The Error is the Feature: how to Forecast Lightning using a Model Prediction Error.

Despite the progress throughout the last decades, weather forecasting is still a challenging and computationally expensive task. Most models which are currently operated by meteorological services around the world rely on numerical weather prediction, a system based on mathematical algorithms describing physical effects. Recent progress in artificial intelligence however demonstrates that machine learning can be successfully applied to many research fields, especially areas dealing with big data that can be used for training. Current approaches to predict thunderstorms often focus on indices describing temperature differences in the atmosphere. If these indices reach a critical threshold, the forecast system emits a thunderstorm warning. Other meteorological systems such as radar and lightning detection systems are added for a more precise prediction. This paper describes a new approach to the prediction of lightnings based on machine learning rather than complex numerical computations. The error of optical flow algorithms applied to images of meteorological satellites is interpreted as a sign for convection potentially leading to thunderstorms. These results are used as the base for the feature generation phase incorporating different convolution steps. Tree classifier models are then trained to predict lightnings within the next few hours (called nowcasting) based on these features. The evaluation section compares the predictive power of the different models and the impact of different features on the classification result.