Ken made landfall upon Shikoku early on September 25, and moved onward into the Sea of Japan where it evolved into an extratropical cyclone.

[1] On September 15, the Japan Meteorological Agency (JMA) started to monitor the system.

[2][nb 1] The next day, a Hurricane Hunter aircraft reported a closed atmospheric circulation.

[2] Initially, Ken was expected by the JTWC to move west and pass near Luzon, but this did not occur.

At 0600 UTC on September 17, Ken was upgraded into a severe tropical storm by the JTWC[1] and the JMA.

[2] That evening, Ken was upgraded to typhoon status by both the JTWC[1] and the JMA[2] when the hunters recorded a pressure of 976 mbar (28.8 inHg).

[1] Ken continued to gain strength; at 1800 UTC on September 18, the Hurricane Hunter aircraft reported winds of 185 km/h (115 mph).

Several hours later, the JTWC reported that Ken attained peak intensity of 200 km/h (125 mph) while centered about 800 km (495 mi) east-southeast of Taiwan.

That day, the system moved into the Sea of Japan, where it transitioned into an extratropical cyclone while producing winds just below typhoon-force.

[4] Upon making landfall in Japan, Ken became the fourth storm to strike the nation during the season.

[13] Airlines cancelled 74 flights and the Japan National Railways halted 17 trains on the southernmost main island of Kyushu.