NOAA’s flood mapping tool now covers nearly 100% of U.S.

NOAA’s National Weather Service announced today that Flood Inundation Mapping (FIM), a revolutionary tool for predicting river flooding, is now available on an experimental basis to nearly 100% of the U.S. population. This is a massive expansion from FIM’s prior coverage of 60% of the country. 

FIM produces estimates of land area covered in water based on model forecast river flows and current conditions that predict where flooding impacts may occur in the following days. It’s a tool for forecasters, emergency managers and the public that alerts users to the latest river and stream flooding conditions. 

“Inundation maps are a critical tool for assessing the impacts of flooding,” said NOAA Administrator Neil Jacobs, Ph.D. “NOAA prioritized expanding FIM to ensure that nearly every American can access detailed information beyond the expected river crest height. These maps further support NOAA's mission to protect lives, safeguard property, and strengthen our national economy.”

FIM puts river and stream flooding on the map at a neighborhood scale. It depicts flooding potential along 3.3 million river miles throughout the continental U.S., U.S. territories and Hawaii. For the most recent expansion, FIM’s new coverage areas include: the southeastern U.S. coast and Florida; Great Lakes region; New England; the Rocky Mountains; the Dakotas; and western Nebraska.

Making a difference from day one

FIM has already helped the NWS understand, assess and communicate maximum river flood potential to emergency management personnel, medical care facilities, and other critical decision makers. Success stories from local NWS offices include: 

• NWS’s office in Nashville, TN used FIM to provide a Senior Assisted Living facility in Macon County information to safely evacuate residents in the spring of 2025, hours before floodwaters reached their doors.
• In April 2025, NWS office in Little Rock, Arkansas shared FIM with the city of Hardy, who went door to door to evacuate residents. The city reported a nearly 100% success rate in evacuations, saving lives. 
• As storms rapidly developed in central Texas over the weekend of July 4-7, 2025, the NWS office in Austin/San Antonio distributed FIM to Emergency Management in Georgetown, TX, allowing them to close roads and evacuate residents.
• In January 2025, the NWS local office in Shreveport, LA noted a large river rise imminent at the Glover River in Oklahoma. FIM allowed local emergency personnel to evacuate residents before the river rose.
• The Muskegon River in Michigan experienced major to record flooding in April 2026. The NWS office in Grand Rapids used FIM as a critical awareness tool in areas with little additional guidance.  

"FIM has been a game changer when briefing emergency managers, first responders, and communities facing flood risk," said National Weather Service Director Ken Graham. “It helps focus their response on the extent of flooding by using a strong and precise visualization tool.” 

About NOAA’s Flood Inundation Mapping 

FIM services first launched in 2023 covering 10% of the U.S. population and reached 60% in 2025. This latest expansion covering nearly 100% of U.S. residents does not yet cover northern and western portions of Alaska, Guam, the Northern Mariana Islands and American Samoa. Expanded FIM maps are publicly available on the National Water Prediction Service website, in several GIS applications available in multiple file types. 

Four versions of FIM are available in near-real time for the Lower 48 states and parts of south-central Alaska:

• National Water Model hourly analysis of current conditions
• National Water Model five-day inundation forecast
• NWS River Forecast Center (RFC) five-day inundation forecast
• Static “categorical” FIM (CatFIM) for select NWS River Forecast Points

FIM services for Hawaii, Puerto Rico and the U.S. Virgin Islands include:

• National Water Model hourly analysis of current conditions
• National Water Model 48-hour inundation forecast
• Static “categorical” FIM (CatFIM) for select points at gauged locations

NOAA’s Office of Water Prediction (OWP) is a division of the National Weather Service. In partnership with NWS national, regional and local offices, the OWP coordinates, integrates and supports consistent water prediction activities from global to local levels.