Central Sierra Nevada

Avalanche problems

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  1–2

  Gale force wind will drift and deposit high intensity snowfall onto avalanche terrain near ridgetops, in gullies, and on open slopes, creating a wind slab avalanche problem. Slopes that are more filled in than surrounding areas with wind drifted snow are the main areas of hazard. Most slab avalanche potential will occur in above treeline and near treeline terrain today, but may extend below treeline to a lesser extent due to the strength of the winds.

  Slopes below cornices and wind drifts are the main areas of concern, but consider any avalanche terrain that in rapidly filling in with wind drift snow as suspect. Snow surface cracking and/or fresh avalanches are indications of unstable snow in the immediate area. Consider avoiding any avalanche terrain where indications of potentially unstable wind slabs are present.

  

• 

  Loose Dry

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–1.5

  Some long-running sluffs, aka dry loose avalanches, are possible this afternoon, especially in wind protected areas where new snow is accumulating on top of firm rain crust. The warm to cold trend and expected snowfall amounts for today's storm is more conducive to dry loose avalanches than for storm slab avalanches.

  The main concern here is being caught and carried into downslope terrain hazards such as rocks, trees, or terrain traps that increase the consequences of an otherwise small avalanche. The easy way to avoid this problem is to choose less steep, less consequential terrain on a day like today when peak instability is expected to occur.