Powerful Typhoon Hinnamnor moved toward Okinawa on Tuesday morning. At 11:00 a.m. EDT on Tuesday the center of Typhoon Hinnamnor was located at latitude 26.4°N and longitude 132.8°E which put it about 360 miles (575 km) east of Okinawa. Hinnamnor was moving toward the west at 18 m.p.h. (29 km/h). The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h). The minimum surface pressure was 910 mb.

Powerful Typhoon Hinnamnor was the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale on Tuesday morning. A circular eye with a diameter of 10 miles (16 km) was at the center of Hinnamnor’s circulation. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Hinnamnor. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the typhoon.

The circulation around Typhoon Hinnamnor increased in size when the typhoon intensified. Winds to tropical storm force extended out 40 miles (65 km) from the center of Hinnamnor. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Hinnamnor was 31.6. The Hurricane Size Index (HSI) was 15.3 and the Hurricane Wind Intensity Size Index (HWISI) was 46.9. Hinnamnor was capable of causing regional severe damage.

Typhoon Hinnamnor will move through an environment capable of supporting a strong typhoon during the next 24 hours. Hinnamnor will move over water where the Sea Surface Temperatures are 30˚C. It will move through region where the winds at all levels of the troposphere are blowing from the east. Since the winds at different levels are blowing from the same direction, there will be little vertical wind shear. Typhoon Hinnamnor could intensify during the next 24 hours, if the inner end of rainband does not wrap around the existing eye and eyewall. Hinnamnor could strengthen to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale. If concentric eyewalls form, then an eyewall replacement cycle could cause Typhoon Hinnamnor could to weaken temporarily.

Typhoon Hinnamnor will interact with a tropical depression that formed southeast of Okinawa during the next 24 hours. At 11:00 a.m. EDT on Tuesday morning the tropical depression was centered at latitude 19.7°N and longitude 133.1°E which put it about 585 miles (945 km) southeast of Okinawa. The tropical depression was moving toward the west at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h). The minimum surface pressure was 1000 mb.

Typhoon Hinnamnor will move toward the west-southwest during the next 24 hours when its circulation interacts with the tropical depression. On its anticipated track Typhoon Hinnamnor will be near Minami Daito Jima in 12 hours. Hinnamnor could cause severe wind damage on Minami Daito Jima. Very heavy rain could cause flash floods. Typhoon Hinnamnor will also cause a significant storm surge along the coast of Minami Daito Jima. Widespread electrical outages are likely. The center of Hinnamnor could be south of Okinawa in 24 hours.

Typhoon Hinnamnor will eventually absorb the circulation around the tropical depression. Hinnamnor could move slowly around the southern Ryukyu Islands while it absorbs the depression. A prolonged period of strong winds and heavy rain could affect the southern Ryukyu Islands later this week.