Heavy rain led to flash flooding that closed roads and required widespread swift-water rescues from trapped vehicles Tuesday.
A flash flood warning was in effect across parts of the Baltimore region through 6:45 p.m.
At Baltimore-Washington International Thurgood Marshall Airport, 2.7 inches of rain fell in just one hour, from 1 p.m. to 2 p.m. More than 6 inches of rain fell as of 4 p.m., surpassing a record for Tuesday's date, 4.91 inches on Aug. 12, 1955. It was at least the fifth-most rain recorded at BWI in any single day on record.
At BWI, water flooded the airport's maintenance shop, and filled long-term parking lots around the airport, rising to vehicles' headlights, according to the weather service.
About 2 p.m., northbound Interstate 895 was temporarily held just before the Harbor Tunnel because of high water, according to the Maryland Transit Authority.
Multiple rescues were reported in the Brooklyn Park area, at Hanover Street and Reedbird Avenue and at West Patapsco Avenue and Potee Street. Five people were rescued from three vehicles at the latter intersection, Baltimore fire officials said on Twitter.
In Laurel, Bowie Road was closed because water levels reached cars' headlights
A coastal flood advisory is in effect along the western shore of the Chesapeake Bay through 10 p.m., with high tides expected to be a foot above normal.
Storms could be severe, with damaging winds and isolated tornadoes the possible threats, according to the Storm Prediction Center.
Temperatures are forecast in the 70s with high humidity.
Shower chances could linger into Wednesday morning, with clearing by the afternoon. Highs are forecast in the lower 80s.
Low humidity and highs in the upper 70s are forecast Thursday and Friday into the weekend.