Flooding is seen in Ellicott City, Maryland, May 27, 2018, in this still image from video from social media. Todd Marks/via REUTERS

A flash flood warning was issued for Illinois until 12.15 a.m. local time (1.15 a.m. EDT) Tuesday by the National Weather Service (NWS) in Chicago. The doppler radar indicated thunderstorms in the region at 6 p.m. local time (7 p.m. EDT), which caused heavy rain.

“Strong storms with gusty winds and heavy rain shifting into northern IL over the next couple hours. Flash flooding poss,” NWS tweeted.

Rockford, Belvidere, Loves Park, Machesney Park, Rockford Airport, Roscoe, Poplar Grove, Cherry Valley, Winnebago, Pecatonica, Capron, Timberlane, Caledonia and New Millfors are some locations that will face flooding, the agency said in a statement.

“Flash Flood Warning including Rockford IL, Belvidere IL, Loves Park IL until 12:15 AM CDT,” The National Weather Service in Chicago tweeted.

Rockford was the most affected area, as thunderstorms swept through it wreaking havoc in the evening. Flash flood emergency is expected to go through midnight Tuesday in the region.

“About 4.5" of rain fell in Rockford, IL in 90 mins this evening - leading to the ongoing Flash Flood Emergency there,” Weather Nation tweeted.

Evacuations are underway at Mercy Health Hospital, Rockford, due to flooding inside the hospital. The hospital stopped taking new patients and has sought assistance to evacuate parts of the building.

Several water rescue calls were reported with numerous people stuck in vehicles, Rockford Scanner reported. A number of houses have reported power outages and flooding in basements.

“The benefit to not having a basement is that we’re not getting flooded or water inside. The pictures of flooding throughout Rockford are crazy!” Beth, a resident of Illinois, tweeted.

“We are getting several reports of flooded roads and stalled cars in the Rockford area. Remember and share...Turn Around Don't Drown!! We had a report of 3.1" of rain on the east side of the metro in just over one hour,” NWS tweeted.

Rockford Scanner also reported an occupied van floating away in flooded water. Emergency personnel have reached the scene. Also, some cars were found submerged in the parking lot of a grocery store in Rockford.

“Move to higher ground now. This is an extremely dangerous and life-threatening situation. Do not attempt to travel unless you are fleeing an area subject to flooding or under an evacuation order. Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicle,” the NWS statement said.

“A serious flooding situation across the Rockford metro as very heavy rain has brought significant flooding this eve. Numerous roads are impassable. Do not cross flooded roads! Non-emergency travel in this area not recommended these next few hours,” NWS Chicago tweeted.

Rockford was facing a three-day heat wave that broke with the heavy rains. RRStar reported that weather forecasted for Tuesday is 77 degrees with scattered rain showers throughout the day. Rockford experienced a high temperature of 99 degrees on Monday.