Large Dangerous Tropical Cyclone Amphan Nears Kolkata and Bangladesh

Large dangerous Tropical Cyclone Amphan neared Kolkata, India and Bangladesh late on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Cyclone Amphan was located at latitude 18.8°N and longitude 87.0°E which put it about 310 miles (505 km) south-southwest of Kolkata, India.  Amphan was moving toward the north at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 951 mb.

Tropical Cyclone Amphan was the equivalent of a major hurricane as it neared Kolkata, India and the coast of Bangladesh on Tuesday.  An eyewall replacement cycle caused the circulation around Amphan to expand in size.  Some satellite images showed evidence of the remnants of the original small inner eye inside the larger second eye.  The larger eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Amphan.

Tropical Cyclone Aphan had a large circulation that covered much of the northern Bay of Bengal.  Winds to hurricane/typhoon force extended out 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out 230 miles (370 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Amphan was 20.6.  The Hurricane Size Index (HSI) was 20.8 and the Hurricane Wind Intensity Size Index (HWISI) was 41.4.  Amphan was capable of causing major damage.

Tropical Cyclone Amphan will move through an environment capable of supporting a large powerful tropical cyclone during the next 12 to 18 hours.  Amphan will move over water where the Sea Surface Temperature is near 30°C.  It will move under the western side of an upper level ridge.  The upper level winds will be weak and there will be little vertical wind shear.  The circulation around Tropical Cyclone Amphan could start to pull in some drier air that is over eastern India when it get closer to the coast.  Amphan will remain a large dangerous tropical cyclone until it makes landfall on the north coast of the Bay of Bengal.

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-northeast during the next 36 hours.  On its anticipated track the center of Tropical Cyclone Amphan will pass near Puri, India in about 12 hours.  The center of Amphan could make landfall south of Kolkata near Haldia, India in about 18 hours.  Tropical Cyclone Amphan could cause major damage.  The wind will blow water toward the coast around the northern Bay of Bengal.  Amphan could generate a storms surge of up to 12 to 15 feet (3 to 4 meters) along past of the Bangladesh coast.  Tropical Cyclone Amphan will also drop heavy rain over parts of northeastern India and Bangladesh when it moves inland.  The heavy rain is likely to cause floods in some locations.