“SNL50” spirit has been sweeping New York in the run-up to Sunday’s show. Even the MTA has joined in celebrating “Saturday Night Live.” Since Feb. 10, Thompson has been the voice of the transit authority, relaying messages to New York City subway riders to pay fares and stay inside moving subways cars.

We [will] have about 450 people in the studio, which is essentially about 200 people more than we would normally have.”