Book excerpt: Improved technology is teaching us more about the weather all the time, and with new knowledge comes new concerns and confusion. Is global warming real? What is a NEXRAD Doppler? Meteorologist Paul Douglas provides the answers to all these questions and more, along with fascinating illustrations, photos, trivia, and graphics. Find out what a difference a degree makes; as well as information about El Ni�o and how to protect yourself against the worst that the weather can bring. From the distinctions between a weather warning, watch, and advisory to the definition of an F-5 tornado, all the essentials are clearly explained.