NEW YORK - (AP) - New York City's 250th St. Patrick's Day Paradehas stepped off with best-selling author Mary Higgins Clark asgrand marshal.

The parade started at 11 a.m. Thursday at 44th Street and FifthAvenue. Throngs of green-wearing marchers and spectators areenjoying sunshine with temperatures expected to reach the low 60s.

New York Mayor Michael Bloomberg attended Mass at St. Patrick'sCathedral before marching in the parade.

Earlier this month, Bloomberg got a less than warm welcome at aSt. Patricks' Day parade in Queens. Some parade-goers were angryabout the mayor's joke last month that he usually saw "people thatare totally inebriated" at the American Irish Historical Societyin Manhattan. Bloomberg apologized shortly after making thecomment.