Lawinenlagebericht

Central Sierra Nevada

Sierra Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
Open full map
Veraltet — dieser Lagebericht ist 8 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

MODERATE avalanche danger exists at all elevations today due to rapid warming allowing loose wet avalanches to become possible and lingering wind slabs on wind-loaded slopes. The April sun will help destabilize the snowpack and conditions could change in a matter of minutes once the sun hits the new snow. Once any signs of warming snow or wet snow exist it is time to move to colder aspects, lower angle slopes, or switch an activity that does not involve snow.

Lawinenprobleme

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1

    Even though temperatures should remain slightly below normal today, intense April sunshine on the new snow will cause enough warming for wet snow instabilities to form. Human-triggered roller balls, pinwheels, and loose wet avalanches are possible on steep slopes today. Some natural loose wet instabilities may occur on the most sun-exposed slopes near rocks or trees as well. These loose wet instabilities could entrain most of the new snow and could injure a person. They may even involve enough snow to bury a person if they occur in an area with terrain traps or where the most new snow exists. Due to the high sun angles and intense sunshine, loose wet instabilities could occur on any aspect today.

    As soon as the sun hits the new snow today wet snow will start to form on the surface. Conditions will change quickly from cold soft snow to sunny warm unstable snow. Once the snow starts to feel wet and sticky or small signs of loose wet instabilities like small roller balls or pinwheels start to occur, it is time relocate to a colder aspect or abandon the snow for a different afternoon activity.

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1

    Human-triggered wind slab avalanches will remain possible today on wind-loaded N-NE-E aspects and cross-loaded NW, SE, and S aspects in near and above treeline terrain. Some of these could entrain enough snow to bury or injure a person. As the intense April sun warms up the new snow, it will also make wind slabs easier to trigger especially on sun-exposed E-SE-S facing slopes. 

    Clues like cornices above a slope, drifted snow, ripples in the snow surface, and other wind created features can help identify where these wind slabs may exist. Use this information to avoid the wind slabs and seek out more sheltered slopes.

Avalanche Discussion

* Yesterday observations found fragile cornices above wind loaded slopes on Andesite Ridge (Donner Summit area) and along ridgelines near Heavenly. Ski and snowboard cuts on wind loaded test slopes triggered small wind slabs and some shooting cracks on Andesite Peak and in the Carson Pass area.

* Even though the sun only came out for short periods of time yesterday, warm wet snow formed on the surface on E aspects of Andesite Peak as soon as the sun hit the slopes. Ski kicks triggered a shallow surface slab on an E aspect that had just experienced sunshine on Andesite and some roller balls were reported on E aspects near Heavenly in the afternoon. 

* On steep more northerly slopes on Carson Pass, some loose snow sluffing occurred during the day.

* The new snow rested on top of a mix of firm crusts on Carson Pass and moist crusts on Donner Summit. 

Abgedeckte Regionen