Avalanche forecast

East Slopes North

Northwest Avalanche Center
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Avalanche danger

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

Expect at least some blowing snow in the alpine on Thursday as the next front makes its way in. You could trigger small, freshly forming slabs on exposed slopes at upper elevations. Small loose wet avalanches may be possible in the morning on steep east and south facing slopes.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Ridgeline winds should ramp up on Thursday, and should be strong enough to drift snow. There are older, well bonded slabs in many areas, but it's the fresh ones that you are more likely to find instabilities with. Keep abreast of changing conditions, and be especially cautious near ridges, beneath large cliff features, and confined or convex rollers where a small avalanche could have high consequences.  Textured surfaces and stiff snow over softer snow are all ways to identify wind slabs. Look for signs of instability in small test slopes, such as long shooting cracks. If you identify any signs of unstable snow, steer around these stiff pillowlike slabs or choose lower-angled slopes or entrances. Cornices could also begin to peel away with warm temperatures, give them some space.Warm temperatures could melt snow surfaces that receive direct sun, and theres a chance that loose wet slides become possible in very steep areas by mid morning. Be mindful of steep or complex terrain if you find any wet snow surfaces, or rollerballs because these are signs that you could trigger small wet loose slides.

    Example photo showing wind drifting on a slope.

    Photo: Matt Primomo

Avalanche Discussion

Willie reported thick wind drifts above 6,500ft in the mountains north of Mazama on Wednesday, and obvious plumes from ridgelines. Wind slabs have been reactive in the zone over the past number of days. From Sunday through Tuesay, observers  reported triggered small avalanches in pockets of freshly drifted snow. Observers reported some rollerballs on Wednesday, and that slopes that face the sun will have sun crusts. 

We've been tracking a layer of buried surface hoar from January 5th. Near Washington Pass, it's ~2' below the snow surface. On Monday, observer Willie Webster found large (5-10mm) rounding buried surface hoar near the crown of one of many avalanches that ran during the MLK storm near Rainy Pass. January 12 was the last known human triggered slidethat we know of in this zone on this layer, though one was triggered on the 19th on the east side of Stevens Pass. That same day an observation near Tiffany Mt indicated that triggering avalanches on the 1/5 surface hoar may be possible in this portion of the zone. Warm, wet conditions have transofmrmed previously weak, low elevation snow of the foothills into melt forms. 

The last significant cycle of avalanches occurred around the 13th and 14th, with wet avalanches in the lowland hills gouging to the ground and multiple very large natural avalanches running on persistent weak layers higher in the mountains. A very large slide in Liberty Bowl/Blue Lake Pk likely occurred on January 13 or 14th. This avalanche failed on the Christmas crust and stepped down to the mid-November facets (11/22). The crown depth was 5-8 feet. Check out the media reel below and our observation platform to see more.

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