Tropical Cyclone Courtney began a transition to an extratropical cyclone over the South Indian ocean on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Cyclone Courtney was located at latitude 25.0°S and longitude 88.7°E which put the center about 1020 miles (1645 km) south-southwest of the Cocos Islands.  Courtney was moving toward the south at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 986 mb.

Tropical Cyclone Courtney began a transition to an extratropical cyclone over the South Indian Ocean south-southwest of the Cocos Islands on Monday.  An upper level trough was producing strong northwesterly winds that were blowing across the top of Courtney’s circulation.  Those winds were causing strong vertical wind shear.  The strong wind shear blew off the tops of many of the thunderstorms in Tropical Cyclone Courtney.  A few thunderstorms were still occurring in a bands in the southeastern periphery of Courtney’s circulation.  Bands in the other parts of Tropical Cyclone Courtney consisted primarily of showers and lower clouds.

The lack of thunderstorms in much of Tropical Cyclone Courtney caused the distribution of winds speeds to become asymmetrical.  Winds to tropical storm force extended out 165 miles (265 km) in the southern half of Courtney’s circulation.  Winds to tropical storm force only extended out 85 miles (135 km) in the northern half of Tropical Cyclone Courtney.

Tropical Cyclone Courtney will move through an environment that will be unfavorable for intensification of a tropical cyclone 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  strong northwesterly winds that will blow toward the top of Courtney’s circulation.  Those winds will cause strong vertical wind shear to continue.  The combination of colder Sea Surface Temperatures and strong vertical wind shear will cause Tropical Cyclone Courtney to continue to make a transition to an extratropical cyclone during the next 24 hours.

Since much of the circulation of Tropical Cyclone Courtney only exists in the the lower levels of the atmosphere, Courtney will be steered by the winds at those levels.  Courtney will move around the northern side of a high pressure system over the South Indian Ocean.  The high pressure system will steer Courtney toward the west during the next 24 hours.  On its anticipated track, Tropical Cyclone Courtney will move farther away from the Cocos Islands.