Tropical Storm In-Fa Forms Southeast of Okinawa

Tropical Storm In-Fa formed southeast of Okinawa on Saturday. At 5:00 p.m. EDT on Saturday the center of Tropical Storm In-Fa was located at latitude 22.4°N and longitude 132.3°E which put it about 420 miles (675 km) southeast of Okinawa. In-Fa was moving toward the north-northwest at 7 m.p.h. (11 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 998 mb.

The circulation around a low pressure system southeast of Okinawa exhibited more organization on Saturday and the Japan Meteorological Agency designated the system as Tropical Storm In-Fa. The distribution of thunderstorms around In-Fa was asymmetrical. Thunderstorms were occurring in bands in the eastern half of Tropical Storm In-Fa. Bands on the western side of the tropical storm consisted primarily of showers and lower clouds. An upper level low centered west of Japan was producing westerly winds that were blowing toward the top of In-Fa. Those winds were causing moderate vertical wind shear and they were also contributing to the asymmetrical distribution of thunderstorms.

Tropical Storm In-Fa will move into an environment that is forecast to become more favorable for intensification during the next 48 hours. In-Fa will move over water where the Sea Surface Temperatures are near 28°C during the next two days. The upper level low west of Japan is forecast to move toward the north. When the upper low moves north, the upper level winds around In-Fa will weaken and the vertical wind shear will decrease. Tropical Storm In-Fa is likely to strengthen during the next 48 hours. When the upper level winds weaken, In-Fa could intensify more quickly. Tropical Storm In-Fa could strengthen to a typhoon within 72 hours.

Tropical Storm In-Fa will move south of a surface high pressure system centered southeast of Japan on Sunday. The high will steer In-Fa toward the northwest during the next 24 hours. A second surface high pressure system over eastern Asia is forecast to move north of Tropical Storm In-Fa on Monday. The second high pressure system will steer In-Fa more toward the west early next week. On its anticipated track Tropical Storm In-Fa could approach Okinawa in 60 hours. In-Fa could bring wind and rain to the southwestern Ryukyu Islands. In-Fa could eventually affect Taiwan and eastern China later next week.