Tropical Cyclone Anja (01S) East-Northeast of La Reunion16.1S 66.0E
Tropical Cyclone Anja (01S), located approximately 715 nm east-northeast of La Reunion, has tracked south-southwestward at 11 knots over the past six hours. Maximum significant wave height is 26 feet.
Animated infrared imagery shows Anja has maintained a small (just over 60 nm in diameter) but compact symmetry with annular characteristics.
The cyclone is being steered along the western boundary of a deep-layered subtropical ridge to the east. Upper level analysis indicates the system is directly under the ridge axis in a zone of low vertical wind shear. Animated water vapor imagery shows good radial outflow overhead.
TC 01S is expected to maintain its current intensity over the next 12 hours as it crests the western edge of the steering ridge. After TAU 12, it will begin to track over colder water and shift to a more southeastward track. This transition is in response to the approach of a mid latitude trough from the southwest.
At this stage, Anja will also begin to rapidly weaken and accelerate southeastward as it gets exposed to the strong westerly vertical wind shear. This will coincide with the cyclone’s transition into an extra tropical (ET) system with full ET status by TAU 72. The available numeric guidance is in close agreement with this track forecast with the sole exception of GFS that is significantly right of the envelope from TAU 12.