Tag Archives: Robyn

Tropical Cyclone Robyn Weakens Over South Indian Ocean

Tropical Cyclone Robyn weakened over the South Indian Ocean on Friday.  At 10:00 a.m. EST on Friday the center of Tropical Cyclone Robyn was located at latitude 18.9°S and longitude 94.5°E which put the center about 485 miles (780 km) south-southwest of the Cocos Islands.  Robyn was moving toward the southeast at 14 m.p.h. (22 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 999 mb.

The western end of an upper level ridge that was west of Australia produced strong northwesterly winds that blew across the top of Tropical Cyclone Robyn.  Those strong winds created strong vertical wind shear.  The strong northwesterly winds also blew the tops off of all of the thunderstorms in Robyn’s circulation.  The circulation around Tropical Cyclone Robyn consisted entirely of bands of showers and lower clouds.

The circulation around Tropical Storm Robyn was small.  Winds to tropical storm force extended out 80 miles (130 km) from the center of Robyn’s circulation.

Tropical Cyclone Robyn will move through an environment that will continue to be unfavorable for intensification during the next 24 hours.  Robyn will move over water where where the Sea Surface Temperatures are near 25°C.  The western end of the upper level ridge that is west of Australia will continue produce strong northwesterly winds that will blow toward the top of the Robyn’s circulation.  Those winds will continue to cause strong vertical wind shear.  The combination of strong vertical wind shear and marginal Sea Surface Temperatures is likely to cause Tropical Cyclone Robyn to continue to weaken during the next 24 hours.

Tropical Cyclone Robyn will move around the western end of a high pressure system that is west of Australia.  The high pressure system will steer Robyn toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone Robyn will move farther away from the Cocos Islands.

Tropical Cyclone Robyn Spins Southwest of Cocos Islands

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.