Shortly after the end of today's football game between Howard University and North Carolina A&T State University, scores of men -- many wearing their purple and gold Omega Psi Phi fraternity colors -- will drift from the stadium and gather around a sundial just north of Howard's main library.

Dozens of other men, wearing black and gold colors of the Alpha Phi Alpha fraternity, will follow, gathering about 50 yards away around a tree near the campus chapel.

The reunions of fraternity members, and several other groups, are part of a tradition of Howard University homecoming activities that culminate at 1 p.m. today with a kickoff of the football game.

No one knows how or when Howard's fraternities and sororities started the post-game mini-reunions. But the tradition continues.

"It started before my time," said Walter I. Ray Jr., a member of the Omega Psi Phi fraternity who graduated from Howard in 1949. "We have just kept up the tradition."

Ray knows that he will be there. A self-described "successful businessman" with homes in Silver Spring and New Jersey, Ray returned to his Maryland residence yesterday afternoon "because it is homecoming."

Howard officials estimated that nearly 15,000 graduates -- about 30 percent of the university's 50,000 living alumni -- return to the campus on Georgia Avenue in Northwest Washington for the annual event.

All 147 rooms at the Howard Inn have been booked for almost one year, almost half of them set aside for alumni from the 1950s. Nightspots from Silver Spring to Alexandria -- and several in downtown Washington -- have been marked for smaller celebrations during the weekend.

Jim Nabors, a New York City dentist and a 1960 Howard grad-

uate, has not missed a homecoming weekend in 30 years.

"The reasons are quite simple," said Nabors, one of at least 200 alumni who live in the New York area and will attend homecoming. "Camaraderie. Friendship. Thinking about all the good times, reminiscing about the bad."

And a sense of belonging. R. Chester Redhead, a 1950 graduate who is national president of the Howard Alumni Association, said that Howard offers its alumni an opportunity that black Americans who attended predominantly white institutions don't get.

"Those graduates don't get to sit on the 50-yard line," said Redhead, who has been coming home to Howard for 35 years. "They don't get to spend time with their university's president.

"I think the reason so many of us come back year after year is that we get out into the world and find out we need our roots," Redhead said. "Our roots are at Howard University."

Roland Burroughs has missed two homecoming weekends since he graduated in 1957. That was in 1966 and 1967, when he was in the military serving in Vietnam.

But even then, Burroughs said, he had his homecoming. "I always say that wherever I go, I run into somebody who went to Howard," he said. "That includes Saigon," the former capital of South Vietnam. "A group of us found each other over there and had our own celebration."

Homecoming 1990 is the first under the administration of Howard President Franklyn G. Jenifer, who in an interview soon after he assumed the office last April complained that university alumni donated too little money to the school.

But Jenifer said he will not pressure alumni this weekend for more contributions.

At least one fund-raiser is planned, a $100 package of a game ticket, food and drink that university officials said will raise about $300,000 for the athletic department.

"We're going to go light on them," Jenifer said. "We want them to enjoy the weekend and each other's company. We'll have plenty of time to go after them for more money."