Early Friday morning, torrential rain fell across Cook County. Multiple crashes were reported on Chicago roads and highways and thousands were left without power across the Chicago area.

A tornado watch has been issued until 11 p.m. Friday for Cook County and most of northern Illinois. Strong storms are expected to hit the Chicago area between 8 p.m. and midnight, the National Weather Service said.

Chicago faced a stormy weekend with severe weather threats, including hail and gusty winds, according to forecasts.

In parts of Chicago, flash flood alerts rang Tuesday, warning of dangerous conditions as cars were stranded and submerged on highways and water rescues were conducted, but how much rain actually fell across the region and how fast did it all happen?

Not only were people in the Austin community trying to push water out of their homes, but Chicago area plumbers also responded to numerous calls late Tuesday night and early Wednesday morning.

More than a month's worth of rain fell on Chicago in 90 minutes on Tuesday evening, according to the National Weather Service (NWS). "There were numerous reports of flooded viaducts, several reports of water rescues, and a few reports of flooded basements," the NWS said.

Friday, temperatures are expected to reach the mid 80s with a 40 percent chance of heavy rain. Saturday, the chance of thunderstorms is 50 percent with highs in the upper 80s.

A number of weather alerts were issued for portions of the Chicago area on Thursday evening as thunderstorms trekked across the region.