The death toll from flooding in eastern Kentucky increased to 37 on Monday, as further rain slowed cleanup efforts and expected severe weather overnight threatened to exacerbate the situation.

"We are ending the day with more heartbreaking news out of Eastern Kentucky. We can confirm the death toll has now risen to 37, with so many more still missing," tweeted Andy Beshear, governor of the south-central US state."

"Let us pray for these families and come together to wrap our arms around our fellow Kentuckians," he added. Beshear has stated that he expects the death toll to climb as search and rescue teams spread out over flood-affected areas and retrieve additional dead.

Their efforts were hampered by more rain on Monday, with a series of new storms forecast to arrive overnight. "If things weren't hard enough on the people of this region, they're getting rain right now," Beshear said earlier in the day.

"There is severe storm potential today in all of the impacted areas. "That is just not right." The National Weather Service issued flood watches for most of eastern Kentucky for the evening and into Tuesday morning, warning that "a complex of storms is expected to move over the region tonight."

"Heavy rain rates which could lead to flash flooding along with severe thunderstorms are possible," the weather agency tweeted.

Read next: Death toll rises to at least 25 in Kentucky flooding: Governor

Last week, several regions in eastern Kentucky received more than eight inches (20 centimeters) of rain in 24 hours, causing severe flash flooding.

The water level in the North Fork of the Kentucky River near Whitesburg climbed to a dizzying 20 feet in just a few hours, breaking the previous record of 14.7 feet.

Some portions of the rugged Appalachia region remain unreachable as a result of the flooding that converted roads into rivers, washed out bridges, and washed away dwellings.

The floods affected a region of Kentucky that was already in deep poverty, owing to the demise of the coal industry, which was the backbone of the state's economy.

President Joe Biden has declared the state a disaster, allowing federal funding to supplement state and local recovery efforts.

The flooding in eastern Kentucky is the latest in a string of extreme weather occurrences that scientists say are undeniable evidence of climate change.

Nearly 60 people were killed in western Kentucky by a tornado in December 2021.