Rainfall is likely to be fairly widespread till Monday under the influence of a cyclonic circulation persisting over the Kanyakumari region and the coast of Sri Lanka, the IMD has indicated.
All districts except Thiruvananthapuram, Kollam and Pathanamthitta, Alappuzha are on yellow alert on Monday for isolated heavy rainfall.
The cyclonic circulation is expected to emerge into the Arabian Sea region by Monday. It is likely to move in a north-northwestward region subsequently.
According to a Sunday evening update, rainfall is likely to taper off from Tuesday.
Meanwhile, a low pressure area is likely to form over the south Andaman Sea by Tuesday. It would become more marked and move north-northwestwards over the subsequent 48 hours.
An extended range forecast by the IMD has indicated the possibility of it concentrating into a depression.