Central Sierra Nevada

Problèmes avalancheux

• 

  Deep Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Likely

  Taille

  2

  Natural and human triggered persistent slab avalanches are very likely today on near and below treeline NW-N-NE aspects. New slabs made of heavy snow that has fallen since yesterday now exist on top of a snowpack that consists of several persistent weak layers on these aspects. The snowpack could barely support itself before the new load arrived. As more snow falls today the slabs will grow in size and extent. Heavy slabs on top of persistent weak layers create very serious avalanche conditions. These kind of avalanches can be triggered from a distance or from "safe" slopes connected to steeper terrain. These avalanches could involve the entire snowpack. These conditions look more like a typical Colorado snowpack than a Tahoe snowpack. Don't let habits and familiarity or "powder-fever" dictate decisions today. These unusual conditions require extra caution and superb travel skills. Travel in, around, or near avalanche terrain is not recommended today.

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Likely

  Taille

  2

  New snow and strong winds have created wind slabs on the near and above treeline NW-N-NE-E-SE aspects. As snow and wind continue today these slabs will increase in size and extent. Human triggered avalanches involving these wind slabs are likely and natural avalanches are possible. On the NW-N-NE aspects where these slabs exist above the old persistent weak layers natural and human triggered avalanches are very likely, and they will behave more like the persistent slabs discussed above.