A low-pressure area near the Andaman coast is expected to intensify into this year’s first cyclone in the Bay of Bengal next week, the Met office has said.
“Under the influence of Thursday’s upper-air cyclonic circulation over the southeast Bay of Bengal and the adjoining south Andaman Sea, a low-pressure area formed over the southeast Bay of Bengal at 5.30am on Friday,” a Met bulletin issued on Friday said.
“It moved west-northwestwards during the past three hours and lay over the same region at 8.30am. It is likely to move west-northwestwards, intensify into a depression over the southeast and adjoining central Bay of Bengal by October 25 (Saturday); further into a deep depression by October 26 (Sunday) and into a cyclonic storm over the southwest and adjoining westcentral Bay of Bengal by the morning of October 27 (Monday),” it added.
Once the system becomes a cyclone, it will be named Montha — a name given by Thailand, meaning flower. The storm will still be far away from land. Its projected path and potential impact on land are not yet clear, the Met office said.
The Met office has predicted rain in Bengal from October 26 to 30. In the coastal areas of south Bengal, the heaviest showers are likely on October 28, 29 and 30. Heavy rain is likely in several districts, including North and South 24-Parganas, East and West Midnapore, Howrah and Jhargram.
Currently, the forecast for Calcutta is limited to thunderstorms with mild gusts of wind. But this may change in the coming days as the storm’s likely path becomes clearer, weather scientists said.
“The system is currently a low-pressure area. What we have now is a pre-genesis track. After the system develops into a depression, a more accurate projected track and forecast will be available,” said H. R. Biswas, head of the weather section at the Regional Meteorological Centre in Alipore.
October-November marks the post-monsoon cyclone season. Last October, Cyclone Dana made landfall in Odisha, causing heavy rain in Calcutta and surrounding areas.
A pre-genesis track shared by the Met office on Friday indicated that around 12am on Sunday, the system would be a deep depression, with peak wind speeds of approximately 56kmph. By 12am on Monday, it is expected to become a cyclone, generating peak wind speeds just under 90kmph.
In the recent past, cyclones have deviated sharply from projected paths. In May 2020, Cyclone Amphan initially moved north-northwest but took a sharp north-northeast recurve, bringing it much closer to Calcutta than expected.
“The system is very nascent. It can be assumed that the storm may head towards the Indian or Bangladeshi coast. Beyond that, nothing is certain. The sea surface temperature is around 29° Celsius — warm enough for the system to maintain momentum,” said a Met official.
A cyclone is a large system. If it does not fizzle out at sea, any eastward movement could impact Bengal. Even if the storm heads towards Odisha or the southern coast of Bangladesh, which borders the Indian Sundarbans, south Bengal is still likely to experience effects, the official added.
“Fishermen are advised not to venture into the sea along and off the West Bengal coast from October 28 until further notice,” the Met bulletin said.