Storm events will likely intensify under climate change. However, much uncertainty surrounds the intensification of high-magnitude events that are often inadequately resolved by global climate models. One major focus of my research efforts is devoted to understanding the evolution of atmospheric rivers (ARs) driven extreme storms over the largely impacted western US Coast. Capturing and representing the large-scale water vapor transport and landfalling features of AR-induced intense storm events can be quite challenging given the different tracks of ARs and complex interactions for both the heat and moisture transport over the coastal and inland terrains. In this seminar talk, in the first part, I will discuss the work involving AR-induced intense storm events investigation and an optimized climate modeling framework development. The work focuses on studying extreme AR event occurrences and their future changes under continuous warming, with dynamically linking large-scale forcings to mesoscale processes at event-based using large ensemble simulations. The results not only highlighted the future increases in intense atmospheric river-induced precipitation extremes, but also provided an effective modeling framework and diagnosing methods for studying other extreme weather events at rarely fine-scales. In the second part of the talk, I will discuss hydroclimate responses and impacts over the Sierra Nevada mountains driven by the extreme AR storm events. This work quantified that future changes of surface runoff driven by intensified storm events are dramatic, reflecting both the precipitation increase and reduced snowfall. The results from those work not only have significant implications for natural hazards predictions and assessments, water resource management and flood control, but also disaster resilience planning and emergency response exercises.