Avalanche forecast

Mount Shasta

Mount Shasta Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

It is likely that you could trigger an avalanche today. Two feet of new snow, wind, and weak layers in the snowpack have created a myriad of avalanche problems on all aspects and elevations. Increase your safety margins today by avoiding being on or under steep slopes greater than 30°. Watch for shooting cracks, roller balls, and natural avalanche activity as red flag indicators of instability.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    Throughout the duration of the storm, winds have blown from west to southwest at velocities of 15 to 33 miles per hour. These are prime wind speeds for developing wind slabs. Your odds of finding a wind slab are highest near and above the treeline on NE, N, NW, W, SW, and S aspects. These slabs will be sensitive to the weight of a rider and may even release naturally on their own. Common catchment areas for wind-blown snow are near ridgetops, cliff bands, gullies, and on mid-slope convexities. A few popular areas you may find a wind slab today include, but are not limited to, Sun Bowl, Powder Bowl, and eastern aspects of Gray Butte and Ash Creek Butte. Your safest option is to avoid steep leeward terrain altogether.

  • Storm Slabs

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

    Recent snowfall is setting up into storm slabs on all aspects below and near the treeline. We have yet to observe crack propagation on these weak layers, but with nearly two feet of snow in the past 48 hours and a slight warming trend, the threat of triggering a storm slab avalanche is present. Folks may be caught off guard by this problem because a storm slab avalanche could occur down in the trees where folks sometimes mistakenly let their guard down considering this a "safe area". Pay attention to the angle of the slopes that you're traveling on and under. A small avalanche could bury you in a terrain trap such as a gully or a tree well.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Above freezing temperatures paired with the potential for nearly half an inch of rain will create instability in the deep new snow on all aspects below and near the treeline. All that new snow we've picked up over the past 72 hours is resting on a melt-freeze crust or weak faceted crystals in lower elevations and or northerly aspects. With this weak bed surface, the lubricating effect of rain, and the added weight to the snowpack, you could trigger a long running wet loose avalanche on steep terrain over 30°.

Avalanche Discussion

As you travel in the mountains today, keep an eye out for red flags and adjust your trip accordingly. Be vigilant in measuring the angles of slopes that you're traveling on, near, or beneath. Keeping it under 30° will decrease your chances of being caught and carried in an avalanche. Don't forget that avalanches can run in trees and downslope into low angle terrain. Use maps to boost your awareness of runout zones and increase your margin of safety by traveling one at a time through avalanche terrain.

If you' get out there, let us know what you see by submitting an observation. This is an excellent way to support your backcountry community and improve the avalanche forecast.

Storm totals thus far:Old Ski Bowl (7,617 feet): 22 inchesCastle Lake (5,860 feet): 24 inchesMt Eddy (6,660 feet): 14 inches

Regions covered