Tornado threat, flash flooding put millions on alert across 17 states

Nearly 50 million Americans were under the threat of severe thunderstorms Tuesday as a powerful weather system swept across the eastern United States, bringing the potential for tornadoes, damaging winds, large hail and life-threatening flash flooding from the Ohio Valley into the Northeast, USA TODAY reported. Forecasters warned the storms would intensify through the afternoon and evening, affecting portions of 17 states.