Typhoon Bolaven, named after highlands in Laos, has gained in strength and will affect Korea more powerfully than expected. Bolaven is moving towards Jeju Island after landing in Okinawa, Japan, with a maximum wind speed of 70m/s on Sunday night.

The Korea Meteorological Administration on Sunday predicted that Bolaven will bring the wind speed of over 50 m/s and more than 30 mm per hour of rainfall in Jeju and the south coast on Monday, with some parts of Jeju seeing up to 500 mm of downpours until Wednesday.

Bolaven is expected to be more powerful than Kompasu, which devastated Korea in 2010. The KMA said its winds will be stronger than Kompasu's in 2010 and Muifa's in 2011, making it the most devastating typhoon to come to Korea since 2000. 

Kompasu's maximum gale speed was 45.4 m/s, and it killed six and caused W170 billion worth of damage (US$1=W1,135) along a trajectory similar to Bolaven's.

The KMA said all of Korea will come under Bolaven's influence by Monday night. "We are especially concerned about possible damage to the Seoul Metropolitan Area and the west coast, which lies to the right of the typhoon's path," a weatherman said.

By Tuesday evening, Bolaven is expected to reach Ongjin in North Korea and leave the Korean Peninsula 180 km northeast of Sinuiju.

The KMA warned people to pay extra attention to facilities such as traffic lights and signboards in gale-force winds.

High waves pound seawall in Yonabarucho, Okinawa Prefecture, southern Japan on Sunday. /AP-Yonhap

Okinawa was paralyzed when Bolaven arrived on Saturday night. The entire island experienced gales of up to 70 m/s and waves over 10 m high. Okinawa's weather agency said it was the strongest typhoon it has witnessed since typhoon observation began in 1952 and issued its highest level of warning.

Meanwhile, Korea's Ministry of Education, Science and Technology announced on Sunday that it has sent an advisory to all 17 Offices of Education nationwide to adjust school hours or close schools if the weather warrants it.