Powerful Typhoon Lekima moved through the southern Ryukyu Islands on Thursday. At 5:00 p.m. EDT on Thursday the center of Typhoon Lekima was located at latitude 25.8°N and longitude 124.2°E which put it about 405 miles (655 km) south-southeast of Shanghai, China. Lekima was moving toward the north-northwest at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (270 km/h). The minimum surface pressure was 935 mb.
An inner rainband wrapped around the original eye and eyewall of Typhoon Lekima and a larger outer eye formed around the original eye. The inner eye remained intact and the strongest winds were occurring in a small ring of thunderstorms around the inner eye. The diameter of the outer eye was about 60 miles (95 km). Additional bands of showers and thunderstorms were revolving around the two concentric eyewalls.
The formation of two concentric eyewalls increased the size of the circulation around Typhoon Lekima. Winds to typhoon force extended out about 80 miles (130 km) from the center of circulation. Winds to tropical storm force extended out about 275 miles (445 km) from the center. The Hurricane Intensity Index (HII) for Typhoon Lekima was 28.3. The Hurricane Size Index (HSI) was 28.1 and the Hurricane Wind Intensity Size Index (HWISI) was 56.4. Those indices indicated that Typhoon Lekima was capable of causing widespread significant damage.
The inner eye of Typhoon Lekima wobbled between Ishigakijima and Miyakojima on Thursday. The inner eyewall appeared to pass over Taramajima and Minnajima. No reports were available from a weather station on Taramajima. Stations on Ishigakijima and Miyakojima reports winds to tropical storm force, but the strong inner eye passed between those two islands.
The formation of the larger outer eye probably indicates that an eyewall replacement cycle will occur. Typhoon Lekima will weaken when the inner eyewall dissipates. However, the circulation will remain large. Typhoon Lekima will be in an environment favorable for strong typhoons during the next 24 hours. Lekima will move over water where the Sea Surface Temperature is near 28.5°C. It will move through a region where the upper level winds are not strong and there will not be a lot of vertical wind shear. Typhoon Lekima will weaken because of an eyewall replacement cycle, but it will remain a large, powerful typhoon.
Typhoon Lekima will move around the western end of a subtropical ridge over the Western North Pacific Ocean. The ridge will steer Lekima toward the north-northwest during the next several days. On its anticipated track Typhoon Lekima could approach the coast of China south of Shanghai in about 24 hours. It is likely to be a large typhoon at that time.
Elsewhere around the Western North Pacific Ocean, Typhoon Krosa was nearly stationary south of Iwo To on Thursday. At 5:00 p.m. EDT on Thursday the center of Typhoon Krosa was located at latitude 22.1°N and longitude 141.0°E which put it about 195 miles (315 km) south of Iwo To. Krosa was nearly stationary. The maximum sustained wind speed was 110 m.p.h. (180 km/h) and there were wind gusts to 130 m.p.h. (210 km/h). The minimum surface pressure was 950 mb.
The circulation around Typhoon Krosa was also large. Winds to typhoon force extended out about 75 miles (120 km) from the center of circulation. Winds to tropical storm force extended out about 250 miles (405 km) from the center. The Hurricane Intensity Index (HII) for Typhoon Krosa was 19.2. The Hurricane Size Index (HSI) was 28.4 and the Hurricane Wind Intensity Size Index (HWISI) was 47.6.
Typhoon Krosa is forecast to move slowly north toward Iwo To on Friday. On its anticipated track Krosa could approach Iwo To in about 36 hours. It will be a large typhoon capable of causing serious damage at that time.