Flooding in Tennessee and central U.S. hits levels rarely seen in the last 200 years

An outbreak of extreme weather has roiled the country with deadly dust storms in the plains and hundreds of tornadoes across the eastern U.S. over the past few weeks. Now, heavy rainfall across parts of the South and Midwest is prompting comparisons with some of the worst flooding on record for the region. Very moist air from the record-warm Gulf of Mexico is being drawn northward into a stalled frontal system creating a perfect recipe for torrential rains. Parts of the Ohio and Mississippi River Valleys received more than 15 inches of rain over the past four days. High water swept away buildings, forced water rescues in river towns, and cut off rural areas when roads flooded. More than 18 people have died, just days after damaging tornadoes swept through some of the same locations. The rains prompted dire wording from the National Weather Service including warnings of a “potentially historic, prolonged flash flood event” and “serious concern of catastrophic, life-threatening” consequences from “generational” rainfall. “This isn’t routine. This is a rare, high-impact, and potentially devastating event,” said a social media post from the Memphis office of the National Weather Service. This week’s floods are set to reach a mark set only a handful of times over the past 200 years. The region’s last floods of this magnitude were in 1997 and 2011. In 1997, parts of western Kentucky received more than 10 inches of rain in a single day, which created turbulent currents on the Ohio River strong enough to flood the lock-and-dam infrastructure that allows barge traffic to operate. In 2011, water rose so rapidly that the U.S. Army Corps of Engineers had to blast a hole in levees along Mississippi River farmland in rural southern Missouri in a last-ditch effort to avoid an uncontrolled breach of the levees further downstream in Memphis, Baton Rouge, and New Orleans. The worst-case scenario for the Ohio River was the flood of 1937—in which the river peaked about 10 feet higher than current forecasts. Although that magnitude isn’t expected this time, a similar amount of rain fell—just about 100 miles further north than this week’s storms, enough so nearly all runoff went into the Ohio River. More than a million people were homeless after the 1937 flood, and only one bridge was left intact between Pittsburgh and Memphis. The flood struck during the middle of the Dust Bowl and at the end of the Great Depression, and it paved the way for the modern system of flood control through levees and dams. Although weather forecasts for the rains have been reliable, the National Weather Service continues to be stretched thin due to Trump’s budget cuts. A staffing assessment gathered by NWS employees and published by the Associated Press on Friday found that nearly half of all local forecast offices are now critically understaffed, reducing meteorologists’ ability to interface with the public and local emergency management. “Detailed vacancy data for all 122 weather field offices show eight offices are missing more than 35% of their staff—including those in Arkansas and Kentucky where tornadoes and torrential rain hit this week,” said the report. A four-day total rainfall of 15 inches is more than Memphis typically receives in April, May, and June combined. According to NWS data, in a stable climate, that kind of rainstorm is only expected to recur approximately once every 500 to 1,000 years. This is exactly the sort of extreme weather event that our infrastructure isn’t built to handle. According to the Corps of Engineers, many of the locks and dams along the Ohio River are beyond their 50-year lifespan. Climate change increases the risk of extreme rainfall events, and the Corps is in the process of updating its flood maps to account for those changes nationwide. This week’s rains have already created major flash flooding in cities and smaller rivers from Texas to Ohio. Near the confluence with the Mississippi River, the Ohio River is expected to crest by mid-April at its highest level since 2011—just a few feet below the tops of the levees there. All that water will gradually make its way into the Mississippi and out to the Gulf of Mexico through Louisiana. In addition to physical damages, the flooding could bring weeks of shipping delays for companies that rely on the roads and river barges that form the backbone of the Midwest’s economy. This week’s flooding could add to supply chain chaos as Trump’s latest tariffs go into effect. The governors of Arkansas, Kentucky, and Tennessee have asked the federal government for help, and Kentucky has also activated its National Guard to help respond to the floods. The governors have also declared states of emergency as waters continue to rise.

