Magnolia Horn said she can't sit on her front porch because of the catcalls and obscenities shouted by prisoners in the D.C. Jail two blocks away. And then there are the escapes.

"Those fellas are yelling and cursing," said the 83-year-old resident of Southeast Washington. "And we have to worry about them getting out as well. One time, three of them ran down my alley and one of them threw his coat over my fence," Horn recalled, seated in the neat living room of her two-story, brick row house, which is typical of the neighborhood.

Horn and her neighbors despise the current jail but Mayor Marion Barry announced last week the neighborhood would be getting another. After an intensive, 14-month search for a site for a new, 700-bed prison, punctuated with howls of protest from every neighborhood considered, the mayor decided to put the new prison right next to the existing one.

Tonight hundreds of residents are expected to meet to discuss only one thing: how they will oppose their prospective new neighbor.

"We are opposed to another jail in our neighborhood," said Advisory Neighborhood Commission Chairwoman Flossie Lee. "Our office was flooded with calls today from residents asking what they can do to stop it."

The neighborhood is already the home of D.C. General Hospital, Robert F. Kennedy Stadium, the Armory, the city morgue and a drug treatment center. The city institutions are all located generally between 19th Street NE and the Anacostia River, Independence Avenue and Congressional Cemetery.

So far, the community has launched a petition drive and no one interviewed seemed to think it would be quite proper to march around the area with protest signs as residents of a community a few blocks to the west had done in the last few weeks after the city tried to convert an old police precinct to a jail

D.C. City Council member Nadine Winter (D-Ward 6), whose ward includes both neighborhoods and who joined neighbors in actively opposing the precinct plan, said yesterday she expects a more subdued response from the neighbors of the newest site proposal.

"I let residents take the lead and I support them," she said. "Over in the 19th Street neighborhood, it is a more conservative, older community. They are very well organized and will turn out for a meeting, but I expect they will be more reserved than the 9th Precinct neighborhood."

These two neighborhoods are located about 20 blocks from each other but are drastically different.

The community around the old Ninth Street precinct is a gentrifying Capitol Hill neighborhood with longtime black homeowners and renters living next door to recently arrived white professionals.

The neighborhood near the existing jail is predominantly black, made up of longtime homeowners, many of whom are retired District and federal employes.

"The 19th Street community is a place where I am invited for 50th wedding anniversaries and funerals," said Winter. "It is a family place where we all know each other by first name."

Shirley Campbell, who lives with her mother near 18th and D streets SE, said, "We have breakouts from the jail and we have hospital patients wandering through the neighborhood half-dressed."

Edward Boyd, 40, a government clerk who has rented an apartment directly across from the jail for 13 years, was somewhat supportive of the new jail.

*"They have to go somewhere," he said. "These people who oppose the prison have to consider the alternative of turning those prisoners loose."