After unleashing dozens of destructive tornadoes, a slow-moving storm system dumped heavy rain across the U.S. Midwest and Southeast in early April 2025. In some areas, 10-15 inches (25-38 centimeters) fell between April 1 and 6. According to hydrograph data from the National Weather Service, the rain fueled major floods on several tributaries of the Mississippi River, particularly within the Ohio River watershed in Kentucky, Illinois, and Indiana, and along the Black River and White River in Arkansas.
A break in the clouds on April 7, 2025, revealed to satellites the widespread flooding that spanned several states. The image above (right) was acquired by the VIIRS (Visible Infrared Imaging Radiometer Suite) on the NOAA-21 satellite. The other image, also acquired by VIIRS, shows the same area before the deluge.
Both images were assembled from false-color data using a combination of infrared and visible light (VIIRS bands M11-I2-I1). Floodwater appears navy or black; vegetation is bright green; and bare ground is brown. This band combination makes it easier to spot changes in river dimensions.
Western Kentucky was particularly hard hit, according to news reports. In Frankfort, floodwater destroyed dozens of homes as the Kentucky River rose to 48.27 feet (14.71 meters) on April 7, the second-highest level on record. Floods swamped many buildings downtown, as well as America’s oldest continuously operating distillery and part of a water treatment plant.
Though rain in the region has stopped and flooding on some rivers has crested, forecasts from the National Weather Service show that water levels on the Mississippi River will continue to rise in the coming days as water works its way downstream through networks of lakes, reservoirs, and rivers in the region.
While scientists and water managers use many types of data to anticipate flooding, they have a relatively new source of information from the SWOT (Surface Water and Ocean Topography) satellite. Since early 2023, this NASA-CNES satellite has been measuring the height of nearly all water on Earth’s surface at least once every 21 days, including in the Ohio River Basin.
With this information, researchers are developing new ways to incorporate SWOT data into the National Oceanic and Atmospheric Administration’s National Water Model, which predicts the potential for flooding and its timing along U.S. rivers. SWOT data can help fill in spatial gaps in observations from ground-based water gauges, improve estimates of streamflow, and help quantify how much water lakes and reservoirs can store in ways that will help scientists build better flood models.
NASA’s Disasters Response Coordination System has been activated to support federal partners in the identification of damage, flooding, and landslide risks following the severe weather in the southern U.S. The team will be posting maps and data products on its open-access mapping portal as new information becomes available.
NASA Earth Observatory images by Wanmei Liang, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite System (JPSS). Story by Adam Voiland.
