Kolkata: A deep depression over the Bay of Bengal is likely to concentrate into a cyclonic storm by Saturday evening and make landfall on May 26 night along the adjoining coasts of West Bengal and Bangladesh, the Met office said.
The cyclone is likely to make landfall with a wind speed of 110-120 km per hour, gusting to 135 kmph, it said.
The Met office has warned of extremely heavy rainfall in the coastal districts of West Bengal and north Odisha on May 26-27.
Extremely heavy precipitation may hit parts of northeast India on May 27-28.
Storm surge of up to 1.5 metre is expected to inundate low-lying areas of coastal West Bengal and Bangladesh at the time of landfall.
The weather office warned fishermen not to venture into the sea in north Bay of Bengal till May 27 morning.
The Meteorological Department issued a red alert for West Bengal's coastal districts of South and North 24 Parganas on May 26 and 27, where extremely heavy rain is likely in some places.
The weather system - a deep depression situated over the east-central Bay of Bengal, about 380 kms south of Sagar Island in South 24 Parganas district is likely to concentrate into a cyclonic storm by Saturday evening and move northwards', the Met said in a bulletin.
It is likely to concentrate further into a severe cyclonic storm by Sunday morning and cross West Bengal and adjoining Bangladesh coasts between Sagar Island and Khepupara with a wind speed of 110 to 120 kmph gusting to 135 kmph at around midnight of Sunday, the bulletin said.
This is the first cyclone in the Bay of Bengal this pre-monsoon season and will be named Remal, given by Oman, according to a system of naming cyclones in the north Indian Ocean region.
An orange alert was issued for Kolkata, Howrah, Nadia and Purba Medinipur districts by the Met, warning of 80 to 90 kmph gusting to 100 kmph wind speed, and heavy to very heavy rain at one or two places on May 26-27.
Wind speed will reach 60 to 70 kmph gusting to 80 kmph over Hooghly, Purba Bardhaman and Paschim Medinipur districts, accompanied by heavy rain.
Other districts in south Bengal will experience a wind speed of 40 to 50 kmph, gusting to 60 kmph, it said.
In north Odisha, the coastal districts of Balasore, Bhadrak and Kendrapara will receive heavy rain on May 26-27, while heavy precipitation is likely in Mayurbhanj on May 27.
The India Meteorological Department warned of localised flooding and major damage to vulnerable structures, power and communication lines, kutcha roads, crops and orchards in South and North 24 Parganas districts of West Bengal.
People in the affected areas have been asked to remain indoors and vacate vulnerable structures.