Silver Valley & Bitterroot Mountains

Problemi valanghivi

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1–2

  Weather data from Wardner Peak shows that wind came in from all directions at various times during this storm, with gusts exceeding 50mph coming out of the Northeast. With plenty of that Champaign powder available for transport, expect reactive 12”-18” wind slabs in unusual places.

  Wind slabs look like chalky pillows that will sound/feel stiff and hollow. Watch out for them on exposed ridgelines and cross loaded gullies at lower elevations. Low angle wind sheltered terrain will offer the safest skiing and riding.

  

• 

  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1–2

  As the temperature modulates we can expect all the lite new snow from the past week to stiffen into a 1’ to 2.5’ slab, while 4” to 6” new denser snow will pile on top today. How this interacts with the previous snow surface and various density changes within the storm snow will determine its likelihood of propagating. We already have observations of a 2.5’ storm slab remote trigger avalanche on the old snow/new snow interface and natural releases in the past few days, so treat this with abundant respect.

  Mitigate this hazard by sticking to low angle slopes (<30°), and avoid traveling below avalanche terrain. Heed red flags like shooting cracks and whumpfs.

• 

  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

  You are probably sick of hearing us talk about this, but although it is becoming increasingly less likely to trigger this layer, if it were to go now might be the time. All the recent snow has added weight that is now bearing down on this layer buried 2/3 of the way down in the snowpack. If weakness persists in this layer and it is triggered from a shallow point in the snowpack, a convex rollover, or smaller avalanche steps down, the consequences of being taken for a ride would be dire with the potential for large to very large avalanches that run a long way. While increasingly unlikely, triggering one of the persistent weak layers would be very bad.

  The new snow, having buried this layer deeper, might be what puts this problem to bed for the season, but its too early to tell. Let things settle and assess its stability in coming days.