Tropical Cyclone Robyn was spinning over the South Indian Ocean southwest of the Cocos Islands on Thursday. At 10:00 a.m. EST on Wednesday the center of Tropical Cyclone Robyn was located at latitude 16.6°S and longitude 91.2°E which put the center about 485 miles (780 km) southwest of the Cocos Islands. Robyn was moving toward the south-southeast at 13 m.p.h. (20 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 988 mb.
Tropical Cyclone Robyn strengthened on Thursday as it spun over the South Indian Ocean southwest of the Cocos Islands. More thunderstorms formed near the center of Robyn’s circulation. Thunderstorms were occurring in bands revolving around the center of Tropical Cyclone Robyn. Storms near the center of Robyn generated upper level divergence that pumped mass away to the southeast of the tropical cyclone.
The distribution of winds speeds in Tropical Cyclone Robyn became more symmetrical on Thursday. Winds to tropical storm force extended out 105 miles (165 km) from the center of Robyn’s circulation.
Tropical Cyclone Robyn will move through an environment that will become unfavorable for intensification during the next 24 hours. Robyn will move over water where where the Sea Surface Temperatures are near 26°C. It will move under the western end of an upper level ridge that is west of Australia. The upper level ridge will produce northerly winds that will blow toward the top of the tropical cyclone. Those winds will cause moderate vertical wind shear. The combination of moderate vertical wind shear and marginal Sea Surface Temperatures is likely to cause Tropical Cyclone Robyn to weaken during the next 24 hours.
Tropical Cyclone Robyn will move around the southwestern end of a high pressure system that is west of Australia. The high pressure system will steer Robyn toward the south-southeast during the next 24 hours. On its anticipated track, Tropical Cyclone Robyn will move farther away from the Cocos Islands.