Implementation of Forecast Flood Inundation Mapping Services for the Nation

The NOAA National Weather Service (NWS) has a mission to issue forecasts for the protection of lives and property, the delivery of impact-based decision support services, and the enhancement of the national economy. The longstanding demand for event-driven flood inundation mapping (FIM) has increased dramatically in recent years as a high value source of actionable information for emergency and water resource managers to prepare, mitigate, and respond to flood impacts. In response, the National Water Center of the National Weather Service (NWS), in coordination with NWS River Forecast Centers (RFC) and Weather Forecast Offices (WFO) along with Federal and other partners, has developed and demonstrated high-resolution inundation modeling capabilities which complement and expand upon existing static FIM libraries providing geo-referenced visualizations of forecast flooding extent at the continental scale. The NWS FIM methods deploy a model agnostic approach to map the inundation at a 10-meter horizontal resolution for rivers and streams in the National Hydrography Dataset network.

On September 26th, 2023, the NWS began disseminating a suite of flood inundation mapping services to 10% of the nation’s population including portions of east Texas as well as for parts of the Mid-Atlantic and Northeast. These services include: a) an hourly updating Latest Conditions inundation analysis extent base on the the NWM hourly streamflow analysis, b) the NWM 5-day maximum flood inundation extent forecast based on the NWM medium range streamflow guidance, and c) the RFC 5-day maximum flood inundation extent forecast which is based on RFC streamflow predictions. Over the next 3 years, NOAA will expand services to 30% of the U.S. population by the end of September 2024 including Puerto Rico and the U.S. Virgin Islands as the first OCONUS area, 60% of the U.S. population by the end of September 2025, and nearly 100% of the U.S. population by the end of September 2026.

This presentation will highlight the current suite of services available to the first 10% of the nation, discuss how broadcast media partners can access these services as both visualizations and as GIS services, and will present the full rollout over the next 3 years.