As a significant step forward to transform NOAA’s water prediction services, NOAA plans to implement a new National Water Model (NWM) Version 1.0 in August 2016 on NOAA’s Weather and Climate Operational Supercomputing System (WCOSS). A continental-scale water resources model, the NWM is an evolution of the WRF-Hydro architecture developed by the National Center for Atmospheric Research (NCAR) and its global collaborator community. WRF-Hydro is a community-based, Earth System Modeling Framework (ESMF)-compatible hydrologic modeling framework. Version 1.0 of the NWM provides a foundation that supports out-year growth in operational hydrologic forecasting capability. Goals for the initial implementation of the NWM include: Provide forecast streamflow guidance for underserved locations; Produce spatially continuous national estimates of hydrologic states (soil moisture, snow pack, etc.); Seamlessly interface real-time hydrologic products into an advanced geospatial intelligence framework; Provide a modeling architecture that permits rapid infusion of new data, science and technology.
The NWM represents NOAA’s first foray into high performance computing for water prediction and will expand NOAA’s current water quantity forecasts, at approximately 4000 U.S. Geological Survey (USGS) stream gage sites across the country, to forecasts of flow at 2.7 million stream reaches, as well as spatially-continuous forecasts of soil moisture, evapotranspiration, runoff, snow water equivalent and other parameters on a high resolution 1-km grid nationwide. This new guidance will be provided to NOAA's River Forecast Centers around the country and other field offices, along with guidance for evaluation and validation, and tools to visualize these data. Initially, a subset of NWM guidance will be available via NOAA’s Office of Water Prediction (OWP) web site and the full output of the NWM simulations will be available via the NOAA Operational Model Archive and Distribution System (NOMADS). These enhancements will improve NWS' ability to deliver impact-based decision support services nationwide through the provision of short through extended range, high fidelity “street level” water forecasts and warnings.
Early evaluation of the model at validation locations nationwide indicates promising skill, particularly in areas of unregulated (natural) flow. In addition, initial case studies have demonstrated valuable forecast skill at current Advanced Hydrologic Prediction Service (AHPS) locations and in areas which lack both stream gauge observations and AHPS forecasts. Planned out-year enhancements to the NWM include the expanded assimilation of anthropogenic water management data, the incorporation of enhanced forcings, the provision of real-time flood forecast inundation maps, an operational nest to provide higher resolution forecasts needed to account for the built environment in urban areas, two-way coupling of the NWM with coastal estuary models for “total water level” forecasts in coastal zones, coupling with more advanced groundwater models to improve forecasts of low flow and drought, and tackling deeper challenges associated with water quality.
The NWM is a NOAA-led interagency effort that relies on the National Hydrographic Dataset (NHD) Plus Version 2 of the USGS and Environmental Protection Agency (EPA), as well as the National Streamflow Information Program of the USGS. The development and implementation of the NWM Version 1.0 is the result of strong collaboration with NCAR and a partnership with the Consortium for the Advancement of Hydrologic Sciences, Inc. (CUASHI), the National Science Foundation (NSF), and Federal Integrated Water Resources Science and Services (IWRSS) partners. To facilitate scientific collaboration and accelerate research to operations activities, NOAA OWP’s National Water Center (NWC) began hosting an annual Innovator’s Program in 2015. The Innovator’s Program is a partnership between NOAA, CUASHI and NSF that has two overarching goals: Provide a framework for collaboration between the federal and academic communities that fosters innovation and creativity; and Target emerging technologies such as advanced water resources modeling capabilities, cutting edge data and interoperability services, or interdisciplinary techniques aligned with NOAA and the OWP strategic science and service plans. Year one included a competitive Summer Institute for 45 graduate students from 19 Universities at the NWC from June 1 to July 17, 2015, which demonstrated the ability to utilize WRF-Hydro to simultaneously model the entire continental United States river network at high spatial resolution, in near real-time for 2.7 million stream reaches. A more elaborate version of this prototype, which leverages the NHD-Plus, enhanced data assimilation, and improved computational efficiency, is being implemented as NWM Version 1.0. Year two included a competitive Summer Institute for 34 graduate students from 21 Universities at the NWC from June 6 to July 21, 2016, which successfully demonstrated the ability to generate flood inundation maps utilizing NWM output for Tuscaloosa County, Alabama. The 2016 program engaged social scientists and stakeholders from the Fire, Police and Emergency Management Communities to explore ways to best communicate water information. Future advancements in NOAA’s water predication capabilities will continue to leverage these partnerships, as well as expanded collaboration with Federal partners and the broader water resources enterprise. This presentation will highlight the policy, programmatic, and service transformation of NOAA’s water resources mission leveraging the NWM.