Severe thunderstorms that began in northern Indiana appeared to spawn multiple tornadoes in southern Michigan on Friday.
The threat of severe weather continued on Saturday in the nation's midsection, with strong thunderstorms possible stretching from Texas and to the northeast all the way to Ohio and western parts of Pennsylvania and New York.
Later Saturday, the National Weather Service said an initial assessment confirmed that a EF3 tornado with winds of at least 240km/h struck the Union Lake area. Surveys in other damaged areas were pending. Tornado watches were posted on Saturday afternoon for eastern Ohio, northern West Virginia and western parts of Pennsylvania and New York.
Three people were killed and 12 were injured in the Union Lake area, according to the Branch County Sheriff's Office.
About 80km southwest of Union Lake, the Cass County Sherriff's Office said a 12-year-old boy died and several other people were injured during a possible tornado.
In Oklahoma, just south of Tulsa, a tornado in Beggs was blamed for the deaths of two people in a house on Friday, the Okmulgee County Sheriff's Office said. Two other people were taken to a hospital.
The tornado cut around a path of damage in Okmulgee County including Beggs, some 50km south of Tulsa.
Oklahoma Governor Kevin Stitt declared a state of emergency in several counties to free up support and resources for affected areas.
The Oklahoma deaths came a day after storms killed a 47-year-old woman and her 13-year-old daughter in Fairview in the western part of the state. Authorities said they were found dead in a vehicle.
The National Weather Service said strong storms and flash flood risks on Saturday stretched from the Great Lakes to Texas. A tornado watch that was issued for a large portion of Arkansas and parts of Texas and Louisiana expired in the morning.
The spring storms come near the start of what many call tornado season, which generally begins at various times in different parts of the US Experts recommend a few simple safety steps to take before tornadoes hit, including having a weather radio and a plan for where to take shelter.
In parts of the southern US, the weather pattern is also expected to usher in extremely warm temperatures for this time of year by the weekend.
