Salt River and Wyoming Ranges

Avalanche problems

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Very Likely

  Size

  1–2

  Wet loose avalanches will be very likely today. This hazard is expected to increase throughout the day as things warm up. The risk of wet loose avalanche is lowest early morning when snow surfaces are still refrozen from overnight cooling. While we expect to see these avalanches today, they are most likely on slopes that have been impacted by the sun. Lower elevations will begin to thaw earlier. So far, wet snow avalanches have been relatively small and easy to predict. However, melt-water is working its way down towards deeper weak layers during the heat of the day and putting wet slab avalanches on the radar. Steep and rocky south facing slopes are the first places that these avalanches might occur. Wet slabs are difficult to predict and can be large. This time of year it can be helpful to track when the snow starts to soften each day, then use that information to plan when to get out and when it might be time to start avoiding sunny slopes.

  Cornice Fall: This hazard is also becoming more likely as temperatures warm each day. Large cornices have formed throughout the Greys zone and are being weakened by the daily spring thaw. Cornices should be given a large margin throughout this warming period. Travel on or under cornices is not advised. Be aware that they often fail far back.

  

• 

  Deep Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  2–3

  In much of the Greys forecast zone at middle and upper elevations, weak snow from December is buried up to 5 feet deep. The layer is very stubborn to human or snowmachine triggers in most locations but it continues to produce avalanches with each round of new snow, wind-loading, or cornice fall. These rapid changes in stress to the snowpack appear to be the most likely way to trigger an avalanche but don't overlook the potential to step on or ride over a thin spot which then causes a crack to propagate widely across a slope. Watch for cornices as you travel and evaluate convex slopes and thin, steep rocky, and wind-affected areas carefully. Terrain configuration and wind affect over time matter. Check out recent observations here and here for other examples of this problem.

  The best way to manage this avalanche problem is to build in a large margin for error in your intended route. Increase your safety margin by traveling where the snowpack is deepest, identifying the presence/depth of the weak layer (probing or digging), and avoiding thin, steep, rocky, and wind-affected areas. This problem can be hard to identify and will not show signs of instability like cracking or collapsing. Furthermore, tracks on a slope are not conclusive evidence of stability.