Tropical Cyclone Darian Weakens over South Indian Ocean

Tropical Cyclone Darian weakened over the South Indian Ocean on Tuesday. At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Darian was located at latitude 19.9°S and longitude 78.5°E which put it about 965 miles (1560 km) south-southeast of Diego Garcia. Darian was moving toward the southwest at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 984 mb.

Tropical Cyclone Darian weakened to the equivalent of a tropical storm when it moved over cooler water in the South Indian Ocean on Tuesday night. Thunderstorms did not grow as high into the atmosphere after Darian moved over cooler water. Thunderstorms were still occurring in bands in the southern half of Tropical Cyclone Darian’s circulation on Tuesday night. Bands in the northern half of the circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 200 miles (325 km) from the center of circulation.

Tropical Cyclone Darian will move through an environment unfavorable for a tropical cyclone during the next few days. Darian will move over water where the Sea Surface Temperatures are colder than 25˚C. It will move under the western end of an upper level ridge over the South Indian Ocean. The ridge will produce northerly winds that will blow toward the top of Darian’s circulation. Those winds will cause moderate vertical wind shear. A combination of colder water and moderate vertical wind shear will cause Tropical Cyclone Darian to continue to weaken during the next 36 hours.

Tropical Cyclone Darian will move around the northwestern part of a high pressure system over the South Indian Ocean. The high pressure system will steer Darian toward the southwest during the next 36 hours. On it anticipated track, Tropical Cyclone Darian will pass far to the south of Diego Garcia in 24 hours. Darian could be southeast of Rodrigues in 48 hours.