Severe convection nowcasting in the Alpine region: the COALITION approach

COALITION (Context and Scale Oriented Thunderstorm Satellite Predictors Development) is an innovative object-oriented model developed in the context of the EUMETSAT Fellowship program. The main purpose of this project is to increase the lead time in nowcasting severe convection over complex terrain. Data provided by different sources (e.g. Meteosat Second Generation Rapid Scan, Weather Radar, Numerical Weather Prediction and climatology) are merged into a heuristic model. Furthermore, the orographic forcing (often neglected in heuristic nowcasting models) is considered and included in the system as an additional convection triggering mechanism. This is particularly important over areas characterized by complex terrain like the Alps.