India, May 26 -- West Bengal's Kolkata and southern parts of the state experienced light to moderate rainfall on Monday, which the Indian Meteorological Department calling it a precursor to the arrival of the Southwest Monsoon, which is progressing into various parts of the northeastern region.

A low-pressure area is likely to form over west-central and adjoining north Bay of Bengal around May 27, possibly bringing heavy rainfall from May 28 over some districts of the state, PTI news agency quoted a weather official as saying.

"Southwest Monsoon has further advanced into some more parts of west central and north Bay of Bengal, remaining parts of Mizoram, entire Tripura, Manipur, Nagaland, Arunachal Pradesh and some parts of Assam and Me...