Rugby World Cup organizers were on Saturday monitoring an approaching tropical storm that will strengthen into a typhoon and could brush Japan's southernmost main island over the weekend but they said no disruption to matches was expected.

Several typhoons a year make landfall on Japan's four main islands and the World Cup is being held in peak typhoon season. On Sept. 9, a storm roared ashore just east of Tokyo, knocking out power to hundreds of thousands of people.

Tropical Storm Tapah, the season's 17th storm, is powering through the Okinawa island chain and set to head northeast, possibly brushing the southernmost main island of Kyushu and the western tip of Honshu island from Sunday through Monday.

"Based on the latest weather information ... the typhoon could bring high winds and heavy rain to the southern island of Kyushu on the evening of Sept. 22 and into Sept. 23," the organizing committee said in a statement.

"While no match disruption is anticipated at this stage, we have advised teams of potential disruption to training and team movements as a precautionary measure," it said.

Italy play Canada in Fukuoka on Sept. 26 and there are also matches in Oita and Kumamoto, but not until October.

"As a precaution for fans, Kumamoto and Fukuoka have also announced the temporary closure of their Fanzones on Sept. 21 and 22," the committee said.

Tapah, a Malaysian word for a type of giant catfish, will strengthen as it moves northeast and become a Category 1 storm as it approaches closest to Kyushu.

Some forecasts of its track show it moving slightly further north, minimizing its direct impact on Japan, although it is likely to bring heavy rain and wind to Kyushu over the weekend.