Avalanche forecast

Stevens Pass

Northwest Avalanche Center
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Avalanche danger

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

Wednesday should be a fairly calm day before the storm, with increasing winds that drift snow around in the afternoon. Fresh, shallow slabs could form later in the day, but older, stubborn wind slabs could still be triggered on upper elevation slopes. Steer around steep, consequential slopes if you find instabilities or stiff slabs over weaker snow.

Avalanche problems

  • Wind Slabs

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

    Older wind slabs are becoming more stubborn, but you may be still be able to trigger shallow slabs on steep, exposed terrain. Winds have been shifting from southeast to southwest over the past number of days, so you could find slabs on a variety of aspects. Instabilities could linger with older wind slabs, and shallow ones may form towards the end of the day.  Most likely, slabs would be shallow, and you can avoid them by steering around pillows and drifts on slopes steeper than 30 degrees.

    Outside of wind affected areas, there is some potential for buried persistent weak layers (see the persistent slab problem in the neighboring East Central zone.) Look for long shooting cracks to clue you into this instability.

    Example of heavy wind transport.

Avalanche Discussion

Expect a fairly calm day before the storm on Thursday. Southeasterly winds should pick up and become strong enough to move snow later in the day. Expect rapidly increasing danger Wednesday night into Thursday as a major storm arrives. The storm comes with a rapid warmup, and snowfall is likely to change over to rain at some point during the middle of the day on Thursday.

The pass picked up another 3" of new snow by Tuesday morning, and travel conditions had improved markedly.  Bouts of easterly winds from the Southeast have been strong enough to move snow in exposed areas over the past few days. Althought temperatures have been fairly warm, winds were plenty strong enough to drift the  snow. In total, you can expect to find around 6-10" of newer snow since January 4th, resting on old surfaces. Just to the east, the recent storms have amounted to higher snow totals near Leavenworth and Wenatchee. Many widely propagating ski triggered avalanches have occurred, with a layer of buried surface hoar being the culprit. This layer could be problematic in the eastern edge of the Stevens Pass zone.

Regions covered