Abstract. This paper contains a preliminary analysis of flood risk in Mediterranean countries, conducted within the framework of the FLASH European Project. All flood events recorded between 1990 and 2006 in the Mediterranean region have been included in the study. Results of previous international projects (STORM, SPHERE, AMPHORE, RI-NAMED and MEDEX), as well as information provided by FLASH Project partners and data included in scientific papers were the main source used in building this database. All the above information had been dispersed in various places, and an attempt was made here to create, for the first time, a verified and complete single database for the entire Mediterranean region. The work analyses the spatial and temporal distribution of flood events, as well as their social impact, with special attention to certain case studies that have been analysed in detail.

Abstract. Dynamically induced rainfall is strongly connected with synoptic atmospheric circulation patterns at the upper levels. This study investigates the relationship between days of high precipitation volume events in the eastern Mediterranean and the associated geopotential height patterns at 500 hPa. To reduce the number of different patterns and to simplify the statistical processing, the input days were classified into clusters of synoptic cases having similar characteristics, by utilizing Kohonen Self Organizing Maps (SOM) architecture. Using this architecture, synoptic patterns were grouped into 9, 18, 27 and 36 clusters which were subsequently used in the analysis. The classification performance was tested by applying the method to extreme rainfall events in the eastern Mediterranean. The relationship of the synoptic upper air patterns (500 hPa height) and surface features (heavy rainfall events) was established, while the 36 member classification proved to be the most efficient.

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One of the costliest natural hazards around the globe is flash floods, resulting from localized intense convective precipitation over short periods of time. Since intense convective rainfall (especially over the continents) is well correlated with lightning activity in these storms, a European Union FP6 FLASH project was realized from 2006 to 2010, focusing on using lightning observations to better understand and predict convective storms that result in flash floods. As part of the project, 23 case studies of flash floods in the Mediterranean region were examined. For the analysis of these storms, lightning data were used together with rainfall estimates in order to understand the storms' development and electrification processes. In addition, these case studies were simulated using mesoscale meteorological models to better understand the local and synoptic conditions leading to such intense and damaging storms. As part of this project, tools for short-term predictions (nowcasts) of intense convection across the Mediterranean and Europe, and long-term forecasts (a few days) of the likelihood of intense convection, were developed and employed. The project also focused on educational outreach through a special Web site http://flashproject.org supplying real-time lightning observations, real-time experimental nowcasts, medium-range weather forecasts and educational materials. While flash floods and intense thunderstorms cannot be prevented, long-range regional lightning networks can supply valuable data, in real time, for warning the public, end-users and stakeholders of imminent intense rainfall and possible flash floods.

Abstract. The hydrological year 2007–2008 is the second drier in Cyprus since records are kept, for more than one hundred years. Since most of the rainfall is associated with depressions that affect the area during the cold months of the year, a study was carried out to investigate the characteristics of these synoptic-scale systems. The study comprises a statistical analysis of the synoptic and dynamic characteristics of the depressions that affected the area of Cyprus during the winter of 2007–2008.