By the time commuters were getting ready to venture home Wednesday, a colossal traffic jam already was developing - in the atmosphere.
A cluster of showers moved into the Philadelphia region at midafternoon, and then, "it just kind of stopped," said Valerie Meola at the National Weather Service in Mount Holly.
The result was the region's wettest spring day in 142 years of record-keeping, widespread major flooding along suddenly chocolate-brown waterways, a rash of water rescues, streets more suitable for kayaks than cars, and prodigious cleanup chores likely to lap into the first weekend of May.
More than a half-foot of rain - or two months' worth - fell on some areas, and flood warnings remained posted for the Schuylkill from Philadelphia to the Norristown area, the site of major flooding, into Thursday afternoon.
No serious injuries or deaths were reported, but thousands of the region's residents are likely to spend more time scraping mud off their properties than tending flower beds this weekend.
The worst of the flooding occurred west of the Delaware River. But in New Jersey, just about any place prone to flood - the Admiral Wilson Boulevard and the Cooper River, or Lumberton's Main Street - did so.
In Chester County, emergency officials reported 65 water rescues. Along the Brandywine Creek at Chadds Ford, the water was so deep that two large Dumpsters drifted away from Fellini's Cafe on Baltimore Pike, where framed pictures and furniture were floating in the basement.
"You cannot fight nature," said Peter Skiadas, owner of the nearby Hank's Place, which had become a lakefront restaurant Thursday as water reached to the front steps.
Ray Williams, who lives on Parker Street in Chester, where flooding is often a fact of life, said he was about to concede - and move. Having stacked his couch and TV on several milk crates in his basement, on Thursday he was vacuuming his soggy floor preparing to put his "man cave" back in place.
Inside Fibber's Suds & Sodas, a beer distributorship next to Darby Creek in Darby Borough, half the merchandise - 24 cases of Corona, collapsed cartons of a Seagram's fruity alcohol drink, even soggy cans of Pringles - went underwater. Owner Mike Truong said he lost about $30,000 when his store flooded three years ago because he stayed closed for a month while waiting for federal officials to inspect the damage.
"And this time, I'm not waiting," Truong said, standing with a hose and broom inside the muddy store. He said he hoped to reopen in a few days, or as soon as the store dried out.
Some of the worst flooding occurred on the Schuylkill, shutting both the Kelly and Martin Luther King Drives on Thursday.
A SEPTA bus was nearly submerged after it got stranded in Manayunk, requiring firefighters to rescue the driver and two passengers Wednesday night.
Crews worked throughout the night and into the morning, rescuing people who drove into high water or were trapped in their homes by flooding.
Water cascading through manholes and storm drains ruptured a steam line near 16th and Cherry Streets, cutting power to traffic lights at 18 Center City intersections and leading to the temporary closure of two schools, Friends Select and Greenfield Elementary, Mayor Nutter said.
The Schuylkill at Norristown crested seven feet above flood stage.
"This is one of the worst ones I've seen out here," said Jefferson Fire Company No. 1 Chief John Bergstrasser in neighboring West Norriton Township, one of the most flood-prone communities in the region.
At the Riverview Landing apartment complex in West Norriton, water from the Schuylkill surged into the parking lot and underground garages, forcing a mad dash for many residents to move their cars Wednesday night before the floodwater rose. Fire crews arrived around 7 to assist.
By Thursday morning, several feet of water stood in the parking lot as residents looked down from their balconies. Those who wanted to go to work had to leave via small boats manned by marine rescue crews.
Officially, 4.81 inches of rain was measured at Philadelphia International Airport, and the 4.42 inches that fell Wednesday represented records for an April 30, the month of April, and the entire spring.
Heavy rain had been forecast, but some of the totals exceeded even the high-end predictions, rapidly swelling waterways that had been quite low.
"We have had more rain in the last two days than we did in the previous five weeks," said Tom Kines, a meteorologist with AccuWeather Inc.
"We were kind of heading toward drought conditions," said Tony Gigi, a weather service meteorologist in Mount Holly, noting the recent outbreak of brush fires.
"This will put an end to the fire season."
inches of rain on Wednesday in Philadelphia, a record for April 30, all of April, and all of spring.
inches of rain on Wednesday and Thursday in Spring City, Chester County.
feet of river height on the Schuylkill at Norristown on Thursday. A major flood stage is 19 feet; the record is 25.1 feet.
water rescues in Chester County.
SOURCES: National Weather Service, Chester County emergency management
Contributing to this article were Inquirer staff writers Allison Steele, Chris Palmer, Mark Fazlollah, Aubrey Whelan, Barbara Boyer, and Anthony R. Wood.