Cyclone Bulbul is likely to become a severe cyclonic storm in the next 12 hours. Heavy rainfall is expected in West Bengal, Odisha and parts of Maharashtra.he severe cyclonic storm Maha, which is currently over the Arabian Sea, is "very likely" to weaken into a depression by Thursday evening and the Cyclone Bulbul, which is over the Bay of Bengal, may intensify into a severe cyclonic storm during next 24 hours, the Indian Meteorological Department (IMD) said.In a bulletin released on Thursday morning at 5:45 am, the weather department said Cyclone Maha has been moving eastwards with a speed of 10 kmph from past six hours."The Cyclonic storm Maha lay centered at 02:30 hrs of November 7 over east-central and adjoining northeast the Arabian Sea about 220 km south-southwest of Porbandar [Gujarat], 190 km west-southwest of Veraval (Gujarat) and 230 km west-southwest of Diu," the IMD said.The weather department has further said that Cyclone Maha is very likely to move east-northeastwards, weaken into a deep depression over the northeast and adjoining east-central Arabian Sea during next 12 hours.Air pollution may be strengthening cyclones in the Arabian Sea, climate scientists and experts have said while expressing concern that it could become a regular feature in the coming years if emissions are not controlled. Air pollution may be strengthening cyclones in the Arabian Sea, climate scientists and experts have said while expressing concern that it could become a regular feature in the coming years if emissions are not controlled.