Avalanche forecast

East Slopes Central

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Dangerous avalanche conditions will persist on Sunday, and you can easily trigger large avalanches in areas where very strong winds have built deep slabs. These large slabs may linger in unsuspecting areas at all elevation bands. Choose conservative terrain and avoid steep slopes in wind-exposed locations.

Avalanche problems

  • Wind Slabs

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

    Winds associated with this storm averaged 30 - 50mph with 50-60mph gusts. These winds have likely built large slabs on various aspects, sometimes further down from ridges than expected. Wind-exposed slopes in lower elevations may have been cross-loaded and built slabs on the lee side of convexities.  Identify and avoid wind-loaded areas using visual clues such as cornice formation or drifts around trees.  Use your pole or probe to feel for areas of stiff snow over soft snow. Watch for shooting cracks or collapsing. If you experience or observe these signs, stick to wind-sheltered terrain and avoid steep slopes.  Below treeline, choose conservative terrain to avoid the high consequences of being caught in small avalanches where you could be carried over and into many obstacles.

    Shooting cracks in wind drifted snow near Mission Ridge.

    Photo: Joe Dellaporta

Avalanche Discussion

It appears most of the East Central zone avoided the forecasted “wintery mix” and experienced 6 to 12 inches and 2 to 6 inches of snow accumulation in western and eastern portions of the zone, respectively. Expect a quieter day on Sunday with cooler temperatures and light winds. If you venture out to enjoy the lull in the weather, it will be essential to approach new terrain slowly, use hand pits to identify weak interfaces in the new snow and make observations frequently as you travel. After a heavy-hitting storm like this, it takes the snowpack time to adjust to the new snow load. 

In areas in the northern portion of this zone, weak snow may be lingering above crusts, creating the potential for larger avalanches. We have limited data from these areas, approach complex or large terrain cautiously. Use snowpack tests to determine how well bonded the overlying snow is to these crusts.

Most areas in the zone have a significant snowpack, though some still lack significant coverage to produce avalanches. We have little information and a lot of uncertainty about the snowpack structure near and above treeline. There is a lot of variability throughout the zone, and a more substantial snowpack exists in the western portions. Strong winds have built unstable slabs on lee aspects even in the eastern parts of the zone that lack a substantial snowpack. Expect the avalanche danger to differ throughout the zone, and stability on one slope may not represent adjacent slopes. 

Regions covered