Storms could soak weather-weary residents of southwestern Pennsylvania again tonight, potentially causing additional damage and complicating the process of cleaning out basements, salvaging stranded cars and repairing flood-ravaged roads and bridges.

After working through the night to deal with Wednesday's storms, city of Pittsburgh crews are preparing for more downpours, swirling winds and flooding, Public Safety Director Michael Huss said.

"There is the potential for some severe weather tomorrow afternoon," he said yesterday at a news conference. Crews are clearing catch basins, culverts and storm sewers in the hope that they will not become clogged and overwhelmed.

"People are urged not to drive through the flooded areas" if flooding resumes, Mr. Huss said, who advised motorists to call 911 if their cars become trapped in flood water. "Don't drive into standing water."

Beginning at about 5 p.m. on Wednesday, a series of slow-moving cloud bursts socked the region with a record-setting 2.92 inches of rain, nearly all of which fell over a few hours. The total is nearly three times the previous record of 1.07 inches, set June 17, 1973, according to the National Weather Service.

Most recent radar image of southwestern Pennsylvania. (image updates every 30 minutes)

Some areas got even more rain than the official mark. Murrysville got 3.78 inches, Churchill got 4.02 inches and a weather gauge at the University of Pittsburgh recorded 4.03 inches.

The wild weather spawned several funnel clouds, along with a spectacular and sometimes frightening barrage of lightning and thunder. By the count of one meteorologist, 3,000 lightning strikes hit the region in five minutes at the height of the storm. The heavy rains produced flash flooding that turned streets into rivers that washed away everything in their paths.

Despite the mayhem, the region mostly was spared serious damage. None of the funnel clouds touched, no major river flooding has been reported and no major injuries were reported. Most of the damage came in the form of flooded basements, downed trees and stuck cars, Mr. Huss said.

He said 29 people were trapped in cars, and Emergency Medical Services crews rescued 14 of them. The others escaped on their own or with help from others. Those who abandoned their vehicles and have been unable to locate them should call 911.

Though 15 roads were closed at midnight, almost all reopened except Washington Boulevard, which is limited to one lane in each direction due to pavement damage between Allegheny River Boulevard and Frankstown Avenue.

Duquesne Light Co. officials said the remaining 1,000 people without power in the eastern suburbs of Allegheny County were expected to have service restored overnight.

The city will hold a special Saturday trash pick-up to help residents who have flood-damaged appliances, furniture and other items, officials announced.

Areas covered by the special garbage runs include Lower Greenfield, and Maryland Avenue in Shadyside. But residents of other areas who have flood-damaged items can call the city's 311 help line and request a Saturday pick-up. All items must be at the curb by 6 a.m. on Saturday.

Allegheny County Executive Dan Onorato also reinstated a program to repair or replace flood-damaged furnaces and water heaters for residents who meet income guidelines. County residents can apply by calling 412-350-3723 between 8:30 a.m. and 4:30 p.m., Monday through Friday, or by e-mailing their name and phone number to furnace@alleghenycounty.us.

One area of Allegheny County that was hard hit was Electric Avenue in East Pittsburgh, which dips below Route 30, where an underground storm water pipe burst near an abandoned house on Wednesday.

A chocolate-colored geyser of water ripped through the sidewalk and front of the home, reaching as high as the power lines and carrying away the structure's three-story front porch. Within minutes, the roadway turned into a river that sucked tree trunks, Dumpsters, chunks of sidewalk and pickup trucks down the street. At some points, the water was up to 6 feet deep, completely engulfing cars in its path.

"It looked like a tidal wave," said Clayton Ott, who watched the river of water rip down the street from the safety of his elevated front porch.

Among those picking up the pieces were Najat and Henry Nazarian, owners of a Najat's Cuisine, which makes and sells Lebanese food to restaurants, grocery stores and at farmer's markets.

Yesterday, a mucky water line ringed the store about a foot above the ground and a thin residue of mud covered the tile floor. In the basement, where the water rose to the ceiling, large bags of onions and bulk containers of olive oil were strewn about among buckets and milk crates, making it totally impassable.

The couple estimates the storm did about $10,000 to $15,000 worth of damage. They have no flood insurance and wonder how they'll get back on their feet.

Down the road, the borough of Turtle Creek -- one of the hardest-hit communities, remained under a state of emergency yesterday, said Mayor Adam Forgie.

Thirty homes were evacuated when the community was inundated with floodwater as Turtle Creek, Thompsons Run and Saw Mill Run burst their banks, and the deluge from Electric Avenue flowed into town.

Excessive damage from the storm also destroyed Balint Lane Bridge in Wilkins Township and forced officials to declare a state of emergency in the area.

Township Manager Rebecca Bradley could not estimate of how long it will take to replace the bridge or how much the project will cost.

Officials in Westmoreland County also declared a state of emergency yesterday while crews continued to assess the damage, including flooded houses and damage to roads and smaller bridges.

Hardest hit were Greensburg and Jeanette, said Sandy Smythe, a spokeswoman for Westmoreland County 911. Officials in Penn Township, Hempfield and Jeannette also declared their municipalities in a state of emergency, she said, while Greensburg, North Huntingdon, Export and Penn Borough planned to make the same declaration.