Tropical Cyclone Courtney weakened over the South Indian Ocean southwest of the Cocos Islands on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Cyclone Courtney was located at latitude 23.0°S and longitude 88.0°E which put the center about 935 miles (1505 km) southwest of the Cocos Islands.  Courtney was moving toward the south at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 980 mb.

Tropical Cyclone Courtney weakened over the South Indian Ocean southwest of the Cocos Islands on Sunday.  An upper level trough over the South Indian Ocean produced northwesterly winds that blew toward the top of Courtney’s circulation.  Those winds caused moderate vertical wind shear.  The vertical wind shear caused the distribution of thunderstorms in Tropical Cyclone Courtney to become asymmetrical.  Thunderstorms were occurring in bands in the eastern and southern parts of Courtney’s circulation.  Bands in the western and northern parts of Tropical Cyclone Courtney consisted primarily of showers and lower clouds.

The size of the circulation around Tropical Cyclone Courtney increased on Sunday.  Winds to hurricane/typhoon force extended out 45 miles (75 km) from the center of Courtney’s circulation.  Winds to tropical storm force extended out 135 miles (220 km) from the center of Tropical Cyclone Courtney.

Tropical Cyclone Courtney will move through an environment that will be unfavorable for intensification during the next 24 hours.  Courtney will move over water where where the Sea Surface Temperatures are near 24°C.  It will move under the eastern side of an upper level trough over the South Indian Ocean.  The upper level trough will produce northwesterly winds that will blow toward the top of Courtney’s circulation. Those winds will cause moderate vertical wind shear to continue.  The combination of colder Sea Surface Temperatures and moderate vertical wind shear will cause Tropical Cyclone Courtney to continue to weaken during the next 24 hours.

Tropical Cyclone Courtney will move around the western end of a high pressure system over the South Indian Ocean.  The high pressure system will steer Courtney toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone Courtney will move farther away from the Cocos Islands.