Pat Callahan perched on the hood of her car yesterday morning, secure in her spot as "next in line" at the pumps of a Merit station in Arlington. Behind her, a line of at least 30 other gasoline-thirsty vehicles wound across Wilson Boulevard and down 10th Street.

Suddenly, a man from near the end of the line walked up and discovered what Callahan had known for about half an hour.

"Hey," he exclaimed to no one in particular. "There's nobody here."

Nobody was coming, either, yesterday as the now familar Washington area weekend gasoline search endured its worst Sunday yet. Virtually all the service stations were closed. The few that remained open - and some that had opened on Sundays past but didn't yesterday - attracted long lines of motorists in hope that a closed station would eventually open.

In their gigantic search for gasoline, drivers rushed to fall into line wherever two or more cars had gathered at service stations. Sometimes, as was the case with the Arlington station, this proved to be a waste of time - and gas.

"It's called faith," said Jeff Sweet, explaining why he and Callahan were waiting in line to get gasoline from a station that was closed. "They're usually open on Sundays here," said Sweet, who had been waiting for about 30 minutes. He said he was "holding out until 10 a.m.," which then was just 15 minutes away.

The line at the Merit station included several taxicabs, two tow trucks, a student on a Honda motorcycle and a woman looking for gas so she could drive to the Shenandoah Valley. All were unaware that the station of their choice was closed.

It was "no big deal" for Kathy Corser, bound for the Virginia mountains, when she found out. With a half tank of gas already in her car and a $5 bill on the seat beside her, she resigned herself to staying home.

But Richard Miller, a North Arlington resident trying to get enough gas to drive to Baltimore and pick his daughter up from a hospital there, said he had learned his lesson.

"I was busy like everybody else, and the lines were too long Saturday," said Miller, explaining why he was trying to get gasoline yesterday.

Tourists didn't have it any easier than area motorists, and - fearing they might be stranded here - they had a lot less patience.

"We brought the kids to see the historical sights of Washington," said Irving Mandell, a New Yorker. "I didn't think that meant body shops and B.F. Goodrich signs."

Mandell, in line at the Merit station at Montana and New York avenues NE, said he would never again take another long trip in the summer.

A new Jersey woman on her way to a new home in Florida groused she would have to stay overnight in Washington because she couldn't find gas. Having gotten up early to begin her search, she quit abruptly after discovering her line had formed in front of a closed station.

"I'm going back to bed," she said. "I'm going home to call the president."

Those in lines at service stations that were open considered themselves lucky, despite long waits in cars that became like ovens in the hot and humid weather. The wait gave drivers time for comtemplation, and several began making promises to themselves to start walking or taking public transportation.

One of the longest lines stretched for more than two blocks along 14th Street NW, where motorists impatiently inched their way up to a self-service Mobil station on the corner of Corcoran Street.

Calvin Price, a District resident, said he had spent Saturday night watching television instead of attending a Jacksons concert at the Capital Center. "I still have two $16 tickets on my dresser at home," said Price, who was in the 14th Street line trying again to get the gasoline he couldn't find the day before.

Motorists told of canceling trips to the beach, postponing camping outings and abandoning plans to visit sick relatives because of the gasoline worries. Most blamed the oil companies or the government for the unavailability of gas, but some said the problem had been greatly exaggerated to justify higher prices at the pumps.

"I don't care if it costs $100 a gallon," said Price. "Just put the price up on the gas and turn it loose because I need some."

At a Crown station in Alexandria, manager Cecil Click directed the anxious motorists into several lines leading to pumps. He said he expected the station's 6,400-gallon supply to be gone by 1:30 p.m.

Other stations, like the Mobil self-service in the District, closed at 1 p.m. and reopened at 5 p.m. This prolonged their operations for the day, but infuriated motorists who had waited in line and used up the last of their gas trying to get more. When the Mobil station reopened, the line was five blocks long a policeman had to be on hand for crowd and traffic control.

Many of those waiting in line yesterday complained that they had tried to get gasoline earlier in the week but found the stations closed by the time they left work.

For Nancy Siegel, however, the need for gasoline was so great yesterday that she got up at 7 a.m. to search her Gaithersburg neighborhood for an open station. Her mission accomplished, she then drove to Alexandria to her job as pool supervisor for a swimming pool firm.

She was one of those at the Crown station in Alexandria, wearily waiting in line to get gas for the firm's company car.

A cabdriver who pulled into a closed Lanham station and then watched as 10 cars pulled in behind him said his followers were "like sharks. They don't even look. They see anything and think it's food so they go after it." CAPTION: Picture 1, Cars waiting for gasoline line up along Montana Avenue NE for service at Merit station at Montana and New York avenues. Line extended onto Bladensburg Road. By Douglas Chevalier - The Washington Post; Picture 2, Attendent at New Carrollton Citgo station waves off any more customers after station sold its gasoline quota. By Douglas chevalier - The Washington Post