With Typhoon Trami predicted to pass over Okinawa Prefecture this weekend, candidates for Sunday’s gubernatorial election are making efforts to get voters to the polls early out of concern over the effect the storm could have on the final result.

As of Wednesday morning, the typhoon was forecast to pass over the smaller islands of southern Okinawa Prefecture early Saturday morning before turning northeast and passing over the main island on Sunday.

Because of the predicted path of the storm, the Okinawa Election Commission has announced that Taketomi, a small town of about 4,100 people in the prefecture’s southern island chain, and Tsukenjima, a small island inhabited by about 430 off the central part of the main island, will go to the polls on Thursday.

The decision was made after the election commission judged it could be difficult to deliver ballot boxes to the voting booths on the outlying islands by ship due to the approaching typhoon. The plans are now to have the boxes delivered by Coast Guard helicopters.

“We’re keeping an eye on the typhoon, but as of today, there are no discussions about moving up the election elsewhere on Okinawa,” said the election commission’s Maiko Shigehisa on Wednesday.

Sunday’s election is being closely watched outside of Okinawa for its impact on the controversial plan to relocate U.S. Marine Corps Air Station Futenma in Ginowan to a partially offshore facility now under construction at Henoko on the northern part of the main island.

Atsushi Sakima, the former mayor of Ginowan, is strongly backed by Prime Minister Shinzo Abe and the Liberal Democratic Party, as well as its coalition partner Komeito. His campaign strategy has been to avoid discussing Henoko directly and instead emphasize the need to quickly close Futenma and negotiate with Tokyo on economic aid.

His main opponent is Denny Tamaki, a former member of the House of Representatives, who is backed by the major opposition parties and a broad coalition of traditional anti-base activists and local business leaders who support Japan’s alliance with the United States but oppose the Henoko plan.

Advanced polls have been open since Sept. 14.

Through Sunday, 95,143 people had already cast their ballots according to the election commission, an increase of 75 percent over the same period in the 2014 election.

Both sides said Wednesday that the typhoon could play a factor in Sunday’s results.

“If Okinawa Prefecture gets a warning for severe winds, then we’ll suspend outdoor canvassing with our campaign truck. At that point, our volunteers will hit the phones to appeal to voters,” said Jinichiro Asato, a spokesman for Sakima’s office.

“If the typhoon moves slowly, it could affect voter turnout on Sunday. But if it moves through quickly, turnout probably won’t be affected,” he added.

Yui Senaga, a spokeswoman for Tamaki’s office, said there were no plans yet to make changes to the weekend’s campaign schedule.

“But at this point, we’re watching the situation carefully. All we can do is to tell people, especially elderly people who might not be able to move about easily, that the weather is OK now so they might wish to get out and vote,” she said.