Fujiwhara effect
Around the time of reaching peak intensity, Mireille turned more to the northwest along the southwestern periphery of the subtropical ridge. The increasing size began to impart wind shear in Typhoon Nat to the west, and the two storms underwent the Fujiwhara effect, in which Nat turned sharply southward while Mireille progressed toward the Ryukyu Islands of Japan. After maintaining peak winds for about 30 hours, Mireille began weakening, passing just east of Miyako-jima on September 26 with 10‑minute winds of 165 km/h (105 mph), according to the JMA. That day, the typhoon accelerated to the northeast due to increasing mid-level winds from the southwest, passing west of Okinawa. According to the JMA, Mireille re-intensified slightly on September 27 to a secondary peak of 175 km/h (110 mph), aided by unusually warm water temperatures in the East China Sea. The typhoon made landfall at that strength at 07:00 UTC between Saikai and Nagasaki along southwest Kyushu. The pressure at landfall was , the lowest in the country since Typhoon Trix in 1971.