Central Sierra Nevada

Problemi valanghivi

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta quota
  • Limite del bosco
  • Sotto il limite del bosco

  Probabilità

  Likely

  Dimensione

  2

  More snow and hurricane force winds will build new wind slabs on leeward aspects. The largest of these wind slabs will exist on wind-loaded N-NE-E aspects and cross-loaded SE and W-NW aspects above 8500 ft. where more precipitation falls as snow. As snow levels start to fall this afternoon and evening, wind slabs will form on lower elevation slopes and become larger and more widespread. Due to the strength of the winds at all elevations, wind slabs could exist in below treeline terrain as well as near and above treeline terrain. Human triggered wind slab avalanches will become likely on any slopes exposed to wind loading where significant snow accumulates today. Some natural wind slabs avalanches may become possible this afternoon and evening in areas where the most wind loading occurs. In areas where the precipitation falls as rain, wind slabs will be unlikely.

  Looks for signs of recent wind loading such as cornice features and wind pillows to help identify where problematic wind slabs are likely to exist.

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta quota
  • Limite del bosco
  • Sotto il limite del bosco

  Probabilità

  Likely

  Dimensione

  1

  Wet loose avalanches and instabilities like point releases, pinwheels, and roller balls will remain possible today on steep slopes below 8500 ft. that receive additional rain. If snow levels climb higher than 8500 ft. these wet snow instabilities will become more widespread; if the snow levels fall lower than 8500 ft. the wet snow issues could become less widespread. Since the snowpack has well-established drainage to deal with the additional rain, wet slab avalanches remain unlikely, but they are not impossible in some areas. 

  Most loose wet snow avalanches should remain small, but they could still knock a person off balance or cause a twisting fall. Be aware of terrain traps that could magnify the consequences of loose wet avalanches.