Inter-Agency Committee on the Hydrological Use of Weather Radar. Eighth report 2010 to 2012

As with the previous session report, we open reflecting on a period of significant UK flooding. The Summer and Autumn 2012 floods are still very fresh in the memory of those who have been trying to manage and respond to these events and for some the impacts are still affecting daily lives. Initial estimates indicate that the 2012 summer floods affected 2,700 properties with 70,000 properties receiving flood warnings. No doubt these damages estimates will increase as further information is gathered. However, what has changed from the previous 2007 to 2010 session has been the further development of meteorological and hydrological forecasting approaches and the emergence of hydrometeorology capabilities across England, Wales and Scotland to help improve prediction of these types of events. Radar continues to play an important role in flood risk and water management and the application of emerging science is the focus of this report. At the beginning of this current session, the Committee were keen to promote ways to influence the greater use of weather radar by operating agencies and to highlight areas of improvement and research in support of the user community. Specifically, the Committee wanted to explore various service and system developments, understand various ongoing research areas and their application for hydrology and water management, and promote the role of radar in flood risk management. Section 3 of the Committee report highlights research needs and presents the considerable range of ongoing science developments across various research groups. The approaches to raingauge-radar merging and data assimilation of radar data for Numerical Weather Prediction are presented as are the requirements from an established hydrological and emerging water management community. The requirement to provide forecasting capabilities for the whole of the country and for longer lead times was driven as an outcome of the Pitt Review. In Section 4, the efforts of some agencies in developing these capabilities are presented with emphasis on the development of countrywide grid-based hydrological models. In addition, Section 4 reflects on the largest upgrade to the UK radar network in its 30 year history and the introduction of significant radar capabilities that will benefit the user community once completed. Section 5 presents what has been the main focal point for the Committee’s attention during the session period. Following the Committee’s successful bid to host the International Symposium on Weather Radar and Hydrology, most of the Committee have been in some way involved in the successful delivery of this major event. Held over four days at the University of Exeter, this was the 8th in the symposium series and attracted over 250 international delegates. It is worth highlighting that following the organisation of Weather Radar and Hydrology 2011, the International Association of Hydrological Sciences has now published the conference proceedings as part of their Red Book series. The volume brings together over 100 peer-reviewed papers from the symposium providing a valuable record of the current activity in this field. Finally, the appendices to this session report provide an overview of the UK academic and operational agency activity in this sector