Identifying the potential risk for an avalanche is not an exact science. Weather including the volume and type of snowfall, temperature changes, even wind all play a role in increasing the risk. There is a classic scenario of a heavy snowfall on top of a weaker thin layer with rapidly increasing temperatures, but there is still the maybe it will, maybe it won't factor as long as man doesn't get involved. Sometimes people are advised to be alert of the risk and proceed at their own risk, sometimes trails are closed. In extreme cases mortars or artillery rounds are fired into high-risk areas purposely causing a smaller avalanche to prevent a larger event from happening.
People are complacent to the risks that a serious avalanche poses.
Cartoons and movies show avalanches as a survivable, almost comical event. In one real life film a skier is seen outrunning the advancing avalanche as he desperately flies down the side of the mountain. The reality is the mortality rate of people caught in avalanches is extremely high and the chances of out maneuvering or outrunning a wall of snow and ice are pretty slim. There are also a lot of myths about avalanches. Despite what you have seen in the movies a loud noise isn't likely to trigger an avalanche.