With the likely formation of a low pressure area over east central Bay of Bengal by Tuesday, monsoon is set to advance into West Bengal, Odisha, Sikkim and some parts of northeastern states by June 11-12, the Met department said here on Sunday.
The low pressure area is likely to move west-northwestwards and become more marked by Wednesday, regional Met director GK Das said.
"Due to the formation of the low pressure area, conditions are likely to become favourable for advance of Southwest Monsoon into some parts of northeastern states, Sikkim, Odisha and West Bengal during June 11-12," Das said.
The metropolis and several south Bengal districts were lashed by moderate rain on Sunday afternoon, bringing in relief from the scorching summer heat, which hovered between 37 degree Celsius and 40 degree Celsius in different places in the region. Some areas in the city were waterlogged due to the rain.
The weatherman in its forecast said that rain or thundershower will occur at a few places in south Bengal districts for the next three days, following which it is likely to occur in many places of the state.