Lawinenlagebericht

Mount Shasta

Mount Shasta Avalanche Center
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Lawinengefahr

Thu
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
3 · Erheblich
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Veraltet — dieser Lagebericht ist 2 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

An impactful multi-day storm has left a wake of wind slabs and storm slabs over buried weak layers. Triggering an avalanche remains likely on all aspects and elevations. Watch for red flags of avalanche danger, and carefully evaluate the snowpack before committing to terrain over 30 degrees. Expect deep and arduous travel conditions. 

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    2–3

    The January facet layer has consistently been loaded by feet of new snow. This layer exists on northwest, north, and northeast aspects near and below treeline. This layer is buried over 40 inches below the surface, both on Mount Shasta, and in the Eddy Mountains. Because of its depth, sings of instability and the chance of triggering has decreased. This is a low likelihood, high consequence scenario. However, triggering remains possible from large loads like snowmobiles, or multiple people on a slope. Shallow spots are also potential trigger points, specifically near rock outcroppings and abrupt rollovers. Best not to roll the dice in steep terrain until the snowpack has had time to recover.   

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Very Likely
    Größe
    1–3

    Over the last two days, the mountains have received multiple feet of snow with moderate to strong west-southwest winds. This duo has created very large wind slabs near and above treeline on NW-N-NE-E-SE and S aspects. Yesterday evening, the wind direction trended to west-northwest, placing east aspects in the cross-fire for wind loading. Today, wind slabs on east aspects will likely be the largest and most sensitive to triggers. Common catchment areas for wind-blown snow are the leeward sides of ridgetops, below cliff bands, the side walls of gullies, and on mid-slope convexities. Signs of fresh wind lips, actively blowing snow, or rounded surface appearance, should divert you to different terrain. 

  • Storm Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    2–3

    Copious amounts of new snow pose a risk for avalanches on all aspects near and below treeline. Recent snowpack observations, both on Mount Shasta and in the Eddy Mountains, display harder snow overriding softer snow, creating an unstable structure. Recent stability tests have resulted in stubborn results. While this may be the case, additional snowfall is expected today, along with freezing temperatures. These factors may keep the snowpack from settling quicker than expected, and prolong the threat of a large consequential avalanche.

    After a quick pause in overnight precipitation, today's new snow may create an additional reactive surface interface. Take time to investigate. Observe for red flags of avalanche danger, and use conservative terrain management to best inform yourself, and widen your safety margin against this problem. And remember, in deep conditions, even a small avalanche could bury you in a terrain trap such as a gully or a tree well.         

Avalanche Discussion

The snow faucet has been left open, creating deep conditions. During these times, it's important to be aware of avalanche danger, and equally important to be properly prepared. Deep snow travel can be arduous, and lead to significant risk if injury were to occur. Carry a communication device and don't let complacency get the best of you. Snowmobiling in such conditions is for experts only. 

If you observe any avalanche activity or noteworthy findings, please drop us an observation at shastaavalanche.org.

Everitt Memorial Highway is CLOSED as of this morning. County road crews are actively working on plowing. TBD on opening.

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