A reconnaissance aircraft was then deployed to investigate the area;[1] the next day the system was upgraded to a tropical depression, which was then located 1,900 km (1,200 mi) southwest of Tokyo, Japan.

As it moved northwestward, a rapid intensification phase occurred, and by September 23, Ida reached typhoon intensity as a 50 to 55 km (30 to 35 mi) elliptical eye was reported by reconnaissance aircraft.

[3][4] Maximum wind gusts at the top of Mount Fuji reached 324 km/h (201 mph) during the storm's passage, a proof of the typhoon's power.

[2] Ida then weakened over land as its structure deteriorated, and less than 12 hours after striking Japan, it exited into the Pacific Ocean near Tohoku as a 95 km/h (60 mph) tropical storm.

[4] Following Tropical Storm Helen in quick succession, Ida wrought tremendous damage across eastern Japan and was regarded as the worst to strike the nation since Typhoon Vera in 1959.