Bulletin d’avalanche

Mount Shasta

Mount Shasta Avalanche Center
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Danger d’avalanche

Thu
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 3 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Near and above treeline is loaded with wind slabs. These will be most pronounced on west, north, and east aspects. Near and below treeline, the possibility of triggering a storm slab remains. These problems exist on steep, shaded, and convex leeward slopes. Red flags may not be obvious today. Careful terrain choice and thorough snowpack evaluation is needed. 

Problèmes avalancheux

  • Wind Slabs

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

    Observations have been limited to near and below treeline over the past four days. With uncertainty regarding the conditions in the alpine, it's safe to assume very large wind slabs exist on leeward west, north, and east aspects, with cross-loaded slopes on south. Snow will remain available for transport today, and could add to the development and sensitivity of this problem. Travel with caution.

    A predominant S-SE wind has been blowing at light to moderate speeds over the last 72 hours. Over two feet of new snow has been at the winds' disposal for creating slabs. Said slabs will likely average multiple feet in depth and would be traumatic if triggered. Large overhanging cornices will point to unsafe slopes. Watch for actively blowing snow, recent avalanches and wind effected surfaces to identify areas worth avoiding.

    (1/15/2024)

    Sun Bowl Avalanche Debris. Slab the size of refrigerators  

    Photo: Samuel Clairmont

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    The snowpack still requires time to adjust to the new load. A hefty 30 cm thick slab is present on all aspects near and below treeline. This slab has proven to be fairly stubborn and supportable for traveling and riding on. However, the soft snow that exists beneath, is not. This upside-down snow structure will settle with time and is why riders should remain cautious of very steep slopes along convex rolls that hold high consequences. Northerly and shaded aspects among complex terrain will harbor longer lasting instabilities, this is where the right trigger in the right place may prove ill for those willing to roll the dice.  

    (2/19/2024)

    Storm slab below treeline breaking along slight convexity 

    Photo: Eric Falconer

Avalanche Discussion

Over 50 inches of snow has fallen since February 17th. The storm crescendo is over. Limited observations have been taken throughout the advisory area due to inaccessibility causing a high amount of uncertainty. For this reason, it's prudent to not let powder fever get the best of you and continue to travel conservatively. The snowpack has trended upside-down giving it a supportable feel when actually it still needs time to adjust. Encountering one of these problems today is a low likelihood, high consequence scenario. Yesterday's storm observation From Gray Butte is posted HERE.

The Everit Memorial Highway and Castle lake roads are closed for snow removal. We will inform on our social media platforms when they re-open.  

24-hour storm totals (inches):Old Ski Bowl (7,600 feet): 4.2 - Total snow depth: 167Castle (5,800 feet):               5.8 - Total snow depth: 115Eddy (6,600 feet):                  2 - Total snow depth: 134

 

Régions couvertes