Salt River and Wyoming Ranges

Avalanche problems

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2

  Heavy snowfall and strong winds from early March have built wind slabs and cornices on upper elevations. Wind slabs could be 1-2 feet and possibly 3-4 feet thick in isolated areas. Watch for signs of wind-affected snow such as pillows, drifting, and stiffened surfaces. You are most likely to encounter wind slabs around ridgelines, rocky areas, and cross-loaded terrain (gullies and roadcuts). Signs of instability - such as cracking and collapsing - could be less obvious than in previous days due to 3-4" of snow from two nights ago. Assess steep terrain thoroughly for reactive slabs. Travel in sheltered terrain to steer clear of this problem.  

  

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  2–3

  Clear skies yesterday revealed multiple avalanches that potentially failed on buried weak layers.  Large loading events and large triggers, such as cornice falls, have been able to produce very large avalanches on weak snow buried in January. It is unlikely a rider could trigger one of these layers, however, a wind slab avalanche or cornice fall will make it possible to trigger one of these very large avalanches. Very steep slopes, hanging snowfields above cliffs, and rocky or notably shallow slopes are where you're most likely to find this problem. Weak snow formed in January currently sits 3-5+ feet beneath a firm slab at middle and upper elevations in the Salt and Snake River ranges. In drier parts of the forecast zone and lower elevations, the weak snow is closer to the surface. Travel on lower-angle slopes to steer clear of this problem entirely. 

  

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1

  Yesterday's sun and low winds allowed surface snow to start heating on southern aspects. Cold temperatures overnight refroze any wet snow, but with another day of intense sunshine and calm wind expect snow surfaces to warm by afternoon. Triggering one of these slides is most likely on steep rocky terrain directly facing the sun. Monitor the snow surface as you travel - look for roller balls, pinwheels, and wet snow (easy to make a snowball). While these avalanches will be small, they easily can push you off your feet making them dangerous in consequential terrain. The onset of wet avalanche activity can be sudden. Pay attention to signs of warming and minimize time spent lingering on or under steep, sunny slopes.