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 4 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

A large low pressure system in the Pacific continues to fire blasts of wintry weather at the West Coast. More snow and more wind is in the forecast. South, upslope flow turbocharges these systems for Mount Shasta. Expect to see temporal spikes in avalanche danger with the continued storm jamboree impacting the forecast area. Stay on your toes out there, be vigilant with your safe travel protocol and pay attention to red flags of avalanche danger...they don't lie.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2.5

    Small wind slabs were touchy yesterday. Larger slabs could be, too. Over the past three days, the wind has blown predominantly out of the south and southeast, averaging 13 mi/hr with gusts to 61 mi/hr. Near and above treeline, slopes on the top half of the compass will be most wind loaded. Cross-loaded slopes (SW-W and SE-E) could also be wind loaded. Wind is notable with this next system today. New and existing snow is available for wind transport. The recipe is there. Stomp on small, wind loaded features of non-consequence. Look for signs of unstable wind slabs, like cracking and blocking. Use those indicators as the canary in the coal mine for what is possible in bigger terrain.

    Cracking in small wind slab on Gray Butte, near treeline, 1.11.2023

  • Storm Slabs

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

    Yesterday, storm slabs were touchy below treeline in the late morning, just after fresh snowfall. The new snow settled rapidly, and storm slabs were unreactive in the afternoon. We will continue to see these brief spikes in avalanche hazard with the parade of storms impacting Mount Shasta. Should new snow accumulation (4 - 8 inches) verify today, a repeat of yesterday is possible. Look for rapid accumulation of new snow. When your measurements exceed six inches, start to think about storm slabs. Ski cut small test slopes. Does slab like snow peel or slide off easily? If so, use this as an indicator that larger slabs are possible in avalanche terrain.

    (1/10/2023)

    Shallow storm slab ski cut off test slope below treeline on Gray Butte, 1.10.2023. If you see red flags like this, don't ignore it and stay off larger slopes of consequence.

Avalanche Discussion

Fluctuating precipitation, wind, snow levels and avalanche danger has been the name of the game this week. Conditions seem to change from one hour to the next. Avalanches this season have all occurred in storm snow layers. We have not observed in persistent weak layers last more than a couple of days. This type of weather should keep you on your toes if you're heading into the backcountry. With the Everitt Memorial Highway and Castle Lake roads still closed, observations have been limited, especially above treeline observations on Mount Shasta. Historical weather can mean historical avalanches. We haven't seen any whoppers yet, to our knowledge, but certainly they are possible with the incessant winter weather. Continue to try and avoid large avalanche path run out zones on the big hill. 

REDDING FOLKS! We have a FREE, Know Before You Go Avalanche Awareness presentation coming up for you in your hometown at Sports LTD, January 12th at 7pm. If you want to avoid getting caught in an avalanche, then you must know some things. Casey Glaubman, MSAC's outreach and education coordinator, will give a 1-hour presentation, providing all the juice. MSAC swag will be available for sale, too!

ROAD STATUS: 

  • The Everitt Memorial Highway and Castle Lake road are closed.

Régions couvertes