Lawinenlagebericht

Southeast Mountains

Crested Butte Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Tue
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
Open full map
Veraltet — dieser Lagebericht ist last year abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

You will find a generally stable snowpack below treeline and on southerly aspects this morning, and the danger on these slopes will rise to Moderate as shallow wet avalanche problems develop.  See recent examples here.  On colder aspects at higher elevations, the threat of triggering a dry slab lingers where last week's snow accumulated above a faceted crust, or on deeper weak layers in unusually shallow, rocky terrain. This skier-triggered avalanche on Mt. Emmons illustrates the problem.  Carefully evaluate snowpack structure before riding in larger or more consequential terrain.  

Lawinenprobleme

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–1.5

    Manage for shallow wet avalanches once the upper few inches of snow get wet.  Today's wet loose avalanches should entrain just the recent snow, and most are relatively small in size.  Long, steep terrain could grow larger or a few slopes could propagate wider as thin wet slabs.  Rollerballs, pinwheels, and ankle-deep wet snow indicate decreasing stability.  Move to less consequential terrain as the problem develops.  You can avoid wet avalanches by traveling early while snow surfaces are frozen or moving to colder aspects as the day warms up.   

    These recent wet loose avalanches exemplify the average size you can expect to encounter later today. 

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2.5

    New and windblown snow last week formed soft slabs about a foot thick, especially on terrain features favored by westerly winds.  These slabs have bonded well in most terrain, with some potential exceptions where they formed over a faceted crust.  This buried weak layer is variable across the landscape.  Carefully assess slab size and terrain consequences before riding in steep terrain. Expect spatial variability in how slabs bond; use small steep slopes to gather stability feedback.  Problematic slabs are rare below treeline and have improved on sunnier aspects from ongoing warming.     

    There's a rare chance you can still trigger a deep persistent slab on high, northerly aspects where the snowpack remains winter-like. Terrain where the snowpack is unusually shallow due to wind effects or previous avalanche activity is most concerning.  Choose deeper, more uniform snowpacks over thin, rocky areas to reduce your risk.   

    On Saturday, this soft slab avalanche was triggered in Climax Chutes on Mount Emmons.  The avalanche failed on a thin layer of facets above a stout crust.  

Avalanche Discussion

We made it through the weekend with only one skier-triggered persistent slab reported in the Elk Mountains (a D2 in Climax Chutes). Of course, more people were testing the waters at the Slush Huck than on suspect slopes, so take that with a grain of salt. We also observed improving stability tests yesterday on a hit-or-miss problem that is difficult for our forecasters to zero in on.  This newest generation of persistent slabs is narrowing in distribution as warm, sunny weather cooks more slopes, and it will likely phase off the list by later this week.  There's a chance that these same structures could produce thin wet slabs as meltwater pools on the faceted crust buried below last week's snow.  By managing for developing wet loose instabilities, you can avoid any surprise wet slabs too. 

The gradual warmup has been docile on our snowpack so far, and that pattern is expected to continue for the next few days.  It's a great opportunity to tick off some corn-skiing objectives.  We are getting good refreezes at night to delay the onset of wet avalanches until later in the day. Wet avalanche concerns remain limited to the recent snow, which is often small and manageable.  More new snow is available for entrainment in the Northwest Mountains, so some avalanches there could grow larger (like this long running wet loose yesterday near Marble).   Wet avalanches will likely become more common and expand to more aspects as temperatures rise higher today.   Later this week, we will see weaker refreezes and water moving deeper into the snowpack.  

The snowpack remains dry and winterlike on high northerlies. This requires consideration for weak layers near the ground that have plagued us this winter, especially on terrain with unusually shallow snow depths.  It's been a couple of weeks since we've observed an avalanche breaking on deep, weak layers (ex. Axtell).  A lack of major loading events and warmer temperatures in recent weeks are working in our favor.  The isolated and high-consequence threat remains.  For example, last week a skier in the San Juans was surprised when they triggered a shallow wind slab that stepped down and produced a very large avalanche. 

Events: CBAC's Party for the People is at the Talk of the Town next Thursday.  Come celebrate the end of the season with us!  (Don't worry, we'll be forecasting for at least a few more weeks.)

Abgedeckte Regionen