Salt River and Wyoming Ranges

Problemi valanghivi

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1–2

  New snow and southwest wind overnight have formed slabs in the 1-foot range in the middle and upper elevation on leeward aspects. Up to 7 inches of snow fell in the Salt and Wyoming Ranges last night. These slabs will increase in size and sensitivity - growing up to 2 feet thick- as an additional 8 inches of snow and moderate to strong winds are forecasted today. Natural avalanches may be possible by the afternoon. Use caution in terrain where wind slabs typically form - ridgelines, cross-loaded gullies, and leeward slopes. The formation of drifts, fresh cornices, or blowing snow will give you an early indication of where wind slabs may be forming. Watch for obvious signs of instability such as shooting cracks, collapsing, and recent avalanches. Pay attention to rapidly changing conditions as the storm continues today. Seeking lower-angle or wind-sheltered terrain will help reduce your risk. 

  Additional Discussion: Temperatures above freezing may cause small wet avalanche activity at low elevations. Pay attention to - and stay out from under - very steep slopes where the new snow feels heavy or wet. Colder temperatures this afternoon will help reduce this problem. 

  

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1.5–2.5

  Triggering a very large avalanche big enough to bury you is possible on steep, rocky, convex, or wind-loaded slopes over 35°. 2-3 feet of snow that fell this week sits on a variety of weak layers that were covered on January 31st. This 1/31 weak layer is widespread and consists of facets and crusts. Avalanches failing on the 1/31 interface could travel far distances (including above you) due to the widespread distribution and continuous nature of the overlying slab. Managing this problem will be difficult because signs of instability, such as collapsing, cracking, or recent avalanches, may not be present. Many slopes may appear stable due to the nature of the hard slab. Multiple tracks on a slope are not necessarily an indication that it is safe – it might take one more rider to find the trigger point. Choose conservative and lower-angle terrain to manage the dangerous high-consequence avalanche conditions. 

  Weak snow near the base of the snowpack lurks 3-6 feet below the surface. Loading from the recent storm snow is stressing these weak layers in locations that contain a shallower snowpack, such as the Wyoming Range. Avalanches involving these layers could occur with a significant trigger, such as a large avalanche triggered at the 1/31 interface. Keep these layers on your radar if traveling in shallow parts of the forecast zone.