Typhoon Pabuk, a massive, powerful storm system, is moving northward in the Pacific Ocean south of the Japanese archipelago and may directly hit western Japan this evening or early Wednesday, the Meteorological Agency said Monday.

Strong winds caused by Pabuk have already disrupted sea and air traffic in the southwestern part of the country, airlines and steamship companies said.

The 11th typhoon of the season, Pabuk, which means "big freshwater fish" in Laotian, was about 250 km southeast of the island of Tanegashima at 3 p.m. on Monday and moving north at 15 kph, the agency said.