Salt River and Wyoming Ranges

Lawinenprobleme

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  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Possible

  Größe

  1–2

  Wind slabs up to a 18" thick were triggered or showed signs of reacitvity yesterday. Most reports indicated that the warm snow and strong winds created slabs on the reactive side of the sensistivity scale rather than touchy.  However, observed buried surface facets in a crust on a SE aspect of Mavericks support the idea that some of the wind slabs, like the one triggered on Wimpy's shown at right, maybe be failing on a layer that is weaker than just new snow particles. Look for this layer and consider if it may turn an othewise firm and apparently stubborn slab into something that you can trigger today. Additionally, you will find fresh wind slabs in the lee of west winds today that were formed by westerly winds. These winds were much more moderate than mid-storm winds making it likely that these slabs will be softer, possibly more sensitive and most likely under a foot thick. Your likley to find both wind slab problems located primarily in the upper elevations were snowfall yesterday was more intense.

  Note that the avalanche problem rose includes solar aspects at mid-elevations due to the potential for heating of wind/storm slabs this afternoon. Monitor temps and solar input onto steep slopes and beware of signs of dampening of snow surfaces. This will make slabs more reactive.

   

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  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Possible

  Größe

  1.5–2.5

  Lingering beneath a hard slab (and beneath new snow or wind slabs) lies weak layers buried 2-3’ down. The Feb 18th layer is our main concern due to an increase in avalanches in the Wyoming Range(Shepard Creek, Hoback Peak). The Greys River forecast zone has a diverse snowpack with stark differences between each individual mountain range. The Salt and Snake River Ranges have not seen the uptick in recent avalanche activity or propagating results in stability tests. Our main focus continues to be on the heightened avalanche danger in the Wyoming Range. Increased loading from this  storm will add stress to these weak layers, especially in wind loaded terrain. Reported avalanches have been triggered remotely, and this potential will remain today. Avoid slopes over 30° and understand that large avalanches can be triggered remotely from gentler slopes above, below, or beside steep slopes.