The extremely large Typhoon Hagibis is gaining force over the Pacific south of Japan and is forecast to approach the main islands of Kyushu, Shikoku and Honshu during the upcoming three-day weekend, the Meteorological Agency said.
On Tuesday, the agency urged caution and called for early preparations in anticipation of the season's 19th typhoon hitting the country's main islands.
As of Tuesday morning, Hagibis was moving over the Mariana Islands on a west-northwesterly track, the agency said.
The typhoon was expected to turn north and approach areas around the Daito Islands in Okinawa Prefecture around Friday.
Hagibis may head on to Kyushu, Shikoku and Honshu, lashing those areas from Saturday to Sunday, the agency said.
The storm was forecast to cause high waves in Okinawa as well as the Ogasawara Islands south of Tokyo around the middle of the week, and on the Pacific coast of Honshu around Friday.
There is also a risk of storms and heavy rains starting around Saturday in a wide range of areas from western to northern parts of the country.
Last month, two typhoons wreaked havoc in Japan, with Faxai hitting Tokyo and causing a massive power outage in Chiba Prefecture, while Tapah brought heavy rains and caused tornados in Kyushu.