As a light snow began to swirl across the region Thursday afternoon, it immediately began to wreak havoc with unprepared commuters on roadways that quickly were covered by sheets of ice.

It was barely a thimble-ful - officially, it was 1/77th of what fell in the first snow of last winter - and by 3:30 the traffic jams were piling up a whole lot faster than the flakes.

In Philadelphia, police reported severe icing problems throughout the city. During the peak of the evening commute, medic units reported delays of five or 10 minutes getting patients to hospitals. Some complained for a while of being stuck in gridlock in Center City.

"It's very treacherous out there," Fire Commissioner Lloyd Ayers said early in the evening.

"It's cut down the response times considerably because people have to be extra careful," he said.

To compensate for the delays, Ayers said he had ordered medic units to work extra overtime until 8 p.m. At that time, he said, he would evaluate the situation and see if they were still needed.

Steve Buckley, deputy commissioner with the city Streets Department, said trucks were out brining the major roadways around 1:30 p.m., but the snow fell later than expected and the efforts were not as effective.

The trucks will continue to work the streets throughout the night. But the surfaces will definitely refreeze and drivers should be extra careful until traffic gets in full gear Friday morning.

"We can put as much salt as we want, but until the [morning] traffic hits it, the ice won't break," Buckley said.

It was quickly clear that the region's drivers, with no snow-and-ice experience since February, were grossly out of practice.

The forecast is saying that they may get another crack at their winter-driving skills on Sunday with a possible significant snow on the horizon, and one hopes everyone fares better.

Countless fender-benders were reported, said Gene Blaum, spokesman for the Pennsylvania Department of Transportation, and the concept of miles per hour became more like hours per mile.

Business Route 30 turned into an ice rink, and the 15-minute drive from Exton to Downingtown took two hours; the 15-minute ride from the Ben Franklin Bridge to the 295 on-ramp became a half-hour drive.

Drivers on Interstate 95 faced an obstacle course of cars and pickup trucks that had skidded to a stop along the eastcoast's major thorofare. Sections of the Interstate through Delaware were rendered into parking lots. A trip from Center City to Washington D.C., usually 2 hours and 15 minutes, stretched into four hours because of the ice and snow.

More than 40 flights were canceled at Philadelphia International Airport, where a whopping 0.3 inches was measured.

"I tell people that, in some ways, you'd rather get 2 or 3 inches," said Larry Nierenberg, meteorologist at the National Weather Service in Mount Holly.

The heftiest total, 1.5 inches was measured in Cape May, but most other places weighed in with under an inch.

Blaum said that PennDOT had treated roadways with brine in the morning and that 180 trucks were out salting last night, but with temperatures in the 20s, the ice-cold ground was the perfect surface for the falling crystals.

The snow that fell stuck, and whatever melted was able to re-freeze.

Nierenberg said that while this one won't go into any record books, the timing made it more disruptive than a more-substantial snow occurring on a weekend.

Speaking of which, it appears that Philadelphia does have a good chance of seeing some snow on Sunday from a storm forecast to form along the coast. Computers have flip-flopped wildly all week, but the National Weather Service is calling for a 70 percent chance of snow on Sunday.

"It could be anything from a couple of inches to something more substantial," said Nierenberg.

"What we know at this point is there's going to be some snow, at least down the Shore," said John Feerick, a meteorologist with Accu-Weather Inc., in State College, Pa.

"The farther east you go, the better chance you have of seeing snow."

Contact staff writer Robert Moran at 215-854-5983 or bmoran@phillynews.com.