Lawinenlagebericht

Northwest Mountains

Crested Butte Avalanche Center
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Lawinengefahr

Sun
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
2 · Mässig
Open full map
Veraltet — dieser Lagebericht ist 8 months ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Dangerous avalanche conditions exist, requiring cautious route-finding and conservative decision-making to manage a diverse list of avalanche problems. Two skiers were caught and carried in avalanches yesterday. More avalanches were both human-triggered and occurred naturally. The most serious concern is a reactive, persistent slab problem on northerly-facing slopes where large avalanches can be triggered. On other aspects, thinner storm slab avalanches remain possible, and warm temperatures today may even produce hybrid, spring-like avalanches on steep, sunny slopes. 

 

Lawinenprobleme

  • Persistent Slabs

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

    The snowpack on the north side of the compass holds a variable mix of weak snow. The primary layers of concern are facets in the bottom half of the snowpack from the mid-December drought, and near a crust between ~10,000ft and ~11,000ft that was created by a rain event on Christmas day. Many human-triggered avalanches have released on these layers over the past week (Pittsburg Rollers, Irwin, Anthracites, Schuylkill Ridge, Marble 1, Marble 2). This snowpack structure is variable due to past wind events and well-above-average temperatures. This variability can create inconsistent feedback and problem distribution.Use caution today if you travel near steep slopes on the north side of the compass, as cracking and collapsing may not provide reliable feedback before you trigger a dangerous avalanche.  You can reliably avoid the problem by choosing slopes less than 30 degrees and not connected to steeper slopes above, or head to sunnier aspects where sensitive weak layers are less common.

    The crown of a skier-triggered avalanche that occurred in the Anthracites on Friday, January 2nd.   

  • Storm Slabs

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

    The recent storm created thick slabs around the compass. These slabs will become more stubborn to human triggering today, and will most likely not provide obvious signs of instability. Consider avoiding previously wind-loaded terrain, higher-consequence steep slopes, and convex rollers where this avalanche problem is more likely to trigger. If cloud cover clears today, the unseasonably warm temperatures today may create a hybrid spring-like avalanche problem on steep southerly-facing slopes, such as a wet loose avalanche or roller balls that could trigger a wider slab avalanche. 

    Near the ridge, you can see faint crowns from storm slab avalanches that further stepped down into the deeper persistent slab avalanches on Schuylkill Ridge on Friday. 

Avalanche Discussion

1/1 to 1/2 snow water equivalent (SWE) totals: 

Irwin Tenure: 1.45" SWE. Snow was still falling when this measurement was taken.

Lake Irwin: 1.1" SWE.

Schofield: .8 SWE.

Butte: .6 SWE.

Snow density was high, with warm temperatures and thick storm snow. The NW Mountain forecast area picked up nearly twice as much snow as the SE Mountain forecast area. This is the primary driver behind the different avalanche danger ratings for the two forecast areas. Many human-triggered avalanches occurred yesterday as the recent storm created reactive avalanche conditions. More avalanche activity is expected to be documented today. 

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