People in Japan are bracing for Typhoon Hagibis, which could hit a wide swath of the country over the weekend.
Forecasters say the storm could pass directly over the greater Tokyo area, one of the largest urban centers in the world.
Weather officials are urging people to be prepared for gale-force winds and heavy rain.
The Japan Meteorological Agency says Hagibis has intensified into a particularly powerful storm.
It was moving north-northwest near the Ogasawara Islands in the Pacific on Friday morning, Japan time.
Officials say it could make landfall in eastern Japan on Saturday.
And they're warning storm conditions are expected off Japan's Pacific coast on Friday, with eastern Japan seeing storm surges from Saturday through Sunday.
Train operators in the Tokyo area say they will announce any service cancellations on their websites and through social media.
JR East says it wants commuters to watch for advisories, as the company may have to suspend operations on local and Shinkansen bullet trains.
All Nippon Airways is cancelling all domestic flights on Saturday to and from Haneda and Narita airports.
Japan Airlines is cancelling almost all its flights.
Japan's justice minister is also calling on visitors and foreign residents to pay attention to the weather updates.
He said, "Please stay informed by checking the government's official twitter accounts, such as the Japan National Tourism Organization."
He's urging people to download an app called "Safety Tips," which the Tourism Agency provides for foreign visitors. He also suggests following the official twitter account of Japan's tourism organization to stay informed.
The storm is already causing problems for the Rugby World Cup. Organizers have had to call off two matches between New Zealand and Italy, and England and France.
It's the first time a World Cup match has ever been cancelled. Tournament rules say the games will be recorded as a draw.
Four matches are scheduled for Sunday, and officials are still deciding whether those will go ahead.