Tropical Cyclone 17S Forms in the Indian Ocean
Tropical Cyclone 17S, located approximately 515 nautical miles east of the Cocos Islands, has tracked east-southeastward at 11 knots over the past 6 hours.
In the full-sized image, the Indonesian islands of Java (right) and Sumatra (left) are visible north of the system.
The cyclone has a well defined low-level circulation center (LLCC), and Dvorak estimates suggest the 35-knot threshold has been reached. Maximum significant wave height is 12 feet.
An SSMI/S image continues to show the main convection sheared to the southwest of the LLCC.
TC 17S has been tracking east-southeastward in response to a midlatitude trough west of Australia. By TAU 24, this trough will move eastward, allowing an anticyclone to build south of the system. This anticyclone will cause TC 17S to turn back to the West.
TC 17S is currently in a region of moderate vertical wind shear. However, as the previously mentioned midlatitude trough moves out, the wind shear gradient is forecast to relax, allowing for slow intensification through the forecast period.
This warning supersedes and cancels the previous tropical cyclone formation alert.