Typhoon Chataan is fast approaching Japan and could affect the southern parts of Korea from Wednesday, forecasters said Monday. Chataan, the sixth typhoon of the year, reached southeast of Okinawa, Japan, Monday and was moving north-northwest at 15kph. Packing central winds of 49mps and 930 hectopascals in pressure, Chataan is expected to reach as far up as 180km south-southwest of Kyusu and affect Japan by Wednesday morning.