The storm spawned tornadoes in four states Tuesday: Texas, Indiana, Kansas and Missouri, the National Weather Service said.
And a 62-year-old woman died when a tree fell on her mobile home in Tomball, Texas, Harris County sheriff's spokesman Deputy Thomas Gilliland said.
The threat of imminent tornadoes is likely over, CNN meteorologist Pedram Javaheri said. But fierce straight-line winds -- which could reach up to 80 mph -- will likely continue as the storm heads east.
Next under the gun: states along the lower Mississippi River, from Missouri to Louisiana. Those areas can expect severe storms through Wednesday night.
"Strong to isolated severe winds will be the primary hazard south, with a mix of severe hail and damaging wind north," the weather service's Storm Prediction Center said.
Spate of twisters
One of the most damaging tornadoes touched down in Grayson County in north Texas.
Farther north, a tornado touched down in Checotah, Oklahoma, McIntosh County Emergency Manager Harry Trottier said. The storm caused a major gas leak, but there were no injuries.
And Indiana suffered two tornadoes, the National Weather Service said: one west of Bloomington and the other in Vanderburgh County in the south. No injuries were reported.
Intense hail and lightning
More than 195 reports of hail-related damage emerged from the storm, the Storm Prediction Center said.
And about 11,000 lightning strikes touched down between Kansas City and Dallas in just 30 minutes Tuesday night, CNN's Javaheri said.
The storm also snarled airline traffic across the Midwest. Passenger Leah Wilmington was stuck on a plane in Cincinnati as torrential rain prevented her departure.
"I think I'm going to miss my connection...," she wrote. She said the rain was so intense it was difficult to see the planes at nearby gates.
Be prepared
Forecasters warned those in the path of storms to prepare.
"Make sure you have a severe weather plan for you and your family," National Weather Service meteorologist Bill Bunting said. "If you don't, today is the day to develop it."
Among his tips:
• Know where to seek shelter in your home or building.
• Have a way to get in touch with family or friends, or set a designated meeting point, to let them know you're OK after the storm.
• Have multiple ways of receiving information and weather alerts, including a weather radio and weather apps on your smartphone.
CNN's Shawn Nottingham, Tina Burnside, Steve Almasy, Keith Allen, Rachel Aissen and Melissa Gray contributed to this report
