Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Wed
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

Stormy weather will create dangerous avalanche conditions Tuesday. You may trigger avalanches large enough to bury you in wind-loaded terrain and in areas that receive more than 8 inches of new snow. Expect the most dangerous conditions on the volcanoes where significant snowfall may occur.

Avalanche problems

  • Storm Slabs

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

    Stormy weather should continue to build slabs in a variety of locations Tuesday. Exactly what type of slab and where largely depends on your location. In places that receive less snow, identify and avoid wind-loaded terrain. Blowing snow, sharp cornices, and fresh drifts should help you quickly figure out which steep slopes you need to steer around. 

    In places that receive more snow, you may find that you can trigger slides in many open areas greater than 35 degrees. Small test slopes will help you observe how the snow reacts under your weight. If you see cracking or small avalanches, dial it back and avoid steep terrain. In these places, expect slides to be much deeper and more dangerous in wind-loaded areas.

Avalanche Discussion

Avalanche Accident Colchuck Pk, East Central Zone

We’ve received preliminary information of an avalanche incident on Colchuck Peak, SW of Leavenworth, WA. (East Central Zone) The accident occurred on Sunday, February 19 and involved a group of 6 backcountry travelers. Three members of the group are suspected to have been buried and perished in the event. Another sustained injuries and was evacuated by SAR.  Rescue efforts are ongoing. NWAC is working with Chelan County Sheriff’s office and will make updates as more information becomes available.

 Forecast Discussion:

A winter storm should start to target the West South zone through Tuesday. During the peak of the storm Monday night, warm temperatures, strong winds, and heavy precipitation could combine to cause a natural avalanche cycle in some locations like Mt Rainier and Mt St Helens. Since the storm should start to taper throughout the day, expect the most dangerous conditions in the morning. Even as the storm starts to wind down, give the snowpack time to adjust to the new load before jumping into bigger and more consequential terrain. 

Our President's Day storm didn't shake out quite like we anticipated. New snow totals were modest with 2-6 in reported around the zone. Observations indicated mild and damp conditions, with the snow surface feeling the warmer air and becoming moist well into the near treeline band. This should help the new snow “stick” to the old surface and will likely form a crust at these elevations. New snow totals were modest with 2-6 in reported around the zone. Large cornices were also noted along ridgelines as a result of sustained strong winds. 

The good news is that the upper snowpack should handle the new snow loads on Tuesday easily. While we can still find the 2/17 and 2/13 interfaces in the upper snowpack, we don’t expect most avalanches to fail on these older layers.

Regions covered