Avalanche forecast

Mount Shasta

Mount Shasta Avalanche Center
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Avalanche danger

Mon
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired 6 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Storm intensity and avalanche danger will increase throughout the day. Surface instabilities will be most pronounced on slopes steeper than 35 degrees, especially near wind-exposed terrain and where more than six inches of new snow has accumulated. Watch for red flags of avalanche danger. A conservative mindset and simple terrain selection will reduce your exposure to this problem. 

Avalanche problems

  • Storm Slabs

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

    A winter storm has arrived! Powerful southerly winds and double-digit snow totals are expected over the forecast period. Avalanche danger will rise with increased snowfall rates and wind activity.

    On slopes with more than six inches of new snow, storm slabs are a primary concern. Slabs may fail within the new snow or at the interface between the new and old snow on a recently observed grain type called graupel. Instabilities will be greatest during or just after heavy snowfall. The stormiest conditions are expected in the second half of the day. Monitor snow totals and assess the cohesiveness of surfaces as you travel. Use small test slopes to gauge this problem's trend. Sudden collapses and shooting cracks underfoot or machine indicate unsafe conditions and should steer you to simpler terrain.  

    Leeward slopes near and below wind-exposed terrain features will hold the most reactive and consequential slabs. Light to moderate southerly winds—ideal speeds for snow transport—have persisted overnight and will have formed slabs in leeward areas by daybreak. Today’s stronger winds may also affect more sheltered areas, including glades, gullies, and open faces below treeline. Look for wind-textured or stiffened snow surfaces and watch for where blowing snow is accumulating.  

    (3/13/2023)

    Photo taken year prior: Shallow storm slab breaking along convex roll below treeline.  

    Photo: Eric Falconer

Avalanche Discussion

Today is all about clueing back in. If snow totals verify, avalanches large enough to bury a person will be possible and may release naturally. Manage this hazard by self-evaluating conditions and using conservative terrain management, like traveling one at a time, not traveling directly in large avalanche paths, and identifying features and areas of concern.  

Yesterday, observations from near and below treeline in the Old Ski Bowl, on Gray Butte, and in Avalanche Gulch all noted graupel as a predominant surface grain. Once buried, graupel can act like a weak layer and remain reactive days afterward. There’s uncertainty whether this grain type exists in avalanche start zones and is worth digging down to investigate its presence and reactivity on representative terrain. 

Remember, “When snow is the problem, terrain is the solution.”  

Regions covered