Avalanche forecast

Mount Shasta

Mount Shasta Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

Multiple days of heavy snowfall and strong winds have created dangerous avalanche conditions. Storm slabs, wind slabs, and buried weak layers exist. Natural avalanches are possible, and human triggered avalanches are likely on all aspects and elevations. Keep a tight rein on your terrain management and decision-making. Avoid being on, near, or below slopes steeper than 30 degrees.   

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    Weak faceted snow that formed during January has been overloaded by several feet of snow and rain. This layer has been identified on northwest, north, and northeast aspects near and below treeline. Burial depths range from a few feet, to several feet, especially in wind-loaded locations. This weak layer will undergo further stress today, from additional snow and wind loading. As this layer gets buried deeper and deeper, triggering will become less likely. However, the consequences will not. Shallow spots, or wind-loaded areas, could still be enough to trigger it. Recent stability tests continue to yield unstable results, and cracking/collapsing have remained prevalent. These are mother natures ways of telling us the snowpack is unsafe. Not trusting slopes steeper than 30 degrees is your best defense, until the snowpack has time to settle, or proven otherwise.    

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    1–3

    It's been snowing and blowing for nearly five days, which means large wind slabs have developed. Your odds of finding a wind slab are highest near and above treeline on NE, N, NW, W, SW, and S aspects. These slabs will be likely to release naturally on their own and very likely with the weight of a rider. Common catchment areas for wind-blown snow are near ridgetops, below cliff bands, on the side walls of gullies, and on mid-slope convexities. Fresh wind lips and actively blowing snow should divert you from leeward wind loaded areas. 

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–3

    Slabs of surface snow ranging from several inches to multiple feet, exist on all aspects near and below treeline. Interfaces within the new snow have resulted in propagation. Today's storm will further the development and reactivity of slabs. This widespread problem exists in the trees, where you might mistakenly let your guard down and consider a “safe area”. Be aware of you, and your partners' exposure to avalanche terrain, and exercise caution around slopes steeper than 30 degrees. To assess potential size, monitor storm totals and expect deeper accumulations at higher elevations and in leeward terrain. Look for feedback, such as recent avalanches, or shooting cracks on small, inconsequential test slopes. Even a small avalanche could bury you in a terrain trap such as a gully or a tree well.     

Avalanche Discussion

Five days of stormy weather, with a myriad of avalanche problems and rapid change on the snowpack, has made the backcountry a dangerous place. Pay attention to the red flags of avalanche danger, and move cautiously and conservatively through terrain. Even if you aren't traveling on a slope steeper than 30 degrees, Mount Shasta is a 14,000-foot volcano with several historic avalanche paths - DON'T FORGET WHAT'S ABOVE YOU!    

Uncertainty exists in the forecast regarding above treeline conditions, and how much load this buried weak layer can support. Read an observation regarding its depth and reactivity in the Eddy Mountains HERE.

If you observe any avalanche activity or noteworthy findings, please drop us an observation at shastaavalanche.org.

Everitt Memorial Highway is CLOSED as of this morning. County road crews are actively working on plowing. TBD on opening, hopefully by this afternoon.

Regions covered