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

Wednesday will be a dangerous day in the mountains with new snow and extreme winds that will build stiff, unstable slabs at all elevations. To avoid triggering or being caught in an avalanche, travel on low angle slopes and avoid deep pillow-like drifts on steep terrain features. 

Avalanche problems

  • Wind Slabs

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

    The East South zone could end up with around 8-10inches of new snow, with higher amounts possible near the Cascade Crest. With forecasted wind speeds that could reach 65mph, it may be hard to find locations where the wind hasn't drifted the snow around. While these wind slabs may be smaller at lower elevations, they will quickly gain size as you ascend in elevation to more exposed terrain. You should also anticipate that these slabs may form further down from ridges than you would typically see or in areas you would usually consider sheltered. These new slabs may rest on a freezing rain or sleet crust from Christmas, and there is uncertainty about how well the new snow will bond to this slippery underlying surface. Sensitive, fresh wind slabs and slick, old snow surfaces are a perfect setup for avalanches. Wednesday will be a good day to stick to low angle slopes in sheltered areas. You can identify wind-affected terrain by surface texturing, shooting cracks, and stiff hollow sounding snow. If you observe any of these signs, be sure to steer clear of steep slopes and terrain features. 

    (11/27/2022)

    Examples of textured surfaces and fresh drifts behind natural objects are signs of fresh Wind Slabs. 

    Photo: Andy Harrington

Avalanche Discussion

We have been on a wild weather ride for the last few days, and Wednesday will be a continuation of that pattern. Times of rapidly changing and active weather limit the ability to gather information on a broad spatial scale throughout the area. Since we have limited information, we also have significant uncertainty about snowpack conditions. We suspect many areas have a widespread ice crust from the freezing rain/sleet over the Christmas weekend. This crust may never have formed at higher elevations, and you may find a melt-freeze crust from rain instead. At trailheads at the lowest elevations, the freezing rain crust may have broken down with the recent warm temps, and you may find a saturated snowpack. With this complicated snowpack setup, you may find a complex set of avalanche problems. While wind slabs are the primary concern, low elevations may still present some wet loose avalanche concerns. Look for signs such as roller balls or heavy saturated snow to indicate the potential for wet loose or wet slab avalanches. At higher elevations, new snow falling on slick crusts could form storm slabs in even sheltered locations. Use quick hand pits or inconsequential test slopes to see how well the new snow bonds with the underlying surfaces. 

If you get out into the mountains, let us know what you see by submitting a public observation!

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