He has developed/improved statistical and physically-based frameworks to solve critical water resources problems at the regional and global scales. His research works have been publications in high-profile journals such as Nature Climate Change, Water Resources Research, and Journal of Hydrology among others. He received the 2017 Best Technical Paper Award for his publication: “Ensemble Combination of Seasonal Streamflow Forecasts” in ASCE’s Journal of Hydrologic Engineering. Najafi’s main interests are hydroclimatic extremes, detection and attribution, climate change impact, uncertainty assessment, multi-modelling, and hydrologic forecasting.