A depression in the Bay of Bengal is likely to concentrate into a severe cyclonic storm and make landfall between Sagar island in West Bengal and Khepupara in Bangladesh around May 26 midnight, bringing heavy rain in the coastal districts of the state, the Met department said on Friday.

The Met issued a red alert for West Bengal's coastal districts of South and North 24 Parganas district, warning of 100 to 110 km per hour wind speed on May 26 and 90 to 100 kmph on May 27, accompanied by extremely heavy rainfall at one or two places on both days.

An orange alert was issued for Calcutta, Howrah and Purba Medinipur districts by the Met, warning of 80 to 90 kmph wind speed on May 26 and 70 to 80 kmph wind speed on May 27, accompanied with heavy to very heavy rain at one or two places on the two days.

The depression, which lies over central Bay of Bengal, about 660 km south-southeast of Sagar island, is likely to concentrate into a cyclonic storm by May 25 morning, the Met said.

The weather office forecast heavy rain in Purba Medinipur on May 25, on which date elections are scheduled to be held in Tamluk and Kanti Lok Sabha constituencies located within the coastal district.

Moving in a northward direction, the system will further concentrate into a severe cyclonic storm by May 25 evening, the weather office said.

The severe cyclonic storm is very likely to cross West Bengal and Bangladesh coasts between Sagar island and Khepupara around midnight of May 26, it said.

The weather system will bring heavy to very heavy rain in South and North 24 Parganas, Purba Medinipur, Kolkata, Howrah and Hooghly districts of West Bengal on May 26 and May 27, the Met said.

Heavy rain is likely in the districts of Paschim Medinipur, Purba Bardhaman and Nadia on May 26 and 27, it said.

The weather office warned fishermen not to venture into the sea in north Bay of Bengal till May 27 morning.

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