Avalanche forecast

East Cabinet Mountains

Idaho Panhandle Avalanche Center
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Avalanche danger

Sat
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Out of date — this forecast expired 4 years ago.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

The snowpack is currently variable across the Kootenai zone. In the East and West Cabinets on north aspects the snowpack is 180-190 cm deep with a buried surface hoar layer 18-24 inches deep.  The persistent weak layer that formed near the base of the snowpack in early November is beginning to heal and gain strength, but it could still be triggered in a stepdown avalanche or in areas where the snowpack is shallow.  The snowpack in the Purcell’s is much thinner and continues to be reactive in stability tests. 

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    The persistent slab at the base of the snowpack is becoming less reactive where the snowpack is deep, but it is still reactive and alive in the Purcells and shallow areas of the snowpack.  The layer of buried surface hoar was stubborn in the Cabinets on Wednesday and Thursday. Observations in the Purcells earlier in the week revealed this layer to be more prone to triggering avalanches. Steep and sheltered openings near treeline will be the locations where you are most likely to find this surface hoar and trigger an avalanche.

  • Wind Slabs

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

    Windslab may be present on leeward slopes.  The windslabs we observed this week were not reactive to ski cuts, but is worth being aware of and should be assessed prior to venturing onto steep, exposed terrain.

Avalanche Discussion

Getting stuck on the snowmobiles was less of an issue this week in the Cabinets, which means the snowpack is starting to settle and gain strength. Good for riding and good for avalanche conditions!  The snowpack is generally healing and will continue to gain strength where it is deep.  In areas where the snowpack is shallow, facets will continue to develop around the November rain crust. Forecasted cold temperatures and minimal snow accumulation in the coming days will likely preserve any persistent weakness, ie.  surface hoar and facets, where they are present.  Windslabs may continue to form in leeward locations and some vigilance may be needed to manage this problem.   

The layer of buried surface hoar is the most likely layer in our current snowpack to fail, which if triggered could cause a step-down avalanche to the deep persistent weak layer.  If this scenario occurs it would be a large avalanche with a potentially catastrophic outcome.  See the photo below of a natural avalanche that occurred earlier this week in the Selkirks.

There is great riding in sheltered terrain and given the variability across the zone, I would personally take a conservative approach to stepping out into exposed terrain where there is a possibility of waking up our "persistent" buried weaknesses. Triggering an avalanche could have detrimental consequences.   Stay safe by taking the time to dig into the snow and look for weak layers at your location.

There is still slots available in IPAC's motorized avalanche Level 1 classes. Follow the link below to learn more!

https://www.idahopanhandleavalanche.org/friends-ipac-avalanche-safety-courses

 

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