Typhoon Hinnamnor stalled near the southern Ryukyu Islands on Thursday. At 11:00 p.m. EDT on Thursday the center of Typhoon Hinnamnor was located at latitude 21.7°N and longitude 125.3°E which put it about 200 miles (320 km) south-southeast of Ishigaki, Japan. Hinnamnor was moving toward the northwest at 2 m.p.h. (3 km/h). The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h). The minimum surface pressure was 960 mb.

Typhoon Hinnamnor stalled and weakened southeast of the southern Ryukyu Islands on Thursday. When Hinnamnor stalled, strong winds in the lower levels of the atmosphere mixed cooler water to the surface of the Western North Pacific. Typhoon Hinnamnor was unable to extract enough energy from the upper ocean to maintain its intensity and it weakened. The northern and western parts of the eyewall weakened. Most of the thunderstorms were occurring in bands in the eastern and southern parts of Hinnamnor’s circulation. Bands in the northern and western parts of the circulation consisted primarily of showers and lower clouds. Storms near the center of Hinnamnor still generated upper level divergence that pumped mass away from the typhoon.

The size of the circulation around Typhoon Hinnamnor increased on Thursday when the typhoon weakened. Winds to typhoon force extended out 35 miles (55 km) from the center of Hinnamnor. Winds to tropical storm force extended out 230 miles (370 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Hinnamnor was 19.2. The Hurricane Size Index (HSI) was 13.8 and the Hurricane Wind Intensity Size Index (HWISI) was 33.0. Typhoon Hinnamnor was capable of causing regional serious damage.

A high pressure system over the Western North Pacific Ocean will start to steer Typhoon Hinnamnor toward the north during the next 24 hours. On its anticipated track Typhoon Hinnamnor will approach the southern Ryukyu Islands in 24 hours. Hinnamnor will bring strong winds and locally heavy rain to the southern Ryukyu Islands. Heavy rain could cause flash floods in some locations.

Typhoon Hinnamnor will move through an environment unfavorable for intensification during the next 24 hours. The core of Hinnamnor will still be over cooler water that was mixed to the surface for much of Friday. An upper level ridge over China will produce northerly winds that will blow toward the top of Hinnamnor’s circulation. Those winds will cause vertical wind shear which will inhibit intensification. Typhoon Hinnamnor could weaken further during the next 24 hours. Hinnamnor will move over water where the Sea Surface Temperatures are 30˚C during the weekend, when it moves north of the cooler water that has been mixed to the surface. Typhoon Hinnamnor could strengthen again when it moves over warmer water..