Weather radar and hydrology: a UK operational perspective

Weather radar forms an essential and integral tool for water management in the UK, especially for monitoring and warning of flooding: the main focus of this perspective paper. An overview is first given of the radar network and its associated rainfall data products used by the environment agencies responsible for flood defence. The Hyrad (HYdrological RADar) system is deployed to receive, visualise and analyse these products, and to further process them for use within flood forecasting systems. Regional systems employ networks of models configured to make forecasts at specific locations. Very recently, countrywide systems employing an area-wide G2G (Grid-to-Grid) hydrological model have been implemented. Both types of system, used operationally in a complementary way, are reviewed in relation to their use of, and demands for, weather radar-related data. Activity on implementing probabilistic approaches to flood forecasting which benefit from using radar in ensemble rainfall prediction is outlined, and future prospects discussed.