Avalanche forecast

Selkirk Mountains

Idaho Panhandle Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 4 years ago.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

Highlights

It's becoming less likely that you'll trigger an avalanche on the weak, buried, persistant weak layer (PWL), but if you do, it could result in a large avalanche. The most likely place to trigger an avalanche is on north facing slopes near treeline. Listen and look for signs of instability such as cracking in the snow, whoomphing sounds or signs of previous avalanches.

Avalanche problems

  • Persistent Slabs

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

    We’ve been tracking a persistent weak layer problem in the snowpack for the past couple of weeks. Although the layer of concern continues to get buried with each passing storm, it remains the biggest problem in the snowpack. The good news is that the deeper the layer gets, the less likely we are to trigger it. The bad news is that if it does get triggered, it has the capability to produce a large avalanche. As the snowpack settles and stiffens, the likelihood of a remote trigger increases. Currently, the most likely place we’ve found to trigger the weak layer is near shallow spots in the snowpack such as, rocks, stumps or brushy areas.

     

Avalanche Discussion

The snowpack is slowly healing, but it's a double-edge sword scenario. The big snow that we received last week is bonding well to the snow below it. I haven’t seen instability associated with that layer except some natural avalanche activity on north facing ridges in the mid-slope area. All of the avalanches we observed yesterday were on sub-ridges, well below the main ridgelines, on north facing slopes. The blast of NE winds last week created wind slabs on those types of slopes. Place a critical eye on your route finding because the slopes that are sliding are the slopes that you may have thought of as a ‘safe line’ under different circumstances. We didn’t see avalanches in the bigger areas near ridges, just pockets mid-slope. It'll be less likely to trigger an avalanche today (Saturday), but if you do, it'll be a bigger, firmer slab. The most likely place to find the trigger point is near shallow parts of the snowpack or digging your snowmobile track in deep in the wrong spot.  Don't go high marking on slopes with lots of snow above you. That would be a great way to find the weakness today. 

Get ready for cold! Models aren't all in agreement, but NOAA is forecasting air temperatures to continue getting colder. A high of 2 degrees is expected in the Cabinets by Monday. The snowpack generally changes at a slower rate during cold spells. I’d expect to see the slab of snow become firmer and more supportable as the cold spell runs it course. Don’t let a firmer, more supportable snowpack lure you into thinking the snowpack is getting stronger. I’m a little worried about building false sense of security during the next 10 days. Just because you ‘get away’ with something doesn’t mean it was a good decision. The snowpack has entered a ‘low frequency, high consequence’ time. You may travel a slope and get away with it…or you may find the weak spot to trigger an avalanche. I’ll feel better about the weak layer when it gets buried a little more. At this point, the thing that will give me a little trust in the PWL is more snow to isolate it at the bottom of the snowpack to a point that snowmobiles and skiers can’t trigger it. Right now, the layer is still able to be triggered in most places. Maintain a good margin of error and be heads up about route finding and you’ll have a great day in the mountains!  

Regions covered