Significant rainfall from storms caused flash flooding in parts of Montgomery County, Maryland, located north of Washington, D.C., on Saturday, trapping many in buildings and cars.

Flash Flood Watch issued in Central Indiana, expecting heavy rain and potential severe storms, with rising heat over 100 degrees to follow.

Around 11 million Americans are under flood alerts Saturday evening as a "ring of fire" weather pattern continues to impact the eastern two-thirds of the country through the weekend. A flash flood emergency was issued near the Washington, D.C., area, including suburban Maryland, such as Chevy Chase and Silver Spring until 9 p.m. ET.

Storms outside the higher-risk zones caused problems in central Maryland with Flash Flood Warnings and a Flash Flood Emergency being issued outside Washington, D.C. Areas such as Bethesda, Takoma Park,

NWS issues weather advisory for potential storms with damaging winds, isolated tornadoes, and flash flooding around Columbus, OH.

“The biggest thing is making sure you have a plan ahead of time when it’s not raining,” he said. “I highly recommend weather.gov/safety/flood. That will walk you through flood preparedness tips and what to do before, during, and after an event.”

Early on Thursday morning the National Weather Service's Lake Charles office announced that it would be expanding the flash flood warning that previously went as far west as Vermillion Parish to include Calcasieu, Cameron, Allen, Jefferson Davis and Beauregard parishes. The watch is in effect from 7 a.m. on Thursday to 7 p.m. on Saturday.