His current research focuses principally on physical understanding and prediction of climate in North America through regional atmospheric modeling and analysis of observations. Specific topics include improving seasonal climate forecasts, convective-resolving simulations of severe weather, water resource projection at the regional and local scale, and contributions to parameterization development in the Weather Research and Forecasting model. Through regional atmospheric modeling and climate data analysis, he has studied North American monsoon for more than a decade. His SERDP-funded research investigates the changing nature of severe weather during the monsoon in relation to climate change. Dr. Castro is a member of the American Meteorological Society.