Tropical Storm strengthened on Thursday as it moved closer to Okinawa. At 11:00 p.m. EDT on Thursday the center of Tropical Storm Saola was located at latitude 22.2°N and longitude 129.4°E which put it about 350 miles (570 km) south-southeast of Okinawa. Saola was moving toward the north-northwest at 17 m.p.h. (27 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 987 mb.
The circulation of Tropical Storm Saola exhibited more organization in recent hours. For much of the past several days many of the showers and thunderstorms were in a single primary rainband that wrapped around the outer part of the circulation. There were few showers or storms near and to the north of the center of circulation. A broken ring of showers and thunderstorms began to develop around the center during the past few hours. The ring could represent the initial formation of an eyewall. Additional bands of showers and thunderstorms also began to form outside the core of Tropical Storm Saola.
Tropical Storm Saola will be moving through an environment that will be favorable for intensification during the next 24 hours. Saola will move over water where the Sea Surface Temperature is near 29°C. The winds will be similar in all levels of the atmosphere and there will be little vertical wind shear. Tropical Storm Saola will intensify on Friday and it could become a typhoon. After about 24 hours Tropical Storm Saola will reach the upper level westerly winds in the middle latitudes and the vertical wind shear will increase. More wind shear will start to weaken Saola.
Tropical Storm Saola was moving the western end of a ridge which is steering the tropical storm toward the north-northwest and that general motion is expected to continue for about another 24 hours. On its anticipated track Tropical Storm Saola will approach Okinawa in about 24 hours. When Saola nears Okinawa, it will encounter the westerly winds in the middle latitudes. Those winds will turn Saola toward the northeast. Tropical Storm Saola will bring gusty winds and locally heavy rain to Okinawa and the Ryukyu Islands.