Evaluating Flood Inundation Maps Using Innovative Tools

The National Weather Service (NWS) currently offers three real-time Flood Inundation Mapping (FIM) services to 30% of the United States population. NWS plans to expand the capability to 100% of the United States population through 2026. The National Water Center (NWC) and field forecasters continuously and rigorously review and evaluate the NWS FIM services before, during, and after high impact flooding events. These evaluations allow NWS forecasters to offer scientific understanding and actionable intelligence derived by FIM services to NWS partners in real-time.

The NWS FIM services are built upon the expansive spatial and temporal resolution capabilities of the National Water Model (NWM) which includes 3.6 million river miles. This includes the contiguous United States, Alaska, Hawaii, and Puerto Rico. The expansiveness of these services present a multitude of new challenges for forecasters responsible for conducting evaluations due to the millions of river miles of available FIM. These challenges include gathering of intelligence from a multitude of sources for evaluating the vast amount of FIM data and communicating the results of those evaluations in a timely manner so that partners can use that information to protect lives and property.

The NWC has made great efforts to mitigate these challenges through the development of innovative tools. These tools consolidate critical data used in the evaluation of FIM, provide real-time evaluation metrics, and automate and streamline collaboration among NWS forecasters. This has allowed the NWS to provide near real-time intelligence on predicted flood impacts using FIM services at the neighborhood-level in a consistent and timely manner. During this presentation, we will discuss the national center’s unique approach to the evaluation of real-time FIM used to support impact-based decision support services with innovative tools.