Avalanche forecast

East Slopes North

Northwest Avalanche Center
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Avalanche danger

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

Significant new snow and winds have built large slabs of wind drifted snow on various aspects at higher elevations. Look for stiff pillow-like drifts of snow that feel or sound hollow. In steep terrain, choose routes that avoid these stiffer slabs of snow to avoid triggering or getting caught in an avalanche. 

Avalanche problems

  • Wind Slabs

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

    We are just starting to get a better picture of the snowpack after this Christmas storm changed the snowpack significantly. The East North zone recovered quickly, returning to snow and cold temperatures after the freezing rain event. Strong winds accompanied the new snow, and wind slabs likely formed on all aspects as winds shifted from east to west. While these slabs are gaining strength, it may still be possible to trigger an avalanche in wind loaded terrain on Thursday. Avalanches that run on the recent freezing rain or sleet crust from Christmas may travel further than anticipated. 

    A dusting of new snow on Thursday may obscure wind-textured surfaces. Instead, use your probe or ski pole to feel for stiff wind-driven snow over softer snow to identify areas where wind slabs exist. Shooting cracks and hollow sounding pillows of snow are also signs of wind slabs. Steer around these deeper drifts of snow in steep terrain. 

    Example wind slab from Blue Lakes Col.

    Photo: Josh Cole

Avalanche Discussion

After a few days of challenging weather and travel conditions, we are getting a few more observations on the state of the snowpack in East North. Initial information indicates that the new snow bonded well to the underlying freezing rain crust from Christmas. However, recent observations near Washington Pass also indicate that buried persistent weak layers may still lurk in the snowpack despite the warm temperatures and rain. On Tuesday, an NWAC forecaster found approximately 16 inches of snow over the Christmas crust near the Cutthroat Drainage. Below the 2-4 inch thick Christmas Crust, he also found a layer of preserved surface hoar buried 2 ft deep, which showed the propensity for propagation in stability tests. While triggering an avalanche is unlikely on this layer and would involve a large trigger, it is something to keep in mind as we step out after this storm. On Wednesday, an observer shared a photo of a very large natural avalanche on a NW slope at 7400ft. This widely propagating avalanche occurred during the Christmas storm and potentially failed on weak, faceted snow from November (11/22). This avalanche coincides with elevations and aspects of previous sporadic signs of instability on this layer. We are just getting a break in the weather to see the extent of this avalanche cycle and are still determining the distribution of these large avalanches. Therefore it is too soon to tell if this layer will continue to produce avalanches. While it would likely take a large trigger to initiate an avalanche on this layer. With this uncertainty, it will be best to approach high elevation northern aspects cautiously and dig down to identify these weak, sugary snow grains near the ground before committing to steep terrain. In the mountains further east of Washington Pass, a thin snowpack exists with just around 2 ft of snow in the lowland foothills. There is 6 inches of new snow over the Christmas Crust, and while water percolated below the crust, there are still dry, weak, faceted grains near the ground. Compression tests failed suddenly on these weak grains. Similar to other areas, the Christmas Crust will make avalanches on this layer unlikely. But it is still a layer to be aware of if traveling in steep terrain in these lowland areas. 

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