
"Pneumonia Front to Bring Rapid Temperature Drop to Chicago and Wisconsin"
A "pneumonia front" is set to bring a sudden chill to Chicago and Milwaukee, with temperatures expected to plummet 20 or more degrees "in a matter of minutes" as the front swings through. Pneumonia fronts are a staple of the Great Lakes and happen a couple of times per year, most commonly in spring when the lake waters are still cold and the air is warm. The term pneumonia front was coined by the Weather Service office in Milwaukee back in the 1960s.

