on this crust. In sheltered areas, there isn't much of a slab over this crust, but it could make wind slab avalanches easier to trigger. They also found the facets over the Early February Crust to be moist and rounded. This persistent weak layer is getting stronger and, combined with the stout surface crust, makes avalanches on this layer unlikely. However, there is always lingering uncertainty with these tricky, persistent weak layers, so step into large, north-facing alpine terrain with this in mind. A big warm-up or powerful storm could also bring this problem back to life. 

If you get out this weekend, let us know what you see by submitting a public observation here. 

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