Central Sierra Nevada

Problèmes avalancheux

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Likely

  Taille

  2

  Widespread rain on snow will cause wet snow instabilities to form on all aspects on slopes steeper than 35 degrees below 9600 ft. Loose wet point releases, roller balls and pinwheels should represent the majority of these wet snow instabilities and could entrain enough snow to carry a person down a slope. Terrain traps like gullies, cliffs, creeks, etc. would magnify the consequences of these loose wet avalanches and could allow for them to bury or injure a person. Human triggered loose wet avalanches are likely today and natural loose wet avalanches are possible. While loose wet avalanches will comprise the majority of wet snow instabilities, some wet slab avalanches may also be possible in isolated areas that receive the most rain. While the danger posed by these wet snow instabilities will increase as more rain impacts the forecast area today, it will quickly decrease as the snow levels drop this evening and tonight. 

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Likely

  Taille

  2

  Strong winds will allow wind slabs to form on wind loaded N-NE-E and cross loaded NW and SE aspects on the upper elevation near and above treeline slopes. Since snow level should remain high today these wind slabs should remain limited to terrain above 8000 to 8500 ft. where more of the precipitation falls as snow. At these upper elevations human triggering of heavy wind slabs will become likely today and some natural wind slab avalanches may become possible. These wind slabs will become larger, more widespread, and move down in elevation as the snow levels drop this afternoon and tonight. Use clues like blowing snow, cornices above a slope, wind drifted snow, ripples in the snow, and other wind created textures to help identify where wind slabs have formed.