Avalanche forecast

Mount Shasta

Mount Shasta Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

Heightened avalanche danger exists today. Over half an inch of water has fallen across the forecast area, mostly in the form of rain up to 9,000 feet. Continued warm temperatures, poor overnight refreeze, and a wet snowpack, will make wet slab avalanches possible in most areas, combined with wind drifted snow at the uppermost reaches of Mount Shasta. Evaluate the snowpack carefully, looking for signs of instability before committing to avalanche terrain.

Avalanche problems

  • Wet Slabs

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

    The last two days have brought skyrocketing temperatures and rain-on-snow up to 9,000 feet. In addition, the past two nights have barely experienced a refreeze. Water has percolated deep into the snowpack, pooling at interfaces as low as 25 inches below the surface. Wet slab will be possible on all aspects, below, near, and, above treeline, up to around 9,000 feet. If triggered, these wet slabs could break up to 2 feet deep, and potentially bury you. At higher elevations, this problem is unlikely due to the colder temperatures, and no rain.

    Wet loose avalanches will also be possible in the same elevations and aspects, running far and entraining 8–10 inches of snow. Look for signs of rising instability such as pinwheels and roller balls, previous wet loose avalanches, and deeper than usual boot penetration. Assess avalanche terrain carefully, performing ski cuts on test slopes before committing to larger lines.

    (1/27/2024)

    Pit on a west aspect of Green Butte Ridge

    Photo: Samuel Clairmont

  • Wind Slabs

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

    At the highest of elevations, which can only be reached on Mount Shasta, dry snow will have fallen instead of rain. At these elevations, cold dry snow and moderate to strong westerly winds likely developed wind slabs on easterly aspects, with cross loading possible on north and south aspects. These slabs have proven stubborn to trigger, but could break 1 to 3 feet deep. At lower elevations, snow will quickly become saturated, allowing for minimal to no wind transport. In extreme terrain, wind blown snow can accumulate in unusual patterns, lower on slopes, and underneath rock outcroppings. Check out this recent skier-triggered wind slab avalanche, as this is a great example of location and terrain.

Avalanche Discussion

It's January, and the weather appears to be on the fritz. Temperatures will continue to climb today, potentially reaching record highs for this time of year. Tonight, freezing levels are forecast to be around 9,100 feet, resulting in no-freeze for most of the forecast area. These types of conditions are bringing wet avalanche problems (with particular concern of wet slab) into the realm of possibility. These problems can be tricky to decipher regarding when and how large they will fail. Approach avalanche terrain with caution, keeping a sharp eye for rising instability such as growing roller balls, previous wet avalanches, and general loss-of-supportability like severe boot penetration and punching deep on skin tracks. Hold tough, colder temperatures and lighter snow are on the horizon.

Regions covered