Kevin Mannix, the longtime TV weather forecaster on WCSH’s top-rated morning news program, is changing shifts and expanding his on-air duties.

Mannix, who has been with WCSH (Channel 6) in Portland since 1989, will do the weather report on the weekday noon news beginning Oct. 20. He also will launch a reporting series on mental health issues that’s related to one he did last year called “Kevin’s Story.” In that series, he revealed his time spent in counseling as he struggled to overcome shame surrounding his upbringing by an alcoholic father. The move also will give Mannix time to continue work on a book about his experiences.

Mannix announced the changes Monday with what he called “a mix of sadness and excitement.” His last day on the station’s morning report will be Friday.

On his Facebook page Monday, Mannix wrote that the change was “unexpected and sooner than I would have liked it,” but that it would allow him more time for his projects. He also welcomed suggestions from people on stories for his new series and said that he was “proud of the commitment of the station” to reporting on mental health.

He could not be reached for comment Monday.

His move from mornings will make room for new WCSH meteorologist Todd Gutner, who started at the station last week after working for seven years at WBZ in Boston. Gutner will take over the morning weather forecast on WCSH on Oct. 13.

Gutner started his career at WCSH, working at the station from 2000 to 2007. He had most recently done the morning and noon forecasts at WBZ.

WCSH officials began talking to Gutner about coming back to the station more than a year ago, said Steve Carter, WCSH’s president and general manager.

“In this business, when you have an opportunity to attract someone like Todd, you go for it,” Carter said Monday. “We’re adding a quality guy with Todd. Kevin is a quality guy, too.”

The addition of Gutner won’t lead to fewer work hours for the rest of the weather staff, Carter said. Demands have increased, as the staff is responsible for weather updates online, as well as the TV newscasts. Joe Cupo will continue to do evening newscasts, while Tom Johnston and A.J. Burnett will do weekends and fill in at other times.

Steve McKay, based at WLBZ in Bangor, is also seen on some WCSH newscasts. WCSH’s morning, noon and some evening newscasts are seen on WLBZ in Bangor, meaning the station’s weather forecasters have a statewide audience.