Question: how are weather forecast predictied ?

Werner Muller answered on 19 Nov 2013:

Big computer systems are used. They have all the old weather data in their memory. Based on the past data, the computer looks for patterns and if the current development fits to past patterns then the computer suggests the future based on past experience. However, a lot can change and the prediction has to be updated continuously, over time the predictions get better and better because the computers can calculate faster and more information is captured.