The National Weather Service said a “multitude of hazardous weather” would impact the U.S. over the next several days — from thunderstorms and potentially baseball-sized hail on the Plains, to heavy mountain snow in the West and dangerous heat in the South.

A wave of severe weather has resulted in tragedy as multiple tornadoes swept across the central and eastern United States, claiming at least 28 lives, injuring dozens more, and leaving as many as a half-million without power.