A developing Bay of Bengal weather system could intensify into Cyclone Arnab by Monday, October 26, bringing heavy rain, thunderstorms and gusty winds to parts of West Bengal before potentially making landfall along the Andhra Pradesh coast by October 28.
According to the Regional Meteorological Centre (RMC), the system could affect Kolkata and several districts of south Bengal from Tuesday. Some areas are forecast to receive heavy rainfall between October 28 and 30, as cloud bands associated with the developing cyclone move towards eastern India.
The system began as a low-pressure area over the east-central and adjoining southeastern Bay of Bengal. It became a well-marked low-pressure area early Saturday before developing into a depression later that day. A cyclonic circulation associated with the system extends up to approximately 5.8 kilometres above sea level.
Kolkata and South Bengal Brace for Rain
Kolkata is expected to experience cloudy skies and light to moderate rain from Tuesday. Rainfall could become more frequent and intense between Wednesday and Thursday, according to Sourish Bandopadhyay, a weather scientist at the RMC.
The outer cloud bands of the developing cyclone are expected to spread over south Bengal ahead of the system’s projected landfall. Rain could continue into Friday, although its intensity may decrease after the cyclone moves inland.
Squally winds and heavy rainfall are also possible along the south Bengal coast, with wind speeds forecast to reach 30–40 km/h.
Heavy Rainfall Forecast for Several Districts
The RMC’s special bulletin warns of rain and thunderstorms across several districts during the coming days.
On Tuesday, October 27, light to moderate rain and thundershowers are expected in East and West Midnapore, North and South 24 Parganas, Kolkata, Howrah and Hooghly. Thunderstorms, lightning and gusty winds may affect parts of South 24 Parganas, East and West Midnapore, and Jhargram.
The risk of intense rainfall is expected to increase on Wednesday, October 28. Rainfall of 70–110 mm is possible at isolated locations in South 24 Parganas, East Midnapore, West Midnapore and Jhargram.
On Thursday, October 29, light to moderate rain is forecast across south Bengal, including Kolkata. Heavy rainfall is also possible in parts of Midnapore, Bankura, Jhargram and Purulia, while thunderstorms and gusty winds may affect South 24 Parganas and both Midnapore districts.
Weather Warnings and Safety Concerns
The RMC has cautioned that lightning strikes could pose a risk in open fields on October 28 and 29. Heavy rainfall may also cause waterlogging and damage standing crops in affected agricultural areas.
Residents in coastal and rain-prone districts should monitor official weather updates and follow local safety advisories as the system develops.
Cyclone Arnab’s projected track and landfall timing remain forecasts and may change. The system’s eventual intensity and the extent of its impact will depend on its development and movement over the Bay of Bengal.