Good morning. Illinois. I'm Aaron Jolly. If you stepped outside this morning and couldn't see your neighbor's house, you're not alone. Dense fog has swallowed much of the state overnight. Visibility's down to a quarter mile or less. And a Dense Fog Advisory runs through 9 A.M. For areas along and north of Springfield to Danville. Take it slow if you're commuting — that fog's thick as soup. In the next 24 hours. Southern Illinois is dealing with something more serious. A Flash Flood Warning stays active until 8 A.M. For Alexander. Johnson. Pulaski. And Union counties. We're talking 2.5 to 4.5 inches of rain already on the ground. If you're down there, stay off flooded roads. Chicagoland wakes up at 37 degrees under that gray blanket, barely climbing to 39 this afternoon with a chance of showers through midday. Northern Illinois starts warmer at 40 ...