The primary application running at the supercomputers of HMS is the short range numerical weather prediction model, ALADIN. The operational version of the ALADIN/HU model is running twice a day for 48 hours integration. The recent version of the model has 8km horizontal and 49 levels vertical resolution. The capacity of the machines makes it possible beside operational activities to pursue extensive research and development activities around the ALADIN model. The most important development activities are briefly listed below:

• The further development of the three-dimensional variational data assimilation scheme for the ALADIN model with special emphasis on new data types and background error modelling.
• The development of ALADIN-based short range ensemble prediction system. This development work requires significant computer power due to the fact that the ensemble systems are based on multiple model runs. The common evaluation of the performances of the individual forecasts serves as a basis for probabilistic forecast guidance.
• The recently started project on regional climate modelling requires computer power for the adaptation, testing and validation of regional climate models. Two regional climate models are considered: ALADIN/Climate and REMO.

The developments briefly described above are supporting on the one hand the improvements of the nowcasting and short range weather prediction systems and on the other hand making possible to establish the modelling basis for regional climate modelling.