NEW : Excessive-heat watches , warnings and heat advisories were in effect in more than 30 states Wednesday , in what the weather service described as `` a large portion of the central U.S. and Ohio River Valley , as well as portions of the mid-Atlantic and northeastern states . National Weather Service says 22 deaths may be due to tornadoes in Midwest . 141 million people are under watches or warnings , a spokesman said . Watches , warnings , and advisories cover more than 50 states .
NEW : National Weather Service says 22 deaths may be due to tornadoes in Midwest . 141 million people are under watches or warnings , a spokesman said . Watches , warnings , and advisories cover more than 50 states .