Thousands of Washington's poorest and loneliest will turn to charitable organizations tomorrow for a hot meal and perhaps a faint reminder of better Christmases, better times.

Those providing the meals and some moments of holiday cheer say they're expecting more diners this Christmas than in recent years. Several attributed this to rising unemployment and federal cuts in a variety of social welfare programs.

"We expect to feed at least 1,000 at the shrine and deliver 400 meals to shut-ins," said Dolores Scott of Catholic Charities, which each year hosts Christmas dinner at the Shrine of the Immaculate Conception. Last year, Scott said, fewer than 1,000 came to the meal. Catholic Charities will provide transportation to the shrine for those who need it, she said. Rides will be available by calling 526-4100.

According to William Grillo, deputy director of the shrine, "we're not going to turn anyone away and if 2,000 turn up, we'll find a way to feed them." The food is being donated by the Marriott Corp.

"I have received so many calls that I've lost track," said the Rev. Rodney Young of the Council of Churches of Greater Washington. "They're coming from people seeking any kind of assistance they can get -- food, clothes, beds, anything. It's just unbelievable.

"People are unemployed, public assistance is being reduced, food stamps are being cut. The whole economic crisis we're faced with has brought about this great need."

The council will provide Christmas dinner for 400 at its Blair Shelter and, through Park Road Community Church, will deliver meals to 30 elderly residents of the Potomac Gardens housing project in Southeast D.C.

Michael Ferrell, director of the council's two men's shelters, said there has been an increase in the number of whites living at the centers. "Our overall population is 300, about the same for this time of year," Ferrell said, "but there are more white clientele than in the past. Last year, there were no more than 10 white faces; this year there are 25. I believe it's a result of Reaganomics."

Because of spreading economic problems, Ferrell added, the council will begin on Jan. 11 to offer counseling on finding jobs as well as obtaining welfare payments and food stamps. "This will go beyond our normal, year-round services of food, shelter, clothing and a hot shower," he said.

Dorothy McKinney of the United Planning Organization said that supplies in the agency's food bank, a depository of manufacturers' surplus, were at their lowest level for any month since the bank began functioning in 1976. "I have no help for anyone," McKinney said. "There is great need, great demand for food because of layoffs and unemployment."

The Salvation Army will have dinner ready for 500, in addition to the 100 residents of its adult rehabilitation center, said Maj. Robert Griffin. "We've already mailed food certificates to about 3,200 people in the District and about three times that throughout the metropolitan area," Griffin said. With these certificates, he explained, families may buy their own food for preparation at home.

The Salvation Army has also given new toys to some 9,000 children at a toy center it set up at 300 Sixth St. NW. "Whatever toys we have left over we're giving to children of unemployed parents," Griffin said. "We're seeing an increase in that category this year. We're also seeing an increase in the number of single men coming in for food."

Last year, according to Griffin, the Salvation Army provided Christmas-related services to 74,000 people throughout the Washington metropolitan area. "I believe that figure will be higher this year," he said.

At S.O.M.E. (So Others Might Eat), an interdenominational group that daily provides breakfast and lunch to the the city's homeless, 25 members of a suburban synagogue will help serve Christmas dinner for 500.

"I'm a people person," said Sue Rudo of Temple Emanuel in Kensington, "and it gives me a warm glow from within, a true sense of satisfaction." Rudo said this is the fourth Christmas that she and other members of the Reform Jewish congregation have served the holiday meal at S.O.M.E.

Throughout the year, she added, more than 180 families cook meals or provide canned foods to the organization. "That's over a third of our membership, the largest participation in the temple."

Here is a list of some of the Christmas dinners for the needy that will be available:

The Shrine of the Immaculate Conception, Fourth Street and Michigan Avenue NE, 1:30-3:30 p.m., 1,000 meals.

Salvation Army, 526 First St. NW, noon-3 p.m., 500 meals.

S.O.M.E., 71 O St., NW, noon-1:30 p.m., 500 meals.

Blair Shelter, 611 I St. NE, 4-7 p.m., 400 meals.

First Congregational United Church of Christ and Metropolitan Community Church, 10th and G streets NW, noon-3 p.m., 300-400 meals donated by D.C. Eagle restaurant.

New York Avenue Presbyterian Church, 1313 New York Ave. NW, noon-2:30 p.m., 375 meals.

St. Alban's Episcopal Church, Wisconsin and Massachusetts avenues NW, noon-1:30 p.m., 100 meals.

House of Ruth, 651 10th St. NE, 2-5 p.m., 100 meals.

New Macedonia Baptist Church, 4200 Alabama Ave. SE, 2-4 p.m., 50 meals.

Mt. Carmel House for Women, 471 G Pl. NW, beginning at 6:30 p.m., 45 meals.