COLUMBIA, Tenn. — Forecasters warned a wave of dangerous storms in the U.S. could march through parts of the South early Thursday, after storms a day earlier spawned damaging tornadoes and massive hail, leaving two dead in Tennessee and one dead in North Carolina. The storms continue an outbreak of torrential rain and tornadoes that has cut across the country this week, from the Plains to the Midwest and now the southeastern U.S.