Tropical Cyclone Ockhi Strengthens Quickly Southwest of India

Tropical Cyclone Ockhi strengthened quickly southwest of India on Thursday.  At 7:00 a.m. EST on Thursday the center of Tropical Cyclone Ockhi was located at latitude 8.0°N and longitude 76.2°E which put it about 810 miles (1305 km) south-southeast of Mumbai, India.  Ockhi was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 988 mb.

The core of the circulation of a tropical depression that developed near Sri Lanka on Wednesday organized quickly on Thursday.  A primary rainband wrapped most of the way around the center of circulation and an eye began to appear on some satellite imagery.  The storms in the eyewall were strongest west of the eye and weakest north of the eye.  Additional bands of showers and thunderstorms formed outside the core of the circulation.  Thunderstorms in the core of Ockhi generated strong upper level divergence which was pumping mass away to the north and west of the tropical cyclone.  The divergence was allowing the surface pressure to decrease and the wind speeds to increase.

Tropical Cyclone Ockhi will be moving through an environment favorable for intensification during the next several days.  Ockhi will move over water where the Sea Surface Temperature is near 29°C.  Tropical Cyclone Ockhi is near the western end of an upper level ridge.  The ridge is producing southeasterly winds which are blowing toward the top of the circulation.  Those winds are causing some vertical wind shear, but they are also enhancing the upper level divergence to the north and west of Tropical Cyclone Ockhi.  The positive effects of enhanced divergence will exceed the negative effects of the vertical wind shear.  Tropical Cyclone Ockhi will continue to intensify and it could intensify rapidly.  Ockhi will likely become the equivalent of a hurricane/typhoon within the next 24 hours.

The upper level ridge is currently steering Tropical Cyclone Ockhi toward the west-northwest.  Ockhi will turn more toward the north in a day or two when it reaches the western end of the ridge.   On its anticipated track Tropical Cyclone Ockhi will move farther away from the coast of India during the next 24 to 48 hours.  The outer rainbands on the eastern side of Ockhi will drop locally heavy rain over portions of southern India and flash floods could occur in some places.  Tropical Cyclone Ockhi is likely to turn toward the northeast in three or four days and it could eventually make landfall in western India.