The deal will see him remain with the club until at least the end of 2027.
Rated as one of the brightest young stars in the game, the 19-year-old has already been on the Storm's top 30 squad for one year, although failed to make his debut in 2021.
That is likely to change this time around for the centre and second-rower though, with Howarth not only representing the Australian Schoolboys, but also playing in the Queensland under-18s team during 2019 alongside the likes of Hamiso Tabuai-Fidow, Fanitesi Niu, Xavier Coates, Sam Walker and Jake Simpkin, as well as Storm teammate Trent Loiero.
The Storm are known for their incredible knack of identifying future talent for the club, and the young gun will serve as no exception when he eventually makes his NRL debut.
He made five appearances for the Sunshine Coast Falcons in 2021 as well, impressing on each occasion.
In an official club statement announcing the news, he said he was looking forward to continuing to develop his game.
“I love being part of Storm and love living in Melbourne,” Howarth said.
“The coaching staff and the boys are great to be around and are helping me a lot with my footy and life in general.
“It’s a top class environment to be part of.
“Footywise I’m looking forward to playing a lot more this year and developing my game even more.
"The dream is to wear the purple jersey in the NRL and it’s getting closer but there’s still a lot of work ahead.
“My future is sorted now with a great club for a few more years and I can fully focus in on my footy.”