The storm's west-southwest path brought the center across the Ryukyu Islands and near Okinawa on August 16 as Kathy began to execute a loop in its track.

[1]: 141  This system developed into a tropical storm, gaining the name Kathy the following day east of Iwo Jima based on ship observations.

[2][3]: 76  Maintaining a west-northwestward heading, Kathy reached typhoon strength on August 13,[2] passing well south of Tokyo on approach towards the Ryukyu Islands.

[1]: 50  Between August 15–16, Kathy briefly fell to tropical storm intensity before regaining typhoon status southeast of Amami Ōshima.

[6][1]: 146  The storm's west-southwest path brought the center across the Ryukyu Islands and near Okinawa on August 16 as Kathy began to execute a counterclockwise loop in its track.

On August 23, Kathy made landfall on Kagoshima Prefecture with winds of 130 km/h (81 mph) and weakened to a tropical storm as it crossed the Seto Inland Sea and southern Honshu.

[2][3]: 76  On August 25, Kathy transitioned into an extratropical cyclone and continued northeast towards the Aleutian Islands before it was last in the Bering Strait on September 1.

[13] As Kathy moved across southern and central Kyushu, damage was reported in Kagoshima, Kumamoto, Miyazaki, and Oita prefectures.