Nearly a month’s worth of rain in 1 hour triggers travel nightmare in DC area

Commuters in the Washington, D.C., and Baltimore area faced an extremely difficult and dangerous drive back to work on Monday morning following the long holiday weekend as heavy downpours flooded local roadways.

Videos have surfaced on social media in which the raging floodwaters turned roads into rivers. One social media user captured a video while driving through high floodwaters in the Virginia Avenue Tunnel on Monday morning and said, "You’re going to need a boat to pass underneath the Virginia Ave. underpass on I-66 in NW D.C."

Several water rescues were performed as high waters overflowed the roads. Local officials urged motorists to stay off the roads on Monday morning due to flash floods. Numerous roads in downtown Washington, D.C., as well as surrounding areas, were closed on Monday morning due to the floodwaters.

Pete Piringer, a spokesman for the Montgomery County Fire and Rescue Service, told local news station WTOP that “all our folks are deployed right now” at about 8:30 a.m. He said “the storm drains are overwhelmed.”

Heavy showers inundate streets around DC

Deep tropical moisture across the mid-Atlantic states supported areas of slow-moving heavy rain over parts of Maryland and northern Virginia on Monday morning, said AccuWeather Meteorologist Max Vido.

"The heaviest rain targeted portions of Montgomery, Frederick and Carroll counties and prompted the National Weather Service to issues multiple flash flood warnings," Vido said.

Much of D.C., Arlington, Montgomery, Frederick, and Carroll counties received 2 to 4 inches of rain, with many areas picking up those amounts in only 1 or 2 hours. A National Weather Service Employee told the Associated Press that about 6.3 inches of rain fell near Frederick, Maryland. This heavy rainfall prompted street flooding, collapsed trees and water rescues.

In Arlington, Virginia, 3.3 inches of rain fell over the course of an hour at Reagan National Airport early Monday, according to AccuWeather Senior Meteorologist Alex Sosnowski. That's nearly a month's worth of rain, as the normal monthly total is 3.7 inches.

The heavy rain also flooded the runway at Frederick Municipal Airport, covering the wheels of some aircraft. At the White House, the rain started to flood the basement. Meanwhile, the second floor entrance of the Pentagon "leaks" on Monday morning, CNN Pentagon Correspondent Barbara Starr reports. The flooding captured in Starr's photo is from rain coming in from the fifth floor ceiling and is also bubbling up from the Potomac River below.

A large sinkhole was reported on Belfast Road in Potomac, Maryland. WUSA9 News Anchor Annie Yu reported that her friend’s mother drove right up to it and needed to stop several other cars from driving over it.

Another sinkhole appeared under a home in Potomac. The backyard collapsed into the basement, and the home is now in danger of collapsing, reports WJLA-TV News Reporter Sam Sweeney.

Amtrak stopped all trains south of D.C.'s Union Station due to the poor weather conditions and high water on tracks. The Metrobus in Washington, D.C., experienced delays in both directions due to high standing water at the entrance of McLean Metrorail Station. Videos shared on social media captured water pouring down from the ceiling into the Virginia Square Station in Arlington, leading to single-tracking at the station.