Monday commute to be wet and foggy with flood advisory issued for Chicago area

The Chicago area could see some minor flooding as the dense fog starts to lift through Monday morning.

The National Weather Service issued a flood advisory for northeast Illinois and parts of northwest Indiana lasting until 9 a.m. The scattered showers and isolated thunderstorms that started overnight should continue through the early morning hours, with up to 1 1/4 inches of rainfall possible by the time the rain stops, according to the advisory.

Much of the rainfall will become immediate run off due to the frozen ground, but it could make small ponds in low-lying and poor-drainage areas, the weather service said. Minor flooding could happen in the Chicago metropolitan, LaSalle-Peru, DeKalb and Pontiac areas.

“Motorists this morning should exercise caution and be on the lookout for standing water on roadways,” the weather service said.

The scattered showers and thunderstorms are expected to end during the early- to mid-morning hours, the weather service said. But scattered thunderstorms could resume Monday afternoon and evening. The conditions will bring a limited risk for hail or a brief tornado, mainly west of the Fox River.

At night, the rain could turn into snow if temperatures dip back below freezing, mainly after midnight, according to the weather service. Heavier snow showers could develop north of interstates 88 and 290, bringing an inch or two of slushy accumulation.

Tuesday is expected to be snowy, mostly after 7 a.m. and gradually ending, according to the weather service. The freezing temperatures could continue Wednesday before rising back above 32 degrees for the rest of the week.