From 80° to snow in just four days

The fall transition into winter is always erratic, but this week Chicagoans will probably witness one of the more drastic atmospheric maneuvers in recent memory. Today gusty southwest winds will push warmer temps into NE Illinois in advance of a cold front approaching from the northwest. Afternoon highs should reach into the mid 70s over much of the metro area, perhaps even hitting 80° not far to the south and west. After the cold front passes tonight, tomorrow’s highs will be some 15 to 20° cooler and that is just the beginning. Showers and t-storms are expected Tuesday night and Wednesday ahead of the leading edge of an arctic-source high pressure air mass. Thursday temperatures will struggle to warm out of the 30s, along with strong gusty NW winds and wet snow showers. If snow does occur here on Thursday, it will be the earliest onset of snow in Chicago since Oct. 7, 2000 and the second earliest in 71 years.
-Paul Dailry WGN-TV meteorologist