HOPKINSVILLE, Ky. — Another round of torrential rain and flash flooding was coming Saturday for parts of the South and Midwest already heavily waterlogged by days of severe storms that also spawned some deadly tornadoes.

Round after round of heavy rains have pounded the central U.S., rapidly swelling waterways and prompting a series of flash flood emergencies in Missouri, Texas and Arkansas. The National Weather Service said 45 river locations in multiple states were expected to reach major flood stage, with extensive flooding of structures, roads, bridges and other critical infrastructure possible.

At least seven people were killed as the tornadoes destroyed entire neighborhoods, with more twisters possible in places this weekend. Flooding killed at least two more in Kentucky — 9-year-old boy swept away Friday on his way to school, and a 74-year-old whose body was found Saturday inside a fully submerged vehicle in Nelson County, authorities said.

And interstate commerce is affected — the extreme flooding across a corridor that includes the major cargo hubs in Louisville, Kentucky and Memphis could lead to shipping and supply chain delays, said Jonathan Porter, chief meteorologist at AccuWeather.

The outburst comes at a time when nearly half of NWS forecast offices have 20% vacancy rates after Trump administration job cuts — twice that of just a decade ago.

Downtown Hopkinsville, Kentucky, reopened early Saturday after floodwaters from the Little River receded, giving a much needed reprieve, but still more rainfall was on its way Saturday and Sunday, Mayor James R. Knight Jr. said.

Torrential rain since Wednesday had turned the downtown of the city of 31,000 into a lake Friday before the bands of weather shifted slightly.

“We got a little rain but most of it went north of us,” Knight said Saturday. “Thank goodness on that. Gave us a little break.”

Flash flood threat looms over many states

Flash flood emergencies continued to be issued Saturday across Arkansas, Mississippi and Tennessee, with more heavy rains and damaging winds in the mix. Weather officials in Tennessee, at least, predicted that the crescendo of severe weather risks would subside after Sunday.

“The finish line is in sight!” NWS Nashville posted on social media.

Yet worst of it was expected Saturday afternoon and evening in Hopkinsville, where predictions of another 3-4 inches of rain had people filling more sandbags to hold back another potential surge of floodwaters, Christian County Judge-Executive Jerry Gilliam said Saturday.

“We anticipate this water coming back quickly if it comes down quickly,” he said. “There are supposed to be three or four bursts of heavy rains throughout the day.”

Hundreds of Kentucky roads were impassable Friday because of floodwaters, downed trees or mud and rock slides, and the number of closures were likely to increase with more rain Saturday, said Kentucky Gov. Andy Beshear.

Flash flooding is particularly worrisome in rural Kentucky where water can rush off the mountains into the hollows. Less than four years ago, dozens died in flooding in the eastern part of the state.

In north central Kentucky, emergency officials ordered a mandatory evacuation for Falmouth, a town of 2,000 people in a bend of the swelling Licking River, as the rising water summoned fears of damaging floods. The warnings were similar to catastrophic flooding nearly 30 years prior when the river reached a record 50 feet high, resulting in five deaths and 1,000 homes destroyed.

Over in Arkansas, weather officials pleaded with the public to avoid all travel unless absolutely necessary due to the widespread flooding.

On Saturday, BNSF confirmed that a railroad bridge in Mammoth Spring was washed out by floodwaters that caused the derailment of several cars. No injuries were reported, but BNSF had no immediate estimate when the bridge would reopen.

“The magnitude of flash flooding taking place in portions of the state is catastrophic, the NWS warned.

Why so much nasty weather?

Since Wednesday, more than a foot of rain — or 30.5 centimeters — has now fallen in parts of Kentucky, and more than 8 inches (20 centimeters) has fallen in parts of Arkansas and Missouri, forecasters said Saturday.

Forecasters attributed the violent weather to warm temperatures, an unstable atmosphere, strong wind shear and abundant moisture streaming from the Gulf.

At least two reports of observed tornadoes were noted Friday evening in Missouri and Arkansas, according to the NWS. One, near Blytheville, Arkansas, lofted debris at least 25,000 feet (7.6 kilometers) high, according to weather service meteorologist Chelly Amin. The state’s emergency management office reported damage in 22 counties from tornadoes, wind, hail and flash flooding.

Tennessee Gov. Bill Lee said entire neighborhoods in the hard-hit town of Selmer were “completely wiped out,” after it was hit by a tornado with winds estimated by the NWS of up to 160 mph (257 kph). Advance warning of storms likely saved lives as hundreds of people sheltered at a courthouse, the governor said.

Mississippi’s governor said at least 60 homes were damaged. And in far western Kentucky, four people were injured while taking shelter in a vehicle under a church carport, according to the emergency management office in Ballard County.