Tropical Storm Gaemi brought wind and rain to Okinawa late on Friday. At 11:00 p.m. EDT on Friday the center of Tropical Storm Gaemi was located at latitude 26.7°N and longitude 127.9°E which put it near Okinawa. Gaemi was moving toward the east-northeast at 19 m.p.h (30 km/h). The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h). The minimum surface pressure was 990 mb.
Tropical Storm Gaemi became better organized after it moved across southern Taiwan early on Friday. The center of circulation was more evident on microwave satellite images. A primary band of showers and thunderstorms formed in the eastern side of circulation. Other showers and thunderstorms were located farther to the northeast of the center of Tropical Storm Gaemi. An upper level trough west of Gaemi was producing string southwesterly winds which were blowing toward the top of the tropical storm. Those winds were causing moderate vertical wind shear and they were likely the reason why most of the heavier rain was occurring northeast of the center of circulation.
The upper level trough was also steering Tropical Storm Gaemi quickly toward the east-northeast. On its anticipated track Gaemi will move over the middle Ryukyu Islands including Amami-O-Shima during the next 12 hours. Tropical Storm Gaemi will continue to produce gusty winds and locally heavy rain. Most of the rain will fall before the center of circulation reaches a location. Gaemi is likely to make a transition to an extratropical cyclone when it moves south of the larger islands of Japan during the weekend.
Tropical Storm Gaemi formed near Kaohsiung on the southwest coast of Taiwan late on Thursday. At 8:00 p.m. EDT on Thursday the center of Tropical Storm Gaemi was located at latitude 22.8°N and longitude 120.2°E which put it near Kaohsiung, Taiwan. Gaemi was moving toward the northeast at 5 m.p.h. (8 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 992 mb.
A distinct low level center of circulation developed in an area of showers and thunderstorms southwest of Taiwan on Thursday and the Japan Meteorological Agency designated the system as Tropical Storm Gaemi. Thunderstorms developed near the core of the circulation. Several short bands of showers and thunderstorms were revolving around the core. Mountains in eastern Taiwan may have deflected the flow in the lower levels and contributed to the organization of a center of circulation. Storms around the center were generating some upper level divergence which was pumping mass away to the east of the tropical storm.
Tropical Storm Gaemi is likely to weaken during the next few hours while the center of circulation moves across southern Taiwan. Mountains in eastern Taiwan could disrupt the lower portions of the circulation when it moves over them. If the circulation still exists when it moves east of Taiwan in a few hours, then Tropical Storm Gaemi will move into a more favorable environment for intensification. Gaemi will move over water where the Sea Surface Temperature is near 29°C. An upper level trough over eastern Asia is producing southwesterly winds which are blowing toward the top of the circulation. Those winds will cause some vertical wind shear, but the shear will probably not be strong enough to tear the circulation apart. Gaemi could remain a tropical storm for another 24 to 36 hours. When Tropical Storm Gaemi moves farther north in a day or two, it will move over colder water and into an area with stronger vertical wind shear. Gaemi will likely make a transition to an extratropical cyclone at that time.
The upper level trough is forecast to steer Tropical Storm Gaemi toward the northeast. Gaemi will move across southern Taiwan during the next few hours. It will cause gusty winds, but the greater risks will be heavy rain and flash floods. On its anticipated track Tropical Storm Gaemi will move near the southern Ryukyu Islands of Japan. It could pass near Ishigaki Jima and Miyako Jima in the next 12 to 18 hours. Gaemi could be near Okinawa later on Friday.