TELEVISION - Jan. 8, 1993

The Doctor Is In: NBC, which wasn’t planning to make this move until February, has yanked John Forsythe’s “The Powers That Be” and Malcolm-Jamal Warner’s “Here and Now” off the Saturday schedule in the wake of the strong showing by CBS’ new frontier drama, “Dr. Quinn, Medicine Woman.” Hoping to prevent the CBS show from establishing a Saturday-night toehold, NBC will counter-program throughout January with reruns of “Empty Nest” at 8 p.m. and “Nurses” at 8:30 p.m.--followed by the regular lineup of “Empty Nest” at 9, “Nurses” at 9:30 (yes, double doses of both shows) and “Sisters” at 10. Speaking of double doses, in February, NBC will be offering two episodes of “Cheers” on Thursday nights.