Salt River and Wyoming Ranges

Avalanche problems

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Very Likely

  Size

  2–3

  Large, deadly avalanches failing on very weak snow formed in December are a real threat today. In the mid and upper elevations, avalanches will break 3 to 5 feet deep. Below 7,500’ slab depths will be in the 1 to 3 foot range. All aspects (shaded and sunny) at all elevations are suspect. Slabs could be triggered from a distance, or wait until you are riding the slope to release. Nearly 20 inches of new snow has fallen in the upper elevations of the Salt River Range over the past two days. This additional load will push an already weak snowpack over the edge.

  Backcountry travel is not recommended at this time. If you choose to go out, know that extremely careful route finding is of the utmost importance today. Staying far away from terrain that is connected to avalanche paths and keeping slope angles well below 30° is critical. This also means being aware of the terrain that is above you as remote triggering is likely. Natural and rider triggered avalanches have the potential to run long distances. Runout zones should be avoided. Groomed trails that cross avalanche paths should be evaluated carefully and crossed one at a time, if at all.

  We have recieved many avalanche observations over the past few days. Thank you! Please take a moment to look at the recent events here.

  

• 

  Deep Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  2–3.5

  Weak snow formed during a dry period in November persists at the base of the snowpack. This layer is now buried about 5 to 6 feet deep in the Salt River, Snake River, and western portions of the Wyoming Range. It is at its weakest on the north half of the compass. The recent loading events have pushed this deep weak layer to its breaking point in some locations. Deep slab events were observed in the Snake River Canyon two days ago. These very large avalanches are most likely to occur when an avalanche triggered in the most recent snow steps down to weak old snow. Any avalanche involving the entire snowpack will be destructive and likely unsurvivable. 

  Areas in the eastern Wyoming Range, Hoback Canyon, and Gros Ventre Mountains lacked significant snowfall prior to the storm cycle beginning January 4th. In these locations, the new snow has fallen on a snowpack that was primarily made up of weak, sugary snow. Deep slab events are not likely in these locations due to the shallower snowpack.