The heaviest showers of the nor’easter tapered off this afternoon after four days of record-breaking rain, and the slow-moving storm system should move north and out of the state by Thursday morning, forecasters said this afternoon.
Only a few lingering showers remain from a low-pressure area hovering east of Hull, according to the National Weather Service in Taunton. The unrelenting rain caused flooding on some roads this morning in various Boston-area communities, at Logan International Airport, and in the MBTA subway system.
Boston experienced just more than two inches of rain from 8 a.m. to 2 p.m. today, while Blue Hill received nearly an inch, according to the agency. Since the beginning of the storm, some areas of the state have received upwards of five or six inches of rain.
“That’s a good slug of water coming in,” meteorologist Alan Dunham said. “We’re left now just residual rain.”
Observers at the Blue Hill Observatory and Science Center said the unusual storm had unloaded 7.3 inches of rain there since Sunday, the second biggest rainstorm on record for the month of August.
And the number may yet climb. A tropical storm in 1955 dropped close to 13 inches of rain over three days.
A total of 8.5 inches of rain has been recorded this month, according to the observatory.
Parts of Storrow Drive in Boston and the William F. McClellan Highway along the Chelsea River were flooded today, with some cars reportedly needing to be towed out, police said. A woman was rescued from her vehicle in the northbound lanes of Route 1A at Route 145 in East Boston after flood waters trapped her inside, State police said.
Route 16 in Chelsea was closed earlier today for about 40 minutes after four cars had to be towed from the inundated highway, and traffic was detoured to Route 1, State police said. Vale Street in Chelsea was also closed due to flooding, Chelsea police said.
A section of Greenough Boulevard in Watertown was shut down as well, State police said.
Flooding also forced some roadways at Logan Airport to be closed, but the problems were cleared up shortly afterward, said Massport spokesman Phil Orlandella. He said there was some ponding on the airfield, but no flights were affected.
MBTA Green Line service bypassed the Boylston stop westbound this morning due to flooding in the station, the MBTA reported on its website.
A back lot of the Somerville public safety building, which sustained heavy damage earlier this summer due to flooding, also took on six inches of water this morning, but no damage this time was reported.
Officials put down sandbags and moved vehicles out of the lot and from some of the garage levels below the building, as a precautionary measure, but did not evacuate the building, said Michael Meehan, a city spokesman. The city lost 26 vehicles to flood damage last month.
“We’re not messing around with it,” Meehan said. “We learned our lesson last time.”
The National Weather Service had issued a flood advisory for northeastern portions of the state until 2 p.m. today. The forecasters also warned of high surf and rip currents causing dangerous conditions for beach goers on the fourth day of a summer nor'easter.
Sunshine is expected to return Thursday as a frontal system passes across the region, bringing drier weather and highs in the mid-70s to the low 80s. The warm, sunny weather is expected to last until the middle of next week.
Globe correspondent Jeff Fish and Martin Finucane of the Globe staff contributed to this report.
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