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

  2

  Gale force SSW to SW winds over ridgetops today will create areas of drifting snow and new wind slab formation in near and above treeline areas. The vast majority of new wind slabs are expected to form on W-NW-N-NE-E-SE aspects today. Isolated wind slabs are possible on S-SW aspects as well. Wind direction with this storm has a more S component than the more typical SW to WSW. As a result, wind loading patterns could differ today from what is typical during most storms. Some specific slopes that are typically wind loaded may experience scouring and some specific slopes that are typically scoured may experience wind loading.

  Look for and avoid steep slopes in areas where drifting snow is depositing, slopes below cornice features, and steep slopes with newly formed wind pillows.  

• 

  Loose Dry

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1

  High intensity snowfall rates in locations that experience convective snow showers may lead to the formation of unstable storm slabs in wind protected areas near treeline and below treeline on all aspects. Be aware of potential rapid increases in instability in below treeline terrain if rapid new snow accumulation occurs.

  Look for snow surface cracking while making fresh tracks either uphill or down. Avoid steep slopes in areas where snow surface cracking is occurring.

  Loose dry avalanche activity failing on icy melt freeze crusts at the old/new snow interface is also a possibility today on all aspects in wind protected areas near and below treeline.

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1

  Loose wet avalanche activity is possible today on all aspects in any areas where rain falls on new snow. This may occur following convective snow showers where snow level lowers temporarily by up to 1,000'. As the convective shower tapers off, snow level will rise leading to rain on new snow. Rain on old snow is less likely to lead to loose wet avalanche activity today as recent melt has prepared the older snow to handle rain. That said, isolated loose wet avalanches from rain on old snow are not impossible today.