At least 68 million people are under severe weather warnings on Memorial Day, as storms turned toward the Northeast after claiming the lives of at least 19 people and leaving half a million homes and businesses without power across the central United States.

Heavy storms will move across Arkansas and Tennessee and into the Ohio Valley before heading north to the East Coast, through the Carolinas, Pennsylvania and New York. Heavy rain, winds of more than 60 mph and hail more than 2 inches…