Bulletin d’avalanche

Mount Shasta

Mount Shasta Avalanche Center
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Danger d’avalanche

Wed
Alpin
2 · Modéré
Limite forestière
1 · Faible
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré last year. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

You could trigger an avalanche on any slope receiving sun or where wind is transporting snow onto leeward terrain, most commonly on easterly aspects. Travel on steep, south-facing slopes early in the day while keeping an eye out for roller balls and slabs of dense, wind-packed snow.

Problèmes avalancheux

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–1.5

    Rising temperatures and the emergence of the sun today increases the likelihood of wet loose avalanches on all aspects below treeline and on the southern half of the compass near and above treeline. 

    As water works its way through the snowpack, it can exploit any weak layers and trigger an avalanche that starts small and then grows as it entrains more wet snow moving downslope. These avalanches can be small yet mighty, as they could carry you over hazardous terrain such as a section of cliffs or down into trees.

    If you observe roller balls or if you're sinking deep into wet snow when you step off your sled, skis, or board, this is a big indicator that wet loose instability is on the rise.

    (3/4/2025)

    Wet loose avalanche

    Photo: Eric Falconer

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3

    Over the last six days, above treeline elevations have received several feet of new snow and incessant southwesterly wind. Yesterday and into today the wind is now blowing from the northwest and continuing to transport snow to north, northeast, east, southeast, and south aspects of the compass. 

    Given the duration of the last storm period, these wind slabs could be several feet deep and a resulting avalanche may not be survivable. If traveling above treeline, pay attention to snow surfaces for signs of wind affects. This would look like textured surfaces, firm and hollow sounding slabs, and/or lens-shaped depositions of deeper snow.

    (3/14/2025)

    Wind slab avalanche on an east aspect of Gray Butte

    Photo: Mount Shasta Avalanche Center

Avalanche Discussion

Overall, an end to nearly a week of active weather, warmer temperatures, and sunshine will help to heal weak layers in the snowpack. The caveat to these warmer temperatures and sunshine is that we will see some wet loose avalanche instability, mainly on southerly aspects. Our other remaining avalanche problem is wind slabs. Back-to-back days of snow and wind have built slabs several feet deep, most commonly to be found above treeline on the eastern half of the compass. Keep these factors in mind as you navigate the backcountry today AND don't forget your sunscreen.

Régions couvertes