Fred Ogden, Tom Graziano, Ed Clark and Trey Flowers, NOAA-NWS Office of Water Prediction
The NOAA-NWS Office of Water Prediction (OWP) has operated the National Water Model (NWM) since 2016. Improvements in model performance from version to version by calibration are beginning to plateau. Whereas the current NWM applies the same formulation everywhere, the hydrologic literature suggests improvements can be made through use of specific model formulations tailored regionally for individual stormflow generation processes. Potential increases in computational efficiency make possible the use of forcing ensembles, which offers significant potential for forecast improvements and uncertainty quantification.
In considering future improvements to the operational National Water Model, in 2020 the Office of Water Prediction proposed development of an open-source inter-agency "Next Generation Water Resources Modeling Framework" or (Nextgen). The aims of this development include promoting model interoperability, standardizing data and model setup workflows, easing implementation and evaluation of different modeling approaches, and engaging the academic research community.
Built using contemporary open-source standards and methods from computational and data sciences, the framework envisions simulations of coupled BMI-compliant model formulations on a hydrofabric described using the WaterML HY_FEATURES data model, running on hardware ranging from laptops to supercomputers. The Next Generation National Water Model (Nextgen-NWM) will represent a unique operational configuration of the Nextgen water resources modeling framework. Presently, OWP is finalizing development tasks aimed to operationalize the Nextgen-NWM in 2024.