Central Sierra Nevada

Problèmes avalancheux

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Very Likely

  Taille

  2

  New snow and gale force southwest winds during the storm have created problematic wind slabs on wind-loaded slopes. As more snow and wind impact the forecast area today, these wind slabs will become larger and more widespread. Human triggered and natural wind slab avalanches will be likely today. Some of these wind slabs will be deep, large, and would have very serious consequences. The largest and most fragile wind slabs will exist on the wind loaded N-NE-E aspects and on cross-loaded NW and SE aspects in near and above treeline terrain, but wind slabs could also exist in some below treeline areas due to the strength of the winds. 

  Identify where wind slabs might exist by using clues like blowing snow, wind drifts, cornices above slopes, wind-created ripples, and other wind created features. Use this information to avoid the wind slabs.

• 

  Loose Dry

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Likely

  Taille

  1

  Changing snow levels and accumulation rates will create weak layers and slab layers within the storm snow. Human triggered storm slab avalanches will be likely today and some natural storm slab avalanches may be possible. Storm slabs could exist on steep slopes in non-wind-affected terrain and could involve enough snow to bury or injure a person. The areas that receive the most new snow and highest snowfall rates will represent the best places to find storm slabs. Storm slabs and/or loose wet snow instabilities will also be likely in any areas where rain falls on new snow.

  Recent avalanche activity, shooting cracks, snowpits, and probing can all help identify where storm slabs may exist. Use this information to avoid steep slopes where storm slabs may exist.