Earlier, flash flooding and tornadoes killed three people in Arkansas as powerful storms swept through the nation's midsection, including a local sheriff who drowned while checking on residents whose house was eventually swamped by rising water, authorities said Friday. Three other people are missing.
The storms rolled across the region overnight, and more bad weather was poised to strike Friday, with tornadoes and baseball-sized hail forecast from Oklahoma, Kansas and Missouri. Flooding also is a concern in parts of Missouri, Iowa and Illinois through Sunday.
Torrential rain, including at least 6 inches in the rugged terrain of western Arkansas, posed the greatest danger the night before. In Y City, about 125 miles west of Little Rock, the Fourche La Fave River rose 24 feet in just 24 hours.
"The water just comes off that hill like someone is pouring a bucket in there," said Danny Straessle, spokesman for the Arkansas Department of Highway and Transportation. "This was an incredible amount of water."
Scott County Sheriff Cody Carpenter died while trying to check on local residents during the storm. He and wildlife officer Joel Campora had traveled by boat up Mill Creek to reach two people who called for assistance -- and the river swamped the house while they were still inside.
"Other deputies heard a loud crash," said Bill Hollenbeck, the sheriff of neighboring Sebastian County. "They thought that the bridge had actually collapsed. Looking into it further, the house had imploded as a directly result of rising waters from Mill Creek."
Carpenter's body was recovered about a mile downstream. Campora and the two women inside the home remained missing Friday, Hollenbeck said.
"We're here right now for recovery or rescue. We're still remaining optimistic about our officer at this time," said Mike Knoedl, director of the Arkansas Game and Fish Commission. "(Campora) was an epitome of what a wildlife officer should be, and he was doing what he was trained to do last night."
A man died after strong winds toppled a tree onto his car in Tull, just west of Little Rock. Authorities also are attributing the death of a woman in Scott County to the flooding, though they've released no information other than her body was found in her car.
At least nine other people were reported injured.
Up to a dozen tornadoes touched down in mostly rural parts of Arkansas on Thursday, as well as three in Oklahoma and one in Illinois. In Oklahoma, one twister bounced through the Tulsa suburb of Broken Arrow, causing some structural damage, but no injuries.
Still, Greg Carbin, warning coordination meteorologist at the National Weather Service's Storm Prediction Center in Norman, Okla., told CBSNews.com that the U.S. is experiencing fewer tornados than usual this year.
"Although we did have a couple days in January that were active, we have seen below-normal activity through today," said Carbin. "We're running about 25 percent below of normal."
Carbin said roughly 375 tornadoes have hit the nation thus far this year, but that number is partly based on preliminary reports that haven't been confirmed by the service.
By the end of May, around 580 tornadoes have normally hit the U.S., Carbin said.
"We're roughly 200 tornadoes shy of what would be considered a normal year," Carbin said.