Be careful on steep slopes and around terrain traps until the new snow has stabilized. If danger level 3-considerable, wait until the snowpack stabilizes. 

The avalanche problem is generally widely distributed on any steep slope with deep new snow.

Look for cohesive new snow that breaks apart or is poorly bonded to the old snow. Cracks around your skis are a typical sign.

New snow

Characteristics

  • The avalanche problem is related to current or most recent snowfall.
  • The amount of additional loading by new snow onto the existing snowpack is the crucial factor of the new snow problem.
  • Critical snow amount is often 30-50 cm but how critical the loading is depends on various factors such as temperature or characteristics of the old snow surface.
  • The slab is often soft and easy to trigger.
  • Avalanche size is often underestimated, varies in size from small to very large.

 

Spatial distribution

  • Generally widely present and often in all aspects.
  • releases often from 30 degrees and steeper.
  • can release in all types of terrain, but most often above the treeline.

 

Release characteristics

  • Bonding processes in the new snow leads to formation of a soft slab (radiation, vind, temperature).
  • Additional load due to snowfall on existing or newly created weak layers.

 

Possible weak layers

  1. Buried weak layer of new snow
  2. Poor bonding between crust and overlying snow

 

Duration

  • Typically during snowfall and up to a few days after, depending on temperature and radiation.

 

Identification of the problem

  • The new snow problem is fairly easy to recognize.
  • Watch out for new snow amounts and recent avalanche activity.
  • Be aware of slight weather changes affecting new snow conditions.
  • Danger signs:
    • The new snow bonds into a soft slab
    • Cracking
    • Recent avalanches

 

Storm slab at Skogshorn in Hemsedal triggered by low adidtional load. Photo: Ragnar Ekker