How do avalanches start?
Avalanches are started by either someone skiing or stepping on an area of weak snow. They can also be started on purpose by a loud sound by the forest rangers who are trying to keep people safe. They usually occur when there has been a rain or thawing conditions followed by a heavy snow storm. The thawing makes the snow weaker and unstable. Almost 98% of all avalances happen on slopes of 25-50 degrees and are on the non windward slope where the snow blows up and collects.
