Lawinenlagebericht

Northwest Mountains

Crested Butte Avalanche Center
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Lawinengefahr

Sun
Hochgebirge
4 · Gross
Waldgrenze
4 · Gross
Unterhalb
4 · Gross
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Kernpunkte

An Avalanche Warning is in effect. Multiple feet of new snow is overloading our unusually shallow and weak snowpack.  Large and dangerous avalanches are easy to trigger and will run naturally today. Travel in avalanche terrain is not recommended. Powder days have been rare this winter, and this weekend will be a test of our mental strength to keep our decisions in line with the current conditions. This avalanche terrain map can help you plan routes in simple, low-angle terrain without overhead hazards. 

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Very Likely
    Größe
    2–3

    Exceptionally weak facets and collapsible crusts are widespread on the northern half of the compass and on some sunnier aspects at higher elevations below this week's snow.  As these weak layers reach their breaking point, expect insta-weird behavior such as avalanches connecting across multiple terrain features, remote triggers, step downs or gougers into old layers near the ground, and variable feedback.  These issues are less common on most southerly aspects, and can be avoided on slope angles consistently less than about 30 degrees and not connected to steeper terrain above.   

    This avalanche released on Thursday near Marble, and occurred before avalanche conditions became elevated. This avalanche is a good example of the widely propagating behavior we expect to see this weekend as slabs thicken over buried weak layers.  

  • Storm Slabs

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

    Numerous storm slab avalanches were human-triggered or ran naturally on Friday during periods of heavy snowfall rates. Human-triggered storm slabs, 1 to 3 feet deep, remain a concern today. Natural avalanche activity will continue during periods of high snowfall rates or in areas that are receiving additional wind loading. This avalanche type will be most reactive on slope angles above 35 degrees, while they can reliably be avoided on slope angles consistently less than 30 degrees. 

    This storm slab was remotely triggered in Red Lady Bowl on Friday. 

Avalanche Discussion

You don't need us to tell you that a lot of snow has accumulated since Thursday night. That was impressive. Given the prolonged period of accumulating snow, those total snowfall numbers are affected by ongoing settlement. We can simply say that multiple feet of snow has accumulated. Total Snowpack depths increased between 20 and 30 inches. The better measurement of accumulated snow is in the water weight. Areas like Irwin and Schofield Pass have accumulated between 2.6" to 2.8" inches of snow water equivalent (SWE).  The Butte Snowtel on Mt. Crested Butte has recorded 2.1" SWE. The Upper Taylor Snotel recorded 1.8" SWE. 

We are entrenched after yesterday's intense snowstorm with no visibility and few backcountry observations. Natural avalanche activity certainly occurred, and we expect some fairly impressive results. The avalanche activity that was observed primarily consisted of natural storm slab avalanches that ran Friday morning during periods of high precipitation rates and some human-triggered avalanche activity, like this observation from Red Lady Glades and Irwin. Storm slabs will become less reactive today after a break in the loading last night. However, that avalanche problem will take much longer to heal, and additional snow today will delay that process. Persistent slab avalanche activity will be with us for some time to come, and unfortunately, we will likely be plagued with another prolonged period of avalanche activity. 

Natural avalanche activity will continue today during periods of additional snow accumulation or, more notably, as the wind increases later this afternoon and into tonight. We don't have a big wind event in store, but we will see transportable wind speeds with a lot of snow available for transport. 

Upcoming Event - Open the storm floodgates with the Floodgate Operators at the Public House on Saturday, February 15. Tickets are available here.  Proceeds from the show to benefit the CBAC.

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