"A cyclonic circulation has formed over Bay of Bengal and adjoining West Bengal coast. It is likely to intensify into a low pressure," regional MeT Director G C Debnath said here.
"Under the influence of the cyclonic circulation, heavy rains will occur in most districts of Gangetic West Bengal in the next two days," he said.
"The rains may continue further as the cyclonic circulation is likely to intensify into a low pressure," he said.
Kolkata recorded 42.5 mm rainfall since yesterday morning as the day temperature remained low at 29.6 degree celsius.
The weatherman has predicted generally cloudy sky with one or two spells of rain in the sub-Himalayan districts of the state.