Avalanche forecast

Mount Shasta

Mount Shasta Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

Dangerous avalanche conditions exist on all aspects and all elevations, due to a combination of wind and storm slab potential. An already sensitive snowpack will become increasingly loaded as a new round of precipitation hammers the forecast area. Natural avalanches are possible, and human-triggered avalanches are likely. Today, conservative decision-making and careful snowpack evaluation are a must.

Avalanche problems

  • Wind Slabs

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

    Yesterday's weather system brought the perfect ingredients for wind slab development: moderate/strong southeast wind and 9 inches of new snow. Signs of instability were obvious, with reported avalanches happening early in the systems' arrival. A pro observer triggered a small wind slab on a northwest aspect below treeline. Around the same time, forecasters remote triggered a cornice collapse on a northwest aspect near treeline in the Eddy Mountains. Expect these wind slabs to be easily found, and reactive to trigger by ski or foot traffic. Wind slabs will mostly reside on leeward aspects (SW-W-NW-N) with cross loading possible on S and NE aspects. These slopes could fail up to 20 inches deep and entrain enough to bury or kill you. 

    In addition to the current accumulated snowfall, more is expected to fall today and intensify tonight. On the high end, this could be 20 new inches of snow by tomorrow morning. This will surely complicate the wind slab problem by adding additional loading to already reactive slopes. As the day progresses, expect the wind slab problem to become larger, and increase in sensitivity.

    It is crucial today to maintain safe travel techniques. As you get into the backcountry, carefully assess leeward slopes for wind loading, and make conservative route decisions. Use test slopes before committing to avalanche terrain. If in doubt, stay off of and out from underneath slopes greater than 30 degrees.

    (2/14/2024)

    Public submission of skier triggered wind slab avalanche on west aspect near Castle Lake

    Photo: Mount Shasta Avalanche Center

  • Storm Slabs

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

    Today, storm slab avalanches should be on your radar for any slope greater than 30 degrees below and near treeline. This avalanche problem is the release of a soft, cohesive layer of new snow that breaks within the storm snow or at the interface between new and old snow. With 9+ inches of snow in the last 24 hours, storm slabs are likely to exist. On top of that, around 15–20 inches of new snow is expected to fall today through tomorrow morning. This is more than enough snow to produce a widespread storm slab problem on all avalanche prone slopes. Don't underestimate this type of avalanche. Though it is often softer snow, there is more than enough to take you off your feet, carry you long distances and bury you. Like the wind slab problem, assess slopes carefully, while maintaining a conservative route plan. Look for shooting cracks and collapsing slopes for signs of increased instability. Your best bet is to avoid avalanche terrain today.

    Credit: Sierra Avalanche Center

    Small, steep test slopes can help identify unstable storm slabs

Avalanche Discussion

Yesterday marked the beginning of a series of storms that will likely persist through mid-week. Though each system isn't massive on their own, the snowpack will surely reflect the cumulative effects of multiple feet of new snow. A NWS Winter Storm Warning will start at 4pm today through Tuesday night, for areas above 5,000 feet. Yesterday's system provided somewhere around 9 inches at treeline this morning, with the Eddy and Castle weather stations seeing a bit more than Old Ski Bowl. Today will provide a slow in the precipitation (3-7 inches expected), followed by an increase (13–17 inches expected) overnight. Wind transport has been observed throughout the lat 24 hours, with two different avalanche occurrences reported. Though the Mount Shasta area often sees a dramatic drop in instability after a storm, that is likely not the case today. Instability is real out there, and it will be important to respect the potential danger. Travel with caution, and be sure to give yourself a back-up plan.

Regions covered