Central Sierra Nevada

Lawinenprobleme

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  1–2

  A period of high intensity snowfall this morning combined with strong SW winds is expected to drift and deposit new snow into locally deeper slabs of cohesive snow. These winds slabs are expected to form along the down wind side of ridgetops and in gully features, mainly in above treeline and near treeline terrain. Wind slabs may also form in more isolated areas below treeline. In some areas, especially across NW-N-NE aspects, these wind slabs could deposit on top of a weak and sugary (faceted) old snow surface. This will increase the chances of an avalanche in locations where this new snow slab over old snow weak layer combination occurs.

  Use clues such as drifting snow, cornice formation, new wind drifts, and snow surface cracking to identify areas of potentially unstable wind slab. Move around these areas with caution. Consider avoiding them in locations with about 6 or more inches of new snow.

  

• 

  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Possible

  Größe

  1–2

  Avalanches may also be triggered today in wind protected areas where 6+ inches (upper end snowfall forecast) deposit on top of old, weak sugary snow. This sugary old snow surface weak layer (facets) is most prominent on N aspects in the 7,000' to 8,000' elevation range. It has also been observed to some extent across NW-N-NE aspects, and at higher elevations throughout the forecast area on other snow covered, shaded slopes.

  Pay attention to the amount of new snow that has accumulated in wind protected areas. Look for snow surface cracking as a clue for the presence of this avalanche problem. Consider avoiding travel in avalanche terrain or below steep slopes in any area where signs of this avalanche problem exist.