Central Sierra Nevada

Avalanche problems

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  1

  Wind slabs will be likely on NW-N-NE-E-SE aspects in near and above treeline terrain as gale force SW winds along with heavy new snow impact our region.  Natural and human triggered wind slab avalanches are expected with wet slab characteristics possible as snow levels vary during the day.

  Look for clues such as blowing snow, wind pillows, and cornice development to identify where the wind slab problem is likely to exist.  Make a travel plan to avoid steep wind loaded terrain, runout zones, and areas below large cornices. 

   

• 

  Loose Dry

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  1

  Storm slab avalanches will become likely on all aspects in wind protected near and below treeline terrain as additional storm snow accumulates and snow levels fluctuate.  Storm slabs could be upside down and also have wet slab characteristics due to warming temperatures and/or rain on new snow.  These storm slab avalanches could be natural or human triggered and involve all of the recent storm snow.  Rain on new snow could lead to widespread instabilities. 

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  1

  Loose wet avalanches will be likely today on all aspects and elevations.  Varying snow levels could create widespread loose wet avalanches involving the recent storm snow.  Most are expected to be small in size and in the form of roller balls or pinwheels.  In isolated areas, larger loose wet avalanches could occur that entrain more snow.  Keep in mind that even small loose wet avalanches could have increased consequences when downslope terrain traps exist.