Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

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

A beautiful sunny day could make it enticing to head up into higher terrain. As you ascend, expect avalanche issues to change. You’ll need to adjust your mindset from managing small natural wet avalanches near treeline to avoiding pockets of wind drifted snow in the alpine.

Avalanche problems

  • Loose Wet

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

    At mid and upper elevations 2-6 inches of recent soft snow sits on the surface. Mostly cloudy skies and cooler temperatures Friday limited the sun’s influence. That means this snow should still easily produce rollerballs and small natural avalanches on Saturday. While these slides should stay small, even little avalanches can hurt you if they involve a terrain trap like pushing you over a cliff or into a creek. Since this recent snow often rest on a thin crust, some of these small slides may run far distances. Pay attention to the terrain above you and don’t linger underneath steep slopes basking in the sunshine. 

    While we expect loose avalanche activity to stay limited to the shallow surface snow, below the thin crust, older wet weak snow may still exist. This is most likely near treeline and around steep rocky slopes. If you see new avalanches involving older snow, dial it back and stay off of and out from under all steep sunny slopes.

    (3/4/2022)

    Natural loose wet avalanches originating on steep rocky terrain. (3/4/22, SW, 4200, LW-N-R1-D1.5-S)

    Photo: Andy Harrington

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    If your travel plans are taking you into the alpine, you may encounter shallow pockets of wind drifted snow. These potential avalanches are most likely above 7500 ft on the volcanoes. On Friday an NWAC observer found shallow wind slabs in some unusual areas above Panorama Point on Mt Rainier. Similar conditions likely exist on Mt St Helens and Mt Adams. Look for wind textured surfaces to help and anticipate loaded slopes, then steer around firm pillow-like drifts in steep terrain.

    (3/4/2022)

    Wind textured snow above treeline on Mt Rainier. Small pockets of wind loaded snow were found nearby. 

    Photo: Robin Pendry

Avalanche Discussion

Clouds increased across much of the West South on Friday especially at mid and lower elevations. This prevented many slopes from undergoing significant change due to the sun. Even still moist surface snow, rollerballs, and a few small loose wet avalanches were reported. Clear skies Friday night should help wet snow start to freeze and the snowpack to strengthen. This may take more than one night, but the snowpack is on the mend. 

Areas around the West South zone picked up 2-6 inches of snow March 2-3 near and above treeline. This snow generally sits over a growing melt-freeze crust. We expect any avalanche concerns to stay near or above this layer. Below the surface, the snowpack tells the tale of this past week’s atmospheric river. Sites around the zone received 5-7.5 inches of precipitation, 4-5 inches of which fell as rain near treeline (Feb 27-Mar 1). Not surprisingly the upper snowpack is a mix of firm crusts, wet large grain snow, and pockets of small dry rounds. 

Around the landscape you don’t need to look far to see evidence of this storm. Debris piles can be seen on many slopes at mid and upper elevations. Avalanches have been reported from near Mt Rainier, Crystal Mt, White Pass, and Mt St Helens. The rain reached well into our above treeline terrain (rain line ~7500’) and formed bumpy runnels on the surface. As a result you may encounter frozen debris, open creeks, breakable crusts, uneven surfaces, icy slopes, and wet punchy snow as you travel. Give yourself extra time to manage these potentially challenging travel conditions.

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