The main function of weathercasters in South Florida is reassurance. We want them to remind us again and again -- every single night, in fact -- just how lucky we are to be living in this slice of sunbaked paradise. On top of that, we want them to spell out in explicit detail exactly how horrible the weather is in every other godforsaken part of the world: tornadoes in Oklahoma, mudslides in India, earthquakes in California. We want somebody who is enthusiastic about the weather, a cheerleader for our good fortune. (Never mind the occasional hurricane.) Chris Dunn, Channel 7's weekend weatherman, fits the bill. He's goofy in a likable way. With big, bushy eyebrows, a fleshy face, and reddish hair, Dunn moves about the weather map with barely controlled glee. He's just the kind of weather geek we need.