Avalanche forecast

Mount Shasta

Mount Shasta Avalanche Center
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Avalanche danger

Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Avalanche activity is likely, near and above treeline, due to 15 inches of new snow and sustained moderate-strong wind speeds. Look for wind slab instability on W-NW-N-NE-E-SE aspects, where natural or human-triggered avalanches could fail multiple feet deep, and large enough to bury/kill. New snow avalanches are possible, below and near treeline, anywhere significant snowfall has collected. Today, careful snowpack assessment and conservative decision-making will be critical for avoiding these problems.

Avalanche problems

  • Wind Slabs

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

    Wind slab avalanches are likely on W-NW-N-NE-E-SE aspects near and above treeline. With ~15 inches of new snow, and yesterdays observed moderate-intense wind loading, these slabs could be deep and dangerous across the forecast area. In the last 24 hours, SW wind has blown at moderate to strong speeds across all elevations, with extreme speeds above treeline. Expect to find wind loaded snow on leeward aspects below ridges, near rock outcrops, and even mid-slope. Careful assessment of potentially wind loaded slopes will be crucial before committing to terrain. If these slabs fail, they could break multiple feet deep, likely large enough to bury/kill. Look for cracking under foot, hollow sounding surface snow, failing test slopes, and unusually deep snow conditions as signs of wind loading in an area. These slab avalanches have a tendency to break uphill of a skier/snowmobiler, making them particularly difficult to escape or avoid when triggered. If in doubt, avoid steep, wind loaded slopes greater than 30 degrees.

    (1/4/2025)

    Intentional skier triggered wind slab avalanche in Sun Bowl

    Photo: Mount Shasta Avalanche Center

  • Storm Slabs

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

    The forecast area has gained ~15 inches of new snow, and with that often comes storm slab instability. Storm slab avalanches are possible on all aspects below and near treeline. Yesterday's observations at Gray Butte showed specific cracking on interfaces within the new snow, but no significant avalanche activity. This morning, larger scale cracking and collapsing could exist, with the possibility of avalanches large enough to bury a person.  As the day goes on, and snowfall slows, this problem will become less sensitive and less likely. Storm slab avalanches can occur anywhere new snow has fallen, with particular emphasis in wind sheltered areas on steep slopes (greater than 30 degrees). Look for cracking/collapsing under foot, and failing test slopes as signs of broader instability across an area. The best way to avoid this issue is waiting a day for these steep slopes to stabilize. 

    (3/27/2025)

    New snow accumulation at 7,800 feet

    Photo: Samuel Clairmont

Avalanche Discussion

Here are the snow totals for the last 24 hours:Old Ski Bowl (7,600 feet): 15 inchesMount Eddy (6,500 feet): 3.6 inchesCastle Lake (5,800 feet): 4.3 inchesMiddle Boulder (6,200 feet): 3.1 inches

This system has maintained a ~5,000 snow/rain line, with the significant snow accumulation above 6,000 feet. In other words, fresh snowfall is very elevation dependent. Snowfall will taper off quickly today, with cloud cover expected to remain. 

Yesterday, forecasters went to the Gray Butte area to assess the new snow and elevated wind. Read about it HERE. 

If you're headed into the backcountry, please consider sending us an observation. Your photos and field information are very useful in improving the resolution of the daily avalanche forecast. You can submit it HERE. 

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