The Federal Emergency Management Agency is asking Congress for $250 million to bail out its disaster relief fund, which recently helped flood victims in California and West Virginia. The fund is expected to post a $254-million operating deficit by Sept. 30, the end of the current fiscal year, FEMA officials told a Senate appropriations subcommittee. "Our estimated new obligations . . . add up to an additional $464 million," a FEMA official told the panel.