The city took the free Friday of Thanksgiving's long weekend with an air of relaxed contendment. Tourists and schoolchildren swarmed over the Mall in the crisp, clear light of a last temperate autumn afternoon and a small surge of shoppers downtown edged - into the Christmas season with their checkbooks and charge cards, seeming more anxious to brows then to buy.

In the suburbs, however, it was quite a different story.

This is the day the madness is supposed to start. This is when it all happens," said Holly Gudelsky of the Tysons Corner management office early yesterday morning, just before an estimated 300,000 shoppers converged on the complex for the busiest single shopping day of the year.

The temperature rose to 61 degrees, but dark clouds cut across the sky in the late afternoon bringing on an early dusk. The National Weather Service reported that temperatures will drop about 10 degrees today, plunging further down the scale tomorrow. There may be a warming trend next week, but winter - and for some, Christmas - seems to be well on its way.

While there were small snarls of traffic around the major department stores downtown, few parking places - as usual - near the big tourist attractions, and a crush comparable to any pleasant weekend afternoon in Georgetown, the Tysons parking lots turned into a stormy sea of bumpers.

"My husband is still outside trying to park. This parking lot is a madhouse," Norma Saeli said wearily as she deposited her two children and a friend at the Tysons II movie theater before joining the shopping stampede.

Michael Heenan toured the 6,500 space parking lot for what seemed like "forever" before locating a space. As a result, much of his shopping was concentrated in a nearby toystore where his 3-year-old daughter was coaxing him to buy a plastic, croaking frog.

"I guess we are just taking anything that is close so that we don't have to push through the crowds so much," Heenan said.

Santa has been on the scene at Tysons since last Tuesday, though yesterday he was looking disturbingly gaunt. Unfortunately, according to Tysons promotion manager Alte Faust, a new employe in charge of costuming had failed to give young Michael (Santa) Gotay adequate padding and the part-time actor appeared as a "strangely thin" St. Nicholas.

"I was mortified, he seemed so skinny," she said yesterday. "He said he had been going to a health spa and was sorry he had lost so much weight."

Salad-spinners were busily taking over the kitchen-craze among buyers who last year were enamored of the considerably more expensive Cusinart and its variations at the Hecht Co.

Doll houses with elaborate furnishings were doing "considerable" business at Sullivan's Toys, said manager Peter Deely.

The hottest album at Variety Records was Billy Joel's "52nd Street" while Bloomingdales, ever trendy, was busily marketing a "dirty words" game for $7. Players have six minutes to form sentences from dice loaded with suggestive words.

Business was up as well in the downtown stores, but as one older man who had often shopped there in the past described the scene, "If this was 12 years ago, when you didn't have the malls, you'd have a crowd here." There was some congestion on the sidewalks, but as he saw it, "This nothing today. Back then you couldn't even move."

Most shoppers stopped at random downtown said they didn't begun to think seriously about Christmas yet, but were attracted by various advertised sales.

In Georgetown things were a little more hectic, with Cindy Falk, a salesgirl in Britches, moaning "It's crazy. It's really the start of Christmas all over again."

But even where Christmas buying seemed to be getting under way, Christmas giving was decidedly lagging behind.

Roland Jones, an elderly volunteer for the Salvation Army sat shivering, his bell tinkling almost uncontrollably in his hand, outside Hecht's downtown. The bottom of his donation buckett was barely covered with small change. "Along like the week before Christmas they do a little better," he sighed.

For the tourists, walking along amid the leaves still rasping over the pebble-covered paths of the Mall, Christmas seemed very far away indeed. They had their own traffic problems to fight and many were still lingering in the afterglow of Thanksgiving dinners they had shared with relatives in the area.

Several thought they had beaten the summer crowds by waiting until yesterday to see the most popular museums, only to find that everyone else seemed to have the same idea.

"It's like too crowded down here today," said Robin Miele, a junior at the University of North Carolina who is visiting friends in Silver Spring. "We couldn't even get in to see the movie (at the Air and Space Museum), and that's what we came for."

Bill Peters, from Cincinnati trudged through the Air and Space Museum with his year-old boy in a pack on his back accompanied by friends from Baltimore and looking a little put off by the mass of tourists everywhere around him. "I guess the weather came out and so did the crowd."

Was he thinking of Christmas yet? No, he said. "We'll probably be eating some more turkey tonight."