WORTH NOTING ON TV

THURSDAY Thanksgiving Day parades (CBS, NBC, 9 a.m. noon, ET): Live coverage of festivities around the United States - like the Macy's parade in New York, granddaddy of these eye-catching events - will be hosted by assorted celebrities, whose biggest task is filling hours of air time without sounding too banal. FRIDAY Great Performances (PBS, 9-11 p.m.): ``An Evening With Alan J.Lerner.'' Lots of stars (Julie Andrews, Leonard Bernstein, others) were on hand at Lincoln Center's New York State Theatre last month for the taping of this salute to the late composer of ``My Fair Lady,'' ``Brigadoon,'' ``Camelot,'' and other musical-theater classics.

SUNDAY 50 Years of Television (CBS, 9-11 p.m. - later if football games run over): The idea is somewhat self-congratulatory, but the recorded highlights selected from the medium's history - some recalled by the original stars - are varied enough to fascinate almost every viewer at some point.

TUESDAY The American Experience (PBS, 9-10 p.m.): This week's edition is ``Adam Clayton Powell,'' a documentary about the loved, hated, powerful preacher-politician from Harlem who coined the phrase ``Keep the Faith, Baby.'' (See preview coming in this section Friday.)

Please check local listings for all programs, especially on PBS.