Avalanche forecast

Stevens Pass

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Steady winds will continue to blow new snow into wind-drifted slabs at middle and upper elevations. You can avoid this problem by looking for sharp drifts, fresh cornices, or pillow-like slabs on the snow surface. Steer around steep wind-drifted slopes if you notice signs of instability, like shooting cracks under your feet or sled. 

Avalanche problems

  • Wind Slabs

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

    Observers found these wind-drifted slabs to reactive and failing 10-12 inches deep on Wednesday.  On Thursday, moderate east winds will change more southerly and continue to drift snow into cohesive slabs on leeward features.  You’ll typically find these wind slabs just below ridgelines, cornices, and under rock/cliff bands. However, recent east winds may have drifted snow into unusual locations, such as west aspects or across terrain features (cross-loading). So, actively look for these slabs as you change aspects. 

    You can use visual clues to help you identify the hazard. Look for wind-textured snow like dunes and ripples at the snow surface to help you spot where the wind has been at work.  These slabs could break in surprising ways if they overlay surface hoar, facets, or recently buried crusts. You can also use small test slopes and hand pits to evaluate how reactive the slab is. Consider steering around steep wind-loaded slopes if you notice active drifting or signs of instability like shooting cracks or hollow-sounding snow. 

    Use small test slopes and look for signs of instability like this before committing to steeper slopes.

    Photo: Joe Dellaporta

Avalanche Discussion

Thursday will bring increasing freezing levels and light mixed precipitation below 5000 ft. Above this, precipitation should stay dry, and you may find 1-3 inches of new snow by the end of the morning. As temperatures rise, watch for rollerballs and small wet loose avalanches. These likely won’t grow too big or widespread, but consider steering around larger slopes if you notice these signs. 

Stevens Pass picked up about 10" of new snow since the 21st, and about half of that fell on Christmas night. On Tuesday morning, Snow safety at Stevens Pass Mountain Resort reported fairly widely propagating slabs just 2-6" deep with control work, and some dry loose sluffing. Conditions settled out fairly quickly during the day, and became less reactive later. Other observers found minimal instabilities, but the sun had warmed steeper south facing slopes and sent pinwheels into action. Travel conditions and coverage have improved substantially, but its still thin. Beware of hitting exposed rocks, stumps, and creeks.

On most slopes, the most recent crust was buried on December 22nd. On steeper due south slopes and some open terrain, the crust is a stout combination of rain and sun events from the past couple weeks. Elsewhere, the upper snowpack is a series of thin, brittle crusts and weak, faceted layers below the 12/22 interface.

Stevens Pass Ski Area is open. Check uphill policies HERE. You can contribute to the forecast! Let us know what you found by submitting an observation HERE. 

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