Temperature surge here as blizzard rakes Wisconsin

A dizzying set of temperature swings, the by-product of a mammoth winter storm draped across 14 states, is targeting Chicago. As winter’s biggest snowstorm hammers a wide swath of Wisconsin with a blizzard north of Milwaukee, downpour-generating thunderstorms threaten to sweep the Chicago area Thursday afternoon. In the wake of north suburban sleet and snow overnight, unseasonable warmth is to reach south suburban areas beyond midday Thursday. Powerful south winds are responsible and have transported unseasonably mild air more than 800 miles from the Gulf Coast. The set-up sends 60s into Kankakee and Valparaiso—and 50s reach parts of the city briefly before the bottom drops out Thursday night. The equivalent of Chicago’s October to January seasonal temperature decline is to take place in just 12 hours Thursday night.
--Tom Skilling