Provo

Avalanche problems

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  2

  For the past 24 hrs, the wind has been blowing from the northwest direction at speeds of 40-60 mph with gusts into the 70's at 11,000'. Across the upper elevation 10,000' ridges, the speeds have been 20-25 mph. High winds can deposit the lingering snow around terrain features on almost any aspect, called cross-loading. For this reason, I would expect to find hard or soft slabs of wind drifted snow at all upper elevations and on leeward mid-elevation slopes, especially along with terrain features such as ridgelines, sub ridges, and gullies. As always, look for and avoid slopes that look rounded, pillowy, or sound hollow.

  Cornices have grown to an unmanageable size. Stay well back from - and avoid travel below - corniced ridges.

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  4

  The avalanche danger is probably somewhere between MODERATE and CONSIDERABLE. It's hard to know exactly. The North American Danger Scale is broken up into three categories, Travel Advice, Likelihood, and Avalanche Size and Distribution. Based on Travel Advice, I would pick a CONSIDERABLE danger. Based on Likelihood, I would pick a MODERATE danger. Based on Avalanche Size and Distribution, I would choose a blend of MODERATE and CONSIDERABLE danger.

  So, where does this leave us? Well, picture it like playing the classic 1989 game Minesweeper. The game's objective is to clear a rectangular board containing hidden "mines" or bombs without detonating any of them, with help from clues about the number of neighboring mines in each field. Sound sorta like the backcountry right now? Well, it's true.

  As the likelihood of triggering an avalanche goes down, it becomes easier to step into bigger terrain. However, the consequences of triggering an avalanche remains the same, just like minesweeper. If we play the game with 200 mines on the field, we are more likely to hit a mine. If we remove the number of mines on the field, it becomes less likely (this can also be called probability). But if we hit/trigger a mine, we still lose the game.

  For now - it will remain possible to trigger a deadly avalanche 2-5’ deep in an area where the slab is thinner, such as rocky terrain, or in areas that have previously avalanched this winter. While it may be possible to find this layering anywhere in the Wasatch, we are most suspect of terrain along the periphery of the Cottonwoods such as Mill Creek, the PC ridgeline, Lambs/Mt Aire, Snake Creek, and the transitional zone toward the Bountiful/Sessions.

  What to do:

  • Dig down and if you see weak facets in the snowpack, avoid steep terrain.
  • Choose a completely safe uptrack. You are often more vulnerable while ascending.
  • Expose only one person at a time and keep tabs on people all the time.
  • Know what's above and connected to you - these avalanches can be triggered from a distance or below.
  • Slope cuts and cornice drops can be dangerous and dangerously misleading indicators of stability.

  If all of this sounds confusing and hard to understand (it's okay) - take a step back and only ride in terrain that's under 30 degrees in steepness and continue to avoid avalanche terrain altogether. (my plan)