Be careful in avalanche release and runout areas. Avoid terrain traps. For danger level 3: Avoid avalanche release and run out areas.

Wet snow avalanches tend to release spontaneously.

Stability decreases when the snow surface gets wet and soft.

Timing is important

Wet snow

Characteristics

  • The avalanche problem is related to wetting and weakening of the snowpack due to the presence of liquid water. Water infiltrates the snowpack due to melt or rain. 
  • The problem can occur due to rain, sun, warm temperatures or lack of refreezing of the snowpack at night.
  • Avalanches can vary in size from small to large. Runout length can be very long with high water content.
  • Mainly natural release
  • If sun is the problem (typical spring conditions) - the danger increases during the day, most avalanches occur in afternoon when the temperature is higher.

 

Spatial distribution

  • When sun is the main cause, distribution of the problem is mostly depending on aspect and elevation.
  • All aspects are affected in the event of rain on snow.

 

Release characteristics

  • Warming leads to melting and loss of cohesion between snow particles.

 


 

Duration

  • Hours to days, depending on temperature, precipitation and radiation

 


 

Identification of the problem

  • Usually easy to recognize.
  • Wet and soft snow surface, onset of rain, snowballing, pin wheeling and recent loose wet avalanches are signs og instablity.
  • Deep foot-penetration is another sign of increased wetting.

 

Loose wet avalanche in Jostedalen. Photo: Jostein Aasen.