Continental

Avalanche problems

• 

  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  1–3

  Dangerous avalanche conditions exist.  On 4/25 storm slabs were found to be top heavy and sensitive, with signs of instability such as collapsing and easily failing test slopes on wind loaded terrain features, and most importantly, lots of natural avalanche activity.  The depth of settled storm snow varied depending upon wind redistribution, but averaged 2 feet deep.

  We expect conditions to have settled somewhat from Saturday, but still believe that human triggered avalanches are likely especially in windloaded or convex terrain features.  The sun will play a major role in the sensitivity of the storm slab.  Users can expect for slopes to become more sensitive if they are in direct sun.  Weather models are mixed so it is unclear how much of a role the sun will have today.

  Conservative terrain choices are recommended today while the snowpack continues to be under stress.

   

  

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  1–3

  Wet loose and wet slab natural avalanche activity was very active yesterday on all aspects.  These avalanches have removed some stress from the snowpack, however clouds came in mid day which reduced the potential duration and size of activity.  Some wet loose activity was entraining the entire snowpack at lower RFS on north aspects where the snowpack was known to have significant depth hoar.  Expect wet loose activity to have the potential to entrain the entire snowpack moving forward.

  The extent of wet loose and wet slab activity today will directly coorelate with the amount of cloud cover today.  If we see the sun burn through the clouds, expect another round of significant wet loose avalanches.

  Avoid travelling on or below slopes that are steeper than 30° where there is more than 6 " of wet snow present.  Keep in mind that terrain with rocks will heat up quicker than those without due to rocks dark color more effectively taking in heat and transmitting that energy into the surrounding snow.

  

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  2–3

  Multiple weak layers exist throughout our snowpack, including weak snow at the ground. Deep storm slabs that have recently developed at middle and upper elevations have significantly increased the stress on these weak layers. When these layers fail, they can create very large, dangerous avalanches that could run to the valley floor. 

  Another form of stress is warming temperatures as the solar angle continues to march higher.   Persistent avalanche problems are unpredictable and can move from dormant to reactive without warning, especially during times of increased stress, like we have now.

  A cautious approach to terrain continues to be reccommended as temperatures continue to climb and more precipitation is on the way.