Central Sierra Nevada

Lawinenprobleme

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Very Likely

  Größe

  2–3.5

  Gale force winds have drifted and deposited new snow into wind slabs.  A natural avalanche cycle is expected to have occurred last night, with additional avalanches expected today. Wind slabs exist both above treeline and below treeline due to the strength of the winds.

  Large avalanches from above could travel down into forested areas and low angle terrain near the bottom of drainages and valley floors. Travel in, near, or below avalanche terrain is not recommended.

  

• 

  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Very Likely

  Größe

  2–2.5

  Storm slabs exist on top of weak snow with skier trigger avalanches reported yesterday in Ward Canyon and Deep Creek. A weak layer in the form of buried surface hoar and/or thin crust with graupel exists at or just below the old snow surface. The buried surface hoar has been observed across NW-N-NE aspects mainly near treeline and below treeline. The layer of thin crust with graupel is more widespread.  Either of these weak layers could contribute to wider propagating and easier to trigger avalanches.

  These weak layers increase the likelihood of avalanches occurring on slopes near the lower slope angle threshold of avalanche terrain. Some slopes likely had storm slab avalanches occur naturally during the past 24 hours. Other slopes are on the brink and just need the addition of the weight of a person to trigger the slope. Remote triggering may occur with avalanches running into or through treed areas.

  Maintain wide safety margins with an extra buffer between you and any avalanche terrain. If choosing to travel sub 30 degree slopes, be certain of your slope angles. Know exactly where there is any steeper connected terrain above or to the side that could avalanche naturally or be triggered by you or another party.