Bay of Bengal low pressure area may form Nov 13; heavy rain alert for 4 TN districts
Synopsis
A low-pressure area is set to form over the southeast Bay of Bengal on 13 November and could deepen into a depression within 24 hours — but the RMC has not named a landfall zone or declared a cyclone threat. For now, the immediate impact falls on four southern Tamil Nadu districts facing heavy rain on Wednesday, with moderate showers across much of the rest of the state.
Key Takeaways
A low-pressure area is likely to form over the southeast Bay of Bengal on 13 November , according to the Regional Meteorological Centre, Chennai .
The system may intensify into a depression within 24 hours of formation and is expected to move northwestwards .
Heavy rainfall is forecast for Sivaganga , Ramanathapuram , Thoothukudi , and Tirunelveli on Wednesday, 11 November .
Moderate showers are expected across Thanjavur , Tiruvarur , Mayiladuthurai , Nagapattinam , Madurai , Dindigul , Virudhunagar , Tenkasi , and Kanniyakumari .
Chennai is forecast to remain partly cloudy with only light rain possible.
The RMC has not announced a cyclone or confirmed a landfall location as of the latest bulletin.
The Regional Meteorological Centre (RMC) in Chennai has forecast that a low-pressure area is likely to form over the southeast Bay of Bengal on 13 November, with the system expected to move northwestwards and potentially intensify into a depression within the following 24 hours. For Wednesday, 11 November, the weather centre has issued a heavy rainfall alert for four districts in southern Tamil Nadu.
Heavy Rain Alert: Four Southern Districts
The RMC has forecast heavy rainfall at places in Sivaganga, Ramanathapuram, Thoothukudi, and Tirunelveli districts on Wednesday. These four districts in the southern part of the state bear the brunt of the immediate forecast, while the rest of Tamil Nadu is expected to receive moderate to light showers.
Moderate Rain Likely Across Delta and Central Districts
The forecast extends moderate rainfall to several other parts of the state, including the Cauvery delta region. Districts including Thanjavur, Tiruvarur, Mayiladuthurai, and Nagapattinam are expected to receive moderate showers, as is Pudukkottai. Further, Dindigul, Madurai, Virudhunagar, Tenkasi, and Kanniyakumari districts are also in the moderate rainfall zone. Taken together, the district-level outlook covers much of southern Tamil Nadu and parts of the delta region, with varying intensity across locations.
Chennai Outlook: Partly Cloudy, Light Showers Possible
Chennai is forecast to experience partly cloudy skies on Wednesday, with light rain possible in some parts of the city. The capital's conditions are considerably milder than the heavy rainfall warned for the four southern districts, according to the weather centre's bulletin.
Bay of Bengal System: What Is Known — and What Isn't
The RMC describes the anticipated low-pressure area formation on 13 November as a possibility, not a certainty. The system's projected northwestward movement and subsequent intensification into a depression are the key developments to watch in the coming days. Importantly, the current forecast does not specify a landfall location, does not identify which coastal districts may face the strongest impact, and does not announce the formation of a cyclone. The weather centre's language is explicitly cautious — framing these as possibilities rather than confirmed developments. The Wednesday district-level rain predictions and the Friday Bay of Bengal system formation represent two distinct stages of the forecast window and should not be conflated.
What to Watch Next
The projected intensification of the system from a low-pressure area into a depression — and potentially beyond — will be tracked closely by the RMC over the next 48 to 72 hours. Residents in coastal and southern districts of Tamil Nadu are advised to monitor official bulletins as the system's track and intensity become clearer in subsequent updates.
Point of View
'possibility of strengthening' — is a reminder that pre-formation forecasts carry inherent uncertainty, and conflating a potential low-pressure area with an imminent cyclone is a persistent media failure that breeds unnecessary panic. The more immediate and verifiable concern is Wednesday's heavy rain across four southern Tamil Nadu districts, which are already among the state's more flood-vulnerable zones. Tamil Nadu's coastline has faced recurring weather events in the November-December window — the northeast monsoon season — and the lack of a named landfall zone in the current bulletin means authorities and residents have a narrow window to prepare before the system's track becomes clear. Tracking the next 48-hour RMC updates will be critical.
NationPress
11 Nov 2026
Frequently Asked Questions
What is the low-pressure area forecast over the Bay of Bengal?
The Regional Meteorological Centre in Chennai has forecast that a low-pressure area is likely to form over the southeast Bay of Bengal on 13 November. It is expected to move northwestwards and may intensify into a depression within 24 hours of formation, though no landfall location has been specified.
Which Tamil Nadu districts are on heavy rain alert on 11 November?
The RMC has issued a heavy rainfall forecast for Sivaganga, Ramanathapuram, Thoothukudi, and Tirunelveli districts on Wednesday, 11 November. These four southern districts face the most intense rainfall in the current bulletin.
Is a cyclone expected to hit Tamil Nadu?
No. The RMC has not announced the formation of a cyclone. The forecast describes a possible low-pressure area and potential intensification into a depression — preliminary stages in cyclone development. No landfall zone or cyclone warning has been issued as of the latest bulletin.
What is the weather forecast for Chennai on 11 November?
Chennai is expected to experience partly cloudy skies on Wednesday with only light rain possible in some parts of the city. The capital's conditions are significantly milder than the heavy rainfall alert issued for the four southern districts.
Which other Tamil Nadu districts may receive moderate rainfall?
Moderate rainfall is expected in Thanjavur, Tiruvarur, Mayiladuthurai, Nagapattinam, Pudukkottai, Dindigul, Madurai, Virudhunagar, Tenkasi, and Kanniyakumari, covering much of southern Tamil Nadu and the Cauvery delta region.
