Flash flooding kills 4 in Kentucky, 1 in Tennessee

A woman was killed on Sunday in Tennessee as she attempted to rescue her son, who had been swept away in high waters, a local sheriff's office said, as a flash flood threat was in effect for parts of Tennessee and Kentucky, where four other deaths were recorded.

The Grainger County Sheriff's Department in Tennessee said Mary Evelyn Nicole Manning-Kellione, 39, was killed on Sunday after she went to rescue her son after rising water carried him into a culvert.

"The son was able to surface at the other end and came to safety when he realized his mother was in the water," the office said in a statement. "Rescue personnel located the individual lodged inside the culvert."

The National Weather Service (NWS) Prediction Center had upgraded the flood threat on Sunday for parts of Kentucky and Tennessee to a level 3 out of 4 "moderate risk."

Kentucky residents had been bracing for another round of relentless rain, a day after flash flooding killed at least four people and the governor declared a state of emergency.

The heaviest rain had been expected in southeast Kentucky and parts of Tennessee, including Owensboro and Somerset, Kentucky, and Knoxville, Tennessee.

Rainfall rates of 2 to 3 inches per hour are possible, according to the NWS, and daily totals could reach up to five inches in some parts.

Several flash-flood warnings were issued on Sunday morning as ongoing heavy rain and flooding were reported in southern Indiana and northeast Tennessee. A flash flood emergency has been issued for Metcalf, Cumberland and Clinton counties for ongoing life-threatening flooding, according to the NWS. Between 2.6 and 8 inches of rain have reportedly fallen over these areas.

There have been reports of multiple water rescues with some evacuations and homes flooded in Clinton County. Clinton County and the City of Albany, Kentucky, have issued states of emergency due to ongoing flooding.

Northwest North Carolina, which was hit by flash floods over the weekend, is also at an "elevated risk" of flash flooding on Sunday, according to the NWS.

Kentucky Gov. Andy Beshear provided an update early Sunday afternoon in a video posted to X, saying in part that nine counties in all had declared states of emergency, some of which "got hit with record or almost record amounts of rain in very short periods of time," he said. Search and rescue efforts remain underway, he said.

Beshear advised residents to stay off of the roads if they can. "Bridges have been wiped out, entire roads have been wiped away and there is still standing and moving water,” he said. He added that he'd activated the state's price-gouging laws to prevent merchants from increasing prices on essential goods, and had also signed an emergency order “so pharmacies in areas that are hit can go ahead and fill people’s prescriptions that have been washed away or are no longer safe to take.”

The severe weather comes after a weekend of deadly flash flooding that occurred in Kentucky.

More than 10 inches of rain fell on Saturday in parts of the state, prompting flash flooding and deaths.

Beshear announced late Saturday that four people were killed in floods that hit central Kentucky and spread into northeast Tennessee and northwest North Carolina.

"Kentucky, I have some tough news to share," the governor wrote in a social media post on Saturday, announcing the deaths.

Three fatalities occurred in Madison County, Kentucky, and one flood-related death happened in Jackson County, Beshear said.

According to the Madison County Coroner, of the three fatalities in the county, two of the deaths, one adult male and one adult female, occurred at a residence in Richmond.

The third death was an adult male who was swept away in his vehicle on Tates Creek Road in Madison County, the coroner said.

Beshear declared a statewide state of emergency on Saturday.

“This is a serious flooding event, where teams have already had to conduct multiple water rescues from vehicles and homes across the commonwealth," Beshear said.

As crews from Kentucky to North Carolina clean up from the storms, a prolonged spell of extreme heat is forecast to settle in across the Midwest and Northeast this week.

Heat alerts have been issued across the Plains to the Ohio Valley and south to the Tennessee and Mississippi Valleys.

An excessive heat warning has been posted for Kansas City, Missouri, through Thursday night.

Temperatures in Kansas City are expected to climb into the 90s on Sunday.

On Monday, widespread highs in the 90s are forecast across the country's midsection, but high humidity will make it feel hotter.

Excessive heat watches are expected to go into effect for Minneapolis and Chicago on Monday, with the temperature feeling like the triple digits during the afternoon hours.

In Minneapolis, the temperature could feel like 110 on Monday afternoon.

-ABC News' Ahmad Hemingway contributed to this report.