Avalanche forecast

East Cabinet Mountains

Idaho Panhandle Avalanche Center
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Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Snow conditions and depth vary widely across the Kootenai right now, but buried weak layers in the upper snowpack will remain under our current weather pattern.  Upper elevation, north and east aspects, that are sheltered from the sun and wind are the most likely locations to find these layers remaining  intact.  Seek out lower angle terrain where the snow has been preserved for the safest riding.  South and west aspects are less likely to harbor these problems but their presence can not be ruled out.  Strong winds have redistributed snow on all aspects at upper elevations.

Avalanche problems

  • Persistent Slabs

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

    The persistent slab problem may be stubborn to trigger, yet it remains a concern and is not likely to go away in the short term.  Crusts, facets, and surface hoar exist within the upper two feet of the snowpack.  In the right location (thin snow, rocky outcrops, convex rolls) these weak layers will remain possible to human triggering.  They will most likely be a problem in sheltered north and east aspects at middle and upper elevations that have not been exposed to the sun and wind.  Facets are forming around the  "Lucky Friday" crust formed January 13th, but generally, with the exeption of wind depostion, the snow resting on this crust has not consolidated into a cohesive slab.  Variability across the forecast area makes this problem difficult to forecast and site specific information will give you a better idea of the snow structure your riding on.  Take time to dig in the snow and test smaller less consequential slopes before committing to larger objectives.

  • Wind Slabs

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

    Strong winds from multiple directions have redistibuted snow on all aspects and are forming reactive wind slabs in unusual locations.   Pillowy, chalky, hollow, and stiff snow are clear signs of wind slab formation.  Manage this problem by sticking to high points such as ridgelines, and timbered or scoured slopes to avoid them.  Consequences of triggering a windslab avalanche are higher above terrain traps like cliffs and trees. If initiated these wind slabs may have potential to trigger the buried weak layers deeper in the snowpack.  Use good terrain management and riding practices to reduce the exposure to this problem.

    Shooting Crack on a planar slope near ridgeline.

Avalanche Discussion

Mountain weather!  Yesterday we traveled to the East Cabinets where winds were gusting in excess of 25 mph throughout the day.  Blowing snow and shifting winds were constant and even timbered slopes were actively cross loading depressions and gullys during the climb up.  Winds started the day blowing out of the south and by midday were shifting from south to west to north, depositing snow on the firm "Lucky Friday Crust"  and on to most aspects.  North and east aspects had about 20 cm of light unconsolidated snow at 6000' and were actively loading more.  Near ridgelines and in gullys wind effected snow was beginning to exhibit slab characteristics above 6000'.  Evidence of previous windslab avalanches were present in steep terrain at 7000' on a NE aspect.  Given the amount, speed, and shifting nature of the wind on Monday expect windslabs to be present on all aspects above treeline and pay attention to micro terrain where cross loaded slabs may form at treeline in unusual places.

Stability tests resulted in moderate to hard force failures above the "Lucky Friday Crust" on the new snow/crust interface, and below the crust where facets are developing.  Neither of these layers propagated across an extended column and snow above the crust is not yet cohesive enough to form a slab in sheltered terrain.  At this location we could not find evidence of buried surface hoar but we know it's preserved in areas throughout the region. 

Due to the spatial variation of the forecast area and uncertainty of distribution, we are keeping persistent slab on the list of problems.  Slope specific analysis is warranted in consequential terrain.  Riding one at a time, identifying safe areas, and keeping an eye on your partners is always a good practice.

If you're reading the avalanche forecast and getting out in the backcountry please visit the observations tab and take a minute to let us know what you're see out there.  

Lastly, big thanks to all who attended the Avalanche Partner Rescue Training  hosted by the Cabinet Ridge Riders.

 

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