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

  1–2

  S-SW winds increased yesterday afternoon and have remained strong overnight with gusts 40 to 50mph along the Sierra Crest.  Larger wind slabs have been forming overnight with the availability of low density snow for wind transport.  Wind slabs today are expected to be larger in size and distribution to what we saw yesterday.  Human triggered wind slab avalanches will be likely today in the backcountry.

  Look for recent avalanches, blowing snow, wind pillows, and cornice formation as clues to where these wind slabs are forming.  Move around and avoid steep wind loaded slopes and areas below large cornices. 

  

• 

  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1–2

  Convective snow showers, fluctuating temperatures, and varying amounts of sun exposure have all formed different layering in our recent storm snow.  Storm slab avalanches will remain possible today in near and below treeline areas.  These storm slabs will be most likely in areas that have received the higher end of overnight snow totals.  Where storm slab conditions don't exist, dry loose sluffing could run long distances.  As daytime warming progresses, avalanche character will change from dry snow to wet snow instabilities.  Storm slabs could have wet snow characteristics and dry loose sluffing will turn to wet loose avalanches depending on the amount of sun exposure and solar radiation.

  Avalanche conditions could change rapidly today.  Make a plan that is flexible and that can adapt to potential changing conditions in the backcountry.  If we receive more sun exposure than forecasted, these wet snow avalanche problems could become more likely and widespread.