WRF Dynamical Downscaling and Bias Correction Schemes for NCEP Estimated Hydro-Meteorological Variables Prashant K. Srivastava & Tanvir Islam & Manika Gupta & George Petropoulos & Qiang Dai Received: 23 September 2014 /Accepted: 19 January 2015 # Springer Science+Business Media Dordrecht 2015 Abstract Rainfall and Reference Evapotranspiration (ETo) are the most fundamental and significant variables in hydrological modelling. However, these variables are generally not available over ungauged catchments. ETo estimation usually needs measurements of weather variables such as wind speed, air temperature, solar radiation and dew point. After the development of reanalysis global datasets such as the National Centre for Environmental Prediction (NCEP) and high performance modelling framework Weather Research and Fore- casting (WRF) model, it is now possible to estimate the rainfall and ETo for any coordinates. In this study, the WRF modelling system was employed to downscale the global NCEP reanalysis datasets over the Brue catchment, England, U.K. After downscaling, two statistical bias correction schemes were used, the first was based on sophisticated computing algorithms i.e., Relevance Vector Machine (RVM), while the second was based on the more simple Water Resour Manage DOI 10.1007/s11269-015-0940-z P. K. Srivastava (*) : M. Gupta Hydrological Sciences, NASA Goddard Space Flight Center, Greenbelt, MD, USA e-mail: prashant.k.srivastava@nasa.gov Prashant K. Srivastava e-mail: prashant.just@gmail.com P. K. Srivastava Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA T. Islam NOAA/NESDIS Center for Satellite Applications and Research, Greenbelt, MD, USA T. Islam Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO, USA G. Petropoulos Department of Geography and Earth Sciences, University of Aberystwyth, Wales, UK Q. Dai Department of Civil Engineering, University of Bristol, Bristol, UK M. Gupta Universities Space Research Association, Columbia, MD, USA