Met department says the development would take place in the next 12 hours.

Representative Image.
Chennai:
The Indian Meteorological department in its latest update has informed that the low pressure area over Southeast & adjoining Southwest bay has become a well marked one. This could turn depression in the next 12 hours, the notification added.
♦ The LPA over Southeast & adjoining Southwest Bay now lies as a Well Marked Low Pressure Area over Southwest and adjoining Westcentral Bay off north Tamil Nadu-south AP coasts. It is very likely to intensify into a Depression during next 12 hours.
— India Meteorological Department (@Indiametdept) November 18, 2021
Attached: INSAT 3D image. pic.twitter.com/KxUCk5KKQB
This weather development will bring isolated heavy to very heavy rains in areas like Rayalaseema, south Coastal Andhra Pradesh and adjoining north Tamil Nadu districts. The update has provided a caveat to the fishermen of TN, Puducherry and south Andhra to avoid venturing to the sea till 19th November morning. Wind warnings too were issued for the forementioned places.
Conversations