Central Sierra Nevada

Problemi valanghivi

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1

  Despite above freezing air temperatures last night in most locations, a decent snow surface refreeze is expected to have occurred on open slopes due to radiational cooling under clear skies. Snow surface refreeze in treed areas may have been poor. Once last night's surface refreeze melts away in response to daytime warming, areas of loose wet avalanche problems will become possible. Instability is expected to eventually form on all aspects at all elevations today. Sun exposed areas that received wind loading during the last storm event as well as the more shaded northerly aspects hold the most transitional snowpack and could remain especially problematic today.

  Monitor the thickness and supportability of melt-freeze crust at the snow surface. Avoid travel in or below avalanche terrain where this crust has melted away leaving unsupportable wet snow conditions.

• 

  Glide Cracks

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1

  Large to very large cornices exist in many locations around the forecast area. These cornices are becoming weak and collapsing during the current warm spell. Cornices tend to break off much further back along the ridgetop than anticipated. Give cornice areas a wide berth during both ridgetop travel and if traveling on the slope below. During ridgetop travel, look for exposed rocks along the ridgetop that give indications of areas that are truly off of the cornice. A cornice collapse may or may not trigger an avalanche on the slope below. Either way, a person involved with falling high mass cornice pieces stands a good chance of significant crush injury or fatality.