The Japan Meteorological Agency issued a rare special warning on Saturday for Kagoshima prefecture on Kyushu, the southernmost of Japan's main islands, as 2 million people were told to seek shelter before the arrival of Typhoon Nanmadol, a powerful and potentially destructive super typhoon.
The warning came after the weather agency earlier in the day urged residents to evacuate parts of the Kyushu, ahead of the typhoon Nanmadol, expected to bring up to half a meter (20 inches) of rain when it makes landfall on Sunday.
Nanmadol, classified as a super typhoon by the U.S. Navy's Joint Typhoon Warning Center, has the potential to be the most destructive tropical storm to strike Japan in decades.
The 14th typhoon of the season was near Japan's southern Minami-Daito Island heading northwest at 20 kph (12 mph) on Saturday afternoon. Winds at the center of the storm were blowing at 198 kph and gusting up to 270 kph, according to the JMA.
"Unprecedented" storms and rainfall could strike the area, JMA official Ryuta Kurora said at a televised news conference, urging residents there to evacuate before it gets dark.
Southern Kyushu could receive 500 millimeters (20 inches) of rain on Sunday, while the central Tokai region could see 300 millimeters the agency forecast.
The special typhoon warning would be the first such alert for any prefecture north of the Okinawa island chain, domestic media reported.
Kyushu Railway Co began halting some train lines on Saturday ahead of wider suspensions on Sunday. Hundreds of weekend flights in the southern region were being canceled, broadcaster NHK reported, causing confusion among passengers travelling over the long weekend.
Convenience store chain Seven-Eleven Japan would temporarily shut about 610 stores in the Kyushu and Chugoku regions from Saturday night, local media reported.
The storm was forecast to curve east and pass over Tokyo on Tuesday, before moving out to sea by Wednesday.
Domestic broadcasters aired footage of strong winds and rain already lashing down on Japan's southern island chain of Okinawa as the storm approached.