Research Team: Katie van Werkhoven, Chaopeng Shen, Louise Arnal, John Park, Martyn Clark, Grey Nearing, Paul Miller, Seann Reed, Brad Gillies
Insitution: Colorado School of Mines, Golden, Colorado; RTI International; Penn State University; Ouranos; University of Saskatchewan; Colorado Basin River Forecast Center; Middle Atlantic River Forecast Center; Northwest River Forecast Center
Start Date: June 1, 2023 | End Date: May 31, 2025
Research Theme:
Over the past decade, the National Water Model (NWM) has developed limited ensemble prediction products in the NWM; meanwhile the NWS River Forecast Centers (RFCs) have deployed core ensemble prediction through the Hydrologic Ensemble Forecast Service (HEFS) and the Met-Model Ensemble Forecast System (MMEFS). The new flexibility of Nextgen allows for introducing full ensemble methods in the NWM and an opportunity to refine and benchmark variations on HEFS methods. The overarching goal of this project is to connect NOAA ensemble hydrologic forecasting science and development efforts with both the ‘next generation’ Water Resources Modeling framework (Nextgen) as well as the RFC HEFS capabilities, which is implemented in the Community Hydrologic Prediction System (CHPS), and the supporting communities for each forecasting activity. This will be accomplished by developing approaches to extend the Nextgen capabilities to incorporate ensemble forecast methods and models, including those pioneered by HEFS, and to use Nextgen experimentation to identify and test improved methods and datasets that can be used to advance HEFS. The work would advance the state of the practice by creating state-of-the-art ensemble forecasting capabilities in Nextgen, and ultimately in the NWM, while addressing previously identified gaps in HEFS performance. The research will build from the foundation of the existing Office of Water Prediction HEFS Testbed efforts, which have identified approximately 100 catchments across the US and Alaska as a focus for research and development on HEFS techniques. It will use hindcasts to intercompare performance of Nextgen and HEFS ensemble forecast approaches, and seek to cross-fertilize high-performing methods between the two operational systems. The project directly supports CIROH Research Theme 1 (Advancing Operational Prediction), and will expand the hydrologic forecast Testbed being developed in the current CIROH Testbed project that is also led by PI Wood. A major goal is to align NOAA flagship hydrologic forecasting services with the recognized need for uncertainty quantification, and benefit operations through improved ensemble forecasting for risk-based decision making in HEFS, Nextgen, and ultimately the NWM.