Bollettino valanghe

Mount Shasta

Mount Shasta Avalanche Center
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Pericolo valanghe

Thu
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Non aggiornato — questo bollettino è scaduto last year. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

In steep alpine terrain, isolated pockets of wind slab may still persist on north and east aspects. Exercise caution on slopes showing signs of wind effect. Today’s warm temperatures and sunshine could soften snow surfaces to a point of instability. Shooting cracks and rollerballs, indicate unstable snow. Time your terrain selection carefully to match conditions, and stay alert for fragile-looking cornices and falling rime ice.

Problemi valanghivi

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    It’s that time of year when cornices start to drop! Best not to get too cozy around them, as they can fail unexpectedly and further back than anticipated. During the heat of the day is when they are most susceptible to failure. Avoid or limit your travels beneath them, and stay much further back from the edge of ridgelines. Keep bare earth or trees between you and the edge.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    The timing and special variability of this problem can be tricky. You can expect small wet snow instabilities to exist across all aspects below treeline, where snow has remained unfrozen for several days. Near treeline, steep southerly aspects that receive periods of direct sunlight are most prone to destabilize. These mid-elevation slopes carry higher consequences, as slides could be large enough to injure or bury a person.

    Today, clear weather and a high California sun angle will deliver strong solar input to the snowpack. With a thick but brittle melt-freeze crust near treeline, it’s unsure how long it will take for solar radiation and temperatures to break it down. If and when this does occur, instabilities will follow quickly. Pay attention to where surfaces feel supportable and where they don't. Remember, the steeper the slope, the more solar input it can receive.

    Watch for signs like trees shedding snow, rollerballs, and unsupportable surfaces, as these indicate snow no longer wanting to stay in place. Be mindful of both micro and macro terrain traps, and move off steep slopes or aspects once snow surfaces become unconsolidated.

    A 1-inch thick melt-freeze crust on a south aspects near treeline, with over a foot of unconsolidated wet snow below.  If this crust breaks down today, loads of wet snow will be available to avalanche 

    Photo: Eric Falconer

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Mount Shasta stands over 14,000 feet tall, and is highly exposed to the wind. Two days ago, the mountain received fresh snow along with strong W-SW winds. Yesterday, blowing snow was visible off Casaval Ridge. Alpine observations have been limited, so it’s possible that wind slabs may still exist in pockets of steep, unsupported alpine terrain. Potential locations include the Trinity Chutes, Left of Heart, Upper West Face, Casaval Ridge, and the southwest aspects of Green Butte and Sargents Ridge.

    Be prepared to self-evaluate wind-drifted surfaces and identify potential trigger points.

    Southwest wind actively blowing snow onto Leeward north and east aspects above treeline 

    Photo: Eric Falconer

Avalanche Discussion

Thinking about climbing Mount Shasta?

Present hazards include: bad weather, avalanche danger, and falling rime-ice. With Mount Shasta standing tall and proud, barely no visible rock can be seen on the upper mountain. This means a large amount of rime-ice exists. Today’s warm temperatures and sunshine may cause pieces to become unglued. Falling rime-ice is likely the largest hazard climbers face on the upper mountain. Keep an eye to the sky, yell "rock!", and be ready to move out of its path.   

Road status. Currently, the Bunny Flat trailhead is inaccessible due to the closure of Everitt Memorial Highway. The Siskiyou County Road Department is awaiting new snow removal equipment, as their current snow blower is out of service. Snow removal will begin as soon as possible.

Climbers will need to start from the McBride Springs Campground, located lower down on the Everitt Memorial Highway. The route begins on a 4x4 road and follows the Cascade Gulch drainage up to Horse Camp. There is no continuous road all the way to Horse Camp, so route finding is required. This adds roughly an additional 3 miles and 3,000 feet of vertical gain to the climb. Once at Horse Camp, you're ready to tackle the mountain.

Climbing routes and conditions are in great shape. For more information on mountain hazards, required permits, and up-to-date conditions, check out our Climbing Advisory

Regioni coperte