Amid rumors swirling about its demise, the Contemporary Museum announced on Monday it would cease operating at the end of May. Some observers seemed surprised, because the Contemporary recently hosted a few well-attended shows, but it was too little too late and signs pointed towards closure. Founded by George Ciscle in 1989 as a gallery without a permanent home, the Contemporary made quite a splash at that time by mounting shows such as Urban Warrior Myths at nontraditional venues like an old Buick Dealership near the Meyerhoff. Ciscle left in 1996, and the Contemporary eventually settled into a space around the corner from the Walters until last year when it, once again, became nomadic. Although Sue Spaid, the current director, made a spirited effort to reinvent the museum, the odds, considering the economy, were stacked against it.