Avalanche forecast

East Slopes South

Northwest Avalanche Center
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Avalanche danger

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

Forecast updated 07:20 AM to reflect high-than-expected snowfall amounts and an increase in danger level that results at all elevations.

West winds redistributed 6-12" of fresh snow to form large slabs you can trigger. Ease into the terrain, noting slopes with fresh cornices and wind-ripples or pillows on the slopes below. Steep, unsupported wind-loaded rolls in the terrain are where you are most likely to trigger an avalanche.

Avalanche problems

  • Wind Slabs

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

    The East South zone picked up 6-12" of fresh snow by Wednesday morning with a shift to moderate to strong W winds redistributing that snow onto lee slopes. Slabs could be large and dangerous and will be most reactive first thing in the morning. Stay off wind-loaded slopes 35 degrees and steeper. Ease onto smaller consequence slopes and less wind-loaded features or choose wind-sheltered terrain to stay safe as we give these slabs time to heal. Cracking snow surfaces, a wind-stippled pattern, or smooth pillow-like drifts are all warning signs. We don't think this problem will extend into the below treeline elevation band, but if you find 6" of drifts over a crust, you can trigger an avalanche on a steep slope.

    Example: Very small windslab beneath a cornice. These are the types of wind-loaded slopes you will want to steer around on Wednesday.

    Photo: Katie Warren

  • Loose Wet

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

    Wind-sheltered SW-S-SE aspects are where the sun will have the greatest destabilizing impact. Temperatures will start cold, but the sun's energy is strong this time of year and once the winds die down and the sun comes out expect conditions on directly sun-affected slopes to change rapidly. Look for rollerballs as a sign to reduce your exposure to steep slopes and shift to colder, shaded aspects. These avalanches could entrain all the recent snow above the most recent crust.

    Example: A wet loose avalanche on a steep road bank. Squilchuck Ck, E, 4,500ft

    Photo: Josh Hirshberg

Avalanche Discussion

It rained to 4500 ft on Tuesday, but cooling and strong spillover of snow showers onto the lee of the Cascade Crest raised the avalanche danger more than expected. Below, 4500 ft, avalanche danger should be limited to dry snow above the refreezing 2/7 crust. However, at higher elevations, the new snow may sit on a variety of surfaces and you'll need to assess the bond to that surface and any potential weak layering that may linger on shaded aspects. If you find defined weak layers, avalanches may propagate more widely and be larger than you expect. Our uncertainty remains high in this region without recent direct observations.

If you get out into the East-South, please let us know by submitting an observation!

Regions covered