Fresh avalanches from the past day or two. An obvious sign of instability.
Natural or human-triggered avalanches in the past 48 hours are the number one sign of instability. Simply put, if you see avalanches occurring on their own, or you see someone trigger an avalanche, the odds are pointing towards more of the same. Fresh avalanches often have sharp, well-defined edges and crown lines. Older avalanches appear softer and less defined, and their debris and bed surfaces are covered by subsequent snow.