Avalanche forecast

East Slopes North

Northwest Avalanche Center
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Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

While unlikely, there's a chance that you could trigger avalanches on deeper weak layers in the eastern mountains. If you go into the mountains near or east of Mazama, it's worth keeping these avalanches in mind and make your own assessments. There's a chance for moist snow and small wet avalanches on steep south aspects.

Avalanche problems

  • Persistent Slabs

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

    While persistent slab avalanches are unlikely, the uncertainty and consequences of triggering one have kept the problem on the forecast. Mountains in the central third of the zone (near and east of Mazama) would be most suspect for these avalanches. If you travel in areas near Hart's Pass, the Lost River, Eight Mile Creek, the Twisp River drainage, or the Chewuch River, be ready to make assessments of the snowpack. We know less about conditions in those areas other than they hold a weaker snowpack. 

    If you managed to trigger one of these avalanches, it could break widely across terrain features. Any red flag signs of danger, like shooting cracks and whumphing collapses, should be heeded. The problematic snowpack structure is a series of crusts and weak layers buried in December, now in the lower third of the snowpack. To be safe, you can choose well-supported and lower-angle slopes for travel. Stop and regroup in safer areas, well away from and out from under potential runout zones of larger slopes. 

    (1/12/2024)

    Natural avalanches on Tamarack Peak, near Harts Pass. These likely occurred Jan 11th with northwest winds. We don't know exactly which layer these avalanches ran on, but they look suspiciously like persistent slab avalanches. E-SE, 7200ft

    Photo: NCH

Avalanche Discussion

 Saturday's forecast includes some breaks in the clouds and temperatures near freezing. Keep an eye out for warming snow surfaces and small avalanches on steep sun-exposed slopes.

Observers have reported that the recent storm snow has become difficult to trigger. The January 16th interface, below the storm snow, produced resistant failures in tests and no reported avalanches since the 17th. On that day, observers reported widespread slab avalanches in the 1 foot of new snow on almost all slopes steeper than 30 degrees. 

An NWAC observer visiting extensive terrain by snowmobile near Mt Tiffany and the far eastern mountains near Conconully. Generally, there wasn't enough consistent snow cover to sustain large avalanches. The deepest area he found had 2.5 feet of snow at 6,800ft. Many slopes have logs and brush sticking thru the snow that is on the ground.

The last reported signs of instability involving older weak layers was on January 16th, collapsing on an ESE aspect at 6,200ft near Varden Creek. On the 12th, an NWAC observer recorded recent wind slab avalanches, one of which may have stepped down to a weaker layer near Goat Peak. On the 10th and 11th, natural avalanches occurred on persistent weak layers near Harts Pass and Cutthroat Lake.

If you're in the mountains, please let us know what you find.

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