If Saturday night really is "the loneliest night of the week," as Frank Sinatra once sang, then it's going to seem a lot lonelier starting tonight to fans of "Twin Peaks," the space-age supersoap that ABC yanked from its schedule after last week's telecast.

David Lynch, the iconoclastic filmmaker who co-produces the series with Mark Frost, said in an interview from Los Angeles yesterday that he hopes all "Twin Peaks" fans will contact the network to urge that the program be returned to the air, and not on Saturday nights, either.

"Our gung-ho viewers just could not stay home on Saturday night," Lynch said. "We need a huge write-in campaign so that ABC will feel massive pressure to give us a good night -- a week night." The series premiered on a Sunday, then moved to Thursdays until ABC switched it to Saturdays last fall.

While "Twin Peaks" had been holding at fairly respectable ratings through December, it dive-bombed into the yawning pits of Hades when it returned after a long holiday hiatus in mid-January.

"Christmas," said Lynch, by way of explaining the plummet. "After Christmas, we were off for four weeks. There were no advertisements or magazine articles, nothing to say, 'Hang in there,' no little electric jolt to remind people of what was going on.

"That was the critical moment where we lost it, that long hiatus. And the war in the gulf didn't help us, either," Lynch said. Frost said "Twin Peaks" has been partly the victim of "people watching CNN obsessively, and properly so, since that's an issue a lot more important than us."

During the low viewing period immediately after Christmas, networks usually air reruns of their shows. But "Twin Peaks" is a serial and therefore can't really be rerun out of sequence.

Lynch's call for a viewer uprising was answered even before it was issued. Since Tuesday, an ABC spokesman said yesterday, there have been "numerous" calls and letters received at ABC, though it is "network policy" not to reveal how many.

Robert Iger, president of ABC Entertainment, issued a wishy-washy statement yesterday after Lynch and Frost held a press conference on the "Twin Peaks" set in Los Angeles. "Rearranging our prime-time schedule is a complicated business," the statement said. "But we do hope to find a new time period for 'Twin Peaks' inside our regular broadcast season if at all possible.

"The series will definitely return to our schedule to complete its run for this year and definitely be considered for next season." Six more episodes have been ordered for this season by ABC but remain in limbo. Lynch is directing the 22nd, and last, himself.

In Washington, a viewers' group to save the show sprang up almost the instant ABC pulled it off the air. COOP, for Citizens Opposing the Offing of Peaks, was formed by H. Keith Poston, 23, and Michael R. Caputo, 28, both admitted "Peaks" freaks. They held a fund-raiser and protest meeting Thursday night in a bar on 15th Street NW.

"We had almost 200 people, 178 signed letters and petitions to ABC, and we went through 10 dozen doughnuts and at least one cherry pie," Poston declared proudly yesterday. Doughnuts and cherry pies figure prominently in the ambiance of Twin Peaks, the mythical Northwest town where the serial is set.

Poston, a lobbyist, said he has never felt such devotion to a television program before.

"To me, 'Twin Peaks' is the sole creative thing on TV," he said. "Two years ago, if people had told me I would be organizing a grass-roots group to save a TV program, unless it was 'The McLaughlin Group,' I would have said they were crazy."

Poston said he agreed with Lynch and Frost that Saturday was a lousy night for the program. He usually ended up watching it on his VCR early on Sunday mornings after a night on the town, Poston said.

"People who watch 'Twin Peaks' are out on Saturday night. People who are likely to be at home on Saturday night at 10 o'clock are not the kind of people who watch 'Twin Peaks.' " Poston said.

The COOP group makes its headquarters in an Arlington office it has dubbed the Great Northern, after the hotel in the series. A COOP T-shirt, with the two O's made to look like doughnuts, is being sold, Poston said. He overnighted one to Lynch Thursday. Lynch said he had indeed received it and sounded pleased as punch.

Lynch conceded that the quality of the shows dipped a smidge once the murderer of Laura Palmer -- the big mystery of 1990 -- was revealed: "We were fishing a little bit after Laura. But I think we're doing okay now. The shows are still very, very entertaining, because they're about characters that people want to see."

He is particularly fond of an episode directed by actress Diane Keaton that aired Feb. 9. "I love that show!" he exclaimed. "It was very stylized but absolutely great! We have a lot of terrific directors working on episodes. They have a freedom with this they're not going to get anywhere else in television, and they run with it like crazy."

Lynch was asked if perhaps, compellingly fantastic as it is, "Twin Peaks" might not be too special for mass-audience network TV. Perhaps it would be more at home on some flaky cable channel.

"But ABC and other networks have been saying that television needs more interesting things," said Lynch. "They're losing viewers each year to the cables. If you have the right show and the right night, the combo could be magical. We didn't have that magical a combo this year, and that hurt us bad."

The series, said Frost, is doing very well in foreign countries like England and Holland. "Fifty percent of the population of Spain is supposedly watching it every week," Frost said. He and Lynch are planning a second show, a slapstick comedy about the early days of television called "On the Air," but have yet to shoot a pilot episode.

Both Frost and Lynch were speaking from L.A. over a speakerphone. Lynch was speaking very loudly, the way he did as the partially deaf character Gordon Cole, Agent Cooper's boss, in a few episodes of "Twin Peaks" last fall.

Lynch did not think he was speaking loudly, however.

"ARE YOU KIDDING?" he shouted. "I CAN'T EVEN HEAR MYSELF!"