Apr 7, 2025 - 15:35

Flooding in Tennessee and central U.S. hits levels rarely seen in the last 200 years

An outbreak of extreme weather has roiled the country with deadly dust storms in the plains and hundreds of tornadoes across the eastern U.S. over the past few weeks.

Now, heavy rainfall across parts of the South and Midwest is prompting comparisons with some of the worst flooding on record for the region.

Very moist air from the record-warm Gulf of Mexico is being drawn northward into a stalled frontal system creating a perfect recipe for torrential rains. Parts of the Ohio and Mississippi River Valleys received more than 15 inches of rain over the past four days.

High water swept away buildings, forced water rescues in river towns, and cut off rural areas when roads flooded. More than 18 people have died, just days after damaging tornadoes swept through some of the same locations.

The rains prompted dire wording from the National Weather Service including warnings of a “potentially historic, prolonged flash flood event” and “serious concern of catastrophic, life-threatening” consequences from “generational” rainfall.

“This isn’t routine. This is a rare, high-impact, and potentially devastating event,” said a social media post from the Memphis office of the National Weather Service.

This week’s floods are set to reach a mark set only a handful of times over the past 200 years. The region’s last floods of this magnitude were in 1997 and 2011. In 1997, parts of western Kentucky received more than 10 inches of rain in a single day, which created turbulent currents on the Ohio River strong enough to flood the lock-and-dam infrastructure that allows barge traffic to operate.

In 2011, water rose so rapidly that the U.S. Army Corps of Engineers had to blast a hole in levees along Mississippi River farmland in rural southern Missouri in a last-ditch effort to avoid an uncontrolled breach of the levees further downstream in Memphis, Baton Rouge, and New Orleans.

The worst-case scenario for the Ohio River was the flood of 1937—in which the river peaked about 10 feet higher than current forecasts. Although that magnitude isn’t expected this time, a similar amount of rain fell—just about 100 miles further north than this week’s storms, enough so nearly all runoff went into the Ohio River. More than a million people were homeless after the 1937 flood, and only one bridge was left intact between Pittsburgh and Memphis. The flood struck during the middle of the Dust Bowl and at the end of the Great Depression, and it paved the way for the modern system of flood control through levees and dams.

Although weather forecasts for the rains have been reliable, the National Weather Service continues to be stretched thin due to Trump’s budget cuts.

A staffing assessment gathered by NWS employees and published by the Associated Press on Friday found that nearly half of all local forecast offices are now critically understaffed, reducing meteorologists’ ability to interface with the public and local emergency management.

“Detailed vacancy data for all 122 weather field offices show eight offices are missing more than 35% of their staff—including those in Arkansas and Kentucky where tornadoes and torrential rain hit this week,” said the report.

A four-day total rainfall of 15 inches is more than Memphis typically receives in April, May, and June combined. According to NWS data, in a stable climate, that kind of rainstorm is only expected to recur approximately once every 500 to 1,000 years.

This is exactly the sort of extreme weather event that our infrastructure isn’t built to handle. According to the Corps of Engineers, many of the locks and dams along the Ohio River are beyond their 50-year lifespan. Climate change increases the risk of extreme rainfall events, and the Corps is in the process of updating its flood maps to account for those changes nationwide.

This week’s rains have already created major flash flooding in cities and smaller rivers from Texas to Ohio. Near the confluence with the Mississippi River, the Ohio River is expected to crest by mid-April at its highest level since 2011—just a few feet below the tops of the levees there.

All that water will gradually make its way into the Mississippi and out to the Gulf of Mexico through Louisiana. In addition to physical damages, the flooding could bring weeks of shipping delays for companies that rely on the roads and river barges that form the backbone of the Midwest’s economy. This week’s flooding could add to supply chain chaos as Trump’s latest tariffs go into effect.

The governors of Arkansas, Kentucky, and Tennessee have asked the federal government for help, and Kentucky has also activated its National Guard to help respond to the floods. The governors have also declared states of emergency as waters continue to rise.