Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Uncohesive new snow could make for a variety of avalanche problems on Sunday depending on weather conditions in your local area. Both loose snow and slab avalanches could be encountered. Pay attention to changing weather and snow conditions throughout the day and anticipate a higher level of danger if snowfall, wind, or solar radiation are greater than anticipated. Look for deeper new snow and therefore higher danger in the southern portion of West Central due to convergence zone enhanced snowfall. 

Avalanche problems

  • Loose Dry

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

    Uncohesive new snow could create small avalanches whether you are finding cold or warm conditions. Saturday the new snow sluffed easily in terrain steeper than 35 degrees and numerous natural loose avalanches were noted after heavy snowfall. Though they were all quite small they could still take you for a bit of a ride and dump you into a tree or some other terrain trap. New snow could also be reactive as it warms and becomes wet on sun exposed slopes. Move off and away from terrain where you see rollerballs or small wet loose avalanches during sunbreaks or with rising temperatures. Wet avalanches pack much more of a punch than their dry loose cousins and you just don't want to be in the way no matter how small they look.

     

    (4/9/2022)

    Small sluffs occurred during high rates of snowfall Saturday morning.

     

  • Wind Slabs

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

    Stubborn wind slabs were found in most wind loaded slopes and could still be an issue Sunday in steep, unsupported features. The other concern is abundant loose snow will easily drift and make new wind slabs, especially in alpine areas that see higher winds. Track the change in snow depth as you move in and out of wind loaded terrain with the handle of a ski pole, avalanche probe or simply digging down with your hand. A crust is present below the new snow and you can use this marker to determine the new snow depth. Where the snow is deeper above the crust there is a greater chance there is wind slab as well. Hand pits and test slopes can also help you gauge the bond of harder wind slab layers over weaker snow below. Slabs could also become more reactive with warming if a harder slab forms over colder and weaker snow below

    (3/9/2022)

    Small skier triggered wind slab on the White Salmon Glacier in March.  

    Photo: Zach Bunch

Avalanche Discussion

Saturday brought an unexpected 4-8” of light, dry new snow to West Central with minimal wind and cooler temperatures through most of the day.  Greater than forecast snowfall was the story up and down the westside of the Cascades Saturday. Periods of heavy snowfall mixed with clearing to make for rapidly changing conditions in Snoqualmie Pass while Stevens Pass suffered strong west winds longer than other areas. A brief warm up was reported in the late afternoon in multiple zones that may have put a thin crust on solar aspects. Reported avalanches Saturday largely consisted of small natural and human triggered dry loose avalanches with only a few small slab avalanches. In West North the new snow was observed to be well bonded to the crust layer below and generally right side up in wind sheltered terrain.  Wind redistribution Friday night made for some very deep drifts - over 100cm at one site at 5500' - but these were found to be unreactive to ski cuts, etc. 

Regions covered