One from my mother's past. She and my father are from Buffalo which of course is famous for snowfall if not for our poor lamented footbal team the Bills! (Go Bills!)
Anyway, the newscaster got to the weather and had to stop for a moment. In a voice dripping sarcasm he announced that the National Weather Service's forecast included a 20 percent chance of snow. He concluded with "Looking over my shoulder out the window I can see it's 20 percenting outside!"