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

  Possible

  Dimensione

  2–3

  Triggering a very large Persistent Slab avalanche is possible. You're most likely to trigger one of these slides in steep terrain facing W-NW-N-NE-SE terrain (plot). Thick, firm slabs rest above weak snow formed during January's drought, including surface hoar, facets, and facet + crust combinations. Although recent observations point towards an improving Persistent Slab problem, we continue to receive reports of booming collapses and have observations of large natural avalanches in the last 48 hours.Snowpack collapsing or whumpfing is a clear sign of unstable conditions. Unfortunately, you may not receive any obvious warning signs before triggering one of these large avalanches. Persistent Slabs can release in surprising ways, break wider than expected, and release above or hundreds of feet away from where they are triggered.

  Additional Discussion: You may be able to trigger smaller avalanches involving only wind-drifted snow from the tail end of the storm (Wind Slabs). The biggest hazards these soft and hard slabs pose are 1) carrying you where you don't want to go and 2) triggering the much larger Persistent Slabs discussed above as the slides move downslope. Avoid large or consequential avalanche paths where the wind formed large or stiff drifts or slabs.