Another low pressure area is likely to form on September 25 which will bring unwelcome rain in south Bengal districts and Kolkata during Durga Puja festivities. "The low pressure area formed over the northeast Bay of Bengal and its vicinity intensified on Monday morning. "Due to its influence, several areas adjacent to South 24 Parganas district and Kolkata have been witnessing heavy rain. "Due to that low pressure area, a cloudburst occurred in Kolkata which wrecked havoc since last night. "Due to this, light to moderate rain and heavy to very heavy rain is likely to occur over several districts of south Bengal and Kolkata," added the Met department official.