The majority of Milwaukee and Waukesha counties are under a flash flood warning, thus it is advised that you stay inside your home.

Prior to heavy weather, a flash flood warning has been issued for Milwaukee and Waukesha counties.

Up until 11:15 p.m. on Tuesday, Milwaukee and Waukesha Counties were under a flash flood warning.

The NWS advised against trying to drive or walk through floodwaters because more than 1 million people could be affected.

Some folks received an emergency alert message on their phones advising them to stay home due to flash floods in the area.

For the majority of Milwaukee County, the National Weather Service issued a flash flood warning.

"Stay put and don't leave if you are at home. Avoid driving across any flooded roads if you're on the road "Cronce said.

According to a tweet from the NWS, almost 134 inches of rain fell at the airport over the course of 45 minutes. NWS meteorologist Marcia Cronce defined heavy rain as "anything over an inch."

Additional rain and storms are possible overnight into Wednesday morning; however, we aren't expecting severe weather to linger.

For some of Boone, DeKalb, Winnebago, Kane, and McHenry counties in far northern Illinois, a flash flood warning is in effect until 3:00 AM CDT.