Avalanche forecast

Mount Shasta

Mount Shasta Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

Today, the safest move will be to avoid steep avalanche terrain. Avalanches big enough to bury you will be possible. A winter storm has arrived overnight, bringing heavy snow and southerly wind above 4,500 feet. One to two feet of new snow will fall on varied surfaces. While in the backcountry, watch for the five red flags of avalanche danger and use small test slopes for early warning signs. 

Avalanche problems

  • Storm Slabs

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

    What is it?  A storm slab is a cohesive layer of new snow that breaks within the storm snow or at its interface with the old snow. Depending on snowfall, slabs may range from soft and harmless to thick, hard, and dangerous. This problem typically lasts a few hours to a few days.

    Where is it?  Storm slabs usually form in below and near treeline areas with similar snowfall, with deeper accumulations at higher elevations and in leeward terrain. Monitor storm totals to assess potential size.

    What should you do about it? Watch for signs of instability like shooting cracks on small, steep test slopes. Reduce risk by waiting a day or two before entering steep terrain. If storm slabs form over a persistent weak layer (e.g., surface hoar), they may become persistent slabs, leading to longer-lasting instability.

    Hot tip: Check out the Old Ski Bowl, Castle Lake or Mt Eddy snow depth sensors for new snow accumulation, helping gauge storm slab potential.

  • Wind Slabs

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

    What is it? A wind slab is a cohesive layer of wind-drifted snow. Wind transports snow from upwind terrain and deposits it into thicker drifts on the downwind side. Blowing snow, cracking, or collapsing in drifted snow are key warning signs.

    Where is it? In the past 24 hours, SSE winds have been light to moderate, with strong S/SW winds expected today. This will primarily load northerly aspects, with cross-loading on westerly and easterly slopes. Wind slabs form in predictable spots, such as leeward ridges and cross-loaded gullies. They can vary in hardness and thickness, often appearing smooth, rounded, and sometimes hollow-sounding.

    What should you do about it? Avoid wind slabs by sticking to sheltered or wind-scoured areas. If they form over a persistent weak layer (e.g., surface hoar), they may become persistent slabs with longer-lasting instability.

    Hot tip: Check the Gray Butte weather station for wind intensity and direction—blowing snow is a red flag for avalanche danger!

Avalanche Discussion

As with any overnight storm, the impact of the new snow on our existing snowpack remains uncertain. Four inches of new snow is on the ground near treeline early this morning. The snow is landing on a mix of surfaces, including sun crusts, wind affected snow, soft powder, and, most notably, surface hoar in select areas. Surface hoar has been observed primarily on the west side (Eddy Mountains and Castle Lake areas) in below and near-treeline terrain, even near ridge-top starting zones. Since buried surface hoar can create a weak layer, this is something to watch for.  

Strong winds with this storm mean active wind loading near and above treeline. We’re not too concerned about existing weak layers, and instability will likely involve new snow. However, if a thick enough slab forms, larger avalanches could gouge deeper layers. It’s a classic storm day—stay alert out there.

Check out yesterday's forecaster observation and others here.

Access: The Everitt Memorial Highway is closed. Estimated opening is next week sometime.  Castle Lake road is also closed. Unknown opening. Of note, yesterday, a community stakeholder meeting was held in Mt Shasta City with regard to plowing operations for Everitt and Castle road access. We want to share that a passionate, caring and committed group of people are actively moving toward viable solutions for reliable snow removal. Stakeholders recognize the importance of winter access to these areas, and we're excited that momentum is building for near, mid and long-term solutions.  It's a mountain to climb, but this community has some grit!

OPEN - Pilgrim Creek and Deer Mountain Sno-Parks / Mt Shasta Ski Park and Nordic Center / FS31 road motorized/xc-ski access / McBride Springs ski access 

THIS WEEKEND! Click below for details...

Regions covered