Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
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Out of date — this forecast expired 9 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Low avalanche danger continues at all elevations throughout the forecast region.  A persistent slab avalanche problem continues to exist in isolated areas in near treeline and below treeline terrain.  Avalanche danger is expected to increase tomorrow as a strong winter storm impacts our area.

Avalanche problems

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1

    A weak layer of faceted snow continues to persist within the snowpack.  This persistent slab avalanche problem exists on NW-N-NE aspects in below treeline and near treeline terrain.  Snowpack tests continue to show unstable results on this layer at many locations throughout the forecast area.  Although this weak layer has become moist to wet in some locations, it still remains loose and weak.  Triggering this weak layer today will remain unlikely.  Concern exists that this weak layer could become reactive with increased load from the forecasted winter storm on Thursday/Friday. 

    Look for collapsing, cracking, or whumpfing sounds.  Be aware that persistent slabs can be remotely triggered and could also fail low to mid slope.  Handpits and ski pole probing remain effective tools to help identify where this persistent weak layer may exist.

Avalanche Discussion

* Unstable test results reported in near and below treeline terrain on the buried facet layer over the last week:  Elephants Hump (Carson Pass area), Red Lake Peak (Carson Pass area), Slab Cliffs (Mt. Rose area), Tamarack Peak (Mt. Rose area), and Castle Peak (Donner Summit area).  Other locations are showing this layer and the overall snowpack gaining strength.

* 1 natural triggered persistent slab avalanche on Jan. 11 reported.  No human triggered avalanches reported on this weak layer.

* NW-N-NE aspects above 8,000' in the Mt. Rose area and along the Sierra Crest north of Emerald Bay hold the best coverage at 2 to 4+ feet. Overall less snow cover exists south of Emerald Bay. Areas of decent coverage exist above 8,300' on NW-N-NE aspects in the Carson Pass area.  Coverage decreases dramatically on all other aspects.

Regions covered