When Marvin Cetron looks into the tea leaves of real estate, he has visions: dirigibles lofting preassembled houses to concrete pads, vacant cities ringed by satellite towns and electronic homes, wired to alert their owners about everything from babies' cries to dirty furnace filters.

Cetron, president of Forecasting International Ltd., an Arlington research firm, feeds reams of statistics to hungry computers that spit back predictions that have gained him some note as a forecaster of political turmoil in Poland and in several Islamic countries.

Washington's urban sprawl will continue, with Loudoun and Prince William counties becoming "your next bedroom communities," he told a meeting of the Northern Virginia Apartment Association this week.

In Cetron's "vicious cycle" scenario for cities, declining tax bases will force city officials to hike various taxes, which in turn will prompt more residents to move. Cities will then be left to the poor or the very rich, he said.

"There's going to be one big damn corridor running from Boston to Norfolk, and it won't be a bunch of big cities, it will be a bunch of satellite towns," said Cetron in an interview. Cetron started forecasting professionally 11 years ago after a 19-year stint as a Navy weapons system developer.

The wiring of the suburbs for computer-communications devices will eliminate the need to work in the center of the city, he said, pointing to recent decisons by Mobil Oil and Xerox corporations to locate in Northern Virginia. "The corporation that can use computers doesn't have to be downtown," he declared.

Similarly, many workers will be able to work out of their homes in 1990, when 92 percent of residences may be wired, via television cables, to their offices and to a variety of data bases, according to Cetron.

Technological changes will revolutionize the housing industry, contends the computer-gazer, who conducts his rat-a-tat monologues with band director-like gestures.

He visualizes banks of robots putting together tightly machined walls complete with insulation, wiring, plumbing, heat ducts, television cables, phone lines and electronic sensor wires. The wall sections then will be dropped in place by helicopters or by helium balloons and snapped together like Tinkertoys. The prefabricated house will completed in less than a week.

When these houses become common in a few years, Cetron said, a three-bedroom model complete with appliances will cost about $40,000 in today's dollars.

"We're playing with this stuff right now," he said of robot production methods. "We're going to build houses like they build cars in Japan."

He estimated automated techniques will enable housing modules to be built to one-hundredth-inch tolerances, compared with present-day quarter-inch tolerances for custom-built homes. The snap-together houses, for reasons of economy, will have carports and no basements, and could be expanded simply by flipping up part of the roof or swinging out a wall and attaching another section.

Inside, electronic sensors will warn homeowners if they've forgotten to lock a door or close a window, and, while they are outside, will tell them if the baby is crying. Visitors will be greeted at the front door by a recorded voice telling them either to come in or to leave a message if the homeowners are gone, Cetron said.

The real estate market also will be affected, he said, by "a revolution in marriage and long-term friendships." As an owner of 20 town houses in Miller and Smith Inc.'s Ashleigh development, he observes people are beginning to consolidate in dwellings.

"We find a new group who's coming. . . . We have two couples who are living together; one lives in the bedroom upstairs and one lives in the bedroom downstairs, and they use the kitchen and the dining room as a common area," he said.

But these pioneering youngsters are different from their frontier forebears, Cetron finds. "They want their houses like they want their cars," he said, "Compact but luxurious. They don't give a damn about sharing a bedroom, but they want their own bathrooms." They also demand the latest labor-saving appliances and many of them have such luxuries as massage showers and whirlpool pumps for their bathtubs.

Family housing patterns will change too, says this information-age fortune teller. "Prepare yourself," he warned parents of young adults, "they're coming back with a vengeance." Cetron predicted students will choose nearby colleges so they can live at home, and he expects many divorced persons to move back home in the future.

Cetron's electronic "brains" tell him that the inflation rate will level off at 7 percent next year, and, by extrapolation, he precicts interest rates will fall to 11 percent next year. Needless to say, he expects a boom for the housing industry in 1983.

Cetron forsakes his computers when talking about real estate investment potential and falls back on a statement he attributes to Mark Twain: "Buy land. God doesn't make it any more."