Avalanche forecast

East Slopes Central

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

You can trigger loose snow avalanches in steep terrain features. These avalanches will be easier to trigger and possibly larger near and above treeline. Travel cautiously in steep terrain and avoid terrain traps such as cliffs, rocks, and gullies. 

Avalanche problems

  • Loose Dry

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

    Cold temperatures and continued low-density snow accumulations have resulted in a deep and relatively cohesionless upper snowpack. This lack of cohesion can cause the new snow to run fast on steep slopes and entrain additional snow as it moves downhill. Look for signs of fan-shaped avalanches, or point releases, that typically start from a single location and spread out as the travel downslope. They can run naturally, or you can trigger them as you move through steep terrain. Steep test slopes where dry snow moves fast and far downhill indicate that loose dry avalanches are possible. 

    As you gain elevation, these avalanches may become more likely and increase in size. Manage your travel carefully and know where your partner's location. Stay out from under other people in steep or consequential terrain and be wary of terrain traps such as creeks, trees, or cliffs that you could be carried into or over.

    (12/26/2021)

    Several small natural tree-bomb triggered dry loose avalanches below treeline at Hurricane Ridge. SE, L-N-R1-D1-S.

    Photo: ONP Rangers

Avalanche Discussion

Cold, low-density snow has been accumulating steadily over the past five days. Since December 21st, areas near the crest have picked up 40 inches, while Blewett Pass and Mission Ridge only received around 10 inches. Cold temperatures tend to slow the settlement of new snow, and you can anticipate deep travel conditions in many areas, especially closer to the crest. Light snow showers might continue into Monday, along with very cold temperatures.

Observations have shown the new snow to be bonding well to the melt-freeze crust from December 21st. New storm snow instabilities have settled, and the snowpack is gaining strength in areas close to the crest.  However, a shallow and weaker snowpack exists near Blewett Pass and Mission Ridge. In these easternmost areas of the zone, basal facets (weaker snow) may exist near the ground. This weak structure may be perpetuated by the extended frigid temperatures and become problematic in the future with additional snow. 

At higher elevations, there are limited observations, and you may find lingering wind slabs in isolated areas. Look for wind-blown snow textures and watch for shooting cracks as you gain in elevation or approach ridgelines. 

Bitterly cold temperatures are in the forecast again for Monday. Expect single digits and below zero temperatures. Cold injuries to fingers, toes, and noses are common at these frigid temperatures. So it will be worth it to bring some extra layers, extra warm gloves, hand warmers, and a thermos with a hot drink.

Regions covered