Tornadoes at this time of year are not unheard-of, officials said, noting that 57 people in four states were killed by tornadoes in early February 2008.
Powerful winds and heavy rains delivered flooding and property damage to the central and southern United States this weekend, leading to at least four deaths, officials said.
In separate cases in Kentucky, two men were found dead in cars that appeared to have been swept away from flooded roadways. Also in Kentucky, a woman died after a tornado struck her home. In Arkansas, a man was killed after his trailer home was blown into a pond.
“The flooding and tornadoes are loosely related in that the same overall weather pattern led to both,” Bill Bunting, the chief of forecast operations for the Storm Prediction Center at the National Weather Service, said in an email on Sunday.
The tornadoes were caused by a storm system that showered eastern Oklahoma to the Ohio Valley with heavy rainfall. It has also been a rainy month for Pittsburgh, where the Ohio River begins. That contributed to the overflows that flooded properties and closed roads in the river basin downstream.
The river flows west through several states before joining the Mississippi River in Cairo, Ill. At the point where it flows past Cincinnati, the river rose above 60 feet on Sunday, its highest level in two decades.
Residents there are accustomed to some flooding along the riverbank, Trent Schade, the hydrologist in charge at the Ohio River Forecast Center, said in a phone interview on Sunday.
The Ohio River flooding this week “is absolutely significant,” he said, adding, “It is a rare type of event.”
The winds that killed a woman in Adairville, Ky., came from the first tornado to hit the area this year, said Capt. David Kitchens of the Logan County Sheriff’s Department. “We usually don’t start seeing the beginning of tornado season until well into May,” he added.
The winds that killed a man in Arkansas also came from a tornado, said Sheriff Terry Miller of Clay County, in northern Arkansas.
“It’s a little odd,” he said of the timing, though he added that tornadoes in late February are not unheard-of. “We had a lot of high temperatures in the last couple of days and a lot of moisture in the air, and it’s just one of those deals. It popped up on us all of a sudden.”
Possible tornadoes were also reported in Keiser, Ark., and Clarksville, Tenn., where buildings were damaged and several people were injured.
Mr. Bunting said that tornadoes at this time of year were not rare. In 2008, tornadoes killed 57 people in four states in early February.
“With spring approaching and the likelihood of more severe weather and flooding, preparing now is very important,” he said, adding that people should monitor forecasts, heed advice from local officials and have emergency plans in place.
Mr. Schade said that in the case of a flood, roads can be especially dangerous — even if the water does not look deep. “Stay out of flooded waterways,” he said. “The current can carry you away.”
Meteorologists expect another storm system to sweep across the Mississippi Valley and reach the Ohio and Tennessee Valleys later this week. Flood warnings and advisories are still in effect in the central and southern United States, including some areas of Indiana, Kentucky, Missouri, Ohio and Tennessee.
