we could issue warnings with longley time. long lead time means we would have to figure out how to treat them because of you tell someone a tornado is coming in one hour, he may not take shelter right then. groups whoeople in need long lead times. we want to give them information public into knowledge of the weather and knowledge of the warning and knowledge of what to do to be safe. stuff we do here at the national weather center impacts everybody. as is a one-of-a-kind facility. it does not exist anywhere else in our galaxy. this is the only national weather center. are a tourist destination for the state of oklahoma and for the entire country because everybody is interested in the weather and a want to see what's going on in our facility. >> our cities tour staff recently traveled to normand, oklahoma to learn about its rich history. learn more about normand and other stops on our tour at c-span.org/cities tour. you're watching american history tv on c-span3. next on lectures in history, tulane university professor blake go