Lawinenlagebericht

Southeast Mountains

Crested Butte Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Sat
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
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Veraltet — dieser Lagebericht ist 4 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

You could trigger an avalanche in recently wind-drifted snow.  Isolated terrain features may hold sensitive drifts from recent west to northwest winds.  A more concerning possibility is for you to trigger a dangerous avalanche deep in the snowpack.  Terrain with highly variable snow depths or areas with a snowpack around 5 feet or less is the most suspect.  Carefully select terrain that looks uniform in depth and is less than 35 degrees without being connected to steeper terrain.  

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    2–3

    Slabs ranging from 3 to 6+ feet thick are resting over faceted weak layers in the lower snowpack around much of the compass. These weak layers have generally adjusted to their current load and become difficult to trigger. The most suspect areas to release this avalanche problem would be in recently wind-loaded terrain and from trigger points or areas where the snowpack thins to a below-average depth. Such as near rock bands, on some slopes that previously avalanched and have refilled, or where winds have formed variable snow depths. Persistent slab avalanches can propagate widely through the terrain, or be remotely triggered from low-angle slopes connected to steeper slopes. You can reduce your risk by traveling on slopes with a deep, uniform snowpack, and you can reliably avoid the problem by traveling on slope angles that are consistently less than 30 degrees and not connected to steeper terrain above.  

     

     

    1/4:  A destructive natural avalanche in Red Lady Bowl broke full-width last week.  This avalanche would be hard to survive.

Avalanche Discussion

Monday through Wednesday this week delivered an impressive storm with snow totals rangering from 2 to 4 feet.  On Wednesday, an increase in west-to-northwest winds redistributed snow to leeward terrain.  A few recent storm snow avalanches were documented around the area on drifted terrain (Ruby Peak, Northwest Mountains ob); you can look at images in the gallery below.  Carefully read snow surface textures looking for locations where the wind deposited snow recently and steer around stiffer, pillowy-looking drifts.  Recent drifts are not expected to be very sensitive to the weight of a person, but in isolated places, might be.

Weak layers near the bottom of the snowpack still require your attention and management to avoid triggering a very dangerous avalanche.  In the Northwest Mountains, weak layers are deep but some shallow terrain leaves the possibility open.  Consider avoiding terrain that is very rocky or full of cliff bands, wind-eroded slopes that have shallower snow depths than surrounding terrain, and slopes with 5 feet or less of snowpack depth.  Overall, avalanches failing on deep weak layers are trending towards 'unlikely' for snow-favored areas around Crested Butte.  Management techniques in the Southeast Mountains require a different tactic as snowpack depths are generally shallower than in the Northwest Mountains.  This observation from Reno Divide may help illustrate that areas with a shallower snowpack contain more trigger points and thus a greater chance of releasing a dangerous avalanche.  Explosive control work, at our local ski area, continues to produce avalanche activity on basal weak layers; this is clear evidence that terrain with shallower depths harbor the potential to fail near the bottom of the snowpack.  There simply is more terrain with snowpack depths near or below 5 feet in the Southeast Mountains.  Carefully select your terrain in the Southeast Mountains and consider the consequences of being wrong.  Choosing smaller slopes with clean runouts and keeping slope angles less than 35 degrees (not connected to steeper terrain) will help you reduce consequences if you are wrong.

The next week does not appear to have a major loading event and it seems like the snowpack will finally get a chance to adjust to the current load.  Each day without a loading event will result in a slow decrease in the likelihood of triggering an avalanche deep in the snowpack.  If you find yourself uncertain, then simply make more conservative terrain choices (slopes 30 degrees or less) knowing that avalanche conditions will slowly improve as time increases from the last loading event.   

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