Tropical Cyclone Amphan Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Amphan strengthened to the equivalent of a hurricane/typhoon on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Cyclone Amphan was located at latitude 12.3°N and longitude 86.4°E which put it about 695 miles (1120 km) south-southwest of Kolkata, India.  Amphan was moving toward the north at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 85 m.p.h (135 km/h) and there were wind gusts to 105 m.p.h. (165 km/h).  The minimum surface pressure was 969 mb.

Tropical Cyclone Amphan continued to intensify on Sunday.  A small circular eye with a diameter of 10 miles (16 km) developed at the center of circulation.  A ring of strong thunderstorms surround the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Amphan.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone in all directions.  Wins to hurricane/typhoon force extended out 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out 140 miles (225 km) from the center.

Tropical Cyclone Amphan will move through an environment favorable for intensification during the next 36 to 48 hours.  Amphan will move over water where Sea Surface Temperature is near 31°C.  It will move under an upper level ridge over the Bay of Bengal.  The winds in the upper level ridge are weak and there will be little vertical wind shear.  Tropical Cyclone Amphan will continue to intensify and it is likely to strengthen into the equivalent of a major hurricane.

Tropical Cyclone Amphan will move around the western end of a high pressure system over Southeast Asia.  The high will steer Amphan toward the north during the next 48 hours.  On its anticipated track Tropical Cyclone Amphan will approach the coast around the northern Bay of Bengal in less than 72 hours.  Amphan will bring strong winds and locally heavy rain to northeast India and to Bangladesh.  Tropical Cyclone Amphan is likely to generate a significant storm surge along the northern coast of the Bay of Bengal.