During the Palm Sunday Tornado Outbreak of 1965, as many as 78 tornados—47 of which were confirmed—hit the midwestern US over the course of 11 hours. Affecting Ohio, Indiana, Michigan, Illinois, and Iowa, the outbreak resulted in 271 deaths, thousands of injuries, and widespread damage. In Indiana alone, it killed 137 people and injured more than 1,200, becoming the deadliest tornado outbreak in the state’s history. This outbreak led to the clarification of what terms used in weather forecasts? Discuss