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

  Likely

  Größe

  1–2

  Wind increased yesterday and began to form wind slabs  less than a foot thick. Today, these slabs will grow to two feet thick, or even thicker near ridgetops, beneath cliffs and on other wind exposed areas. Remember that this zone has received 8-12" of snow since last Friday and today's snowfall will make up to two feet of loose snow available at upper elevations. Below 9,000', lookout for crossloaded terrain features and other signs of wind affected snow. Slabs will be smaller there but still sensitive to human triggering. 

  Watch out for signs of wind loading like fresh cornices, plumes at the ridgetop of textured surfaces. Hollow sounding, upside-down snow, and shooting cracks are strong signs that you could trigger an avalanche. Seek out sheltered terrain to avoid this problem.

  If you can find wind sheltered terrain above 8,000', you'll have significant amounts of sluffing to deal with. These dry, loose avalanches could become large enough to push you somewhere you don't want to go.  Beware of what's below you and have an exit strategy. 

  

• 

  Deep Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Unlikely

  Größe

  2–3

  Weak snow that formed in December persists at the base of the snowpack across the entire Greys River forecast zone. However, the thickness of the hard slabs that overlay this weak snow varies based on geographic location. In the middle and upper elevations of the Salt, Snake River, and deeper portions of the Wyoming Range, these weak layers are buried 3-5+ feet deep making it unlikely for a human to impact them. In shallow parts of the forecast zone, such as the far eastern side of the Wyoming Range, these slabs are only 2-3 feet thick making it more possible for humans to trigger avalanches on the buried weak layers, particularly if new snow adds stress to the snowpack. Shallow, rocky, and unsupported terrain on the north half of the compass is where you are most likely to impact weak layers. Keep in mind that a large trigger such as a cornice fall could trigger one of these very large avalanches, even in areas where the snowpack is deep.

  Identify thin areas in the Greys River zone as you ride. Probing or digging can provide useful information about the depth of the weak layers preserved at the bottom of the snowpack. This evaluation is critical if you are riding in a shallow part of the zone. A total snow depth of less than 5 feet (150cm) is a red flag.

  The last reported human-triggered avalanche involving deeply buried weak layers occurred on March 9th on the far eastern side of the Wyoming Range.