The deluge intensified Friday, with more than 3 inches of rain on top of the pools that formed across Maryland on Thursday, flooding roadways, clogging drains and requiring rescues from trapped vehicles.
The wet weather is forecast to stretch into the weekend, with rain and drizzle expected Saturday and possibly into Sunday morning, according to the National Weather Service.
It is sure to end up being Baltimore's wettest stretch since the remnants of Hurricane Sandy hit last October and could end up challenging that storm's rainfall totals in the record books. It more than erases a rainfall deficit that built over the summer and early fall.
As of 5 p.m. Friday, 5.59 inches of rain had fallen since late Wednesday at Baltimore-Washington International Thurgood Marshall Airport, the point of record for Baltimore. The 3.17 inches of rain that had fallen Friday since midnight was more than enough to smash the record for rain in Baltimore on Oct. 11: 1.13 inches in 2002.
It came on top of rainfall Thursday that measured 3 inches or more around much of the Baltimore area, according to measurements taken by amateur weather observers reporting to CoCoRaHS, a network of precipitation data. A system moving slowly up the East Coast and carrying heavy moisture, some from the remnants of Tropical Storm Karen, was responsible.
The persistent heavy rain prompted the National Weather Service to issue intermittent flood warnings across Baltimore and surrounding counties Friday afternoon, as water pooled around blocked storm drains in urban areas and overflowed stream banks outside the city. Larger streams like the Little Patuxent and Gunpowder Falls were still rising into the evening, threatening to exceed flood levels, the weather service cautioned.
Some major roads were reported flooded and closed, including Route 623 near the Conowingo Dam in Harford County and multiple sections of Dorsey Road south and southeast of BWI. Some minor roads around the state were impassable. Streams were reported to flow 18 inches deep over several roads in Carroll County, highway officials told the weather service.
A swift-water rescue team freed a woman and small dog from a car trapped in floodwaters 3 feet deep at Furnace Avenue and Ridge Road in Hanover, Anne Arundel County fire officials said. No injuries were reported. Another swift-water rescue was performed Friday evening near Brookeville in Montgomery County, according to a report made to the weather service.
In Harford, authorities were closely monitoring Broad Creek Dam near Darlington. Officials at a Boy Scout reservation there were asking residents of some seasonal cabins to consider temporary evacuation because of high water at the dam.
A flood watch in effect throughout the region until Saturday at 6 a.m. warned residents to monitor forecasts and be alert for possible flooding. A flood warning, meaning “flooding is imminent,” is in effect in Carroll, Frederick and other Washington-region counties through the early morning hours of Saturday.
A coastal flood advisory in effect through Friday night warned of onshore winds and tides along the Chesapeake Bay in Southern Maryland, with more rain ahead, combining to cause potential flooding and "minor inundation" of coastal areas, the weather service said. Docks were reported under water at the Point Lookout Marina on Thursday night, according to the weather service.
More showers were expected today, with periods of drizzle. Shower chances were expected to taper off early Sunday, allowing the sun to reappear in the afternoon and on Monday.
Sandy dumped 6.67 inches of rain over three days at BWI nearly a year ago, with twice as much on parts of the Eastern Shore. That storm helped erase a growing drought, much as this week's storm made up a year-to-date rainfall deficit that had grown to as much as 5 inches earlier this month.