Central Sierra Nevada

Lawinenprobleme

• 

  Cornices

  • Alle Höhenlagen

  Wahrscheinlichkeit

  Possible

  Größe

  0

  For portions of the forecast area along the Sierra Crest, a usable snowpack exists above 8,000' with a marginally usable snowpack between 7,000' and 8,000'. The snowpack above 8,000' is generally 3+ feet deep and supportable. Little to no snow exists below 7,000'. Most of the terrain along the Sierra Crest below 9,000' received significant rain during the last storm.

  Most Sierra Crest areas have either exposed rain crust (firm ice) on the snow surface or a few inches of recent storm snow on top of a rain crust. A potentially problematic graupel layer has been seen on top of the rain crust, just below the few inches of recent storm snow in some areas. This layer could contribute to small human triggered avalanches over the next few days.

  Above freezing air temperatures are expected this weekend. Some surface wet snow may form on southerly aspects, but wet snow avalanche problems are not expected.

   

• 

  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Unlikely

  Größe

  2

  This problem is specific to the Mount Rose portion of the forecast area. Despite signs of improving stability, the deep slab avalanche problem is well understood to have a higher level of uncertainly than other avalanche problems. Additionally, the snowpack does not gain stability at an equal rate in all locations. This leaves some uncertainly as to the ongoing possibility of an isolated deep slab avalanche event in the coming days. While it has become unlikely, it is not impossible.

  NW-N-NE aspects above 8,500' to 9,000' warrant a conservative approach with thorough planning and evidence gathering. Snowpack failure would occur within faceted old snow near the ground, below the 3 feet of recent storm snow. Committing to a line with little evidence to back the decision is simply guessing. This is not a good tactic in backcountry avalanche terrain. There are plenty of smarter terrain choices. Do not allow the absence of signs of instability to lull your group into marginal or sloppy travel techniques in avalanche terrain. A single, isolated (no one in the group thought it would really happen type of) avalanche event could have disastrous consequences.