Sawtooth & Western Smoky Mtns

Problemi valanghivi

• 

  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

  Recent strong winds formed hard and soft slabs up to 3 feet thick in upper and some middle elevation locations. Watch for smooth pillows, dunes, and large wind features below ridgelines and cornices, on the sides of cross-loaded gullies, and below large cliff faces and couloirs in the craggy Sawtooth Mtns. Hard slabs may feel hollow and sound like a drum as you move across them. 

  How can we manage this problem? Fortunately, the fresh wind slabs are easy to spot and avoid. If you feel the surface snow getting stiffer, it's time to stick to gentler slopes. Cracks shooting out from your skis or sled are an obvious sign that you've found a wind slab. Hard wind slabs behave unpredictably; they can break above you and wider than expected. 

  

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Unlikely

  Dimensione

  2–3

  The highest odds of triggering Persistent Slab avalanches lies where you find concerning buried layers AND significant recent wind-loading. Weeks of snowfall, rain, and warm temperatures formed thick, dense slabs on most middle and upper elevation slopes. Multiple crusts and storm interfaces are buried in the upper 3 feet of the snowpack on many slopes, providing possible failure layers. 

  Triggering a large slide in windy or sheltered terrain is unlikely but not off the table. Assume the slab + potential weak layer setup exists on all slopes until you dig in the snow to prove otherwise. If you do trigger an avalanche, you probably won't experience obvious signs of instability—like snowpack collapsing or cracks shooting out from your skis or sled—beforehand. 

  As you change elevation and aspect, or travel through different drainages, you'll see significant variability in the buried crusts and storm interfaces. This uncertainty makes it challenging to accurately predict which slopes could still cause trouble. 

  Additional Discussion: Weak, sugary, faceted snow near the bottom of the snowpack is now buried 4-8 feet deep on W-NW-N-NE-E-SE facing slopes at middle and upper elevations. Triggering a huge slide on these layers is unlikely but would be unsurvivable. The best chance of poking this beast lies in windy and/or rocky areas where the snowpack depth is variable, and near the mouths of the drainages near Smiley Creek.