Central Sierra Nevada

Problemi valanghivi

• 

  Deep Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  2

  The Dec. 11 persistent weak layer is buried under about 1 foot of snow and has been a concern for over a week.  Just as it took time for this layer to facet and weaken, it has taken time for the weak layer to adjust to the current snow load and gain some strength.  Yesterday marks the first day without reports of active whumpfing on this layer from the forecast region.  Unfortunately, reports of unstable snowpack test results did come in and large variability continues from one area to the next.  This weak layer exists on W-NW-N-NE-E aspects in below and near treeline areas.

  Whumpfing sounds, cracking, and/or unstable snowpack test results could indicate that this weak layer is still active in your specific area.  Limiting exposure to avalanche terrain by using only sub 30 degree angle slopes without steeper connected slopes above or to the side is the easy way to manage this avalanche problem.  

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1

  SW winds increased overnight into the strong to gale force range at higher elevation.  Snow transport is expected with small unstable wind slabs forming last night on NW-N-NE-E-SE aspects in near and above treeline areas.  Winds will shift towards the NW today and then to the E tonight remaining gusty in near and above treeline areas and possibly transporting snow to other aspects.  Avoid areas below new cornice formation and newly formed wind pillows and drifts.