This study investigates the performance of neural network algorithms to sense tropospheric instability with the future METEOSAT Second Genertation satellite. Three algorithm approaches are developed with 'EuropaModell' data: (i) Global algorithms (ii) monthly algorithms, and (iii) so called 'on-line' algorithms which use recently observed data for training. ALI three ap preaches retrieve the Surface K-Index, a modified Surface K-Index and the precipitable water content with high performance, where the best performance is achieved with the 'on-Iine' algorithms. Investigations using 'Lokal Modell' data of a limited sample size show a better representation of the tropospheric instability and an increased retrieval performance, especially for other instability indices.