Perhaps the most famous of former weathermen, grouchy and gap-toothed late night chatterbox David Letterman honed his on-air reading (and comedy) skills in the early 1970s as a weatherman at WLWI (now WTHR) in his native Indianapolis where his on-screen antics included referencing fictional cities in his forecasts, congratulating a tropical storm for being upgraded to a hurricane and predicting that an impending storm could potentially produce hailstones “the size of canned hams.” Although Letterman’s irrelevant brand of meteorology caught the attention of Indianapolis TV watchers, in 1975 he left Indiana and moved to Los Angeles in hopes of becoming a comedy writer. Letterman bounced around on the game show and stand-up comedy circuits for several years (he even appeared on an episode of “Mork & Mindy”) and then, with a big boost from his mentor Johnny Carson, debuted the edgy-but-popular “Late Night With David Letterman” on NBC in 1982. That program lasted for 11 successful years until the eternally acerbic late-night host made the switch to CBS with the “Late Show with David Letterman” where he continues to make jokes about canned hams.