Even as some south suburbs struggled to deal with more than 4 inches of rain and a new flood warning, the National Weather Service warned of another round of strong storms that could hit northern Illinois later Thursday.

The weather service verified that some south and southwest suburbs received more than 4 inches of rain overnight, leading to localized flash flooding and power outages around the Chicago area and in northwest Indiana.

A flood warning was in effect for southeastern Cook and east-central Will counties until 5:30 p.m.

As of about 8:35 a.m., “emergency management officials reported continued flooding across the warned area.

Although rainfall has ended and most small streams should be cresting soon, flooding is expected to continue as water drains downstream,” the weather service said in a warning bulletin.

Park Forest seemed to be among the harder-hit areas.

Reports included a person rescued from floodwaters by firefighters about 3 a.m. and at least 3.5 inches of rain in the town verified by the weather service, with a trained spotter reporting more than 4 inches, said Amy Seeley, a meteorologist with the weather service.

Steger also had localized flooding, she said.

“Steger had up to 2 feet of standing water in that city,” Seeley said.

Burnham Avenue near Plum Creek Forest Preserve was reported closed around 7:30 a.m. due to flooding and downed power lines, the weather service noted.

Near Chicago Heights, the weather service noted about 9:30 a.m., Thorn Creek overflowed and water was flowing down 26th Street.

The hardest-hit areas were in Indiana, she said. In Newton County, there were verified reports of 4.4 inches of rain overnight, she said.

“Also, in Lake County, Indiana, we had a railroad underpass flooded in Lowell,” Seeley said.

She said additional numbers would come in later in the morning.

ComEd was reporting about 2,000 customers without power far south of Chicago as of 6 a.m. Thursday, with isolated pockets of much smaller outages around the city.

Despite the rain and flooding overnight, Thursday was expected to be mostly sunny, warm and dry.

“There’s a chance for thunderstorms — mainly this evening — but most of the day is going to be dry,” Seeley said. “Most of the severe (activity) will be along the Illinois/Wisconsin border, but anywhere north of I-80 has a possibility for it.”

“A line of thunderstorms is expected to form across the upper Midwest this afternoon and move south into far northern Illinois this evening,” the weather service said in a statement, cautioning that “Strong to severe thunderstorms are possible” with the system.