Chicago braces for heavy rain as fall storm system rolls in

A fall storm system is moving through Illinois, bringing a sharp cooldown, stormy weather, and the threat of frost to the Chicago area. The weather shift follows a period of record-breaking warmth, with the region hitting a high of 80 degrees on Tuesday and breaking a temperature record on Monday.

NBC 5 Storm Team meteorologist Iisha Scott stated that rounds of thunderstorms producing heavy rain began moving into the Chicago area on Friday night. While Friday morning started quiet, isolated showers developed by late morning and into the early afternoon. Starting late Friday night and continuing into the overnight hours, storms producing heavy rain were expected across the area. Some of these storms could be strong or severe, with the Storm Prediction Center placing counties south and southwest of the city under a "marginal" risk of severe weather, which ranks as level one of five.

"It is going to be soaking wet Saturday morning," Scott said, noting that heavy rain would continue through the late-morning hours. The primary threats include damaging winds, "torrential rainfall," and strong gusts leading to flooding, especially in LaSalle, Kankakee, and Will counties in Illinois and into northwest Indiana. Scattered showers with moderate rain at times continued Saturday afternoon, with rumbles of thunder possible into the evening.

For Saturday night into Sunday, Scott said, "we'll do it all over again," with another cluster of storms rolling in through the early morning hours. "Certainly not the best weekend if you have outdoor plans," she added. Sunday daytime hours were expected to be cloudy, though showers could not be ruled out.

Earlier in the week, NBC 5 Storm Team meteorologist Pete Sack noted that temperatures would be cooler, with highs in the mid-60s compared to the previous day's 80 degrees. Sack described the conditions as a "more normal October day." He indicated that showers would start creeping into Chicago from the south and west, with widespread rain expected through noon and up to an inch of rain possible.