Avalanche forecast

East Slopes Central

Northwest Avalanche Center
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Avalanche danger

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

Avalanche activity should be heightened in areas of wind-drifted snow. Shifting wind directions have redistributed storm snow throughout the East Central zone, but strong winds likely dragged wind slabs to lower elevations in the Wenatchee Mountains. Steer around steep upper elevation terrain if you find cracking or firm over weak snow layering.

Avalanche problems

  • Wind Slabs

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

    Easterly winds Monday and Tuesday have transported snow onto westerly aspects. We're uncertain how much these winds affected the majority of the East Central zone. You'll have to do some detective work to identify clues. Cornices form with the prevailing wind direction, and wind slabs from Easterly winds may form on the opposite side of the ridge with sharper cornice lips. Older wind slabs formed over the weekend may be hidden below a dusting of new snow and becoming more difficult to trigger . Winds slabs likely formed above slick crusts or weak snow over the recent Valentine's Day Crust. Travellers at upper elevations near ridges should be alert for pillow-like drifts of snow on all aspects. Signs of instability include shooting cracks, recent avalanches, or collapsing. You can use your ski pole or probe to look at the depths of wind slabs, and hand pits can identify interfaces where overlying slabs slide easily. When in doubt, stick to smaller terrain features or terrain less than 35 degrees.

    Elevated danger may exist in the Wenatchee Mountains which picked up 5-6" of snow Monday-Tuesday with strong to extreme NE winds blowing the low-density snow onto atypical aspects. In these areas, the strong winds might have dragged wind slabs down into the NTL or even possibly exposed BTL locations. Likely wind drifts on S and W aspects may sit on thin snow cover or bare ground. Remember that if there's sufficient snow to ride, there's sufficient snow to slide. Remember that the risk of an avalanche of any size will be amplified by shallowly submerged terrain obstacles such as rocks.

    (12/8/2021) Long shooting cracks in freshly wind drifted snow

    Photo: Matt Primomo

Avalanche Discussion

Wednesday will be very cold with generally light winds. We are moving towards the end of February, and the sun is increasing in intensity, so you may find isolated wet loose avalanches are a possibility on very steep slopes in direct sunlight. If the snow feels wet and heavy or you start to see rollerballs, you may want to make your way to shadier or lower angle terrain. On shady slopes, cold clear nights may begin to weaken the surface snow and you may also be able to trigger small but fast-moving dry loose avalanches. Snow accumulations tapered quickly from west to east in the zone. Observers found up to 20 inches of snow in areas closer to the Crest and areas further east under 10 inches of snow was reported, with Mission Ridge only receiving around 5-6" of low-density snow. While most reports suggest the snow has bonded well to the 2/19 crust, a recent report from the western portion of the Icicle Drainage found some tendency for propagation on this interface. However, given a lack of reported avalanche activity, we think the chances of triggering an avalanche down to the 2/19 interface is very low. There is still a lot of variability in surfaces throughout this large zone. Therefore, approach new terrain slowly with a conservative mindset and make observations as you travel. Quick hand pits are a great way to investigate shallowly buried interfaces. If the new snow slides easily off the underlying surfaces, or you can get shooting cracks on small test slopes, it is probably time to move to lower angle terrain. In eastern areas of the zone, challenging travel conditions on icy surfaces remain a hazard, particularly in wind-scoured areas. Observers have reported glazed over wind board and bulletproof surfaces on high, north-facing terrain. Sharp tools like crampons and an ice axe may be necessary for travel in some areas to prevent long uncontrollable slides. 

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