This session highlights advances in regional Earth system and hydroclimate modeling to meet urgent societal needs for actionable support. As extreme events intensify and competing demands across the water-energy-food nexus grow — from urban water supply to energy infrastructure and sectors such as AI data centers — reliable regional hydroclimate prediction becomes critical for planning and resource management. This session addresses hydroclimate variability and compound extremes including heatwaves, droughts, and floods, and their cascading impacts on natural and human systems. We invite contributions on high-resolution regional modeling, coupled hydrologic-atmospheric frameworks, downscaling, uncertainty quantification, biosphere-atmosphere feedbacks, groundwater-surface water interactions, and AI/ML innovations including foundation models and physics-informed approaches, leveraging remote sensing, in-situ networks, and subseasonal-to-decadal prediction datasets to advance early warning and actionable information for water managers, energy planners, and emergency response agencies. By fostering interdisciplinary collaboration, this session aims to accelerate environmental resilience at regional to global scales.

• GC - Global Environmental Change
• H - Hydrology
• NH - Natural Hazards