Tokyo, Sep 18 (IANS): Large tropical storm Pulasan is expected to make its closest approach to the main island of Okinawa Prefecture in southwestern Japan on Wednesday evening, the country's weather agency said.

The Japan Meteorological Agency (JMA) said Pulasan, packing winds of up to about 80 kilometres per hour with maximum gusts of 126 kilometres per hour, was moving at 20 kilometres per hour over waters south of Minami-Daito Island in Okinawa on Wednesday morning.

Okinawa's main island and the Amami region of Kagoshima Prefecture are expected to be hit with winds of up to 72 kilometres per hour, with maximum gusts possibly reaching 108 kilometres per hour, according to the JMA.

High waves and swells are likely around the two prefectures through Thursday, Xinhua news agency reported.

Weather officials said severe thunderstorms could bring up to 150 millimetres of rain to Okinawa by Thursday noon, and up to 120 millimetres in the Amami region and the Tanegashima and Yakushima region of Kagoshima.

The agency urged people to stay alert for high waves, strong winds, storm surges, landslides, floodwaters in low-lying areas and swollen rivers.