Sawtooth & Western Smoky Mtns

Problemi valanghivi

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Likely

  Dimensione

  1.5–3

  We're facing two disctinct "flavors" of Persistent Slab avalanches:

  1) You can trigger 1-3 foot thick slides involving the snow from the past week on both sheltered and wind-loaded slopes. Assume this problem exists on all upper and middle elevation slopes and on shadier, lower elevation aspects. These avalanches will be large enough to bury people. Although the slides will be largest in wind-loaded terrain, it's unusally easy to trigger avalanches in more sheltered, middle elevation terrain.    

  2) The avalanches described above can "step down" to weak snow near the ground, producing huge, unsurvivable avalanches. This layer of weak snow exists on all upper and most shaded middle-elevation slopes (W-N-E). 

  Some facts to help you travel safely today:

  • You could trigger avalanches remotely—from flat or gentle terrain below, above, or to the sides of steep slopes.
  • They can break well above you, either while you are descending or at the bottom of a slope.
  • Avalanches are pulling back into relatively flat terrain above steeper slopes.
  • Some recent avalanches were hundreds to thousands of feet wide.

  

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Likely

  Dimensione

  1–2

  While the Persistent Slabs described above are by far the biggest current concern, today's weather will from another generation of fresh Wind Slabs. These slabs will grow during the day and be easy to trigger.  Natural avalanches are possible this afternoon. The Wind Slabs, as well as small loose snow sluffs, can trigger the much larger Persistent Slabs described above.