The analysis and prediction of convective storms is not straightforward due to the complexity of the processes involved and the multiple scales at which they occur. Nowcasting of thunderstorms is generally based on radar images extrapolation. Unfortunately, this technique is not able to predict the evolution of the storm intensity or the initiation of new storms. A better insight of the characteristics of convective storms is required. Weather radars are best suited to observe this phenomenon at high spatial and temporal resolution. The radar volume data archived at RMI since 2003 provide a wealth of information for statistical studies on storm properties. The cell tracking system TITAN has been used to retrieve convective storm tracks from the radar data. Preliminary results obtained for the period 2006-2008 are presented here. Empirical distributions of different storm properties such as duration, maximum reflectivity or echo-top have been generated. Spatial characteristics of the storm tracks are also derived like the mean direction of displacement and a map of the storm initiation density.