A low-pressure system over the Bay of Bengal is likely to intensify into a cyclonic storm by October 26 and move towards the North Andhra Pradesh and adjoining South Odisha coasts, while the India Meteorological Department has warned of rain and squally winds across parts of Bengal from Tuesday.
The system formed over the east-central and adjoining southeast Bay of Bengal on Friday morning, along with an associated cyclonic circulation extending up to 5.8 km above mean sea level, according to a special IMD bulletin. The composite system is expected to persist over the same region and strengthen into a depression on October 24.
The IMD forecast says the system is very likely to move west-northwestwards and intensify into a deep depression on October 25. It may become a cyclonic storm over the west-central Bay of Bengal by the morning of October 26, before moving towards the North Andhra Pradesh and adjoining South Odisha coasts over the following two days.
The weather system could be named Cyclone Arnab if it reaches cyclonic-storm intensity. The name was assigned by Bangladesh and means ocean. The IMD has said the system’s eventual track remains too early to determine with certainty, but coastal areas of Bengal are expected to begin experiencing its effects from Tuesday in the form of squally winds.
The forecast has direct implications for coastal districts and for Kolkata’s rainfall pattern. The Met office expects light to moderate rain in Kolkata from Tuesday, while one or two districts of West Bengal could receive heavy rainfall between October 28 and 30. The strongest effects are currently expected along the coastal belt, although Bengal is not expected to lie in the system’s direct trajectory based on the initial forecast.
H R Biswas of the Regional Meteorological Centre in Kolkata said the city was likely to receive light to moderate rain from Tuesday. He added that coastal Bengal could see a few spells of heavy rain and said a warning had been issued for fishermen.
The developing system comes during the October-to-December period, which is considered conducive to cyclone formation over the Bay of Bengal. Biswas said the weather authorities were continuously monitoring the system, but that it was too early to assess how far it could intensify after becoming a cyclonic storm.
The IMD’s forecast also outlines the possible progression of the system through successive intensity stages. A cyclonic storm can strengthen into a severe, very severe, extremely severe or super cyclone, depending on its development and wind intensity. The current bulletin does not establish that such further intensification will occur.
For Bengal, the immediate official guidance is focused on monitoring changing weather conditions, preparing for squally winds and following the fishermen’s warning. The IMD is expected to refine the system’s track, intensity and rainfall forecasts as it moves through the Bay of Bengal.
