Deep Depression Over Bay of Bengal Likely to Intensify into Cyclone Ditwah, Heavy Rain Expected in Tamil Nadu

Chennai, Nov 2025 : The weather system over the southwest Bay of Bengal and the adjoining Sri Lanka coast intensified into a deep depression on Thursday, with meteorologists warning that it is likely to strengthen into a cyclonic storm by Thursday evening.

The Regional Meteorological Centre (RMC) has projected that the system will move northwestwards across the southwest Bay and along the Sri Lankan coastline, heading toward north Tamil Nadu, Puducherry, and adjoining south Andhra Pradesh by Saturday. Once it reaches cyclonic intensity, the system will be named Cyclone Ditwah, a name contributed by Yemen in the WMO and UN-ESCAP’s list of tropical cyclone names.

RMC reiterated its earlier forecast of heavy rainfall for south Tamil Nadu and the delta districts on Thursday, followed by a sharp increase in rainfall across the State from Friday. Delta and adjoining districts are expected to receive heavy to very heavy showers on Friday, while north Tamil Nadu districts are likely to experience heavy rainfall on Saturday as the system advances along the coast.

After days of relentless rain in the southern districts, rainfall activity eased considerably on Wednesday. During the 24-hour period ending 8:30 a.m. on Thursday, only isolated light showers were reported. Thangachimadam in Ramanathapuram district recorded the highest rainfall at 3 cm, while Oothu in Tirunelveli—previously affected by widespread flooding—registered 1 cm.

In anticipation of the system’s intensification, RMC has advised the hoisting of storm warning signals at major ports including Chennai, Cuddalore, Ennore, Thoothukudi, Nagapattinam, and Karaikal. Mariners have been cautioned against venturing into the southwest Bay of Bengal and adjoining areas until further updates.

The latest forecast also predicts isolated light rainfall over Kanniyakumari, Thoothukudi, and Tirunelveli districts as the deep depression continues to consolidate over the ocean.

Meanwhile, Cyclone Senyar, currently centered over the coastal belt of northeast Indonesia and the adjoining Strait of Malacca, is expected to drift eastwards while maintaining its cyclonic storm intensity. RMC clarified that Senyar poses no threat to Tamil Nadu and will not impact the State’s weather conditions.

Authorities have urged residents in coastal areas to remain vigilant and monitor updates, especially as the system approaches cyclonic strength, potentially bringing heavy rainfall, strong winds, and rough seas along the Tamil Nadu and south Andhra Pradesh coasts.