Avalanche forecast

Stevens Pass

Northwest Avalanche Center
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Avalanche danger

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

On Thursday, you can trigger avalanches in the new and recent snow at all elevations. Avoid steep, wind-exposed slopes where snow drifts form at middle and upper elevations.  If you see recent avalanches or cracks in the snow shooting out from your equipment, stick to terrain less than 35 degrees.

Avalanche problems

  • Storm Slabs

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

    You could trigger a variety of avalanches in the new and recent snow. The most dangerous terrain will be steep, leeward sides of ridges where the wind will form fresh slabs. You should be able to see actively blowing snow or very recent drifts that point out these slopes. Avalanches could be big enough to bury or kill you on these upper and middle elevation slopes.

    You could trigger avalanches in steep, sheltered terrain, as well. They could be shallow only in the new snow, or they could be 1.5 feet deep, entraining all of the snow that fell this week. Snowfall could add up quickly and could be heavy at times. Use small test slopes to see how the snow behaves before traveling on larger slopes over 35 degrees. Watch for triggering wet avalanches on sun-exposed E-S-W aspects, even if the sun isn't shining.

Avalanche Discussion

The Stevens Pass zone could see another 8-10 inches of snow with gusty westerly wind forming fresh wind slabs. 

On high elevation, northerly aspects, there's a chance that you could find buried surface hoar, 1.5 feet below the surface. On the 10th, observers in the Foss River drainage reported triggering very reactive avalanches on isolated leeward slopes, which are suspiciously indicative of surface hoar. Observers in the West North zone reported similar avalanches on the 10th.

On most slopes below the recent snow, you'll find crusts and melt forms. The upper snowpack is mostly frozen, but at low elevation and on east through south through west aspects, you may still find moist, unfrozen layers.  On Monday, a profile at 5,050ft, E near Lake Valhalla revealed weak, unfrozen moist snow 1.5ft (45cm) below the surface, under frozen crusts.

The snowpack underwent a significant transition during the atmospheric river storm of February 21-25th. Significant liquid water entered the snowpack before switching to snow that totaled near 2 ft. Large slab and wet avalanches were reported throughout the zone. Prolonged warming in early March further transitioned the snow that accumulated. Most slopes have multiple stout crusts and/or moist snow in the upper snowpack.

If you make it into the backcountry, please share with us what you find by submitting an observation HERE or on the Avy app. 

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