A portion of the George Washington Parkway closed during the evening rush and water poured into at least one Metro station as heavy rain swept through the Washington region Tuesday afternoon.

Video posted to social media showed a torrent of water falling onto escalators at the Capitol South station as more than two-and-a-half inches of rain fell in less than an hour.

In Virginia, cars became stranded on the southbound George Washington Parkway at the beginning of rush hour. The road was closed in both directions, between Interstate 395 and Marina Drive, for more than an hour.

Warren Stewart, an I.T. program manager from the Mount Vernon area of Fairfax County, said he was northbound on the Parkway to pick up his son in the District when he became stranded for about 30 minutes behind about 20 cars trapped by floodwaters.

“It kept rising and rising and rose up to the guardrail,” he said of the water.

Stewart said he was driving a Chevrolet Suburban and the water only rose to his car’s tires, but he saw other drivers bailing out their vehicles.

Nancy Bateman, who works at the National Building Museum, said she was headed home to Alexandria when floodwaters began to rise. She escaped the flooded Parkway by driving over an embankment in her Nissan Rogue, then ended up stuck on Route 1. Her commute home took more than two-and-a-half hours.

“People in Priuses couldn’t get through the water over the on-ramp,” she said. “I was probably in six inches of water … I was just lucky enough to be at the top of a high area of ground.”

In a tweet, the Arlington Fire Department warned of more than 20 vehicles with water up to their doors near Reagan National Airport, writing: “Avoid GW PKWY!” The department’s water rescue team removed 40 stranded pedestrians from 25 stranded vehicles.

No injuries or other medical emergencies were reported, authorities said. Arlington officials warned motorists in similar situations to stay in their car and call for help unless they’re in immediate danger.

Forecasters said 2.63 inches of rain drenched Reagan National Airport, Washington’s official weather site, over a span of 42 minutes. There had been no measurable rain at the airport in 19 days, including none in the first 16 days of July, which was a record.

In all, 2.79 inches fell in just over an hour, setting a record for July 17. It was the airport’s biggest single-day rainfall in almost a year and the second-most for a July day since 1975.

“That certainly is a very heavy amount for a short period of time,” said Chris Strong, warning coordination meteorologist at the National Weather Service Office in Sterling.

The rain also prompted other road closures in the region.

The Arlington Police Department said Columbia Pike was closed at South Greenbrier Street because of standing water. The National Weather Service placed parts of Arlington and surrounding areas in a flood warning.

Westbound Interstate 66 was closed at the Beltway for a crash, although it wasn’t clear if weather was a factor.

Jason Samenow contributed to this report.