Central Sierra Nevada

Avalanche problems

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  1–2

  Additional snow and continued strong to gale force S-SW winds have formed more wind slabs overnight and into today.  These wind slabs will exist near ridges, in gully features, and in open areas.  Most of these wind slabs will be in near and above treeline terrain where the winds have been the strongest over the last 2 days.  Human triggered wind slab avalanches are likely today along with natural wind slab avalanches.  New fragile cornices have formed above these slopes where wind slabs exist.

  Look for recent avalanche activity, blowing snow, wind pillows, and cornices above a slope as clues to where these wind slabs are forming.  Wind slabs could be large enough today to injure or bury a backcountry user.  Wind protected below treeline terrain, with no overhead hazard, will offer better snow quality away from the wind slab avalanche problem.

  

• 

  Loose Dry

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2

  Low density snow has fallen overnight with more expected today.  Avalanches of loose snow will be possible on steep slopes in sheltered areas today. Most of these avalanches will remain small, but they can entrain more snow as they move downhill.  If more sun and solar radiation occurs than forecasted, these loose snow avalanches could quickly develop with wet snow characteristics.

  Loose snow avalanches can move quickly once they start and may entrain enough snow to knock a person over or push them off course into higher consequence terrain. Pay attention to the terrain around you and avoid areas with terrain traps.