Komen, which lies centred at about 95 km southsouthwest of Chittagong in Bangladesh and about 300 km eastsoutheast of Kolkata, would move northwards and cross Bangladesh Coast by this afternoon, the Met department said.
"After landfall, it will move westnorthwestwards and weaken gradually," it said.
"Heavy to very heavy rainfall will occur at a few places with isolated extremely heavy falls over Gangetic West Bengal today and tomorrow," the Met office said.
Wind speed reaching 65?75 kmph gusting to 85 kmph would prevail along and off West Bengal and north Odisha Coasts, it said.
"Sea conditions will be very rough over north Bay of Bengal.
"Fishermen are advised not to venture into the sea along and off West Bengal and north Odisha coasts," it said.
In view of the situation, West Bengal Chief Minister Mamata Banerjee has cut short her visit to the UK by a day and is coming back to Kolkata by this evening.
The state government has sounded a high alert in all South Bengal districts and has taken necessary precautionary measures to deal with situations arising out of the cyclone.
The metropolis is also likely to be hit by the cyclone and the civic authorities have made necessary arrangements to deal with flooding of streets and low-lying areas in the city.
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