Tropical Cyclone 15S Southwest of Diego Garcia9.7S 66.0E
Tropical Cyclone 15S, located approximately 490 nm southwest of Diego Garcia, has tracked west-southwestward at 08 knots over the past six hours. Maximum significant wave height is 8 feet. Animated infrared satellite imagery and a microwave image show increased deep convection tightly wrapping into a well-defined low level circulation center (LLCC), from which the initial position was based.
Initial intensity estimates ranged from 30 to 35 knots. Upper level analysis indicates the system is located directly under the ridge axis in an area of low vertical wind shear. An upper level trough to the west is increasing outflow. TC 15S is currently tracking along the northwestern periphery of a low- to mid-level steering ridge.
After TAU 36, the system is expected to turn poleward when an upper level trough weakens the steering ridge. The system should significantly weaken by TAU 72, due to increased vertical wind shear associated with an approaching upper level trough. TC 15S will begin to turn southwestward as the low level steering ridge rebuilds in to the south. The system will dissipate as a significant tropical cyclone by TAU 96.