Tropical Cyclone Irondro formed south-southwest of Diego Garcia on Thursday. At 5:00 a.m. EDT on Thursday the center of Tropical Cyclone Irondro was located at latitude 13.5°S and longitude 69.9°E which put it about 460 miles (745 km) south-southwest of Diego Garcia. Irondro was moving toward the southeast 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 1000 mb.
A distinct low level center of circulation developed in an area of thunderstorms over the South Indian Ocean south-southwest of Diego Garcia on Thursday and the system was designated as Tropical Cyclone Irondro. The circulation around Irondro was still organizing. Bands of showers and thunderstorms were forming and the bands were beginning to revolve around the center of circulation. Storms near the center were generating upper level divergence which was pumping mass away from the tropical cyclone. Winds to tropical storm force extended out 145 miles (230 km) from the center of circulation.
Tropical Cyclone Irondro will move through an environment favorable for intensification during the next 48 to 60 hours. Irondro will move over water where the Sea Surface Temperature is near 28°C. It will move under the western end of an upper level high over the South Indian Ocean. The high will produce northwesterly winds which will blow toward the top of the tropical cyclone. Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification. Tropical Cyclone Irondro will intensify and it could strengthen into the equivalent of a hurricane/typhoon.
The upper level high and an upper level trough east of Madagascar will interact to steer Tropical Cyclone Irondro toward the southeast during the next few days. On its anticipated track Irondro will pass south of Diego Garcia and south of Cocos Island.