Salt River and Wyoming Ranges

Problèmes avalancheux

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  1–2

  Yesterday near Housetop Mountain, we found a variety of conditions ranging from dust-on-crust on the south half of the compass to protected, dry snow on the north half of the compass up to 9,500'. The newest snowfall has fallen on this smorgasbord of surfaces. It will likely move very easily on stout crusts on south aspects, so expect to move a fair amount of loose snow if choosing upper or middle-elevation, south-facing terrain today. Though generally regarded as a "manageable" problem, loose snow can catch you by surprise in steeper terrain.

   I expect wind slabs of fresh snow to be sensitive and mostly isolated to the northern half of the compass at and near ridgelines. In the Tetons, wind-transported snow also collects on aprons and slopes below large cliff bands, so be aware of these features additionally.  No matter the size of the slide, managing travel in wind-loaded terrain is straightforward; avoid slopes where you see or feel obviously wind-affected snow to reduce the chances of triggering avalanches. Look for signs of wind-drifted snow such as pillows, rippled surface textures, or sudden changes in new snow depth. 

  Isolated pockets of older wind slabs beneath the newest snowfall can still be found in steep, exposed terrain in upper elevations. This interface lies 30-40 cm below the snow surface and appears to be a mix of weaker, preserved old snow on the northern half of the compass. The trend with this snow has appeared isolated to specific terrain features and lacks a widespread nature, but you could certainly find this problem, particularly if you don't look for it at all before committing to a slope. Look for this weak snow if venturing into upper-elevation terrain today, particularly if that terrain is north-facing. 

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  1.5–2.5

  1. Weak layers that formed during the month of February are now buried ~2' deep. These layers have produced avalanches across most of our forecast area. The pattern of activity outlined by these avalanches points to these layers being most unstable on slopes that face the sun, where they are accompanied by crusts, but they have also produced slides on shaded aspects. 
  2. A pile of large-grained, weak snow exists near the ground in parts of the Wyoming Range. You are more likely to trigger slides on the weak layers higher up in the snowpack, but any slide triggered on this deeply buried weak snow is likely to be unsurvivable.

  As days pass with only small amounts of new snowfall, the snowpack is getting some time to rest, which will gradually decrease the likelihood of triggering an avalanche on these weak layers. However, the possibility of triggering a slide here will be on the table for some time to come. If you choose to enter avalanche terrain, be alert that at least one of these weak layers almost certainly exists in the snowpack underneath you. Even as the danger decreases we continue to advise cautious and conservative terrain selection. Be alert to the consequence of being caught in a large avalanche in the terrain you are recreating in.