The OPERA programme (Operational Programme for the Exchange of weather RAdar information, www.knmi.nld/opera) is the Weather Radar programme of EUMETNET, the Network of the European Meteorological Services (NMSs). The objective of OPERA is to harmonize and improve the operational exchange of weather radar information between national meteorological services. The third phase of the OPERA programme is a joint effort of 28 European countries, runs from 2007 till 2011, and is managed by KNMI. OPERA III is designed to firmly establish the Programme as the host of the European Weather Radar Network. The first OPERA programme (1999-2003) put emphasis on the specification of the meteorological products to exchange, to their exchange format, as well as on the software to enable the data exchange. The second OPERA programme (2004-2006) built on these achievements. Its main goal was to increase the exchange and use of the weather radar data in Europe, and to produce a set of recommendations and algorithms for the production of high quality weather radar data, including both wind and precipitation products. A pilot of an European datahub for weather radar data was established at the UK Met Office during this programme. The new OPERA programme will focus on the operational generation and quality control of an European weather radar composite, exchange of 3D radar reflectivity and wind data, exchange of quality information, and availability of radar data for official duties of NMSs and research. A Weather Radar Data Hub will be specified, developed, and operated during this phase of OPERA. This operational Data Hub is crucial for reaching the main objective of OPERA-3, i.e.; establishing the weather radar networking as a solid element of the European infrastructure. In the presentation, the OPERA programme and its objectives will be discussed, and opportunities for use of European weather radar data in hydrological research and applications will be introduced.