Tropical Cyclone Fani Strengthens to Equivalent of Major Hurricane

Tropical Cyclone Fani strengthened to the equivalent of a major hurricane on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Cyclone Fani was located at latitude 14.1°N and longitude 83.9°E which put it about 670 miles (1080 km) south-southwest of Kolkata (Calcutta), India.  Fani was moving toward the northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 946 mb.

Tropical Cyclone Fani strengthened on Tuesday.  A small eye emerged at the center of circulation.  The eye was surround by a ring of thunderstorms.  The storms were stronger in the western half of the ring and that was where the strongest winds were.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Fani.  The stronger bands were south and west of the center of Fani.  It appeared that a little drier air may have been pulled into the northern half of the circulation and the bands were weaker in that part of the circulation.  Storms near the core were generating upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone Fani had a moderately sized circulation.  Winds to hurricane/typhoon force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 150 miles (240 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Fani was 22.1.  The Hurricane Size Index (HSI) was 14.7 and the Hurricane Wind Intensity Size Index (HWISI) was 36.8.

Tropical Cyclone Fani will remain in an environment favorable for strong tropical cyclones during the next 24 to 36 hours.  Fani will move over water where the Sea Surface Temperature is near 30°C.  It will move near the western end of an upper level ridge and the upper level winds will not be too strong.  The major inhibiting factor will be the drier air over the northern half of the circulation.  Tropical Cyclone Fani could maintain its intensity and even strengthen during the next 24 hours if the drier air moistens over the warm water of the Bay of Bengal.

Tropical Cyclone Fani will move around the western end of a subtropical ridge on Wednesday.  Fani will move more toward the north when it rounds the end of the ridge.  An upper level trough approaching India from the west will turn Tropical Cyclone Fani toward the northeast in about 18 to 24 hours.  On its anticipated track Fani could approach the coast of Orissa state southwest of Kolkata in about 48 hours.  Tropical Cyclone Fani could bring strong winds to parts of Orissa and West Bengal.  Fani could also cause a significant storm surge along portions of the coast around the northern Bay of Bengal.  Locally heavy rain could also cause floods in Orissa and West Bengal.