12-year-old boy swept away by rushing water believed to be dead after flash flooding impacts Mid-Atlantic

A 12-year-old boy who was swept away by rushing water is believed to have been found dead in the wake of major flash flooding in the Mid-Atlantic, authorities said Wednesday.

Constant, heavy rain fell over the Mid-Atlantic on Tuesday and led to flash flooding in the mountainous region surrounding western Maryland, southern Pennsylvania and eastern West Virginia.

Most areas saw 1 to 2 inches per hour rainfall rates, while Allegany County in northwestern Maryland saw 5 inches of rain in a single hour.

One death has been reported in Albemarle County, Virginia, following the rain event.

Jordan Sims, 12, went missing after he was swept away in swift water while walking outside late Tuesday afternoon, authorities said. A body was recovered Wednesday morning that is believed to be Sims, according to Albemarle County Fire Rescue.

The individual's body will be transported to the medical examiner's office for positive identification.

"This is a heartbreaking outcome, and our hearts are with the Sims' family and loved ones," Albemarle County Fire Rescue Chief Dan Eggleston said in a statement.

Severe flooding led to the evacuation of multiple schools in Allegany County, where a flash flood emergency was issued Tuesday, with a dozen students staying the night at a high school.

About 200 students and teachers were evacuated from Westernport Elementary School in Westernport by motorized boats to a nearby church, Allegany County officials confirmed to ABC News.

All students and staff were safely evacuated, according to the Allegany County Department of Emergency Services.

Students at several schools in Allegany County were safely evacuated to a high school, where 12 students spent the night, Allegany County Public Schools said. Those students were picked up by Wednesday morning.

All Allegany County Public Schools are closed on Wednesday, the school district said.

A "significant portion" of Westernmore was evacuated due to the floods, according to the Allegany County Department of Emergency Services, which urged residents to stay home Wednesday to keep roadways clear.

There are no reported injuries or missing persons from the flooding event in Allegany County, officials said.

Amid the heavy rain on Tuesday, the North Branch Potomac River at Cumberland grew 20 feet in 18 hours -- more than 1 foot per hour. The river crested early Wednesday morning and is slowly going down.

More rain is possible Wednesday evening over this heavily saturated region, which could induce additional flooding.

ABC News' Kenton Gewecke contributed to this report.