Southern Decadence, the gigantic annual LGBT gathering sometimes called “Gay Mardi Gras,” is expected to fill up the French Quarter as usual from Aug. 31 to Labor Day (Sept. 4). Jeffrey Palmquist, a former Southern Decadence grand marshal, said no one’s quite sure how many people attend the weekend of partying and parading, “but 250,000 wouldn’t be out of the ballpark.”