The Chicago area may see heavy rain and possible flooding Monday night with up to four inches of rain in some parts of Northern Illinois, according to the National Weather Service.
Most of the region, from Rockford to Gary, is forecast to get between one and two inches of rain. David King, a meteorologist in the weather service’s Chicago office, said a smaller portion of the area is likely to get between two and four inches of rain depending on how the weather system moves.
King said around 3 p.m. Monday there was about a one in three chance that the heaviest rain would impact Cook County and Chicago.
“Depending on where that corridor of the strongest rain actually develops, we want people to be aware that it could be two, three, maybe even upwards to four inches of rain,” he said.
In Cook County, rain is expected to start as early as 6 p.m, King said, while heavier rain will start around 9 p.m. and linger overnight. The rainfall will come alongside strong winds that could reach between 30 and 40 mph, he added. The weather service has issued a wind advisory warning of gusts up to 45 mph for south suburban Cook County, Will County and parts of Northwest Indiana, effective at 6 a.m. Tuesday.
Areas with the heaviest rain are at risk of flooding, King said. Flood-prone areas include roads, fields, basements and other low-lying places, per a weather service advisory. Streams and creeks may also rise dramatically.
King warned that people driving Monday night should be cautious on the roads, particularly under train tracks and while driving at night. Drivers should allow extra space between themselves and other cars and residents should make sure they have a reliable way to receive weather updates.