Avalanche forecast

East Slopes North

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Warming of steep, sunny slopes will be the main concern on Friday.  Look for signs of instability such as rollerballs and wet, sticky snow during the middle of the day. On high shaded slopes and ridgelines, use caution near areas of firm or hollow sounding snow.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Strong sun will melt any surface crusts quickly on steep, south facing slopes. Look for signs of warming instabilities such as rollerballs, or moist sticky snow overlying cooler, unconsolidated dry snow. Be cognizant of this before entering any steep, committing features where the consequences of getting caught in a small entrainment of wet snow could be higher. There may not be natural wet slides on Friday, but if you are riding in the wrong place at the wrong time, you could trigger one of these avalanches. If the snow surface is crusted over and refrozen, then the danger of initiating these slides has likely already passed. 

    Example wet loose avalanches in a southeast facing bowl in the alpine.

  • Wind Slabs

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

    Wind slabs can be found scattered about in pockety distribution on upper elevation slopes. These are becoming less likely, but could still be triggered, as they may rest over a layer of weak snow. Prior to the last storm, weak surfaces and surface hoar were observed in the neighboring East Central zone.  Any recent slabs may continue to be reactive because of it. Use visual clues, such as textured surfaces to identify areas where slabs may be.

    Look for signs of instability such as shooting cracks and whumphing as you travel.  If you see these signs of instability, dial back your terrain choices and stay off of steep features. In this case, be sure to avoid obvious steep, wind loaded slopes, and also take into account unsupported, cross-loaded, and other midslope features. This is also a good time to dig quick pits, looking for weak snow beneath a slab, and to check and see how it is bonding. 

    (12/2/2020) Easterly winds continued to load NW aspects in neighboring East Central zone.

Avalanche Discussion

On Tuesday, an observer noted small loose dry slides on steep shaded slopes where the new snow was sliding over firm surfaces, and minimal slab formation. A natural wind slab was observed on Monday, as intense winds transported snow and loaded exposed slopes. Wind slabs may continue to be reactive and possible to trigger as they sit over a variety of pre-storm weak snow surfaces (11/30) including surface hoar and recycled powder (near surface facets).  Observers have identified a snowpack with a favorable hardness profile and good stability in the mid and lower snowpack. The snow depth in the area is generally 3.5ft to 5ft deep. 

On steep south facing slopes, the sun may warm the snow enough to create small wet loose slides in the middle of the day. Be sure to get off of these slopes if you notice wet sticky surfaces, or rollerballs. In the shade, loose dry avalanches may carry momentum and entrain weakening snow surfaces. 

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

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