Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Dangerous avalanche conditions linger at upper elevations, especially in wind loaded areas. Warming temperatures will add uncertainty and raise concern for wet avalanches and cornice fall. Avoid slopes 35 degrees and steeper with evidence of wind-drifted or wet snow.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Recent storm snow may still be reactive to human traffic on slopes greater than 35 degrees, especially in wind-loaded areas. Avalanches could be 6in to several feet thick. Pay attention as you transition into wind-affected terrain looking for textured snow surfaces and firm and hollow snow. With significant warming Monday, cornices will require extra caution. These unpredictable features could fail, acting as huge triggers on slopes below. On solar aspects, a melt-freeze crust buried Feb 25 may still be a good sliding surface for avalanches. On the aprons of steeper slopes or areas below gullies and cliffs, buried graupel was reported recently as well. With all the variability, be sure to evaluate the upper snowpack carefully and choose conservative terrain. Use visual clues to identify and avoid large wind-loaded features at upper elevations. Recent avalanches, shooting cracks, and collapses should direct you to lower angled terrain. 

    This small slab avalanche failed naturally, probably on Friday, in the West North zone. D1, 1ft failure depth, north facing. The tracks are from 2/27. Photo: Adam U

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Freezing levels are expected to rise to 5500ft by Monday afternoon. These warm conditions will create the potential for loose wet avalanches on all aspects, especially at lower elevations. Watch for changing conditions throughout the day as cold snow from recent storms starts to thaw. Rollerballs and pinwheels indicate snow surfaces are wet and weak and that loose avalanches could follow. Steer away from terrain traps like gullies or slopes above cliffs that magnify the consequences of even a small avalanche. Keep in mind that wet loose slides in motion could even trigger slab avalanches. Seek out lower angled and supported terrain to reduce your risk. 

    Example photo of pinwheels from rising freezing levels and sun a few days after a storm.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    3

    Neighboring zones continue to report very large avalanches failing up to 10ft+ deep on the mid-January persistent weak layer. They are continuing to catch everyone off guard. Chances that you will trigger an avalanche on this layer are unlikely, but not out of the question. Keep this in mind, especially when you approach the runouts of large avalanche paths, even below treeline. Continue to stay out of steep mid to upper elevation start zones as well.

    (2/24/2021) These very large avalanche debris piles crossed the Monte Cristo Trail. Be very careful if you enter large avalanche paths, even at the bottom of a slope way down in the valley.

Avalanche Discussion

Conditions vary throughout the West Central Zone, and observations are limited. Several very large avalanches occurred in the avalanche cycle at the beginning of the week (2/21-22), and others may have occurred in the last few days, possibly on the deep persistent weak layer. Make sure to do your homework and carefully investigate the snowpack. Monday will bring a significant warm-up following a prolonged period of cool and stormy weather. Give cornices a wide berth, especially during conditions like this.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

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