Continental

Problemi valanghivi

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1.5–2.5

  The main avalanche problem continues to be a layer of buried surface hoar (BSH) that exists under 1-3 feet of settled storm snow in isolated locations.  It will be possible for a person or machine to trigger an avalanche 1-3 feet in depth at this layer on protected aspects on the northern half of the compass in the Continental zone.  In the Maritime and Intermountain zones, it is unlikely for an avalanche to be triggered at this layer simply because it is even more spotty in these locales.  However, an observation from the upper Valdez Glacier that identifies BSH under 2+ feet of snow shows that we can not isolate this layer to just the Continental zone.

  The last 4 days of mostly clear weather have allowed for an increase in stability and a decrease in the likelihood for human triggered avalanches.  This has been confirmed by lots of slope testers getting into steeper terrain and only a handful of avalanches failing on BSH. However, many mechanized skiers have likely avoided the areas where it would be most likely to encounter this weak layer.

  Keep in mind that the reason this variety of weak layer is categorized as a persistent weak layer is that instability can persist for long periods.  It is also possible for these layers to go dormant and then go through periods of higher sensitivity like during warming or heavy precipitation.  Continue to assess the snowpack for the presence of this layer, especially when traveling in new drainages.  Snowpits are a useful tool but can also be confusing as this layer can be difficult to identify, especially as it gets older and deforms.  Look for a difference in hardness at the bottom of the settled storm snow just above a hard layer of wind damaged snow from late February.   

  

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

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

  Probabilità

  Possible

  Dimensione

  1–2

  Wet loose activity will become possible below 4000' on the southern half of the compass as the sun begins to heat the surface of the snow.  Wet loose activity has decreased over the last couple of days as the initial shock to the upper snowpack from rising temperature has already taken place with a lot of the recent storm snow already avalanched away.  Hard wind damaged snow beneath and thick melt freeze crusts make it more difficult for the sun to break down and will make wet loose activity lower in volume and distribution.  Cloud cover is expected later today, which will also limit the amount of warming that happens at the surface.

  Wet loose activity is the easiest avalanche problem to work around as it gives clear signs of instability and is very aspect dependent.  Pay attention to the effect the sun is having on the snow surface.  Once more than 4 inches of snow has become moist wet loose will become an issue especially in steep rock terrain.  Hazard doesn't effect all aspects at once.  Hazard begins to rise first on east facing slopes then moves around to the south and finally west.  Pay attention to what slopes are getting cooked by the sun and to what degree.