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

  Gale force winds have drifted and deposited new snow into wind slabs.  As the current storm intensifies over the next 24 hours, wind slabs will become larger and natural avalanches increasingly likely.  The majority of wind slabs exist above treeline and near treeline. Wind slabs exist to a lesser extent below treeline due to the strength of the winds.

  Large avalanches from above could travel down into forested areas and low angle areas 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 have formed on top of weak snow. A weak layer in the form of buried surface hoar and/or thin crust with graupel exists 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 threshold of avalanche terrain, down around the 30 degree slope angle mark. Maintain wide safety margins if choosing to travel non-avalanche terrain, sub 30 degree slopes today that do not have steeper connected terrain above or to the side. Remote triggering may occur with avalanches running into or through treed areas.