Former Tropical Storm Khanun strengthened to a typhoon over the Western North Pacific Ocean south-southeast of Okinawa on Sunday. At 5:00 a.m. EDT on Sunday the center of Typhoon Khanun was located at latitude 20.0°N and longitude 132.5°E which put it about 575 miles (925 km) south-southeast of Okinawa. Khanun was moving toward the north-northwest at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 100 m.p.h. (160 km/h). The minimum surface pressure was 977 mb.

Former Tropical Storm Khanun continued to steadily strengthen during Saturday night and Khanun reached typhoon intensity on Sunday. A circular eye developed at the center of Khanun’s circulation. The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Khanun. Storms near the core generated strong upper level divergence that pumped mass away from the typhoon. The removal of mass caused the surface pressure to decrease.

The large circulation around Typhoon Khanun became much more symmetrical during the past 24 hours. Winds to typhoon force extended out 70 miles (110 km) from the center of Khanun’s circulation. Winds to tropical storm force extended out 275 miles (445 km) from the center of circulation.

Typhoon Khanun will move through an environment that will be favorable for intensification during the next 36 hours. Khanun will move over water where the Sea Surface Temperatures are near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Typhoon Khanun will intensify during the next 36 hours. Khanun could intensify rapidly at times. Typhoon Khanun could strengthen to the equivalent of a major hurricane during the next 36 hours.

Typhoon Khanun will move around the southwestern side of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Khanun toward the north-northwest during the next 36 hours. On its anticipated track, Typhoon Khanun will move toward the Ryukyu Islands. Khanun could approach Okinawa in 36 hours. Khanun could be the equivalent of a major hurricane when it approaches Okinawa.