Avalanche forecast

Mount Shasta

Mount Shasta Avalanche Center
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Avalanche danger

Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Winter is back, hold on to your hat! A wet and windy storm has entered Siskiyou County overnight, hosting ample precipitation, strong low elevation wind and gradually cooling temperatures. These factors will highlight wind and storm slab avalanche problems today. Expect a spike in avalanche danger this afternoon and tonight as new snow and wind bring 1 to 2 feet of fresh snow to the mountains. Anyone in the backcountry will need to have an assessment mindset in avalanche terrain. Dress to impress, it's going to be a nasty one out there.

Avalanche problems

  • Wind Slabs

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

    Strong southerly winds of 30–40 mph will impact areas near and above treeline today, accompanied by heavy snowfall. Fresh wind slabs are likely on northerly aspects, with cross-loading on west and east aspects. These slabs may be especially reactive during peak storm intensity...afternoon and evening. Expect fresh cornices to form as well.  

    Low-elevation winds may create wind-drifted snow in unusual areas. Watch for blowing snow and track where it accumulates. Signs of instability, such as cracking or blocking in wind-drifted terrain, indicate increased avalanche risk. Avoid steep avalanche terrain where wind has deposited snow on leeward slopes, particularly near sharp ridgelines, steep couloirs, and rock outcrops, which are prime zones for wind loading.

  • Storm Slabs

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

    If forecasts verify and said 1 to 2 feet of new snow accumulates, storm slabs may develop. Monitor snowfall totals and slab characteristics. Use small test slopes to gauge conditions on larger terrain.  

    Storm slab behavior can vary from thin to thick, soft to hard, depending on storm intensity and snowfall rates. The highest risk will be this evening and tonight during peak snowfall and rapid accumulation. 

Avalanche Discussion

A large, natural wet slab avalanche occurred in Powder Bowl on Mount Shasta’s south side, likely Tuesday night or early Wednesday morning, following several days of warm weather and poor overnight refreeze. Initial assessments suggest it slid on a persistent weak layer of buried graupel from weeks ago—another reminder of instability on that layer. 

With cooling temperatures, heat-related wet loose or wet slab instability has likely subsided. The focus now shifts to storm snow, as a strong spring storm begins this morning. Forecasts suggest up to 2 feet of fresh snow in the next 24–48 hours, accompanied by strong low-elevation winds. As with any overnight storm, it will be up to you to evaluate slopes carefully today, using small test slopes to gauge larger terrain stability.

The Everitt Memorial Highway and Castle Lake roads are closed.

Regions covered