Improving Near Real-Time Operational Flood Inundation Mapping Capabilities through the use of Replace and Route

Riverine floods are dangerous natural disasters that endanger lives and cost billions of dollars in damages. To better inform the public of flooding events, River Forecast Centers (RFC) generate predictions for ~3800 locations of interest (LIDs) to inform emergency response and water resources management. These forecasts are then routed using the Muskingum-Cunge method as employed in the WRF-Hydro-based National Water Model (NWM) version 3.0, replacing base NWM predictions to provide a more accurate forecast for the LID. This work updates the replace and route functionality to work within the Next Generation Water Resources Modeling Framework (NextGen) suite of capabilities that will comprise NWM version 4.0. In partnership with the Office of Water Prediction (OWP), we are developing a near real-time Replace and Route (RnR) System to ingest RFC forecasts, then route forecasted discharge through sections of the National Hydrologic Geospatial Fabric Reference Hydrofabric to produce forecast hydrographs. Our near real-time methodology is executed when an RFC location generates a forecast, executing an orchestration of microservices to configure the T-Route application with geospatial and NWM initial states, then pushes output files to be viewed as NetCDF files or through Web Services. Additionally, if the RFC determines a forecast is actionable, assimilation is performed to determine upstream flows, better informing the public of a potentially dangerous incoming event. This new methodology improves current NOAA OWP operational near real-time approaches in RFC forecast delivery speed and paves the way for future near-real time applications.