Central Sierra Nevada

Avalanche problems

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Very Likely

  Size

  2–3.5

  Gale force winds continue with wind gusts along the Sierra Crest well exceeding 100mph for the last several days.  Multiple natural wind slab avalanche cycles are thought to have occurred throughout this multi-day storm.  Large to very large wind slab avalanches are expected to occur today.  Wind slabs will exist in above treeline and below treeline areas due to the strong winds.

  Wind slab avalanches could run long distances well into lower angle forested areas.  Travel in, near, or below avalanche terrain is not recommended.

  

• 

  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Very Likely

  Size

  2–3

  High intensity snowfall continues to rapidly load our snowpack with multiple storm slab concerns.  Uncertainty exists about the weak snow at the old snow interface with limited observations and access to terrain during this storm.  A layer of buried surface hoar on NW-N-NE aspects and a more widespread layer of graupel on top of a crust, could still have the potential to produce very large avalanches involving all of the recent storm snow.  Remotely triggering a very large storm slab avalanche remains a concern for today.

  Travel in, near, or below avalanche terrain is not recommended.  If choosing to travel on sub 30 degree non-avalanche terrain, be certain about your slope angles and that you are not connected to any steeper terrain above or to the side.  Maintain wide safety margins with an extra buffer between you and any avalanche terrain.