Lawinenlagebericht

Selkirk Mountains

Idaho Panhandle Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Sat
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
Open full map
Veraltet — dieser Lagebericht ist 5 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

We got a freshener of a few inches of snow yesterday.  You'll find the deepest accumulations of snow on leeward easterly and northerly aspects.  This is due to the stiff westerly wind that was blowing at ridgetops.   Up at Roman Nose lakes we found 6 inches of new snow over the thick crust on a north aspect.  Developing weakness in a change in density in the 6 inches of new was a concern where it would be deeply windloaded at ridgetops, which we did not get to because it was not where you would want to be yesterday.  Today, you might be thinking of the fat snow in those windloaded areas but use caution.  Winds continued last night and more windloaded snow on that new snow weak layer could be touchy.  You'll find more stable conditions off the ridgelines but watch for drifted snow and crossloaded areas on any aspect.  The snow is good in sheltered terrain so you will find good riding and sliding out there.

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    Ryan and I saw wind loading in many areas up around Roman Nose lakes yesterday.  Down below the ridgetops we were not seeing enough slabbing of the snow to propagate an avalanche but we assumed that just below ridges on leeward slopes the snow was loading fast enough that you could trigger a pocket of windslab.  This would be most likely on a north and east aspect.  West and south aspects were getting hit hard by the wind and scoured down to the thick ice crust.  However, in the trees the snow was accumulating enough for some good sliding.  So, watch out for windslabs near ridges and realize that avalanches will be sliding fast over that hard ice crust.

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Unlikely
    Größe
    1–2

    The other layers we revealed in our pit tests do not fit neatly into the avalanche problem categories, so I'm calling it a persistent slab.  One failed with moderate force applied below the thick ice crust but in many places the ice crust is thick and will prevent propagation on this weak layer of facets.  Deeper in the pack we also found a couple weak layers that present the same situation, hard to trigger under the crust.  Why mention them?  If you find areas where the ice crust is thinner, possibly higher elevation, be aware that you may be able to trigger these layers.  I'm thinking high elevation convex terrain trending north.  The same place you'll find the goods for sure but consider this, you trigger a small windslab just below the ridge and that steps down to this deeper weak layer as you slide down the north face of a 6,800 foot peak.  You'll see the weak layer in the attached picture of our pit on a SE at 6,500 feet.  We did have reports of buried surface hoar about 8 inches deep and some instability clues from that, settlement and moderate results in pit tests.  Thanks Selkirk Powder Company for the obs.  We did not find it our hunting, and we looked hard, but that means the onus is on you to make sure.

Avalanche Discussion

A slight cooling trend will influence a gradual stabilizing effect on our pack but winds will maintain pockets of instability.  Today the weakness in the recent snowfall has not stabilized but you should be able to safely avoid avalanche terrain and enjoy good snow conditions on lower angle slopes and sheltered forested slopes.  We are calling the danger Moderate today and that means there are more safe areas than not but we are emphasizing those windloaded areas near ridgetops as possible areas to trigger an avalanche.  Check out the SE slope we skied yesterday.  Fun stuff and we saw two sledders that had a good tour of the lakes too.  Lots of good safe sliding and riding to be had out there.  Everywhere in our forecast region is above 100% for Snow Water Equivalent!  On our SE pit we were right at 10 feet of snow.  Keep it coming.

Abgedeckte Regionen