Tropical Cyclone 20P (Joni) Moves Southward, Away from Cook Islands
Tropical Cyclone 20P (Joni), located approximately 130 nautical miles south-southeast of Rarotonga, Cook Islands, has tracked southward at 5 knots over the past 6 hours.
Joni will continue to track southward along the western periphery of the mid-level steering ridge towards cooler water and increased vertical wind shear.
Although the cyclone is now slowly moving away from the Cook Islands, the local meteorological service reported that strong winds associated with the system are still being felt in the outer islands.
The system has continued to benefit from dual outflow channels aloft – one ahead of a trough advancing from the West, and another into an upper level low to the East – in addition to low vertical wind shear (VWS) and favorable sea surface temperatures.
The initial intensity is based on Dvorak satellite intensity estimates ranging from 45 to 55 knots, and the initial position is based on a SSMI 37h microwave image.
The upper level environment is forecast to degrade as the trough, and a strong jet max, advance closer to the cyclone from the West, and the upper level low moves closer from the East, limiting convection within the eastern semicircle.
Maximum significant wave height is 11 feet.